Evolution final (tests I-III)
Linnean Society presentations
"On the Tendency of Varieties to Depart Indefinitely from the Original Type" (1858) by Alfred Russel Wallace Presented by C. Lyell and J. Hooker to Linnean Society (July 1, 1858) -"Essay on Natural Selection" (1858) Darwin
Tiktaalik
"missing link" thought to be a transitional form between fish and tetrapods
Proterozoic eon
(2 bya --> 550 mya) -oxygen appears in the atmosphere reaching the present level of 21%; eukaryotes appear, even a few with hard parts
phanerozoic/mesazoic era
(250 mya --> 65 mya) -reptilian synapsids, mammals, and flowering plants arise, but land is dominated by dinosaurs (reptiles), gymnosperms, ferns, and lycopods
Archean eon
(4 bya --> 2 bya) -origin (or diversification) of life; all like is prokaryotic; little oxygen is in the atmosphere
Phanerozoic/Paleozoic Era
(550 mya --> 250 mya) -hard-bodied fossils appear; complex multicellular organisms; invasion of the land by plants and animals
Ediacaran fauna
(575 mya --> 535 mya) a group of animal species that existed during the Ediacaran period, just before the Cambrian; include diverse species that looked like fronds, geometrical disks, and blobs covered with tire tracks
phanerozoic/cenozoic era
(65 mya --> present) -land dominated by mammals and flowering plants
paraphyletic
(NOT A CLADE)Pertaining to a group of taxa that consists of a common ancestor and some, but not all, of its descendants.
When was the dawn of animals
(Proterozoic Era) Early animal life resembles sponges -Oldest fossils 650 Ma -Biomarkers also demonstrate existence of sponges during this time
Hadean eon
(formation of earth (4.55) --> 4 billion years ago) -Earth bombarded with large, extraterrestrial objects which repeatedly sterilized the surface, making life impossible
average excess of fitness (of an allele?)
(of an allele) is the difference between the average fitness of individuals bearing the allele and the average fitness of the population as a whole.
Panspermia Hypothesis
* Earth is continuously bombarded with material from interstellar space, much of it consisting of organic compounds. * These may have provided the basic building blocks of life.
If a population is in Hardy-Weinberg equilibrium
- Allele frequencies do not change over time - Populations are large (approaching infinite size) - Mutation and migration do not occur -NO EVOLUTION
Which of the following statements is true regarding hybridization?
- Hybridization occurs in plants more often than in animals. - Hybridization involves the transfer of genetic material between members of similar species. - Natural selection sometimes acts against progeny that result from hybridization. - Hybridization can result in fertile offspring.
The Biological Species Concept is least useful for: - IDing animal species - IDing species represented by fossils - IDing plant species - IDing species in marine environments
- IDing species represented by fossils
Which of the following statements is true regarding reinforcement?
- It "reinforces" reproductive isolation. - It is associated with the selection of certain pre-zygotic factors. - It limits the resources and energy wasted by a population on the production of "inefficient" hybrids. - It is associated with "mating discrimination," where individuals with a certain phenotype preferentially mate with individuals possessing the same phenotype.
Which of the following is true regarding sympatric speciation? - Sympatric speciation requires a population in which all individuals have an equal chance of mating with one another. - Sympatric speciation requires a selective disadvantage of hybrids (e.g., medium-billed birds) of two diverging populations. - Sympatric speciation requires physical separation of two populations. - Sympatric speciation requires that all individuals use the same resources in the area where they are found.
- Sympatric speciation requires a selective disadvantage of hybrids (e.g., medium-billed birds) of two diverging populations.
characteristic of SPECIES
- a common evolutionary ancestry among all individuals - the ability to produce fertile progeny - the ability of all members to exchange genetic material with one another - shared characteristics such as shape, size, and color (in individuals of the same life stage and sex)
The reason that lions (which live in Africa) and tigers (which live in Asia) don't produce ligers (infertile offspring of lions and tigers) in the wild is likely the result of: - an incompatible lock-and-key mechanism between the species. - behavioral isolation of tigers and lions. - temporal separation of lions and tigers. - ecological separation of lions and tigers. - both temporal and ecological separation of lions and tigers.
- ecological separation of lions and tigers.
Darwins critical ingredients for natural selection
- more individuals being produced than can be supported by the available resources but population size remains stable. -this leads to a struggle for existence & only a small portion of the progeny of each generation surviving -survival in the struggle for existence is not random, but depends on the hereditary constitution of the surviving individuals -every population displays variability that is often heritable -natural selection leads to gradual change of population
Which of the following species concepts might differentiate species on the basis of descent from a common ancestor? Please choose the correct answer from the following choices, and then select the submit answer button. - phylogenetic species - ecological species - ring species
- phylogenetic species
Which of the following species concepts is described by populations that are not in direct physical or reproductive contact, but do exchange genetic material through linking populations of the same species? - ring species - ecological species - evolutionary species
- ring species
mutation effect on fitness: non-synonymous mutation
- this mutation effect on fitness does alter the amino acid sequence of the protein -More likely to be subject to selection -if positive selection, will evolve faster -if purifying selection, will evolve slower
John Henslow
-(1796-1861) British Professor of botany at Cambridge University; taught Darwin and helped arrange his travel on the H.M.S. Beagle.
Charles Darwin life-changing events
-1831: Voyage of the HMS Beagle -1838: Read Malthus -1839: Married Emma Wedgwood -1844: Completed essay on "Selection" -1851: Death of Annie Darwin -1846-1854: Pigeons and Barnacles research -1858: Received message from A.R.Wallace
When did autotrophic/photosynthetic anaerobes dominate during ancient history & how do we know?
-3.45-2.7 billion years ago -isotopic signals (change in 12C:13C ratio) -chemical signatures indicate presence of an anaerobe like Cyanobacteria due to the presence of 2α-methyl-hopanes or a eukaryote due to the presence of stearanes
Hadean Eon
-4.55 bya - 4 bya -The oldest of the Precambrian eons; the time between Earth's origin and the formation of the first rocks that have been preserved. -Earth was bombarded by large, ET objects which repeatedly sterilized the surface, making life impossible (or just difficult?).
Epistasis (polygenic inheritance)
-A type of gene interaction in which one gene alters the phenotypic effects of another gene that is independently inherited. -When Multiple Loci are NOT Additive
founder effect
-A type of genetic drift -describes the loss of allelic variation that accompanies the creation of a new population from a very small number of individuals -can cause new populations to differ considerably from the source population
broad sense heritability includes
-Additive effects -Dominance effects -Epistatic effects -Maternal/Paternal & environmental effects
Darwin's enemies
-Alfred Russel Wallace, Hooker, Lyell, & Asa Gray
Hypothesis for where life first arose?
-Alkaline vents. A towering carbonate chimney, about 10 meters in height, from an alkaline vent in the Lost City hydrothermal field provides conditions conducive to the origin of life -Chambers (cell-size) in the serpentine of white smokers that serve as sites of autocatalytic chemistry
what does HW equation show us?
-Allele frequencies (A1 & A2 === p & q) predict genotype frequencies (A1A1 & A1A2 & A2A2 === p^2 & 2pq & q^2) -genotype frequencies (A1A1 & A1A2 & A2A2 === p^2 & 2pq & q^2) predict allele frequencies (A1 & A2 === p & q) -Phenotype frequencies can predict allele (A1 & A2) & genotype frequencies (A1A1 & A1A2 & A2A2)
James Hutton
-Among the first geologists to advocate for gradualism and an old earth -argued that observable processes produce small changes that accumulate over time -agreed with Lyell that Earth transformed gradually
genetic bottleneck
-An event in which the number of individuals in a population is reduced drastically. -Even if this dip in numbers is temporary, it can have lasting effects on the genetic variation of a population because it reduces the genetic variation as a whole -causes genetic drift
Richard Owen
-Aspired to be the British version of Cuvier. Coined the term "dinosauria". -Professional jealousy is thought to be partly responsible for Owen's antagonism to Darwin and his ideas. -British Museum of Natural History -Egotist & Plagiarist
Gregor Mendel
-Augustinian monk and botanist whose experiments in breeding garden peas led to his eventual recognition as founder of the science of genetics -showed that mechanism of inheritance was not blending, but particulate
Robert Chambers
-Author of "Vestiges of the Natural History of Creation", a treatise that predates "Origin" (1844) -Popular book (but critically de-claimed) that advocated the idea that species were not fixed. Initially gave Darwin serious indigestion with the thought that he had been scooped.
Darwin young adult
-Avid Hunter and Gun Enthusiast -Stopped Hunting after Beagle Expedition -Junior Chemist & Naturalist
types of aposematism
-Batesian Mimicry: harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both -Mullerian Mimicry: species with strong defenses evolve to resemble one another.
Alfred Russel Wallace
-British naturalist who developed a hypothesis of evolution by natural selection similar to Darwin's
c3 photosynthesis vs c4 photosynthesis
-C3: utilized by most plant species, it incorporates carbon dioxide into a molecule with three carbon atoms. -C4: utilized by plants like grasses, helps them grow rapidly, it incorporates carbon dioxide into a molecule with four carbon atoms.
C3 plants vs C4 plants
-C4 plants have higher levels of carbon-13 than C3 plants -this is true throughout history -the ratio of carbon isotopes can be utilized to infer the types of plants consumed by extinct animals
How did we infer the diet of early hominins?
-Carbon isotopic signatures -different plants have slightly different ratios of carbon isotopes, depending on how they carry out photosynthesis (C4 vs C3) -C13/C12 ratio used to infer types of plants eaten (C4 has more C13)
Thomas Aquinas
-Catholic theologian and saint; his influence led to the development of "Natural Theology" -Catalog the "links" as a means of revealing and appreciating the wisdom of God
Fins to limbs: homology through time
-Coelacanths are one of the closest living relatives of tetrapods -their fins are homologous to tetrapod forelimb
convergent evolution vs evolutionary reversals
-Convergent evolution: independent evolution of similar trait -Evolutionary reversals: reversion back to an ancestral character state
William Smith
-Created the first geologic map; proposed that different rock layers contain distinct fossils -(1769-1839)
Eukaryotic DNA organization
-DNA is organized with histones and other proteins into chromatin, which can be looped and packaged to form chromosomes
Josiah Wedgwood II
-Darwin's Uncle, hunting companion, & future father-in-law -Endorsed Beagle Expedition to Robert Darwin
Emma Wedgewood
-Darwin's first cousin and wife -Devoted Spouse -Clerical & Editorial Assistant -Nurse
Best explanation for the diversity of life
-Darwin's theory remains the best explanation for the diversity of life -Natural selection and sexual selection are powerful forces in natural populations -Darwin's theory has also been expanded: (Genetic drift: random changes to the gene pool resulting from chance events)
Annie Darwin
-Darwins first daughter died -Contracted Scarlet Fever in 1849 -May have also suffered from "consumption" or typhus
Mary Annig
-Discovered extinct marine reptiles
describe the different allele interactions seen in polygenic traits
-Dominance: Dominance/recessive interaction between alleles -Additive: Linear interaction between alleles -Epistasis: Non-linear interaction between alleles
relationship between natural selection, drift, and population size
-Drift weaker in large populations -Small advantages in fitness can lead to large changes over the long term
neptunism
-Earth's surface features are a consequence floods
Thomas Malthus
-Eighteenth-century English intellectual who warned that population growth threatened future generations because, in his view, population growth would always outstrip increases in agricultural production. -argued that humans would outstrip the available resources necessary to sustain themselves, leading to population growth that would be checked by famine, war, and disease. Malthus' writings were influential in helping Darwin develop his ideas on natural selection.
Thomas Huxley
-English biologist, famous for his defense of Darwinism in his public debate with Archbishop Samuel Wilberforce. Coined the term "agnosticism". Known as Darwin's bulldog
Charles Darwin
-English natural scientist who formulated a theory of descent with modification (transmutation or evolution) by natural selection -(1809-1882)
mutation-selection balance
-Equilibrium frequency reached through tug-of-war between negative selection and new mutation -Explains persistence of rare deleterious mutations in populations
Earliest fossils of the three domains of life
-Eukaryotes: ~1.8 Ga (presence of stearanes indicate earlier origin) -Bacteria: potentially 3.45 Ga; abundant by ~2.6 Ga, corresponding to rise in oxygen -Archaea: ~3.5 Ga
The designer without god (hume)
-Even if one accepts that complexity in living organisms demands a designer, the designer need not be the God of the Bible.
experimental evolution provides..
-Experimental evolution provides important insights about selection
Nicholas Steno
-Father of geology and stratigraphy -First to recognize fossils were remains of organisms -pioneered use of stratigraphy as method for reconstructing the past -(1638-1686)
Carl von Linne (Carolus Linnaeus)
-Father of modern taxonomy -Advocate for binomial nomenclature and originator of the Linnean system of taxonomy (Swedish Naturalist, Botanist-Sexual System, Binomial Nomenclature) [1707-1778]
Jean Lamarck
-French naturalist who proposed a theory of evolution where life is driven from simple to complex, complex species are descended from simple organisms, simple organisms are continually generated spontaneously, traits can be enhanced or lost through use or disuse, and adaptation occurs through inheritance of acquired changes -Species evolve through natural processes; Life constantly generated;Adaptation through inheritance of acquired changes -(1744-1829)
How does natural selection vary over space?
-Gene flow can bring alleles to new locations -Alleles may increase or decrease fitness
genetic drift overview
-Genetic drift is the random, nonrepresentative sampling of alleles from a population during breeding -Alleles are lost more rapidly in small populations -Even brief bottlenecks can lead to a drastic reduction in genetic diversity that can persist for generations
genome-wide association mapping
-Genome-wide association (GWAS) mapping of natural populations groups individuals by phenotype -involves scanning through the genomes of many different individuals, some with, and others without, a focal trait of interest, to search for markers associated with expression of the trait
parapatric speciation
-Geographic barrier only partially separates populations -Some gene flow possible
Erasmus Darwin
-Grandfather to Charles; more-complex forms of life arose from less complex forms of life -The Temple of Nature (E. Darwin, 1803)
HIV example analysis
-HIV made jump from chimps (SIV) to humans (HIV) -Multiple risings of SIV occurred, most likely actually because of the same mutation in several separate lineages!
Asa Gray
-Harvard botanist; exchanged letters with Darwin and thus was privy to some of his early ideas regarding natural selection.
reasons hybrids have low fitness
-Hybrid inviability -Hybrid sterility -Ecological inviability -Behavioral sterility
The weak analogy objection (hume)
-In arguing for the notion of a Designer, the analogy between watches and living organisms is flawed since living organisms have key traits (e.g., reproduction) that distinguish them from non-life.
why are isotopes important in evolutionary history?
-Isotopes offer clues to the habitats where organisms lived, and they also provide clues to their metabolism. -Geologists can also use carbon isotopes for clues about what some extinct animals were eating.
How is the transition from land to water documented?
-Isotopic analysis of fossil teeth -Fossil analysis of hindlimb loss
Darwin outline of selection
-Letter to Emma with publication instructions -Lyell encourages Darwin to publish •Darwin begins writing his "magnum opus" in 1856
Georges Louis Leclerc, Compte de Buffon
-Life emerged as distinct types but changed with environmental change; the Earth formed according to laws of physics and chemistry and is much older than 6000 years old -Species arise as distinct entities; diverse environments give rise to new varieties -(1707-88)
inconspicuous homologies between mammals & reptiles how was this discovered
-Mammalian ear bones are homologous to bones of the reptilian jaw (the mammalian ear is made up of modified parts of the lower jaw and surrounding skull) -Hypotheses of homology tested by assessing embryonic development
Charles Darwin life overview
-Medical school in Edinburgh (1825-1827) -Preferred to study nature -Pre-Theological Training (1827-1830) -Trained to become clergyman at Cambridge -Theological training: set for 1831, postponed for trip on beagle -Invited to serve as unofficial naturalist for HMS Beagle in 1831
What process generates unique alleles and unique combinations of alleles to enhance variation and how?
-Meiosis generates considerable genetic variation through recombination (the exchange of genetic material between paired chromosomes during meiosis) and independent assortment (random mixing of maternal and paternal copies of each chromosome)
Robert Fitzroy
-Mentor to Darwin -Meteorologist & captain of HMS Beagle -Attained Rank of Vice Admiral
multiregional model
-Model that says homo genus did not migrate and stayed in the same region, thus evolving over time and not mixing or spreading, and the similarities found between species are causes of GENE FLOW. -Hominins across Old World were a single species connected by gene flow -Multiregional differences the result of local adaptation
mutation rates & their influence on variation
-Mutation rates for any given gene are low, but considering genome size and population size, many new mutations arise each generation -these mutations are the source of variation for selection and drift to act
germ-line mutations
-Mutations that affect the gametes (eggs, sperm) of an individual and can be transmitted from parents to offspring. Because they can be passed on, germ-line mutations create the heritable genetic variation that is relevant to evolution. -rare, but accumulate over time (raw material for evolution)
Jemmy Button
-Native Fuegian who was kidnapped and subsequently "civilized" by Robert Fitzroy (Captain, HMS Beagle) -Fuegian captive on the HMS Beagle who was re-patriated/civilized to Christian mission on Tierra del Fuego; this did not work, which led Darwin to think Fuegians were just primitive humans -(1816-1863)
natural selection overtime? natural selection over space?
-Natural selection is variable over time and can result in rapid evolutionary change -Natural selection can be variable across space; can lead to variation over the geographic range of a species
Natural Theology
-Observations of the natural world that both reveal and glorify the Creator -complexity is evidence of design
Darwins Ideas in american culture
-P. T. Barnum -The Missing Link -aka Half Ape/Half Man - comic "Zip the Pinhead"
David Hume
-Philosopher and mathematician who challenged argument from design/Teleology -against Paley -(1711-1776)
Phylogenies are? They help?
-Phylogenies are hypotheses based on the best available evidence -Phylogenies help scientists identify questions that can be tested with additional evidence
Why do ratios of C-13 and C-12 differ in plants
-Plants obtain their carbon from the atmosphere, incorporating a mixture of carbon-12 and carbon-13 isotopes into their biomass. Because carbon-13 is heavier than carbon-12, the plants have more difficulty absorbing it. As a result, the ratio of carbon-13 to carbon-12 is lower in plants than it is in the atmosphere. -12C is thermodynamically favored in carbon uptake since it has a greater vibrational energy (only 6 protons and 6 neutrons) and, thus, a lower energy of activation -Thus, 12C will be "enriched" in organic matter compared to non-organic (background) sources of carbon—generally on the order of 2-3%.
effects of population size on drift and natural selection
-Population size influences power of drift and selection -Drift more powerful in small population/weaker in large populations -Selection more powerful in large population
population subdivision and genetic drift
-Population subdivision enhances the effects of genetic drift due to a divergence in allele frequencies
Robert Grant
-Professor at University of Edinburgh and early Darwin mentor -Invertebrate Biology, Unity of Animal Body Plans -Influenced by Erasmus Darwin & Jean-Baptiste Lamarck -(1793-1874)
St. George Jackson Mivart
-Protégé of Huxley -Reconsidered his position on natural selection •Blackballed by the "Darwinian" faction -"Natural selection is incompetent to account for the incipient stages of useful structures." -Accused George Darwin of "inviting licentiousness"
twofold cost of sex
-Refers to the disadvantages of being a sexual rather than an asexual organism. -Asexual lineages multiply faster than sexual lineages because all progeny are capable of producing offspring. -In sexual lineages, half of the offspring are males who cannot themselves produce offspring. This limitation effectively halves the rate of replication of sexual species.
genetic locus
-Refers to the specific location of a gene or piece of DNA sequence on a chromosome. -When mutations modify the sequence here, they generate new alleles - variants of a particular gene or DNA region. Alleles are mutually exclusive alternative states for this
sympatric speciation
-Reproductive isolation evolves without geographic isolation -Requires nonrandom mating based on genetic or phenotypic factors
ecological speciation
-Selection for different ecological traits creates reproductive barriers -Can lead to pre- and postzygotic isolation
selection occurs when? outcome of selection depends on?
-Selection occurs when genotypes differ in fitness -Outcome of selection depends on frequency of allele and effects on fitness
regulatory networks
-Systems of interacting genes, transcription factors, promoters, RNA, and other molecules. They function like biological circuits, responding to signals with outputs that control the activation of genes during development, the cell cycle, and the activation of metabolic pathways. -can be important building blocks for complex adaptations
Early views of diversity
-The Great Chain of Being -The Ladder of Life -Scala Naturae
What was the Late Heavy Bombardment and when did it occur? where is evidence of this?
-The Late Heavy Bombardment (LHB), lunar cataclysm, is a theory that the Earth, and the entire inner solar system, suffered through an intense spike in asteroid bombardment roughly 4 billion years ago during the Hadean Eon -The main piece of evidence for a lunar cataclysm (and, by implication, earth and the other rock planets) comes from the radiometric ages of impact melt rocks that were collected during the Apollo missions
The uniqueness objection (hume)
-The argument from design cannot be supported or tested empirically -The ID hypothesis for living organisms cannot appeal to direct empiricism
Philosophical Naturalism
-The philosophical position that the natural worldis all that exists—that there is nothing that is supernatural.
evolution speed?
-The speed of evolution depends on amount of genetic variation and strength of selection -Leads to rapid resistance in pest populations -Loci that have diverged faster than predicted by drift may be under selection
plutonism
-Volcanos and earthquakes continually changed the face of the Earth
Darwin life-changing events
-Voyage of HMS Beagle (1831-1836): began reading Lyell, darwin's finches -read malthus (1838) -completed essay on selection (1844) -death of annie darwin (1851) -Pigeons & Barnacles -Received Ms. from A. R. Wallace (1858)
describe key concepts from mice coat variation experiment
-When mice colonized coastal habitats cryptic coloration was still favored, but colors conferring the best crypsis shifted -Atlantic and Gulf coast populations both evolved white fur, but the specific mutations responsible are different
Charles Lyell
-Wrote "Principles of Geology" which advocated for uniformitarianism, deep time and plutonism (vs. Neptunism) -Agreed with Hutton that Earth transformed gradually
oxygen statuses overtime (stages)
-[3.8-2.4 bya] stage 1: No atmospheric oxygen. UV may be producing some oxygen (from water) that could be used for early aerobic respiration -[2.4-1.9 bya] stage 2: Oxygenic photoautotrophy. Oxygen largely absorbed by oceans and seafloor sediments -[1.9-0.9 bya] stage 3: Oceans out-gas oxygen, but now terrestrial sediments begin to absorb oxygen -[0.9 bya to current] stage 4 & 5: All sedimentary sinks filled;—oxygen accumulates in atmosphere
Synapomorphy: Synapomorphies between fossil whales & modern cetaceans?
-a characteristic shared by two or more organisms that they inherited exclusively from a common ancestor -bulla, incisors and canines aligned with cheek teeth, narrow postorbital/temporal region, involucrum
Red Queen Effect
-a phenomenon seen in coevolving populations- to maintain relative fitness, each population must constantly adapt to the other simply to survive -called the "biological arms race" -ex. occurs between parasites and hosts
Selection on quantitative traits
-a quantitative trait is a phenotypic characteristic that varies continuously, as opposed to discretely, and involves multiple loci -Selection on quantitative traits can take several different forms -Directional -Stabilizing -Disruptive
When do these first appear? -earliest fossils of algae? Red? Green? -earliest animal? -chordates -terrestrial plants -terrestrial fungi & insects -terrestrial animals -terrestrial vertebrates & tetrapods -mammals & birds -flowering plants -whales, bats, primates -grasses
-algae (1.6 Ga), red algae (1.2 Ga), green algae (750 Ma) -sponges (650 Ma) -chordates (515 Ma) -terrestrial plants (475 Ma) -terrestrial fungi & insects (400 Ma) -terrestrial animal (480-428 Ma) -terrestrial vertebrates/tetrapods (390-370 Ma) -mammals & birds (150 Ma) -flowering plants (174-132 Ma) -whales, bats, primates (50 Ma) -grasses (20 Ma)
multifactorial inheritance
-an interaction between genes and the environment that contributes to a phenotype or trait -generates near-continuous variation
Reconstruction of phylogenies is based on phylogenies illustrate?
-analysis of characters -phylogenies illustrate relationships among known species—not all species. Combining evidence can lead scientists to new fossils discoveries and insights into why lineages may have evolved.
apomorphic vs synapomorphic vs plesiomorphic
-apomorphic traits: derived (only ones used to build phylogenetic trees) -synapomorphic: shared derived traits -plesiomorphc traits: ancestral traits (not used to build phylogenetic trees)
Apomorphy vs. Plesiomorphy
-apomorphy (derived trait) refers to a characteristic which is unique to a clade and is found in all descendants of that particular clade -plesiomorphy (ancestral trait) refers to a characteristic which is present in the clade but may not be present in all members of the clade.
genetic drift features
-causes evolution in finite populations -results from random sampling error; increases as the sample gets smaller -reduces genetic variation in a population -the smaller the population, the faster alleles are lost -alternative allele is fixed -can be caused by bottleneck
Homoplasy
-character state similarity not due to common descent -conflict between characters in a data matrix; generally due to convergent evolution or evolutionary reversals
What are the various locations mutations occur and cause differing effects?
-coding regions -cis-regulatory regions -trans-regulatory regions -physiological pathways (controls expression of the genes responsible for producing endocrine signals)
Georges Cuvier
-confirmed the reality of extinction (e.g., his work with the Irish Elk). -Extinction is real and modern organisms are not necessarily identical to fossil organisms. -Many past species are extinct -(1769-1832)Citing the abrupt disappearance of organisms in different strata of the Paris (France) basin, __?__ favored the notion that the earth had witnessed multiple creation events.
Apomorphy Synapomorphy Symplesiomorphy Homoplasy Plesiomorphy
-derived trait -a shared derived trait -A shared, ancestral trait -Phylogenetic noise -An ancestral trait
gene flow
-describes the movement, or migration, of alleles from one population to another -homogenizes allele frequencies -amount varies with the biology of the organism -counteracts subdivision by homogenizing allele frequencies
Muller's ratchet
-describes the process by which the genomes of an asexual population accumulate deleterious mutations in an irreversible manner -once all genomes in the population reach the same number of deleterious mutations, this has turned
balancing selection types?
-describes the type of selection that favors more than one allele. -acts to maintain genetic diversity in a population by keeping alleles at frequencies higher than would be expected by chance or mutation alone. -Negative frequency-dependent selection -Heterozygote advantage (AKA Overdominance)
benefits of female choice
-direct benefits: food, nest sites, protection, gifts -indirect benefits: those that affect the quality of the offspring
Francesco Redi
-disproved spontaneous generation by showing that maggots do not spontaneously arise from decaying meat. -experiment demonstrated that maggots did not arise through spontaneous generation. Uncovered jars with meat have fly eggs and maggots. When the jars are covered, and flies cannot enter and lay eggs on the meat, no eggs or maggots are found.
William Dallinger
-examined evolutionary change in temperature tolerance in protozoa; produced individual population of protozoa that could tolerate much higher temperatures than is typical; demonstrated that protists could evolve this trait by selection in the laboratory; one of the first studies on evolution in the lab -16 C - 66 C
Cit+ trait
-example of how gene duplication can be utilized to create advantages for an organism by allowing a transporter to be expressed and used to allow growth on citrate -The Cit+ trait was actualized by a duplication mutation that created a new regulatory module by placing a copy of the citT gene that encodes a citrate-succinate antiporter under the control of a promoter that supports expression under aerobic conditions. This mutation results in the CitT transporter being expressed when oxygen is present, permitting growth on citrate
polyandry
-females mate with multiple males -this type selects for male traits that increase paternity
Earthquake at Concepción (1835)
-fresh mussel bed w/ 8 feet of uplift -Darwin Concluded: The Andes, and perhaps other mountain systems, have been raised above sea level by geologic forces
Archean Eon
-from 4 to 2 billion years ago. Origin (or diversification) of life, all life is prokaryotic. Little oxygen in the atmosphere. -Oldest evidence of life dates to 3.7 bya where carbon contained in rocks (controversial) -Oldest stromatolite (bacteria) fossils date to 3.45 bya -cyanobacterial fossils 2.5 bya
Describe the changes in allele frequencies (from ancestral to descendent population) that occur during.. -genetic drift -natural selection -migration (gene flow) -mutation
-genetic drift: imperfect sampling causes some alleles to be underrepresented relative to others => that allele is lost -natural selection: environmental factors are unfavorable for one allele => that allele becomes less common -migration (gene flow): individuals with a new allele enter a population => that allele becomes more common -mutation: change in genetic sequence produces new allele => new genetic variant exists in population
hindlimb reduction in Stenella attenuata (spotted dolphin)
-hindlimb bud with a morphologically distinct apical ectodermal ridge (AER) present at Carnegie 13 -AER persists and hindlimb bud outgrowth is sustained through Carnegie 15
inbreeding
-increases percentage of loci that are homozygous for alleles identical by descent -goes hand in hand with inbreeding and selection because recessive alleles exposed to selection
inbreeding depression
-is a reduction in the average fitness of inbred individuals relative to that of outbred individuals -this arises because rare, recessive alleles become expressed in a homozygous state where they can detrimentally affect the performance of individuals
examples of whale evolution
-loss of teeth in baleen whales -evolution of brain size and complexity -whale diversity over evolutionary time
out-of-africa model
-model that states that the homo genus originated from Africa and migrated out to other regions of the world -All human populations are derived from recent African ancestry THIS MODEL WAS CORRECT
pleiotropy
-mutation in a single gene affects the expression of more than one different phenotypic trait -Can be antagonistic -Net effect on fitness determines outcome of selection
Exaption
-natural selection co-opts a trait for a new function -shaping of a useful feature of an organism by natural selection to perform one function and the later reshaping of it by different selection pressures to perform a new function
heterozygous advantage
-occurs when selection favors heterozygote individuals over either of the dominant homozygotes -AKA overdominance -a type of balancing selection -rare deleterious allele can actually temporarily increase under heterozygote conditions
Fleeming Jenkin
-one of Darwins antagonists -English civil engineer who argued that natural selection had no power to produce stable changes since novel traits that arise in one parent would inevitably be diluted in any offspring when blended with wild-type (normal) traits in the other parent. -Engineer -"Swamping Argument" of Blending Inheritance vs. Natural Selection --> argued that natural selection is not able to overcome the consequences of inheritance (which is blending)
George Howard Darwin
-one of darwins antagonists -Astronomer & Mathematician -FRS 1879 -Plumian Professor of Astronomy & Experimental Philosophy (Cambridge) -Barrister-at-Law
William Thomson (Lord Kelvin)
-one of darwins antagonists -English civil engineer whose expertise in thermodynamics (heat transfer in particular) led to proposals that the earth was likely no older than 20 million years -Heat Conduction Estimate for Age of the Earth •20-100 Million Years
Scala Naturae (great chain of being)
-organisms are unchanging and range from simple to complex; no extinction, no new species, no variation; idea that developed before world exploration and discovery of fossils
isolation by distance
-pattern in which populations tend to breed with those in close proximity -causes variation across the range
allopolyploidy
-polyploidy resulting from contribution of chromosomes from two or more species -can lead to extremely rapid speciation because the organisms can survive dramatic mutations
selective sweep
-positive selection of a favorable allele that causes it to increase in frequency in the population -The situation in which strong selection can "sweep" a favorable allele to fixation within a population so fast that there is little opportunity for recombination. In the absence of recombination, alleles in large stretches of DNA flanking the favorable allele will also reach high frequency.
At what levels is the gene expression of eukaryotes regulated?
-pre-transcriptional -transcriptional -post-transcriptional -translational -post-translational
Describe the ways in which transcription is modified to regulate gene expression:
-pre-transcriptional: a structural modification characterized by coiling or packing of DNA around histones -transcriptional: chemical regulation (DNA methylation, RNA pol specificity, DNA binding regulatory proteins, transcription factors, hormones/signals) that can silence genes, and regulate the timing & activation of transcription -post-transcriptional: chemical regulation (RNA splicing) that influences how much of the RNA is available for translation
William Paley
-proposed that mechanical complexity provided evidence for a Divine Creator (AFD/Teleology) -Analogy of the watch on the heath; advocate of the argument from design (AFD) -"The Argument From Design" or Teleological Argument (purpose) -Wholly Deductive Reasoning -(1743-1805)
promiscuous proteins
-proteins capable of carrying out more than one function, such as catalyzing reactions of different substrates -these are especially likely to take on new functions after gene duplication
negative selection
-refers to selection that decreases the frequency of alleles within a population; occurs whenever the average excess for fitness of an allele is less than zero. (lower fitness experience) -Alleles that lower fitness experience negative selection
life history
-refers to the pattern of investment an organism makes in growth and reproduction; includes and organism's age at first reproduction, duration and schedule of reproduction, number and size of offspring produced, and lifespan -involved in trade-offs due to limited amount of energy to invest in survival, maintenance, and reproduction
fitness (w)
-refers to the success of an organism at surviving and reproducing and thus contributing offspring to future generations -the reproductive success of an individual with a particular phenotype -common components: survival to reproductive age, mating success, and fecundity
Hox genes
-series of genes that controls the differentiation of cells and tissues in an embryo -all similar genes presenting in this in similar order across all vertebrates -all vertebrates have approx 4 clusters
anisogamy
-sexual reproduction by the fusion of dissimilar gametes; larger gamete is female; smaller gamete is male -this results in differential investment in reproduction
what conditions allow an organism to fossilize?
-sheltered from other organisms by sediment -mineral water fills up spaces in bone/shell/cells with sediment - structures filled with stone - bone dissolves, new minerals take its place -organism turns to rock
quantitative trait loci (QTLs)
-stretches of DNA that are correlated with variation in a phenotypic trait; these regions contain genes, or are linked to genes, that contribute to population differences in a phenotype -peaks on a QTL graph show that there are specific loci contributing to a trait -does not tell you that specific genes are involved in a trait, but does give the LOCATION of where you should LOOK for those contributing genes (still need to sequence)
negative frequency-dependent selection
-takes place when rare genotypes have higher fitness than common genotypes -This process can maintain genetic variation within populations; a type of balancing selection
Teleology
-the doctrine that there is evidence of purpose or design in the universe, and that this provides proof of the existence of a Creator or Designer.
deep time
-the immense span of geologic time where the extreme interpretation is of an earth without a beginning
convergent evolution cetaceans artiodactyls
-the process by which unrelated or distantly related organisms evolve similar body forms, coloration, organs, and adaptations -a marine mammal -Artiodactyla, or even-toed ungulates (pig, cow, sheep, etc.)
Deductive reasoning
-the process of applying a general statement to specific facts or situations
narrow sense heritability (h^2)
-the proportion of the total phenotypic variance of a trait attributable to the additive effects of alleles (the additive genetic variance); -this is the component of variance that causes offspring to resemble their parents, and it causes populations to evolve predictably in response to selection
broad sense heritability (H^2)
-the proportion of the total phenotypic variance of a trait that is attributable to genetic variance, where genetic variance is represented in its entirety as a single value -Answers the question: What role does genotype play in heritability? -Proportion of phenotypic variance explained by genetic differences among individuals
relative fitness (of a genotype)
-the success of the genotype at producing new individuals (its fitness) standardized by comparison to the success of other genotypes in the population (for example, divided by the average fitness of the population) -> (1 ≥ w ≥ 0) -> w = 1-s
Uniformitarianism
-the theory that changes in the earth's crust during geological history have resulted from the action of continuous and uniform processes.
positive selection
-the type of selection that increases allele frequency in a population; occurs whenever the average excess for fitness of an allele is greater than zero. (increases fitness experience) -Alleles that increase fitness experience positive selection
rare alleles
-these are likely to be lost during a bottleneck -almost always carried in a heterozygous state -Recessive alleles invisible to selection -Selection cannot drive dominant to fixation
hierarchical gene organization
-this can control development of animal embryos through Hox genes -mutations to genes at top of this can have drastic effects
mutation effect on fitness: synonymous mutation
-this mutation effect on fitness does not alter the amino acid sequence of the protein -Often selectively NEUTRAL -should evolve at neutral rate
polygenic trait
-trait influenced by many genetic loci, like interaction between alleles (epistasis/dominance/additive) or interaction with environment (phenotypic plasticity)
Tiktaalik founded by
-transitional fossil between fish and tetrapods whose forelimbs share more homologies with tetrapods -Ted Daeschler & Neil Shubin searched mid-Devonian rocks in Northern Canada
Describe the ways in which translation is modified to regulate gene expression:
-translational: chemical regulation in which the binding of regulatory proteins, antisense RNA, & ribosomal subunits are used to influence translation initiation -post-translational: chemical regulation in which the activity, function, and structure of proteins is regulated through the cleavage of AA, binding of subunits, and phosphorylation
Nested hierarchy from vertebrates to mammals
-vertebrates: skull, brain, spine -tetrapods: legs, toes, neck; absence of gills -amniotes: internal egg -mammals: hair, milk
When do genetic changes in gene expression occur? How do these effect evolution?
-when noncoding mutations affect where, when, and how much a gene is transcribed -changes in gene expression add another component of heritable genetic variation
Given the following: w11 = 1.0, w12 = 0.95 and w22 = 0.98, the critical frequency of p = __?__ for this trait.
0.375
abiogenesis challenges
1) information-containing molecules must come from inorganic compounds 2) chemical reactions involved must be favored by environmental conditions 3) self assembly is a crucial feature of the macromolecules 4) processes that degrade macromolecules must be thwarted in some fashion
sequential phases of Cit+ evolution (3)
1) potentiation (mutations must be made; laying groundwork) 2) actualization (trait appears as mutation and begins to distinguish self) 3) refinement (new mutations are acquired to enhance actualized trait)
paradigm shifts that had to happen before Darwin's ideas could be accepted (2)
1) universe is not static 2) biology needed to be considered a science
flu life cycle
1) virus enters cell 2) mRNA synthesis and RNA replication highjack cell and use its parts to make new viruses 3) new viruses bud off and can infect more cells
The Big Five Mass Extinctions
1)The Ordovician Event 2)The Devonian Effect 3)The Permian Event 4)The Triassic Event 5)The Cretaceous Event
Two Paradigm shifts in the origins of evolutionary thought
1. A Changing Universe 2. Material Explanations for Biological Phenomena
Key transitions in evolution
1. Natural Theology (Aquinas) vs. Materialism 2. Fixity of Species vs. Evolution (Buffon, Lamarck) 3. Static Universe vs. Changing Universe (Hutton) 4. Young Earth (Ussher) vs. Old Earth (Hutton) 5. Catastrophism vs. Gradualism (Hutton) 6. Catastrophism vs. Uniformitarianism (Lyell) 7.Scala Naturae vs. Distinct Phyla (Cuvier) 8.Fixity of Species vs. Extinction (Cuvier) 9.Fixity of Species vs. Fossils (Steno, Cuvier)
potentiation actualization refinement
1. Potentiation: mutations that lay the foundation for subsequent mutations that "do the heavy lifting" 2. Actualization: a mutation that elicits the trait in question (i.e., Cit+) appears. Does not happen unless potentiation provides a background for the new trait to have some success. 3. Refinement: New mutations are acquired that enhance the acutalized trait.
Proterozoic Eon
2 billion until 550 million years ago. Oxygen appears in the atmosphere reaching the present level of 21%. Eukaryotes appear. Few with hard parts (bone, teeth, shells), few fossils. Eons 1-3 are often referred to as the Pre-Cambrian.
Phanerozoic/Cenozoic Era
65 million years ago until present. Land dominated by mammals and flowering plants
the tape of evolution runs in one direction
??????????
Of the traits illustrated at right, which is the strongest quantitative trait locus as evidenced by the F1 progeny of a cross between heterozygotes?
A
what is a clade?
A MONOPHYLETIC group of species that includes an ancestral species and ALL its descendants.
Phylogenetic tree
A branching diagram that represents a hypothesis about the evolutionary history of a group of organisms.
meiosis
A form of cell division that occurs only in eukaryotes, in which the number of chromosomes is cut in half; gives rise to gametes or spores and is essential for sexual reproduction
underdominance
A form of frequency-independent selection in which the heterozygote genotype has a lower fitness than either corresponding homozygote genotype.
their most recent common ancestor
A monophyletic group is comprised of a set of descendant taxa and __?___.
Enceladus
A moon of Saturn with plumes of salty, liquid water emerging from deep oceans that might be suitable for life.
Monophylyl
A set of descendant organisms and their most recent common ancestor
pleiotropy
A single gene having multiple effects on an individual's phenotype
tree space
A term to describe the total number of possible trees for a particular analysis.
indicates that most phenotypic variation in the population is explained by differences in the environments experienced by individuals
A trait with a value of H2 that approaches zero (0) __?__.
means that none of the variance is attributable to additive traits
A trait with h2 that approaches zero (0) __?__.
Speciation has occurred when: A. divergent populations evolve to the point where interbreeding does not produce viable, fertile offspring. B. mutations in a population reach 100% of the organisms in that population. C. organisms from a single species are separated by a physical barrier. D. a DNA sequence is changed, resulting in an altered protein product. E. an alteration in an organism's genetic material is made permanent.
A. divergent populations evolve to the point where interbreeding does not produce viable, fertile offspring.
two genes that are paralogs:
ALL OF THE ABOVE (arose from gene duplication, are found in the same genome, may perform the same or different functions)
Gene duplication:
ALL OF THE ABOVE (result in genes that are paralogs, leads to functional redundancy, can result in one of the copies gaining a new function)
polar bear genes under strong selection (3)
APOB proteins Heart function Pigmentation
Which of the following is true regarding adaptive radiation?
Adaptive radiation is more likely to occur in a population produced by a dispersal event than in a long-established population on a continent.
Which of the following statements is correct: All cells have the same genes All cells express the same genes All cells have the same proteins All are correct
All cells have the same genes
Antagonistic pleiotropy
Alleles are beneficial early but deleterious late in life
Breeder's equation?
Allows prediction of change due to selection on quantitative traits
Wright-Fisher Model
Alternative to Hardy-Weinberg for small populations
fixed allele
An allele that remains in a population when all of the alternative alleles have disappeared; no genetic variation exists at the locus of this within a population, because all individuals are genetically identical at there.
aposematism
An antipredator strategy used by a potential prey item to signal danger or a lack of palatability; the most commonly known form is warning coloration, in which the bright coloration of prey that are potentially dangerous can act as a deterrent to potential predators.
Lagerstattes and what conditions make them possible
An exceptionally well-preserved fossil deposit is called a Lagerstätte. In almost every Lagerstätte, the fossilized animals were swept into anoxic (or low-oxygen) pools, lagoons, or bays. In these lifeless environments, bacteria and other scavengers did not exist and thus could not destroy the animals' bodies. Instead, the deceased animals were trapped in fine sediments, which preserved even their most delicate tissues in stone.
Trade off
An inescapable compromise between one trait and another
archaeopteryx
An intermediate fossil that shows both reptile and bird characteristics; has teeth
Robert chambers
Anonymous author of Vestiges of the Natural History of Creation
Biological evolution
Any change in the inherited traits of a population that occurs from one generation to the next
beta defensins
Are produced in skin and other parts of the body for bacteria, then it evolved to into fighting bacteria in the snake's pancreas, until finally evolving into crotamine venom which is expressed in venom glands in snakes.
Darwins ideas in scientific racism
Asa Gray - Monogeny (agreed with darwin that there is only one kind of human) Louis Agassiz - Polygeny (Against darwins ideas but still used them to argue that there are multiple species of humans)
Maximum likelihood
Assessing the probability of a set of data given a tree
Bayesian inference
Assessing the probability of a tree given a set of data
maximum likelihood criteria (optimality criterion)
Assessing the probability of the data given a particular tree; REQUIRES A MODEL
Robert Chambers
Author of The Vestiges of the Natural History of Creation; advocated the idea that species were not fixed
Which of the following statements is true regarding polyploidy in plants?
Autopolyploids are thought to be derived from plants of the same species.
Neutral changes in a physical trait of an organism are most commonly fixed in a population by: A. isolation. B. genetic drift. C. increasing population size. D. natural selection. E. predation.
B. genetic drift
Dorsal
Back or toward the back
Jean-Baptiste Lamarck proposed:
Bacteria represent some of the youngest species on Earth Organisms can adapt to their environment Life arises spontaneously
fixed ratio of stable carbon isotopes and when this differs
Biogeochemists have determined that the naturally occurring, stable isotopes have a fixed, background ratio of 0.9889 to 0.00111. EXCEPT...when inorganic carbon is taken up through autotrophy
temporal isolation
Both plants and animals may also be pre-zygotically isolated in time example -- closely related plant species may flower at different times of the year, so there is no chance that the pollen of one will come into contact with the flowers of the other. Similarly, members of a nocturnal animal species simply will not encounter members of a closely related species that are active only during the day.
Alfred Russel Wallace
British naturalist who independently developed a theory of evolution by natural selection that was very similar to Darwin's
reduces genetic variation within a population can lead to divergence between populations that are both experiencing drift
By itself, genetic drift __?__.
always leads to higher fitness of individuals in the population
By itself, natural selection that acts upon heritable variation in a population __?__.
In the animation, fish with a larger body size have a ____________ reproductive fitness than fish with a smaller body size because ____________. A. lower; they cannot access as many different environments B. higher; they can swim farther distances C. higher; they are less vulnerable to predators D. higher; they are less susceptible to additional mutations E. lower; they swim more slowly
C. higher; they are less vulnerable to predators = advantageous mutation --> become fixed by natural selection
Carbon Isotopic Signature 13C:14C
C4 plants have higher quantities of 13C than C3 plants.
Phanerozoic/Mesozoic Era
Ca. 250 to 65 million years ago. Mammals (reptilian synapsids) and flowering plants arise, but the land is dominated by dinosaurs (reptiles), gymnosperms, ferns and lycopods
Phanerozoic/Paleozoic Era
Ca. 550 to 250 million years ago. Hard-bodied fossils appear, complex multicellular organisms, invasion of the land by plants and animals.
Nearly all currently existing animal lineages evolved during which period?
Cambrian
Burgess Shale
Canadian fossil formation that contains Cambrian soft-bodied organisms as well as organisms with hard parts.
Not fixation of recessive, dominant allele or fixation of an heterozygote
Cases of heterozygote advantage generally result in __?__.
ratio change of C3:C4 plants 3.5 mya
Cerling and his colleagues found that, starting about 3.5 million years ago, the C3:C4 ratio shifted. The hominin diet drew more on C4 plants.
How did they use carbon isotopic signatures to determine diet of extinct hominins? what did they find?
Cerling and his colleagues measured carbon isotopes in the tooth enamel from hominin fossils in East Africa dating from 4.2 million years ago to 1.5 million years ago. They found that the earliest hominins had a relatively low ratio of carbon-13 to carbon-12. Indicating that they had a diet high in C3 plants.
what change led to hindlimb loss?
Changes in gene expression during embryonic development (4-9 wks) led to hindlimb loss
Robert Darwin
Charles Darwin's father. Was worried about him because he was always outside and had no motivation in school. (1766-1848)
Robert Waring Darwin
Charles Darwin's father; did not have a lot of faith in him lol
2-Methyl Hopanes
Chemical fossils associated with the presence of cyanobacteria
Stearanes
Chemical fossils associated with the presence of eukaryotic cells
Proximal
Closer to the point of attachment or origin
allopatry
Condition in which two or more populations live in different geographic areas.
sympatry
Condition in which two or more populations live in the same geographic area
who orginally hypothesized the RNA world hypothesis & what did they believe
Crick, Orgel, and Woese hypothesized that the first cellular life had a much simpler organization, with RNA playing all three roles.
cumulative effects of directional selection..
Cumulative effects of directional selection can be large
pseudogenes
DNA sequences that resemble functional genes but have lost their protein-coding ability or are no longer expressed
He wanted to study the diversity of a group of organisms which would become part of his larger study of natural selection
Darwin invested seven years in a survey of fossil and extant barnacles. He did this because __?__.
Variation
Darwin recognized that __?__ existed in natural populations, but he didn't know the source and referred to the consequences as a "condition of life."
Darwin's Pigeon Breeding
Darwin used pigeon breeding to explain artificial selection to the readers of On the Origin of Species.
Thomas Huxley
Darwin's bulldog (biggest supporter); zoologist; coined the term "agnostic"
On the Origin of Species by Means of Natural Selection
Darwin's most famous book regarding natural selection
Transmutation Notebook B
Darwin's notebook where the first phylogenetic tree was discovered
Charles Lyell's advocacy of "plutonism"
Darwin's observation of the aftermath of an earthquake in Chile (1835) provided support for __?__.
Unifying theory(ies) of biological science?
Darwins ideas -the struggle for existence -descent with modification
Intrinsic mortality
Death rate due to physiology and genetics
Were recruited from the pancreas Were duplicated Are similar to defensin genes expressed in skin
Defensin genes that are expressed in venom glands in snakes __?__.
why is natural selection more effective in larger populations?
Deleterious alleles can reach high frequency in small populations because of random fluctuations in allele frequency. This may lead, over time, to reduced average fitness. In this sense, selection is more "effective" in larger populations.
Lewontin & Hubby
Demonstrated considerable genetic variation using isozyme electrophoresis
From a phylogenetic standpoint, the closest relatives of croatimne genes are beta-defensin genes, which are expressed in the pancreas of snakes. Snakes use defensins, like humans, as a way to fight infections. Hence, defensins must have originally evolved in a common ancestor of snakes and mammals.
Describe the evolutionary history of crotamine venom genes.
A trait with a high adaptive value is strongly favored by selection. As a consequence, many of the neighboring loci also rise in frequency even though they did not contribute to the adaptation.
Describe what is meant by the term, selective sweep? (2)
additive allele
Describes an allele that yields twice the phenotypic effect when two copies are present at a given locus than occurs when only one copy is present
Carlos Linnaeus:
Devised a system of taxonomy that is still used today Believed that life's diversity reflected a divine plan
differences in phenotypic plasticity and evolution
Differences in phenotypic plasticity may be heritable and can therefore evolve
Nuptial gift
Direct benefit of mating
Reduces the relatedness of progeny to the parents Includes the cost of a search for mates Provides a means of transmitting disease
Disadvantages of sexual reproduction:
Dll
Distal-less. A Hox gene that controls the expression of appendages such as hindlimbs
Gene recruitment
Duplicated gene expresses in a new tissue or organ
Ediacaran fauna
During the end of the Proterozoic era, diverse and unique animals dominated the oceans from 575 - 535 Ma Many hard to place taxonomically
In the animation, fish with less streamlined fins have a ____________ reproductive fitness than fish with more streamlined fins because ____________. A. lower; the increased fin size hinders mating B. higher; the increased fin size is more likely to attract a mate C. higher; they swim more quickly D. lower; their ability to acquire food is impaired E. lower; they are less able to escape predators
E. lower; they are less able to escape predators = deleterious mutation --> eventually lost by population by natural selection
First eukaryotic fossils
Earliest fossils of algae (photosynthetic eukaryotes) date to 1.6 Ga -Red algae: 1.2 Ga -Green algae: 750 Ma
Proterozoic
Eon after Archean, before Phanerozoic
Archean
Eon that was preceded by the LHB in the Hadean
Non-synonymous substitution
Evidence of positive selection
Are evolution and natural selection the same thing?
Evolution and selection are not the same because selection can occur without evolution if the traits are not heritable
Evolutionary theory and linnean classification on taxonomic groups
Evolutionary theory has added new evidence and insight into taxonomic groupings that sometimes conflicts with Linnaean classification
Exaption
Existing trait that has been co-opted for a new function
Miller-Urey Experiment
Experiment that found that organic molecules can form in a strongly reducing atmosphere.
True or False: Given that they are effectively haploid, alleles in prokaryotic cells are unlikely to be linked.
False
True or False: The diagram at right illustrates alleles that show linkage.
False
True or False: The trait detailed in #27 (frequency of p=0.375) will exhibit balanced polymorphism (among alleles).
False
Distal
Farther from the point of attachment or origin
disruptive selection
Favors individuals at either end of the distribution. If selection is strong enough, populations begin to diverge in phenoytpe (may become dimorphic).
directional selection
Favors individuals at one end of a trait distribution, after selection and provided the trait is heritable the distribution of phenotypes should shift toward the favorable trait; mean phenotype will shift.
stabilizing selection
Favors individuals with a trait near the population mean, and in generations after selection the variance of the population (not the mean) should be smaller than it was in the preceding generation
preexisting sensory bias
Females may prefer males with a certain trait not because it provides a benefit to the females, but because the females are "wired" to perceive that trait
transition of life from sea to land (order)
First to arise to latest to arise: paleozoic: -prokaryotes -plants -fungi -large forest ecosystems -invertebrates -early tetrapods (chordates) mesozoic: -synapsids -mammals -
directional selection
Form of natural selection in which the entire curve moves; occurs when individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve
Vicariance
Formation of geographic barriers to dispersal that divide a population
Reinforcement
Formation of hybrids with reduces fitness (increases reproductive isolation)
speciation
Formation of new species; involves barriers to reproduction
How do scientists determine the age of fossils?
Fossils typically don't contain isotopes like strontium and rubidium that make radiometric dating possible. As a result, it's usually not possible to directly date a fossil this way. Often, scientists look for layers of rock chronologically close to a fossil that can serve as time brackets.
life was brought to earth by an extra-terrestrial intelligence
Francis Crick worried that the early earth lacked the appropriate conditions for chemical evolution. As such, he (with Orgel) speculated that life arose as a consequence of directed panspermia. Directed panspermia is the idea that __?__.
Jemmy Button
Fuegian captive on the HMS Beagle who was re-patriated/civilized to Christian mission on Tierra del Fuego; this did not work, which led Darwin to think Fuegians were just primitive humans
The nematode, C. elegans, and humans have nearly identical numbers of protein-coding genes, yet humans have much more complex organismal features. This is an example of...?
G-value paradox
Beta defensins
Genes that produce antibacterial enzymes on the skin
Autopolyploidy
Genome duplication by genetic mistake in a singe individual
Allopolyploidy
Genome duplication via hybrid formation
Which of the following statements is true regarding the biological species concept?
Given the generation time of certain organisms, the biological species concept can be difficult to test.
Erasmus Darwin
Grandpa Darwin; also was into evolutionist ideas; wrote a poem about it "The Temple of Nature"
Pre-Cambrian Eons
Hadean, Archean, and Proterozoic eons
fundamental null model in population genetics
Hardy-Weinberg serves as this for population genetics
Orthologous
Homologous genes from a gene family
hth
Homothorax. A Hox gene that controls the expression of appendages such as antennae
The genes for teeth have been disabled in Baleen Whales and the genes for hind limb develpment were disabled in an ancestor of modern cetaceans.
How are teeth and hind limbs related in the context of cetacean evolution?
Evolutionary response to selection
How much the population changes depends on -Selection differential (S): strength of selection -Heritability
Narrow sense heritability can be estimated by calculating the slope of the parent-offspring comparison. Thus, you would compare the slopes of the two graphs
How would you determine if tarsus length or pistil length (see figure above) has the highest value for narrow sense heritability?
RNA world
Hypothetical early interval of chemical evolution when RNA served as the genetic information.
Bt cotton has been engineered to produce "Bt" toxins as a pesticide. Refuges are parts of a planting where non-Bt plants are grown. This is done so as to minimize or slow the rate of development of resistance to Bt.
If a farmer plants Bt cotton, he or she must also plant a portion as refuge. What is grown in the refuge and why? (2
While genetic drift does occur in all finite populations, the reason not many go to fixation is due to mutation, gene flow or some forms of selection intervene.
If all natural populations are experiencing drift, why is it that many loci fail to go to fixation?
mutation-selection balance
If mutation, selection and drift are factors in producing the results illustrated in the figure below (10 runs of PopG), then these results are best described as an example of __?__.
Trivers-Willard Hypothesis
If the mother's conditions are *good*, she'll be biased to invest in favor of competitive offspring (*male*). this good health allows them to grow bigger If mother's conditions are *poor*, she'll be biased to invest in favor of non-competitive offspring (*female*).
one needs to test for departure from equilibrium using the Chi square test
If the predicted frequency of the dominant allele is lower than the actual frequency of the dominant allele, then __?__.
maximum parsimony criteria
If you are searching for the tree with the fewest "extra" or ad hoc assumptions of character change, you are using __?__ to reconstruct phylogeny.
Calculate allele frequencies before and after selection
In Hardy-Weinberg calculations, the average fitness of the population is used to __?__.
affects genotype ratios in populations can lead to expression of deleterious recessive alleles increases homozygosity in populations
Inbreeding __?__.
What is meant by the HW-equilibrium stipulation that says mating must be random?
Inbreeding affects genotype ratios. For equilibrium to be maintained, mating must be random with respect to the alleles at a particular locus.
gametic isolation
Incompatibilities between the gametes of two different species -- these specific interactions ensure that a sperm from one abalone species, Haliotis rufescens, fertilizes only an egg of its own species and not an egg from H. corrugata, a closely related species
Convergent evolution
Independent evolution of similar traits in different lineages due to similar selection pressures)
convergent evolution
Independent evolution of similar traits in different lineages; result of similar selection pressures
Parallelism
Independent evolution of similar traits starting from a similar ancestral condition.
parallel evolution
Independent evolution of similar traits, starting from a similar ancestral condition ex. Threespine stickleback example
Which of the following is/are critical for Darwin's idea of natrual selection:
Individuals vary in their traits Natural resources are limited Some individual variation is heritable
What is the prevailing theory of why modern insects are constrained to be relatively small? What evidence was used to test this hypothesis?
Insects get oxygen through tubes that penetrate their exoskeleton. The tubes are less efficient in larger insects as insects become bigger the tubes become disproportionately larger and there is not enough room for muscles and other structural elements. This was tested by examining the fossil insect record during periods where oxygen was more abundant. As expected, insects fossils indicate they were much larger than those alive today.
slope of the isochron line
It is the __?__ that directly provides the estimate of absolute age for the various minerals in a rock.
Darwins mentors
John Henslow Robert Grant Robert FitzRoy
What evidence is there for LUCA:
L optical isomers of amino acids are employed by all organisms
1/2 life of 14C
Less than 6000 Years
organization of life now vs. in earlier RNA world
Life now: DNA plays info-storage role; RNA plays intermediary role; proteins play structural and enzymatic role Life then: RNA played all the roles (info-storage, intermediary, and structural and enzymatic)
directed panspermia
Life was intentionally seeded on Earth by an intelligent agent
Assortative Mating
Like chooses like
negative frequency-dependent selection; rare clones became common in the subsequent generations
Lively and Dybdahl studied parasite infection rates in a population of asexual clonal snails. The graph above shows relative infection rates for the four most common clone genotypes and for several rare genotypes lumped together. Based on these data they hypothesized that parasites adapted to infecting the most common clone genotypes in the population, and thus these genotypes had lower fitness. This is consistent with __?__ operating in the snail population. Further evidence would be provided if __?__.
Homologous
Lizards and Marsupials possess__?__ embryonic structures such as a dorsal hollow nerve cord.
Polygyny
Males mate with multiple females
essay on human population growth
Malthus influence on Darwin was based on the former's __?__.
have no clear affinities with any modern lineages
Many Ediacaran fossils (e.g., Dickinsonia below) __?___.
recombination and independent assortment
Meiosis is a source of variation through __?__.
Phanerozoic
Most recent eon; containing the Paleozoic, and Mesozoic, Cenozoic eras
the irreversible accumulation of deleterious mutations in asexual organisms
Mullers ratchet can be described as __?__.
Luria & Delbrück
Mutations are spontaneous, not induced by environment
Antagonistic pleiotropy
Mutations conferring fitness benefits early in life and fitness costs late in life can be advantageous on balance
natural selection & viral variants?
Natural selection favors flu variants that evade the immune system
stabilizing selection
Natural selection that favors intermediate variants by acting against extreme phenotypes
_____________ is the primary force responsible for changes in allelic frequency of deleterious mutations. _______________ is the primary force responsible for changes in allelic frequency of neutral mutations.
Natural selection; Genetic drift
Paralogous
Non homologous genes from a gene family
Epistasis
Non-additive effects for interactions between loci
All of the following EXCEPT ? represent strategies used by males in at least some species to increase the likelihood that their sperm will fertilize a female's eggs.
None of the above (each strategy has been observed in at least some males)
Eukaryotic genome size compared to eukaryotic complexity
Not well correlated with organismal complexity
Saturation
Nucleotide sites across a sampling of genes have multiple changes
intrasexual selection
Occurs when members of the less-limiting sex (generally males) compete with each other over reproductive access to the limiting sex (generally females). Often called male-male competition.
intersexual selection
Occurs when members of the limiting sex (generally females) actively discriminate among suitors of the less limited sex (generally males). Often called female choice.
parent-offspring conflict
Occurs when parents benefit from withholding parental care or resources from some offspring (e.g., a current brood) and invest in other offspring (e.g., a later brood). Conflict arises because the deprived offspring would benefit more if they received they withheld care or resources.
Indel
Often results in a frameshift mutation
Stromatolites
Oldest known cellular fossils formed from many layers of bacteria and sediment.
three; melatonin
Opsins, which have undergone __?__ duplication events throughout animal evolution, are derived from the __?__ gene.
Which of the following ideas was NOT accepted by Jean-Baptiste Lamarck?
Organisms go extinct
Hardy-Weinberg extended to polygenic traits?
Phenotypes as range of "Trait values"
Opsins
Photosensitive pigments in the photoreceptors; Originated by gene duplication of melatonin gene (and additional subsequent duplications).
Erasmus Darwin
Physician, poet, evolutionist; colleague of Benjamin Franklin
Linnean Society meeting of July 1, 1858
Place where Darwin's and Wallace's essays on evolution were reviewed
geographic or ecological isolation
Plants and animals can also be isolated in space - This type of isolation can be subtle. example -- the two Japanese species of ladybug beetle can be found living side by side in the same field, but they feed on different plants. Because their life cycles are so intimately associated with their host plants (adults even mate on their host plants), these two species never breed with each other.
Polymorphism vs polyphenism
Polymorphism is heritable, and is modified by selection (either artificial or in the wild). In polyphenism, an individual's genetic make-up allows for different morphs, and the switch mechanism that determines which morph is shown is environmental.
Dispersal
Population movement from one region to another with limited return
what populations are ideal for evolutionary studies?
Populations that independently experience parallel environmental changes represent replicated natural experiments
You are an experienced naturalist and biologist and you observe two birds mating that you do not believe to belong to the same species. The eggs from this breeding do not hatch, and when you obtain one of the eggs, you find embryonic development stopped not long after fertilization. Which of the following conclusions is supported by these observations?
Post-zygotic factors prevented successful reproduction.
distance-matrix methods
Procedures for constructing phylogenetic trees by clustering taxa based on the proximity (or distance) between their DNA or protein sequences. These methods place closely related sequences under the same internal branch, and they estimate branch lengths from the observed distances between sequences. Great for rapid estimation NOTE: smaller coefficient of distance correlates with smaller number of distances
are born female but can become male
Protogynous, sequential hermaphrodites __?__
Based on the graph at right for polio virus, which of the following types of data are mostly likely to provide the best signal to noise ratio in a phylogenetic analysis?
Pyrimidine to purine substitutions
What is QTL analysis?
Quantitative trait locus (QTL) analysis is a statistical method that links two types of information—phenotypic data (trait measurements) and genotypic data (usually molecular markers)—in an attempt to explain the genetic basis of variation in complex QUANTITATIVE traits
Most important Lagerstatte in history
Quarries of the Burgess Shale have now yielded more than 65,000 specimens of mostly soft-bodied animals representing at least 93 species all from the Cambrian period (505 mya)
response to selection estimation (R) based on population data across years
R = h^2 * S
plastic traits and rates of environmental change
Rapid change can lead to mismatch between plastic traits and environment
Miller-Urey Experiment
Reducing environment rich in methane, ammonia, and hydrogen favored production of organic molecules from inorganic materials; abiogenesis theory
epigenetic
Refers to the functional modifications to DNA that don't involve changes to the sequences of nucleotides; the study of the heritability of these modifications
Crystallins
Refractive proteins in the lens that are responsible for the clarity and focusing power of the lens
purifying selection (negative selection)
Removes deleterious alleles from a population. It is a common form of stabilizing selection.
Darwins antagonists
Richard Owen St. George Jackson Mivart Fleeming Jenkin Lord Kelvin aka William Thomson Wilberforce
selection differential estimation (S) based on population sizes across years
S = later year - earlier year
Outgroup
Set of reference organisms that serve to root a phylogenetic tree
how do fossils reveal links between whales & land mammals?
Shape of astragalus (talus or ankle bone) unites whales & artiodactyls
describe the evolution of brain size & complexity in whales
Sociality promoted the evolution of large brains so that they could form lasting alliances, compete for mates, & develop a form of complex communication through natural selection.
Shh
Sonic hedgehog protein: important in determination of dorsal-ventral axis and limb development
On what point(s) would Charles Darwin and Jean-Baptiste Lamarck have agreed:
Species give rise to new species
extant
Still in existence
extended phenotypes
Structures constructed by organisms that can influence their performance or success. Although they are not part of the organism itself, their properties nevertheless reflect the genotype of each individual. Animal examples include the nests constructed by birds and the galls of flies.
Red Queen
Survival requires continual acquisition of favorable traits
synapomorphies & what they identify
Synapomorphies are a shared derived character state -they identify clades
regulatory networks
Systems of interacting genes, transcription factors, promoters, RNA, and other molecules. They function like biological circuits, responding to signals with outputs that control the activation of genes during development, the cell cycle, and the activation of metabolic pathways.
Promiscuous
Term given protein with multiple substrates or functions
loss of fertility is associated with a shift in investment to grandchildren
The "Grandmother Hypothesis", which offers an adaptive explanation for menopause in humans, suggests that __?__.
Phylogenetic analysis demonstrated that both beach lineages had a mainland lineage as a sister group. In other words, the two beach populations did not form a monophyletic group.
The Atlantic and Gulf populations of Peromyscus (field mouse) look very similar. Why did Hoekstra and her colleagues conclude that the beach populations of Peromyscus (field mouse) from the Atlantic and from the Gulf have separate origins.
a relatively rapid radiation of major animal phyla
The Cambrian is noted for __?__.
assumes that all base substitutions have the same rate
The Jukes-Cantor model of nucleotide substitution __?__.
the early earth had a reducing atmosphere
The Miller-Urey experiment was based on the assumption that __?___.
Georges Cuvier
The Scala Naturae or "Ladder of Life" did not offer a good model to explain the notion of animal phyla (i.e., clusters of animals) advocated by __?__ (sometimes called the father of paleontology).
Which of the following statements describes a problem in applying the biological species concept?
The concept only works with sexual species.
C-value paradox
The disconnect between genome size and organismal complexity (the C-value is the amount of DNA in a reproductive cell).
the frequency of the allele. the magnitude of average excess fitness. the average fitness of the population
The effectiveness of selection on an allele depends in part on __?__.
is greatest when both the selection differential and narrow-sense heritability are large
The evolutionary response (R) to selection __?__.
small populations are likely to diverge at a greater rate than large populations
The graph above presents data on genetic distance (divergence) under three different population sizes (N) through time (generations). These data indicate that __?__.
directional selection
The greyhound is a dog breed known for its amazing speed. This breed was produced by taking the fastest animals and breeding them together generation after generation. Though artificial, this is an example of __?__.
bayesian interference
The idea that our estimate of the probability of an outcome is determined by the prior probability (our initial belief) and the likelihood (the extent to which the available evidence is consistent with the outcome). assessing the probability of a tree given the data REQUIRES A MODEL
Phenotypic plasticity
The image below illustrates variation in head and tail shape for the water flea, Daphnia. All are representatives of a single clonal type. The changes are influenced by the presence of predators (which favors larger head shield and longer tail spike). What is this phenomenon?
Polyploidy
The least common mutation type (and the most extensive) is __?__.
point mutation
The most common mutation type is __?__
HMS Beagle
The name of Charles Darwin's ship
Fecundity return
The number of eggs that can be produces and provisioned
maximum parsimony
The preferred hypothesis is the one with the fewest extra (ad hoc) assumptions
a synapomorphy for these species
The presence of a bitrochleated astragalus in both Pakicetus and in Sus (pig) is __?__.
Transcription of the gene has occurred
The presence of a mRNA transcript of a gene in a cell means __?__.
a derived trait uniting these cetacean species
The presence of an involucrum in both Pakicetus and in modern dolphins is __?__.
Exaptation
The process in which existing structures take on new functions through descent with modification; Co-option
Disruptive (diversifying) selection
The residues ("tailings") of mines often contain such high concentrations of toxic metals (e.g., copper, lead) that most plants are unable to grow on them. However, some hardy species (e.g., certain grasses) are able to spread from nearby uncontaminated soil into the contaminated areas. These plants evolve enhanced resistance to the toxic metals while their ability to grow on uncontaminated soil decreases. Because grasses are wind pollinated, breeding between the resistant and nonresistant populations continues, but offspring of crosses between the two populations are intermediate and have low relative fitness regardless of the habitat. This is an example of __?__
quantitative trait locus (QTL) analysis?
The statistical analysis and identification of stretches of DNA that are linked to the genes that underlie a particular trait.
great oxygenation event (AKA snowball earth) (AKA Huronian Glaciation)
The time in Earth's history, about 2.4 Ga, when the concentration of oxygen in the atmosphere increased dramatically. -catastrophic extinction of anaerobes? -oxidation of atmosphere methane triggers? (oxidation of atmosphere made planet colder because it caused oxidation of the greenhouse gas methane that made the planet warmer)
maximum parsimony criteria (optimality criterion)
The tree with the fewest "extra" or ad hoc assumptions of character change is the preferred tree.
Wallace's line
The zoogeographical boundary proposed by Alfred Russel Wallace that separates the marsupial fauna of Australia and New Guinea from the non-marsupial fauna of Indonesia
Imagine that a scientist wants to create a new species of minion—one that is a cross between a shark and a wolf. To his dismay, when he introduces shark sperm and wolf eggs into a petri dish, no viable embryos form. Why?
This could be an example of pre-zygotic isolation, where the proteins of the shark sperm and wolf eggs do not interact properly; however, this could also be an example of genetic incompatibility, where genomic differences between sharks and wolves prevent the formation of viable embryos.
Imagine that a zoo in Sri Lanka has started an elephant-breeding program. Zookeepers have introduced an Indian and Sri Lankan elephant into the same enclosure. What will be the result of this mating?
This mating will demonstrate that these elephants are members of the same species and will produce fertile offspring.
Paley vs Hume
Three Objections to AFD Raised by David Hume -The Weak Analogy Objection -The Uniqueness Objection -Designer Without God
Codon
Three base sequence that codes for an amino acid
Late Heavy Bombardment (LHB)
Time during Hadean when the earth and the moon were impacted by collisions with extra-terrestrial bodies.
Methodological Naturalism
To study nature (i.e., the material world) as part of a scientific enterprise, one can only make use of methods that are open to human senses (taste, touch, hearing, sight, smell)
Coalescent
Tool for estimating the origin of different gene copies
Deep homology
Traits in different lineages arise from same fundamental, regulatory network(s)
they are costly for the males to produce
Traits like the bright colors of the male collared lizard or the long tail of the male widow bird are considered honest indicators of male genetic quality because __?__.
True or False: Evidence indicates that senescence may be a consequence of a trade-off between reproduction early in life and longevity.
True
True or False: One reason cited for the increase in "per site mutation rate" for eukaryotic organisms (vs. prokaryotic microbes) is the observation that larger percentages of the genome are non-coding in eukaryotic organisms.
True
Which of the following represents genetic incompatibility?
Two groups of snakes do not produce fertile offspring because they have a different number of chromosomes.
Linkage Disequilibrium
Unequal haplotype representation
Crotamine
Venom produced in venom glands by duplicated beta-defensin gene
What happens as viral strains develop beneficial mutations & what effects do these mutations have?
Viral strains with beneficial mutations increase in frequency through natural selection -strain no longer recognized by immune system--> higher reproduction--> population domination in subsequent generations
How do we know whales are mammals? why do they resemble fish so much?
Whales share synapomorphies with mammals: • Mammary glands • Three middle ear bones • Hair (in developing embryos) -Similarities with fish arose through convergent evolution.
Virtually anyone who does phylogenetic analysis with large data sets uses heuristic approach. The problem though is that you are not searching all tree space, you instead search in a regular fashion, but you can end up with a result that may not be the optimal tree. You end up with the possibility of Global vs. Local Optima. This is due to how tree space is structured. The heuristic approach involves an algorithm, but this also takes apart one tree and compares it to another (branch-swapping algorithms) for tree length or likelihood value—if the tree is shorter/higher likelihood the tree is abandoned, and the search begins again. These heuristic approaches are necessary due to the evidence suggesting that the strucutre of the tree space containing discrete regions of optimality. These algorithms are all "hill climbing" they will relentlessly search for the optimal tree for this region of optimum. However, we don't know what this tree space looks like, and therefore we need to do lots of replicant analysis—one of them will hopefully find the global optimum.
What are heuristic approaches to searching tree space and why are they necessary?
Aposematism is an antipredator strategy used by ppotenital prey item to signal danger or lack of palatability. The most commonly known form of aposematism is warning coloration (aposematic coloration) in which the bright coloration of prey that are potentially dangerous can act as a deterrent to potential predators.
What is meant by aposematic coloration? (2)
Alkaline vents release water that has a high pH, has a high mineral content and is warm rather than hot; an environment that may have been suitable for the origin of life.
What is the significance of alkaline vents (white smokers) in the context of the origin of life
deep homology
When growth and development of traits in different lineages result from underlying mechanisms inherited from a common ancestor
When are hybrid zones expected to disappear and complete the speciation process?
When hybrids are at a selective disadvantage
Assessing the probability of the data given a particular tree
When reconstructing phylogeny using maximum likelihood criteria, you are __?__.
Which of the following is NOT an example of evolution?
When traveling to high altitude, human physiology changes to accomodate lower oxygen levels
beak size had to be at least partially determined by the additive effects of alleles characteristics of the average seed had to change from year to year
Which of the following was necessary for the evolution of beak size in Geospiza fortis on Daphne Major?
higher heritability
Which of the following would increase the rate of evolution by natural selection for a particular trait?
The hemagglutinin (HA) and neuraminidase (NA) are receptors of influenza A virus which are responsible for the surface interactions of the virion with the host; it allows for binding to the host cell and ability to exchange genetic information.
Why are hemagglutinin and neuraminidase particularly important to transmission for Influenza A?
Rigourous QTL mapping requires that you mate at least two individuals who exhibit polar opposites of the trait in question. Then, you analyze markers in the genomes of a large number of offspring from the mating studies. Such an approach for humans is not possible from either an ethical or practical standpoint.
Why is QTL mapping a challenge for evaluating human traits (2)?
An exhaustive search of tree space will be computationally challenging, it doesn't eliminate enough of tree space in the context of the distance matrix method nor are you able to search all of the tree space since this algorithmic method doesn't always result in an optimal tree, it is estimating a tree.
Why is the "tree space" meaningless in the context of distance matrix methods for reconstructing phylogeny?
Some scientists became interested into why opossums die so young, produced this notion of trade offs and intrinsic and extrinsic mortality. Wanted to study this phenomena in the field (natural experiment): Evolutionary Theory of Aging. A population of opossums lived on the Sapelo Island which is perfect as predators were left behind, so opossums have been living without extrinsic mortality. Discovered that the opossums lived much longer than normally, additionally they invest in reproduction differently. Females have fewer litters, but the animals are much larger (much more likely to live longer and produce more offspring). While mainland opossums mature quickly and have much larger litters, this is all because they live shortly due to extrinsic mortality. The intrinsic mortality is also lower in island organisms (measured by arthritis rates); tendons in island opossums were stronger and more flexible later in life (invest in more upkeep of the body). This is not the same in mainland opossums due to investment going towards reproduction over survival.
Why were the Sapelo Island O'Possums studied and what are the main conclusions from the Sapelo Island investigation of O'Possums?
Only one genetic locus contributes to the leaf phenotype
You are studying plants and notice that individuals have one of two discrete leaf margin phenotypes (entire or lobed). From this you can confidently conclude __?__.
The Jemmy Button Episode
__ __ during the voyage of HMS Beagle is/are thought to have profoundly influenced Darwin's ideas about the origin of humans
Negative frequency-dependent selection; heterozygote advantage
__?__ and __?__ represent forms of selection that maintain diversity in populations.
Somatic
__?__ mutations are not generally subject to evolutionary change.
Epistasis
___ occurs when the effects of an allele at one genetic locus are modified by alleles at one or more other loci; non-linaer
prokaryotic vs. eukaryotic genome size
____ have genomes dependent mostly on number genes (thus more conserved), while _____ have genomes varying more in size due to noncoding DNA
red algae vs. green algae
_____ algae is older than _____ algae
viral replication consequence
_____ results in high mutation rates of the virus, and these mutations can be harmful or beneficial; this is how new strains can occur (viral strain no longer recognized by immune system; leads to higher reproduction rate; trait dominates population in subsequent generations)
C4 plants vs. C3 plants
_______ plants have higher C13/C14 ratio than _______ plants
mutation; natural selection
_________ creates diversity, and then __________ acts on that diversity
Burgess shale
a Lagerstatte in Canada that preserved fossils from the Cambrian period; lot of soft tissue fossils found here, like Hallucigenia
the process of reinforcment requires
a and b (genetic variation and preexisting postzygotic isolation)
under the biological species concept
a b and c are correct
the cambrian explosion
a burst of evolutionary origins when most of the major body plans of animals appeared in a relatively brief time in geologic history; recorded in the fossil record about 545 to 525 million years ago. (this still AFTER animals began to diversify)
null hypothesis
a default hypothesis that there is no relationship between two measured phenomena; by rejecting this, scientists can provide evidence that such a relationship may exist.
synapomorphy
a derived form of a trait that is shared by a group of related species (i.e. one that evolved in the immediate common ancestor of the group and was inherited by all its descendants); a SHARED derived trait
neighbor joining
a distance method for reconstructing phylogenies; identifies the tree topology with the shortest possible branch lengths given the data
overdominance
a form of dominance in which the expression of the heterozygote is outside the range defined by the expressions of the homozygous genotypes and most closely resembles the expression of the homozygous dominant genotype
FOXP2
a gene that is important in language and speech production; experiences strong positive selection in human lineage (allowed out language to advance)
When they insert themselves into the coding region of a gene, transposons generally create __?__.
a loss of function mutation
selection differential (S)
a measure of the strength of phenotypic selection; describes the difference between the mean of the reproducing members of the population who contribute offspring to the next generation and the mean of all members of a population
natural selection
a mechanism that can lead to adaptive evolution, whereby differences in the phenotypes of individuals cause some of them to survive and reproduce more effectively than others
natural selection
a mechanism that can lead to evolution, whereby differential survival and reproduction of individuals cause some genetic types to replace (outcompete) others
The oldest currently known fossil of a land animal is:
a millipede
A point mutation that changes codon GGA to codon UGA is termed __?__.
a missense mutation
define pleiotrophy
a mutation in a single gene that affects many phenotypic traits
A point mutation that changes codon GGA to codon AGU is termed __?__.
a nonsense mutation
chronogram
a phylogenetic tree in which branch length is proportional to time
consensus tree
a phylogenetic tree that has all the features shared by the equally parisimonious cladograms in a study, while leaving conflicts unresolved (as polytomies, etc)
parsimony
a principle that guides the selection of alternative hypotheses; the alternative requiring the fewest assumptions or steps is usually (but not always) the best (ex. in cladistics, scientists search for the tree topology with the least number of character-state changes)
alkaline vents (white smokers)
a probable place where life could have arisen in prokaryotic-sized chambers that served as sites of autocatalytic chemistry
landscape genetics
a relatively new field of research that combines population genetics, landscape ecology, and spatial statistics
transfer RNA (tRNA)
a short piece of RNA that physically transfers a particular amino acid to the ribosome
morphogen
a signaling molecule that flows between nearby cells and acts directly to alter expression of target genes
A point mutation that changes codon AUC to codon GUC is termed __?__.
a silent mutation
heuristic
a simple thinking strategy that often allows us to make judgments and solve problems efficiently; usually speedier but also more error-prone than algorithms
limb elongation
a single change in gene expression can give rise to changes in ________, like in crickets and bats
variance
a statistical measure of the dispersion of trait values about their mean
bootstrapping
a statistical method for estimating the strength of evidence that a particular branch in a phylogeny exists (making thousands of random potential populations by drawing randomly); if trees very different, original tree has little support, but if most trees are very similar, original tree has strong support
maximum parsimony
a statistical method for reconstructing phylogenies that identifies the tree topology that minimizes the total amount of change, or the number of steps, required to fit the data to the tree
mass extinction
a statistically significant increase above background extinction rate
Spiegelman's monster
a strand of self-replicating RNA created by microbiologist Sol Spiegelman by putting a simple viral form in an environment that would nourish it. What started out as an RNA strand with 4,500 nucleotide bases ended up as a minor genome trimmed down to 220 bases and able to out-replicate any competition. Life as we know it might have begun somewhat similarly; abiogenesis theory
polyphyletic
a taxon that consists of unrelated organisms who are from a different recent common ancestor. This group lacks a MOST recent common ancestor.
radiometric dating
a technique that allows geologists to estimate the precise ages at which one geological formation ends and another begins
polyphenism; polyphenic trait
a trait for which multiple, discrete phenotypes can arise from a single genotype depending on environmental circumstances; often result from a developmental threshold mechanism -one genotype--> multiple phenotypes via phenotypic plasticity
exaptation
a trait that initially carries out one function and is later co-opted for a new function; the original function may or may not be retained
phylogeny
a visual representation of the evolutionary history of population, genes, or species
phylogeny
a visual representation of the evolutionary history of populations, genes, or species
27. Inbreeding depression is caused by a. A reduction in fitness caused by deleterious recessives b. Random mating c. Mutation-selection balance d. A and B e. All of the above
a. A reduction in fitness caused by deleterious recessives
9. Use the figure below to determine which of the following amino acid sequences would be generated from the RNA sequence: CGA GGC UUA ACG a. Arginine; glycine; leucine; threonine b. Arginine; glycine; phenylalanine; threonine c. Proline; glycine; leucine; threonine d. Proline; glycine; leucine; serine e. None of the above
a. Arginine; glycine; leucine; threonine
Which statement best describes the potential effect of genetic drift in the peripheral isolate model of allopatric speciation? a. Because the descendant populations can be founded by a relatively small number of individuals, genetic drift is more likely to have strong effects in the descendant populations. b. Because the ancestral population is much smaller than the descendant populations, genetic drift can act strongly in the ancestral population. c. Because the descendant populations are relatively large in size, it is unlikely to see the effects of genetic drift. d. Because the ancestral population is much larger than the descendant populations, genetic drift can act strongly in the ancestral population.
a. Because the descendant populations can be founded by a relatively small number of individuals, genetic drift is more likely to have strong effects in the descendant populations.
46. The McDonald-Kreitman test compares substitution rates a. Between and within species b. Within species c. Across genes d. A and B e. All of the above
a. Between and within species
The observation that hybrid offspring of true breeding purple and white flowered plants are purple in color can be explained by the a. Dominance of the purple color. b. Blending of parental characters. c. Law of independent segregation. d. Dominance of the white color. e. A and D
a. Dominance of the purple color.
30. The figure above demonstrates the a. Effects of genetic drift in small populations b. Relationship between population size and the effects of selection c. Relationship between population size and the effects of mutation d. Relationship between population size and effective population size e. Relationship between population size and the effects of migration
a. Effects of genetic drift in small populations
44. Refer to the figure below to answer the following question. A researcher discovers a new bacteria whose genome is ~8 Mb in size. What type of bacteria is this likely to be? a. Free-living b. Obligate parasite c. Obligate symbiot d. Any of the above e. Cannot be determined from the information provided
a. Free-living
How does the dominance theory explain why the heterogametic sex is at a disadvantage in Haldane's rule? a. If a recessive allele linked to a sex chromosome has a negative effect on the fitness of hybrids, that allele will always be expressed in the heterogametic hybrids that possess that allele because they only have one copy of the sex chromosome that carries the allele. b. If a recessive allele linked to a sex chromosome has a positive effect on the fitness of hybrids, that allele will never be expressed in the heterogametic hybrids that possess that allele because they only have one copy of the sex chromosome that carries the allele. c. Beneficial dominant alleles will never be fully expressed in hybrids as they only carry one copy of the sex chromosome that carries the allele. d. If a dominant allele has a negative effect on the fitness of hybrids, it will always be expressed in the heterogametic hybrids that possess that allele because they only need one copy of the respective sex chromosome.
a. If a recessive allele linked to a sex chromosome has a negative effect on the fitness of hybrids, that allele will always be expressed in the heterogametic hybrids that possess that allele because they only have one copy of the sex chromosome that carries the allele.
51. The two figures below represent an asexual and a sexual population, respectively. The letters indicate beneficial mutations. The shaded areas represent the frequency of particular combinations of mutations in the population over time. Why does it take longer for the beneficial allele combination of ABC to go to fixation in the asexual population than in the sexual population? a. In the asexual population, new allelic combinations have to arise via de novo mutations. b. There is no principal difference between asexual and sexual populations. In the sexual population shown, the favorable mutations just happen to be on different chromosomes. c. The effective population size of both populations is the same d. Sexual populations tend to have higher mutation rates.
a. In the asexual population, new allelic combinations have to arise via de novo mutations.
Which of the following is NOT a postzygotic isolating mechanism? a. Male gametes are not transferred to the female gametes. b. Hybrids are sterile. c. Hybrids are inviable. d. Zygotes die early in embryogenesis.
a. Male gametes are not transferred to the female gametes.
4. RNA was likely replaced by DNA as the genetic molecule in most organisms because a. RNA is less stable than DNA b. RNA has a higher chemical stability c. RNA errors are more easily corrected than DNA errors d. A and C e. All of the above
a. RNA is less stable than DNA
39. In the figure above, each new line represents the frequency of a new beneficial mutation. The figure describes the process of a. Selective sweeps b. Disassortive mating c. Genetic hitchhiking d. Background selection e. A and B
a. Selective sweeps
Consider a group of closely related species that vary in the average number of males a single female will mate with. Given the results of studies from the literature, which of the following patterns of sperm competition would you expect to see in each of the species? a. Sperm competition will show a positive relationship to the number of males per female. b. Sperm competition will show a negative relationship to the number of males per female. c. Sperm competition will show no relationship to the number of males per female. d. Cannot predict based on the information provided
a. Sperm competition will show a positive relationship to the number of males per female.
The figure on the left illustrates species boundaries as assigned by the application of the biological species concept, while the figure on the right illustrates species boundaries as the result of the ecological species concept. What is the difference in how these boundaries are delineated when applying these concepts? a. The biological species concept uses the pattern of gene flow to assign boundaries, while the ecological species concept uses competition. b. The biological species concept uses polymorphic characters to assign boundaries, while the ecological species concept uses shared, derived characters. c. The biological species concept uses competition to assign boundaries, while the ecological species concept uses gene flow. d. The biological species concept uses shared, derived characters to assign boundaries, while the ecological species concept uses competition.
a. The biological species concept uses the pattern of gene flow to assign boundaries, while the ecological species concept uses competition.
12. Crossing-over requires a. The physical exchange of parts of homologous chromosomes b. Independent assortment c. The fusion of gametes to restore the diploid number of chromosomes d. A and B e. None of the above
a. The physical exchange of parts of homologous chromosomes
Why is the phylogenetic species concept criticized for delineating too many species? a. The traits used do not have to be ecologically or physiologically significant, leading to fine-grained species categories. b. The traits used must be related to gene flow; this leads to fine-grained species categories. c. The traits used are based on morphology, leading to fine distinctions between individuals and thus more species. d. The traits used are solely based on DNA sequences, leading to fine distinctions between individuals, which leads to fine-grained species categories.
a. The traits used do not have to be ecologically or physiologically significant, leading to fine-grained species categories.
Inbreeding leads to __?___. a. a reduction in fitness caused by deleterious recessives. b. higher rates of mutation. c. mutation-selection balance. d. gene flow e. All of the above
a. a reduction in fitness caused by deleterious recessives.
Estimates favoring a recent coalescence may be indicative of __?__.
a. a small population b. a shrinking population c. a large population d. an expanding population e. A & B f. C & D
Sexual reproduction that is most likely to manifest recombination is termed __?__. a. amphimixis. b. apomixis. c. automixis. d. amphiphilic. e. none of the above
a. amphimixis
In a hypothetical scenario, imagine that you have discovered a rare species of bird on a remote Pacific island. You spend some time studying their ecology and habitation and discover that although these birds look alike, they are indeed two distinct populations with very different mating calls. You propose that these two populations must be two species since they are no longer able to mate with one another. Which of the following species concepts would you use to defend your statement? a. biological species concept b. phylogenetic species concept c. phenetic species concept d. ecological species concept
a. biological species concept
Which position in a codon is LEAST likely to contribute to the degeneracy of the genetic code? a. First b. Second c. Third d. Any position e. No position
a. first
Two common species of frogs from the genus Bombina (B. bombina and B. variegata) live in similar latitudes and ecological conditions, but in two different regions, Central and Eastern Europe. In a narrow strip between these regions, scientists have observed a third species, which might be a hybrid between the former diverging populations of the ancestral species. What evolutionary process might be responsible for the speciation in Bombina? a. parapatric speciation b. sympatric speciation with the ring species model c. allopatric speciation d. sympatric speciation
a. parapatric speciation
The statistical association of alleles at different loci is referred to as __?___. a. physical linkage. b. haplotypes. c. epistasis. d. linkage equilibrium. e. linkage disequilibrium.
a. physical linkage
Different races of the apple maggot fly have different breeding seasons depending on the host species they prefer (downy hawthorn or apple trees). Because of this temporal difference in breeding, which type of reproductive isolating mechanism is occurring? a. prezygotic b. gametic incompatibility c. postzygotic d. hybrid sterility
a. prezygotic
In the figure above, each new line represents the frequency of a new beneficial mutation. The figure describes the process of __?__. a. selective sweeps. b. disassortive mating. c. linkage disequilibrium. d. epistasis.
a. selective sweeps
what are the three sources of vairuance
additive, dominance, and epistatic interaction
sex ratio change to maximize fitness
adjustment of this can lead to maximized fitness for a time, but eventually it will balance out as a consequence of that fitness, and the advantage levels again to 1:1 (frequency-dependent selection)
Aposematism
advertising by an animal to potential predators that it is not worth attacking or eating
stabilizing selection results when
agents of selection act in opposing directions
examples of point mutation effects in physiology
albinism, polydactyly, polysyndactyly, piebaldism, fibrodysplasia, progeria
what is incorrect
all cells have the same genes
what do charles and george agree on
all life shares a common ancestor
If VGNE>0
all of the above
Which statements help explain why oppossums in Sapelo Island, where there are no opossum predators, produce smaller litters:
all of the above
jean lamark
all of the above
some evolutionary biologists have argued that menopause is adaptive. Which statement below helps form the logical basis of their argument
all of the above are true
HW theorem offers proof that
allele frequencies do not change in the absence of drift, selection, mutation, and migration
The image on the right illustrates the phylogeny of Pacific (P) and Caribbean (C) shrimp. This phylogeny offers evidence of...?
allopatric speciation
_____ is the gradual emergence of two or more species as a result of the geographic separation of two or more groups of animals of the same species.
allopatric speciation
Thomas Malthus
an English economist who argued that increases in population would outgrow increases in the means/resources of survival; this would lead to population growth that would be unchecked by famine, war, and disease
What would be most useful for dating an old rock?
an element with a very long half-life
phenotype
an observable, measurable characteristic of an organism; may be a morphological structure, a developmental process or performance trait, or a behavior; can even e the molecules produced by genes (ex. hemoglobin)
Some species of male water striders forcibly copulate with females. In these species, males are often equipped with exaggerated grasping structures, while females have structures that obstruct the male's grasp. Such a situation could arise through:
antagonistic coevolution
biological evolution
any change of the inherited traits of a population that occurs from one generation to the next
mutation
any change to the genomic sequence of an organism
color mimicry is also known as
aposematism
The earliest fossils of our own species date to:
approximately 200,000 years ago
Mammary glands in whales and humans:
are a synapomorphy for these species and other mammals are homologous traits were likely present in the most recent common ancestor of humans and whales
in scarlet kingsnakes alleles that lead to coloration pattern similar to coral snakes
are advantageous where kingsnakes and coral snakes cooccur
two genes that are orthologs:
are derived from a common ancestral gene
Homologous traits:
are inherited from a common ancestor
Speciation has occurred when two populations of organisms: become physically separated from each other. first acquire beneficial mutations. first acquire deleterious mutations. first acquire neutral mutations. are no longer capable of interbreeding.
are no longer capable of interbreeding.
New mutations:
are random with respect to their effects on fitness are necessary for natural selection to cause evolutionary change are rare in a population
The fluke of a whale and the fluke of a shark:
arose through convergent evolution are the result of natural selection
taxonomic diversity increases as a result of ._____...
as mean temperature increases, ______ will increase, too
Muller's Ratchet is a model for understanding why __?__.
asexual lineages are relatively rare
Studies of phonotaxis (response to calling) in the Grey Tree Frog demonstrated that female mate selectivity yielded higher levels of fitness, which is best measured by __?__.
assessing reproductive success
Jukes-Cantor Model
assumes equal base frequencies and equal mutation rates (one parameter model)
ornaments
attractive traits that increase mating success
In many animals, females are more likely than males to provide parental care because...?
b & c: males have invested less than females, males have uncertain paternity
34. Imagine that, of three species, it is known that species 1 and 3 were separated 10 million years ago, based on geologic measurements. Genetic analysis at a neutral locus indicates that these species differ by 100 substitutions. If there are 10 substitutions separating species 1 and 2, approximately how long ago did these species diverge? a. 0.1 million years ago b. 1 million years ago c. 10 million years ago d. 100 million years ago e. Cannot be determined based on the information provided
b. 1 million years ago
How will allele frequencies change through time at an overdominant locus,? a. The heterozygote with the greatest fitness advantage will have its allele fixed. b. A balanced polymorphism of both alleles will be maintained at a stable equilibrium. c. The homozygote with the lowest fitness advantage will go to fixation. d. One or the other allele will be lost depending on their initial frequencies. e. Both alleles will be lost.
b. A balanced polymorphism of both alleles will be maintained at a stable equilibrium.
If a change in allele frequency at one locus does not result in the change in allele frequency at a second locus, these loci probably a. Support Mendel's law of segregation b. Are unlinked c. Support Darwin's view of heredity d. Are dominant e. None of the above
b. Are unlinked
The Dobzhansky-Muller model explains hybrid infertility in crosses between two close species (such as the fruit flies D. simulans and D. melanogaster). Which of the following is the best explanation of this model? a. Changes in the numbers of chromosomes cause hybrid zygotes to have lower fitness and often make them infertile. b. Epistatic interactions between the alleles of two or more loci, undergoing different evolutionary paths in the two speciating groups, lead to the fitness costs of hybridization. c. Hybridization between the two sister species is impossible because of the imminent hybrid sterility. d. Two species develop strong prezygotic mechanisms of reproductive isolation and mating is less likely to proceed.
b. Epistatic interactions between the alleles of two or more loci, undergoing different evolutionary paths in the two speciating groups, lead to the fitness costs of hybridization.
21. Which of the bar graphs in the figure below depicts data regarding a beneficial mutation that will become fixed most rapidly? a. Graph a b. Graph b c. Graph c d. Cannot be determined from the information provided e. None of the above
b. Graph b
Two parapatric subspecies of sagebrush (mountain big sagebrush and basin big sagebrush) produce hybrid sagebrush, which often is found in the intermediate elevation. In the following graph, you can see a relative composite fitness for each of them, raised in three different environments (below 1800 meters in the basin zone, above 1900 meters in the mountain zone, and in the hybrid zone between 1800 and 1900 meters). Which of the following best explains the findings in this experiment? a. Hybrids had significantly better fitness than the other subspecies in the hybrid zone, supporting the ecologically neutral dynamic equilibrium model. b. Hybrids had significantly better fitness than the other subspecies in the hybrid zone, supporting the bounded hybrid superiority model. c. There was no significant difference in fitness between the three subspecies in the hybrid zone, providing support for the ecologically neutral dynamic equilibrium model. d. There was no significant difference in fitness between the three subspecies in the hybrid zone, so the bounded superiority model was not supported.
b. Hybrids had significantly better fitness than the other subspecies in the hybrid zone, supporting the bounded hybrid superiority model.
Parapatric speciation and sympatric speciation both describe how populations diverge into separate species without a geographic barrier to dispersal. What distinguishes these two modes of speciation? a. In sympatric speciation, the populations are adjacent to one another and typically have a hybrid zone between the populations. b. In parapatric speciation, the populations are adjacent to one another and typically have a hybrid zone between the populations. c. In sympatric speciation, the populations are not adjacent to each other but do have a hybrid zone. d. In parapatric speciation, the populations are not adjacent to each other and do not have a hybrid zone
b. In parapatric speciation, the populations are adjacent to one another and typically have a hybrid zone between the populations.
15. When considering the following figure, the top panel refers to ___ and the bottom panel refers to ___. a. Population-level thinking; individual-level thinking b. Individual-level thinking; population-level thinking c. Yule-thinking; Mendel-thinking d. Evolutionary thinking; ecological thinking e. Geographic thinking; special thinking
b. Individual-level thinking; population-level thinking
13. Which of the mutations in the figure below depicts a nonsense mutation? a. Mutation A b. Mutation B c. Mutation C d. A nonsense mutation is not pictures
b. Mutation B
40. Eukaryotic genome size is a. Tightly correlated with organismal complexity b. Not well correlated with organismal complexity c. Largest in humans d. Typically smaller than prokaryotic genome size e. Approximately the same in all eukaryotes.
b. Not well correlated with organismal complexity
31. Population bottlenecks can lead to the fixation or loss of alleles in otherwise large populations because the bottleneck a. Selectively eliminates or fixes alleles b. Reduces the effective population size to close to the size of the bottleneck c. Allows migrant alleles to overwhelm native alleles d. A and B e. All of the above
b. Reduces the effective population size to close to the size of the bottleneck
41. From the figure above, one can deduce that larger genomes a. Tend to have a greater proportion of coding DNA than smaller genomes b. Tend to have a lesser proportion of coding DNA than smaller chromosomes c. Have more splice variants d. Code for more proteins
b. Tend to have a lesser proportion of coding DNA than smaller chromosomes
42. The nematode, C. elegans, and humans have nearly identical numbers of protein coding genes, yet humans have much more complex organismal features. This is an example of a. The C-value paradox b. The G-value paradox c. Cell size paradox d. Linkage disequilibrium e. None of the above
b. The G-value paradox
Which of the following describes the phenetic species concept? a. This concept describes species as groups of actually or potentially interbreeding populations, with no gene flow between them. b. This concept looks at organisms that are clustered together in a phenotype space and is often used by numerical taxonomists. c. This concept draws species boundaries using shared derived characters that are unique to one monophyletic group and absent from all other populations in the phylogeny. d. This concept looks at populations that share a past evolutionary history and a common evolutionary fate.
b. This concept looks at organisms that are clustered together in a phenotype space and is often used by numerical taxonomists.
48. Would there be any disadvantage of sex if sexual reproduction was isogamous? a. No, females would not pay the twofold cost of sex b. Yes, sex may break up co-adapted gene complexes c. No, females would still transmit the same proportion of their genes to the next generation d. Yes, despite contributing the same proportion of offspring as asexual females, isogamous sexual females would only transmit half the proportion of their genes to the next generation.
b. Yes, sex may break up co-adapted gene complexes
__?__ is the term used to describe whole genome duplication via hybrid formation. a. Autopolyploidy. b. Allopolyploidy. c. Megamutaploidy. d. Haplodiploidy e. Parthenogenesis
b. allopolyploidy
The observation that hybrid offspring of true breeding purple and white flowered plants are purple in color can be explained by the __?__. a. dominance of the purple color. b. blending of parental characters. c. law of independent segregation. d. dominance of the white color. e. A and B
b. blending of parental characters
Allopatric speciation requires a. differences in phenology. b. complete geographic isolation. c. abutting distributions. d. overlapping distributions.
b. complete geographic isolation.
___ first proposed sexual selection as an evolutionary mechanism. a. Maynard-Smith c. Aristotle b. Darwin d. Fisher, Haldane, and Wright
b. darwin
In which of the bar graphs in the figure below do the data depict a combination of genotypes and fitness values that will promote longevity or persistence of the A2 allele ? a. Graph A b. Graph B c. Graph C d. Cannot be determined from the information provided
b. graph b
If a change in allele frequency at one locus is not correlated with a change in allele frequency at a second locus, these loci probably are not __?__. a. found in a eukaryotic organism. b. linked. c. subject to mutation d. dominant. e. Recessive.
b. linked
Eukaryotic genome size is ¬¬¬¬__?___. a. tightly correlated with organismal complexity. b. not well-correlated with organismal complexity. c. largest in humans. d. typically smaller than prokaryotic genome size e. approximately the same in all eukaryotes.
b. not well-correlated with organismal complexity.
Refer to the figure below to answer the following question. A researcher discovers a new bacterium whose genome is ~1.8 Mb in size. What type of bacteria is this organism? a. Free-living b. Obligate parasite c. Obligate symbiont d. Any of the above
b. obligate parasite
The nematode, C. elegans, and humans have nearly identical numbers of protein coding genes, yet humans have much more complex organismal features. This is an example of __?__. a. the C-value paradox. b. the G-value paradox. c. cell size paradox. d. linkage disequilibrium. e. None of the above
b. the G-value paradox
Resource competition is likely to occur a. when the same plants produce different seed types. b. when diet preferences are a function of differences in a phenotypic trait. c. infrequently in sympatric speciation. d. only in lakes.
b. when diet preferences are a function of differences in a phenotypic trait.
Prokaryotes include representatives from:
bacteria archaea
which of teh following was neccessary for the evolution of beak size
beak size had to be determined by the additive effects of alleles characteristics of the average seed had to change from year to year
describe the isotopic analysis of fossil teeth
because terrestrial animals drink freshwater & marine animals drink saltwater, which has a higher ratio of O18/O16, there is a higher ratio of O18/O16 in the teeth of marine animals
The McDonald-Kreitman test compares substitution rates...?
between and within closely-related species
The ? assumes that speciation occurs as a consequence of a loss of reproductive cohesiveness among two partitions of a population.
biological species model
The hominin fossil record suggests:
bipedality evolved before larger brain size
what are the types of genetic drift
bottleneck effect and founder effect
genetic load
burden imposed by the accumulation of deleterious mutations
18. Consider a diploid population in which a single locus has only two alleles, A1 and A2, whose respective allele frequencies equal p and q. the summation of p+q would equal a. 0.25 b. 0.5 c. 1 d. 1.5 e. 2
c. 1
Consider a diploid population in which a single locus has only two alleles, A1 and A2, whose respective genotype frequencies are p2, 2pq and q2. The summation of these variables is __?__. a. 0.25 b. 0.5 c. 1.0 d. 1.5 e. 2.0
c. 1.0
5. How many copies of each chromosome will a tetraploid organism have? a. 1 b. 2 c. 4 d. 8 e. 10
c. 4
11. If an RR flower is red, an Rr flower is pink, and an rr flower is white, what percentage of the offspring from a cross between an RR individual and an Rr individual will be red? a. 0 b. 25 c. 50 d. 75 e. 100
c. 50
32. Population bottlenecks occur when a. A large number of genetically diverse individuals found a new population b. Population size dramatically increases c. A consistently large population experiences a brief period of small size d. Drift in consistently small populations become fixed for a single allele e. Inbreeding is high
c. A consistently large population experiences a brief period of small size
35. A haplotype is a. All the alleles at a single locus b. A product of epistasis c. A set of alleles at different loci along a chromosome d. All alleles in a population e. None of the above
c. A set of alleles at different loci along a chromosome
After confirming that Amphilophus citrinellus and Amphilophus zaliosus were indeed two species that originated from a single colonization of Lake Apoyo by their common ancestor, what evidence explained this was a sympatric speciation event rather than an allopatric speciation event? a. Although Lake Apoyo is a very homogeneous habitat, body morphology in the two species supported speciation based on geographic separation, rather than habitat and ecological specialization. b. Although Lake Apoyo is a very heterogeneous habitat, body morphology in the two species supported speciation based on geographic separation, rather than speciation via competition. c. Although Lake Apoyo is a very homogeneous habitat, body morphology in the two species supported speciation based on habitat and ecological specialization, rather than geographic separation. d. Although Lake Apoyo is a very heterogeneous habitat, body morphology in the two species supported speciation via competition, rather than geographic separation.
c. Although Lake Apoyo is a very homogeneous habitat, body morphology in the two species supported speciation based on habitat and ecological specialization, rather than geographic separation.
14. A researcher follows the mutation rates in the nematode Caenorhabditis elegans in five different tissue types across 300 generations. One would expect mutation rates across the different tissue types to be a. Equal b. Approximately equal c. Different d. Deleterious e. None of the above
c. Different
Which of the following defines Haldane's rule and its predictions? a. If among hybrid offspring one sex is absent, rare, or sterile, that sex is always female. b. If among hybrid offspring one sex is absent, rare, or sterile, that sex is always male. c. If among hybrid offspring one sex is absent, rare, or sterile, that sex is heterogametic (has two different sex chromosomes). d. If among hybrid offspring one sex is absent, rare, or sterile, that sex is homogametic (has two of the same sex chromosomes).
c. If among hybrid offspring one sex is absent, rare, or sterile, that sex is heterogametic (has two different sex chromosomes).
Which of the following statements best explains secondary reinforcement? a. If the reproductive isolating mechanisms that developed during the geographic isolation are sufficiently weak as to allow free interbreeding across reunited populations, then the speciation process will halt and a single species will remain. b. When geographic isolation comes to an end, two populations always complete the divergence process and become separate species. c. If the reproductive isolating mechanisms that developed during the geographic isolation are somewhat weak but the hybrids between two populations have lower fitness, then the speciation process may continue. d. If the reproductive isolating mechanisms that developed during the geographic isolation are strong but the hybrids have higher fitness than the parent species, then the speciation process will cease.
c. If the reproductive isolating mechanisms that developed during the geographic isolation are somewhat weak but the hybrids between two populations have lower fitness, then the speciation process may continue.
This figure illustrates the results of selection for yeast strains that are well adapted to either high-salt or low-glucose environments. Over the course of selection, many mutations have occurred in populations in both environments. If the Dobzhansky-Muller model applies to this experiment, what do you predict will happen if the two strains produce a hybrid? a. Matings between individuals from the two strains will be completely unsuccessful. b. Matings between individuals from the two strains will have no difference in reproductive success compared to the controls. c. Matings between individuals from the two strains will have reduced reproductive success compared to the controls. d. Matings between individuals from the two strains will have greater reproductive success compared to the controls.
c. Matings between individuals from the two strains will have reduced reproductive success compared to the controls.
26. What phenomenon is represented in the following figure? a. Overdominance b. Balancing selecition c. Mutation-selection balance d. Back mutation e. Genetic drift
c. Mutation-selection balance
25. Consider a locus in which the fitness of AA and Aa genotypes are greater than the fitness of aa genotype. In addition, this locus experiences forward mutation from the A allele to a allele. At this locus, the A allele will a. Always go to fixation b. Always be lost c. Never go to fixation d. Never change e. None of the above
c. Never go to fixation
28. One consequence of genetic drift is a. Increasing heterozygosity in the population b. The maintenance of multiple alleles across long periods of time c. That populations diverge in terms of their allele frequencies d. That populations maintain the same set of alleles through time e. All of the above
c. That populations diverge in terms of their allele frequencies
47. Why is sexual reproduction believed to be the ancestral trait in eukaryotes? a. Asexual reproduction is completely absent from basal unicellular eukaryotes b. Under the parsimony principle, the most common form of a trait's state is always the ancestral trait. c. The "twiggy" distribution of obligate asexual reproduction in phylogenetic trees suggests that asexuality is a derived trait d. Evolutionary models suggest that obligate asexual taxa are more prone to extinction than sexual ones
c. The "twiggy" distribution of obligate asexual reproduction in phylogenetic trees suggests that asexuality is a derived trait
The law of independent assortment states that a. Characters are blended in hybrid offspring b. Purple flowered plants will never produce white flowered offspring c. The allele passed down to the next generation at one locus is independent of the allele passed down at a second locus. d. Alleles from two separate loci, once combined in a hybrid, cannot be separated in future reproductive events e. All individuals have more than two copies of every gene
c. The allele passed down to the next generation at one locus is independent of the allele passed down at a second locus.
Which choice is considered to be a fundamental problem with application of the phenetic species concept? a. The phenetic species concept only looks at whether reproduction occurs between populations; therefore, it cannot be applied to asexually reproducing species. b. The phenetic species concept weighs all traits equally, which can lead to ambiguous cluster boundaries when defining species. c. The phenetic species concept uses phenotypic traits to create clusters, but phenotypic traits can be similar due to convergent evolution rather than common ancestry. d. The phenetic species concept uses phenotypic traits to create clusters; therefore, it cannot be applied to bacterial and unicellular species.
c. The phenetic species concept uses phenotypic traits to create clusters, but phenotypic traits can be similar due to convergent evolution rather than common ancestry.
10. Which position in a codon is most likely to contribute to the degeneracy of the genetic code? a. First b. Second c. Third d. Any position e. No position
c. Third
Population bottlenecks occur when __?__. a. a large number of genetically diverse individuals found a new population. b. population size dramatically increases. c. a consistently large population experiences a brief period of small size. d. drift in consistently small populations become fixed for a single allele. e. inbreeding is high.
c. a consistently large population experiences a brief period of small size
In a study of red spruce trees and black spruce trees, scientists found that the red spruce was living in a smaller geographic area and had much less genetic variation than the black spruce. They proposed that the red spruce might have arisen from a southern population of black spruce, which became geographically isolated from other black spruce populations at some point during the Pleistocene glaciations. What is this an example of? a. allopatric speciation with the vicariance model b. sympatric speciation with the ring species model c. allopatric speciation with the peripheral isolate model d. sympatric speciation
c. allopatric speciation with the peripheral isolate model
Hybrids with a chromosomal rearrangement often have a. superior environmental performance across a cline. b. increased fitness relative to the parental generation. c. dysfunctional gametes. d. a doubling of chromosomes.
c. dysfunctional gametes.
The ________ species concept defines a species as a cluster of individuals that occupy a particular niche. a. phonetic b. evolutionary c. ecological d. biological
c. ecological
"A species is a lineage of populations which maintains its identity from other such lineages and which has its own evolutionary tendencies and historical fate." This definition best represents the __________. a. phenetic species concept b. ecological species concept c. evolutionary species concept d. biological species concept
c. evolutionary species concept
Which of the following is NOT a prezygotic isolating mechanism? a. habitat isolation b. gametic incompatibility c. hybrid inviability d. temporal isolation
c. hybrid inviability
7. RNA that directs protein synthesis is called a. Ribosomal RNA b. microRNA c. messenger RNA d. transfer RNA e. translocation RNA
c. messenger RNA
RNA that contains a codon sequence is called __?__. a. ribosomal RNA. b. microRNA. c. messenger RNA. d. transfer RNA. e. translation RNA.
c. messenger RNA
Which of the mutations in the figure below depicts what will become a synonymous substitution? a. Mutation A c. Mutation C b. Mutation B d. A nonsense mutation is not pictured
c. mutation c
A researcher is trying to determine if populations of a butterfly seen on the eastern slope of the Rocky Mountains in Colorado are actually separate species. The researcher and her graduate students spent a summer capturing the butterflies at several locations, carefully documenting traits such as color, wing span, antennae length, proboscis length, etc. Which species concept could be applied using these data? a. ecological species concept b. biological species concept c. phenetic species concept d. evolutionary species concept
c. phenetic species concept
The Red Queen Hypothesis __?__. a. states that females must bear an asymmetric burden in sexual reproduction. b. predicts that eusocial species should arise as a consequence of haplodiploidy. c. predicts an "arms race" between host and parasites. d. states that asexual organisms will be favored over sexual organisms.
c. predicts an "arms race" between host and parasites.
The third position transitions curve in the figure at left illustrates the phenomenon known as__?___. a. epistasis b. heterozygosity c. saturation d. silent substitution
c. saturation
One consequence of genetic drift is __?___. a. increasing heterozygosity in the population. b. the maintenance of multiple alleles across long periods of time. c. that populations diverge in terms of their allele frequencies. d. that populations maintain the same set of alleles through time. e. All of the above
c. that populations diverge in terms of their allele frequencies.
A small population of a species invades an island where the species is not found. The island population subsequently diverges from the ancestral population and becomes a new species. This is an example of a. the vicariance model of allopatric speciation. b. sympatric speciation. c. the peripheral isolate model of allopatric speciation. d. parapatric speciation.
c. the peripheral isolate model of allopatric speciation.
Sexual reproduction is favored over asexual reproduction in all of the following cases EXCEPT __?__. a. a fluctuating environment b. parasitism c. the relative investment in young d. the availability of multiple niches
c. the relative investment in young
crypsis
camouflage that makes prey difficult to see
Uniformitarianism
can be described as the assumption that physical laws have remained constant through time
Catastrophism vs gradualism
catastrophism -catastrophic events responsible for mass extinction ex) asteroid kills dinasours -many catastrophists were neptunists -Cuvier gradualism -change based on small steps over time ex) layers of rock -many gradualists were plutonists -Hutton Lyell
evolution (genetic level)
change in allele frequencies from one generation to the next
autosomes
chromosomes that do not differ between sexes
sex chromosomes
chromosomes that pair during meiosis but differ in copy number between males and females. females are homogametic (XX) and males are heterogametic (XY)
male pipefish have a brood pouch
co-option
Some evolutionary biologists argue that changes in the regulation of genes rather than changes in the coding sequence are more likely to be involved in adaptation. Which of the following statements forms part of the basis for this argument:
coding sequence changes are constrained because most genes perform multiple functions
advantages of sex
combining beneficial mutations, generation of novel genotypes, faster evolution, clearance of deleterious mutations
what are two explinations for similarities between species
common descent and covergent evolution
messenger RNA (mRNA)
consists of molecules of RNA that carry genetic information from DNA to the ribosome, where it can be translated into protein
Carl von Linné (Carolus Linnaeus)
contributed the most to the Great Chain of Being by being the father of binomial nomenclature (father of modern taxonomy)
In the Eurasioan penduline tit, what are the costs and benefits for males leaving the females?
costs: if males leave to early, the female may not be able to lay eggs, or another male may come in and mate with the female benefits: By leaving at the right time, males can increase their reproductive success because they are able to mate with another female
William Smith:
created the first geological map
Assume a biallelic locus in a diploid population has the allele frequency: A1 = 0.74. The predicted frequency of the heterozygote is __?__. a. 0.26 b. 0.55 c. 0.86 d. 0.38 e. 0.07
d. 0.38
19. Assume a biallelic locus in a diploid population has the genotype frequencies: A1A1 = 0.59; A1 = 0.16; and A2A2 = 0.25. What is the observed allele frequency (p) of the A1 allele? a. 0.59 b. 0.16 c. 0.25 d. 0.67 e. 0.33
d. 0.67
How many copies of each chromosome are present in cells of a hexaploid organism (e.g., Triticum)? a. 1 b. 2 c. 3 d. 6 e. 12
d. 6
50. Which of the following statements illustrates a potential cost of sexual reproduction? a. Proteins in the seminal fluid of Drosophila males shorten the life expectancy of inseminated females b. Female birds of paradise inspect several males before deciding who to mate with c. Male and female damselflies form characteristic mating wheels, which allow the partners to fly, albeit at slower speeds than single damselflies d. All of the above.
d. All of the above.
24. If no evolutionary force acts on a population besides mutation, genotype frequencies will a. Remain the same over time b. Increase over time c. Decrease over time d. Always be in the Hardy-Weinberg proportions e. None of the above
d. Always be in the Hardy-Weinberg proportions
20. If we follow a population through time and observe that allele frequencies change or genotypic frequencies change in this population, this may be because a. The population size is small b. Selection is operating on the locus c. Mating is non-random d. Any of the above
d. Any of the above
38. In the figure above, a new beneficial allele, B arises on a chromosome containing the ordered loci A, B, C, D, and E, depicted in the top panel. After reproduction, those chromosomes possessing the B allele increase in frequency. Over time, recombination breaks up the association of the B allele with the A, C, D, and E alleles. Assuming that the five loci are spaced evenly along the chromosome, the first pair of allele combinations to be broken up will be a. B and A b. B and C c. B and D d. B and E e. All alleles will break up at an equal rate
d. B and E
In the figure above, a new beneficial allele, B, arises on a chromosome containing the ordered loci A, B, C, D, and E, depicted in the top panel. After reproduction, those chromosomes possessing the B allele increase in frequency. Over time, recombination breaks up the association of the B allele with the A, C, D, and E alleles. Assuming that the five loci are spaced evenly along the chromosome, the first pair of allele combinations to be broken up will be __D__. a. B and A. b. B and C. c. B and D. d. B and E. e. All alleles will break up at an equal rate
d. B and E
What does the figure illustrate? a. Haldane's rule b. Reproductive isolation through chromosomal rearrangement c. Ploidy changes resulting in reproductive isolation d. Dobzhansky-Muller incompatibility
d. Dobzhansky-Muller incompatibility
6. The hypothesis that eukaryotic organelles are derived from once free living prokaryotes is known as the a. Prokaryote origins hypothesis b. Organelle hypothesis c. Hybrid hypothesis d. Endosymbiosis hypothesis e. Early life hypothesis
d. Endosymbiosis hypothesis
This figure illustrates the concept of a ring species formation in Ensatina eschscholtzii salamanders in California. The species originated in northern California and southern Oregon and then expanded south along the Sierra Nevada range. Which statement accurately describes gene flow and gene patterns in these populations? a. Gene flow decreases as you move south, resulting in the southern populations being more genetically similar to one another than other populations. b. Gene flow increases as you move south, resulting in little genetic differentiation between the southern species when compared to other species in the range. c. Gene flow decreases through the middle part of the range but increases as the species comes back in contact at the southern end of the range. d. Gene flow decreases as you move south, resulting in the southern populations being more genetically distinct from one another than other populations.
d. Gene flow decreases as you move south, resulting in the southern populations being more genetically distinct from one another than other populations.
Which of the following statements about changes in ploidy is true? a. It is less common in plants than animals. b. It causes shell coiling in snails. c. It often reduces reproductive isolation. d. It can result in instantaneous speciation.
d. It can result in instantaneous speciation.
In the course of studying plant communities living on an elevational gradient in Rocky Mountain National Park, researchers observed that a plant species growing in the park appears to actually be three species. The low elevation (LE) species is more clearly distinct from the high elevation (HE) species, but the middle elevation (ME) species has characteristics of both. After taking seeds from all three populations back to their greenhouse for a reproductive study, the researchers discovered that ME plants could not successfully pollinate HE plants, but ME did produce sterile seeds with the LE plants. Which statement best describes the reproductive isolating mechanisms between these populations? a. All three populations appear to be isolated through prezygotic mechanisms. b. ME and HE are isolated through postzygotic mechanisms, while ME and LE are isolated through prezygotic mechanisms. c. All three populations appear to be isolated through postzygotic mechanisms. d. ME and HE are isolated through prezygotic mechanisms, while ME and LE are isolated through postzygotic mechanisms.
d. ME and HE are isolated through prezygotic mechanisms, while ME and LE are isolated through postzygotic mechanisms.
37. Which of the following processes that can create linkage disequilibrium is illustrated in the figure below? a. Drift b. Selection c. Mutation d. Migration e. All of the above
d. Migration
22. At an underdominant locus, how will allele frequencies change through time? a. The homozygote with the greatest fitness advantage will have its allele fixed b. A balanced polymorphism of both alleles will be maintained at a stable equilibrium c. The homozygote with the lowest fitness advantage will have its allele lost d. One or the other allele will be lost depending on their initial frequencies e. Both alleles will be lost
d. One or the other allele will be lost depending on their initial frequencies
23. The figure below demonstrates that a. Frequency dependent selection results in a stable polymorphism b. The frequency of the A1 allele (p) will always go to fixation c. The frequency of the A1 allele (p) will always go to zero d. The frequency of the A1 allele (p) may go to one or zero depending on the initial value of p. e. Frequency selection leads to the random loss of alleles
d. The frequency of the A1 allele (p) may go to one or zero depending on the initial value of p.
he law of independent assortment states that __?__. a. characters are blended in hybrid offspring. b. purple flowered plants will never produce white flowered offspring. c. the allele passed down to the next generation at one locus is independent of the allele passed down at a second locus. d. alleles from two separate loci, once combined in a hybrid, cannot be separated in future reproductive events. e. all individuals have more than two copies of every gene.
d. alleles from two separate loci, once combined in a hybrid, cannot be separated in future reproductive events.
During the 1990s, Nancy Knowlton and her colleagues studied pairs of sister species of the genus Alpheus (snapping shrimp) (Knowlton 1993). In each of these sister species, one species in the pair lived on the Caribbean side of the Isthmus of Panama, while the other species lived on the Pacific side. What type of speciation might be responsible for this speciation? a. sympatric speciation with the ring species model b. sympatric speciation c. allopatric speciation with the peripheral isolate model d. allopatric speciation with the vicariance model
d. allopatric speciation with the vicariance model
If we follow a population through time and observe that allele frequencies change or genotypic frequencies change in this population, this may be because ____. a. the population size is small. c. mating is non-random. b. selection is operating on the locus. d. Any of the above
d. any of the above
In order to determine if individuals from separate populations are indeed distinct species, Drosophila biologists often test to see if individuals from different populations will mate with each other. This is an application of the ________ species concept. a. phenetic b. phylogenetic c. evolutionary d. biological
d. biological
From the figure above, one can deduce that larger genomes _____. a. tend to have a greater proportion of coding DNA than smaller genomes. b. tend to have a lesser proportion of coding DNA than smaller genomes. c. have more splice variants. d. code for more proteins.
d. code for more proteins
Which of the following statements describes a challenge of applying the phenetic species concept? a. The concept can only be applied to sexually reproducing species. b. construction of a phylogenetic tree that accurately portrays relationships c. the measurement of gene flow within the population d. how to weigh the relative importance of the characters used
d. how to weigh the relative importance of the characters used
Use the figure below to determine which of the following amino acid sequences would be generated from the RNA sequence: UUC CAC AAA UGA. a. arginine; glycine; leucine; threonine b. arginine; glycine; phenylalanine; threonine c. phenylalanine; histidine; lysine; stop d. leucine; histidine; lysine; stop e. None of the above
d. leucine; histidine; lysine; stop
In a hypothetical flowering plant species, one population evolves a different response to environmental stimuli and begins to bloom significantly later in the season than nearby populations. What type of reproductive isolating mechanism would this be? a. postzygotic b. hybrid sterility c. gametic incompatibility d. prezygotic
d. prezygotic
The graph at left illustrates the phenomenon known as __?___. a. exonization b. reverse mutation c. artificial selection d. the founder effect e. the bottleneck effect
d. the founder effect
The figure at left demonstrates that __?__. a. frequency dependent selection results in a stable polymorphism. b. the frequency of the A1 allele (p) will always go to fixation. c. the frequency of the A1 allele (p) will always go to zero. d. the frequency of the A1 allele (p) may go to one or zero depending on the initial value of p. e. frequency selection leads to the random loss of alleles.
d. the frequency of the A1 allele (p) may go to one or zero depending on the initial value of p.
Of the possible base changes shown below, the purine-purine or pyrimidine-pyrimidine changes are termed ___?___ and these substitutions are __?__ than the purine-pyrimidine or pyrimidine-purine changes.. a. Transversions; less common b. Transversions; more common c. Transitions; less common d. Transitions; more common e. None of the above
d. transitions; more common
What is the most common reason for the disappearance of a hybrid zone, resulting in the completion of the speciation process? a. when hybrids mate assortatively b. when hybrids are found in ring species and no longer mate with the parent species c. when hybrids have a selective advantage and replace the parent species d. when hybrids are at a selective disadvantage compared to offspring from within-population matings
d. when hybrids are at a selective disadvantage compared to offspring from within-population matings
gene flow
decreases divergence between populations and can limit adaptation in some pops
effects of deleterious mutations in diploids
deleterious mutations may be masked by the presence of a functional copy of the gene on the other chromosome
Muller's ratchet is the idea that______ accumulate in asexual populations. In such a situation sex would be beneficial because ____
deleterious mutations: mutation free genotypes can be recreated through recombination
synapomorphy
derived form of a trait that is shared by a group of related species
Apomorphy
derived trait
apomorphy
derived trait
define biological evolution
descent with hereditary variation
homoplasy
describes a character state similarity not due to shared descent (ex. produced by convergent evolution or evolutionary reversal)
monophyletic
describes a group of organisms that form a clade
paraphyletic
describes a group of organisms that share a common ancestor although the group does not include all the descendants of that common ancestor
polyphyletic
describes a taxon that does not include the common ancestor of all members of the taxon
polytomy
describes an internal node of a phylogeny with more than two branches (i.e. the order in which the branchings occurred is not resolved)
mutation
describes any change to the genomic sequence of an organism
microRNA
describes one group of RNAs that act as post-transcriptional regulators of gene expression; bind to complementary sequences on specific mRNAs and can enhance or silence the translation of genes; the human genome encodes more than 1000 of these
incomplete lineage sorting
describes the case when the history of a gene differs from the history of the species carrying the gene
genotype
describes the genetic makeup of an individual; although it includes all the alleles of all the genes in that individual, the term is often used to refer to the specific alleles carried by an individual for any particular gene
evolutionary reversal
describes the reversion of a derived character state to a form resembling the ancestral state
selective sweep (genetic hitchhiking)
describes the situation in which strong selection can cause an allele to go to fixation within a population so fast that there is little opportunity for recombination; and in absence of recomb, alleles in large stretches of DNA flanking the favorable allele will also reach high frequency
eye development
development of this sense organ arose independently in many different lineages
carlo linnaeus
devised a system of taxonomy and believed that lifes diversity relfected a divine plan
Reznick
did experiments with guppies to compare trade-offs in high- and low-predation environments
Klug
did experiments with sand gobies to find out why they devour their own eggs
lord kelvin
didnt realize the planets interior was constantly changing
average excess of fitness (in general?)
difference between average fitness of individuals with allele vs. those without the allele
organisms vary in genome size why
difference in the number of mobile genetic elements
65 mya
dinosaurs go extinct and mammals begin to diversify at this time
Mammals are _____ organisms, whereas plants may be:
diploid; polyploid.
explain the difference between direct and indirect benefits of female choice
direct benefits are those that benefit the female through advantages that she, herself, gains. For example food, nest sites, or protection all increase the likelihood that a female will survive and/ or reproduce. Indirect benefits are those that affect the quality of the female's offspring due to inherited genetic traits.
modes of selection
directional, stabilizing, disruptive
Shh (sonic hedgehog) gene
disruptions in this gene involved in expression block limb growth; also responsible for cetaceans secondary loss of hindlimbs
the residues of mines
disruptive selection
kimura 2-parameter model
distinguishes transitions versus transversions
synonmyous mutations___
do not change the amino acid sequence of the protien; neutral evolution by genetic drift
The ways of evolutionary change?
drift & selection
important mechanisms of evolution (4)
drift, natural selection, migration (gene flow), mutation
John Maynard Smith
driver of game theory
natural selection and trade-offs
due to the concept of trade-offs, ______ ______ will likely maximize number of offspring surviving to maturity, depending on likelihood of survival to different age classes
The "Jemmy Button episode"
during the voyage of HMS Beagle is/are thought to have profoundly influenced Darwin's ideas about the origin of humans
29. The figure above illustrates the a. Increase in homozygosity with time b. The probably effect of over-fishing on heterozygosity c. The decline of heterozygosity with time d. B and C e. All of the above
e. All of the above
43. Horizontal gene transfer a. Is also known as lateral gene transfer b. Occurs via transduction c. Occurs via transformation d. Occurs via conjugation e. All of the above
e. All of the above
45. Transposons can be deleterious to a host genome because they can a. Disrupt a protein coding sequence b. Disrupt regulatory elements c. Generate mutations d. Cause recombination errors e. All of the above
e. All of the above
8. If the wrong protein is produced, it may a. Affect DNA expression b. Alter cellular structure c. Influence development d. A and B e. All of the above
e. All of the above
33. The ancestor to the Hawaiian crickets in the genus Laupala originally colonized the oldest of the islands in the Hawaiian archipelago. As new islands were formed, crickets from the older island would colonize the younger island. Because members of this genus are flightless, these migration events were likely to be extremely rare and would include a small number of migrants. Nonselective differences in allele frequencies in this genus are likely due to a. Differences in mutation rate b. A founder event c. Genetic drift subsequent to colonization d. A and C e. B and C
e. B and C
49. Why is the cost of sex sometimes referred to as the "cost of males"? a. Males do not contribute genes to the next generation b. Males do not produce new offspring c. With finite resources, males take the place of offspring-producing females d. Sperm cells do not contribute any substantial energy resources to the eggs they fertilize e. B, C, and D
e. B, C, and D
Why is the cost of sex sometimes referred to as the "cost of males"? a. Males do not contribute genes to the next generation. b. Males do not produce new offspring. c. With finite resources, males take the place of offspring-producing females. d. Sperm cells do not contribute any substantial energy resources to the eggs they fertilize. e. B, C, and D
e. B, C, and D
36. The statistical association of alleles at different loci is referred to as a. Physical linkage b. Haplotypes c. Epistasis d. Linkage equilibrium e. Linkage disequlibrium
e. Linkage disequlibrium
17. The null model for population genetics is a. Newton's first law b. The competitive exclusion model c. Cell theory d. The endosymbiosis theory e. The Hardy-Weinberg model
e. The Hardy-Weinberg model
Horizontal gene transfer __?___ a. is also known as lateral gene transfer. b. occurs via transduction. c. occurs via transformation. d. occurs via conjugation. e. All of the above
e. all of the above
The physical exchange of parts of homologous chromosomes __?__. a. is termed crossing over b. is termed recombination c. is possible during meiosis d. was unknown to Charles Darwin e. all of the above
e. all of the above
The null model for population genetics is __?__. a. Newton's first law. b. the competitive exclusion model. c. cell theory. d. the endosymbiosis theory. e. the Hardy-Weinberg model.
e. the Hardy-Weinberg model
sponges
earliest animal life; lined with choanocytes (which are identical to choanoflagellates)
Dan Frank studied
ecological speciation
Which of the following species concepts might differentiate species on the basis of specific dietary requirements?
ecological species
Recall the example of different ladybug species described in the text, which each feed on a different species of plant. If two such species inhabit the same types of plants but in different locations (i.e., one near the base of the plant and the other on the uppermost leaves), these species would be considered:
ecologically separated
elderflower orchids (yellow and purple flowers) is an example of sickle cell anemia is an example of
elderflower orchids (yellow and purple flowers) is an example of sickle cell anemia is an example of
Which of the following accurately describes the signal cascade in a typical gene regulatory network:
environmental signal triggers transcription factor, transcription factor binds cis- regulatory element: protein coding gene activated
Bateson-Dozhansky-Muller incompatibilities (i.e., post-zygote barriers) arise as a consequence of...?
epistasis
4.56 billion
estimated age of the Earth by radiometric dating
Which of the following statements is accurate regarding the evolution of drug resistance in a virus:
even before the drug is administered, some virions might be resistant
macroevolution
evolution above the species level involving origination, diversification, and extinction
genetic drift
evolution arising from random changes in the genetic composition of a population from one generation to the next
genetic drift
evolution arising from random changes in the genetic population from one generation to the next
microevolution
evolution occurring within populations and involving adaptive and neutral changes in allele frequencies
unifying theory of biological science
evolution, with its understanding of the struggle for existence and descent with modification, is considered to be _____ for biological science
ΔCCR532 gene
example gene that represents a trade-off in resistance to HIV; presents immunity, but also makes the carrier more susceptible to west nile virus
sickle cell anemia
example of heterozygote advantage; balancing selection
pipefish and seahorses
example of sex role reversal, where males carry young and raise them
miscarriage, spontaneous abortion, and cannabilism
examples regulating the number of offspring to maximize family fitness
The field of evo-devo proposes that many major morphological changes result from changes in gene____ of regulatory genes. The premise for this argument is that these changes ____
expression: can be compartmentalized and need not interfere with the outcome of all interactions
many butterflies....
extrinsic postzygotic isolation
If natural selection is the driving force for speciation of two competing subspecies, you would expect to see a bell-shaped distribution of selected phenotypes after selection.
false
If two populations are reproductively isolated from one another (like certain populations of Russian warblers), they must be genetically isolated from each other and therefore cannot belong to the same species.
false
Natural selection is always the driving force of speciation.
false
True or False: Mutations always result in either an increase or a decrease in an organism's reproductive fitness.
false
True or False: Once a mutation is introduced into a population, it will eventually be passed on until it is found in 100% of the individuals in that population.
false (not always)
nicolas steno
father of geology and stratigraphy
Exaption examples
feathers are an exaptation; they evolved originally for functions other than flight
hadrosaur crest
feature of hadrosaurs that is connected to the nasal cavity and used blowing air to generate sounds for communication; hadrosaur ears tuned specifically to this frequency of sound; discovered via CT scan technology
astragalus bone
feature of the ankle that has been found to unite whales and artiodactyls; bictrochleated nature of both shows that whales are related to hooved animals
involucrum
feature of the ear region that is reduced at the periotic-tympanic contact point for modern cetaceans; important trait that distinguishes fossil whales and modern cetaceans
Which of the following is/are NOT critical for Darwin's idea for natural selection:
features of individuals change during their lifetime
The graph presented below is a Bateman gradient. The slopes of the gradient indicate that __?__ is likely to be observed in this species.
female choice
fecundity
female limitation of reproductive success
based on the outcome of previous experiments, if you moved guppies from predator free streams to predator rich streams for many generations, which of the following would you expect:
females would produce more offspring
Anne Elizabeth Darwin
first daughter of Charles Darwin; died in 1851; contracted Scarlet Fever in 1849 and may have also suffered from "consumption" (typhus)
150 mya
first mammal emergence found to be at this time
Evolutionary biologists debating importance of natural selection and genetic drift
fischer wright kimura
notochords
flexible, rod-shaped structures found in the embryos of all chordates; served as the first "backbones" in early chordates, and in extant vertebrates the embryonic one becomes a vertebral column
zygomorphic flower
flower that has bilateral symmetry
actinomorphic flower
flower that has radial symmetry
pollinator isolation
flowering plants rely on different species for pollination, or apply pollen to different parts of the same pollinating animal
nuptial gifts
food presented by members of one sex (sometimes in spermatophores) to members of the other sex during courtship; she may eat them, but eventually she might inseminate herself
mechanisms of evolution are _______
forces that change allele frequencies
disruptive selection
form of natural selection in which a single curve splits into two; occurs when individuals at the upper and lower ends of a distribution curve have higher fitness than individuals near the middle
reproduction
formation of new individual organisms (offspring)
hindlimb reduction
fossils document this in the land-sea transition, and gene expression also shows it as these structures begin to form but do not fully develop in marine animals
Sepkoski
found dates of mass extinctions and proposed three faunas on record since the Cambrian era
postmating-prezygotic barrier
gametic incompatibility is this type of reproductive barrier
All of the following are pre-mating barriers to reproduction EXCEPT...?
gametic isolation
in the region where the snakes dont overlap
gene flow
Which of the following statements about gene imprinting is True?
gene imprinting is a male reproductive strategy that can reduce the lfetime reproductive success of females & Gene imprinting is a femalereproductive strategy that can reduce the lifetime reproductive success of males
citT
gene involved in citrate metabolism that was duplicated to allow citrate to be metabolized in presence of oxygen~
Hoxd13a gene
gene whose activity is required for limb and fin development by exogenous dexamethasone stimulation; is active longer in tetrapods to allow for further segmentation of the limbs
when components of variation are additive...
genetic and environmental variance sum to total phenotypic variance
analysis of allelic diversity in maize
genetic botttleneck and strong artificial selection
as gene flow increases, genetic distance (Fst) ___________
genetic distance (Fst) decreases as gene flow ___________
proponents of the neutral theory of molecular evolution believe that most substitutions are fixed by__
genetic drift
Which of the following was NOT proposed by Darwin:
genetic drift DNA is the hereditary material
When an allele, B, exhibits a strong fitness advantage, other alleles that are linked to B (even alleles that are mildly deleterious) are termed __?__.
genetic hitchhikers and may be carried to fixation in a selective sweep
Bateson-Dobzhansky-Muller incompatibilities
genetic incompatibilities in hybrid offspring arising from epistatic interactions between two or more loci (QTL mapping can be used to interpret this)
Which of the following are required for speciation to occur? physical separation of two populations genetic variation mutation natural selection
genetic variation & mutation
The red queen hypothesis proposes that sex is beneficial because:
genetic variation in offspring generated through sex is advantageous in a changing environment
phenotypic variance is comprised of
genetics and environment
How do genomes vary across organisms?
genomes vary in size and complexity due to differences in mobile genetic elements
isolating barriers
geographic and reproductive barriers are this type of reproductive barriers
William Smith
geologist who brought to light that different rock layers contain distinct fossils; created the first geological map and created strata names; his ideas were important for developing the idea of strata to give relative age
James Hutton
geologist who recognized that change was gradual; observable processes produce small changes that accumulate over time; uniformitarianism
What mutations are the raw material for evolution?
germ line mutations because they are heritable
D1 + originations - extinctions = D2
global diversity equation
Population geneticists tell us that unless a population has an infinite number of members, alleles in the population will eventually __?__.
go to fixation
Pea females prefer peacocks with more eyespots on their tail feathers. The results depicted in the graph above provide support for:
good genehypothesis
Female stickleback prefer males with brighter red coloration on their belly. Given the results depicted in the graph above, it appears that females that choose redder males benefit from:
good genes
isochron graph
graph used in radiometric dating interpretation that is based on the idea that rocks are made up of different materials; requires that there must be at least three isotopes; slope gives you the time since crystallization
lactose intolerance in European populations
great example of genetic hitchhiking/selective sweep
mysticetes
group of cetaceans where baleen has completely replaced the presence of teeth; the genes for building teeth are disabled
taxa (taxon)
groups of organisms that are judged to be cohesive units, such as a species or order
outgroups
groups of organisms that are outside of the monophyletic group being considered; can be used to infer the ancestral states of characters in phylogenetic studies
narrow sense heritability (h^2) estimation based on graphed parent/offspring data
h^2 = slope of the graph
What is the raw material for evolution?
heritable genetic variation among individuals
With respect to the evolutionary response to selection, high heritability causes
high heritability causes a larger change or Response to Selection (R)
Traits that are similar by descent are
homologous
orthologs
homologous genes separated by a speciation event
paralogs
homologous genes within a single species
as gene flow increases, homology between two populations ________
homology between two populations increases as gene flow __________
inbreeding results in a higher frequency of ____ in a pop. inbreeding depression occurs because___
homozygosity: deleterious recessive alleles are expressed more often
RNA world hypothesis
hypothesis that RNA was the first nucleic acid to evolve and that early life was based on RNA, rather than DNA or protein
Huronian Glaciation
ice age on earth that is thought to maybe have been triggered by oxidation of atmospheric methane (during archean eon when atmosphere was starting to get more oxygenated)
the great chain of being; the ladder of life; scala naturae
idea that every species was a link on a chain extending from lowest forms to humans and on to spiritual beings. All links and been designed at the same time during creation and would never change
Irruptive behavior may have played a role in the initial founding of the Hawaiian honeycreepers, leading to an adaptive radiation. Why?
in times of scarcity, individuals of a species disperse widely in search of resources
hominins
include humans as well as all species more closely related to humans than to chimpanzees; within this group, humans are the only surviving members
genome
includes all the hereditary information of an organism; comprises the totality of the DNA, including the coding and noncoding regions
The image at right shows the pattern of coalescence for some hypothetical gene. This is an example of...?
incomplete lineage sorting/coalescence
Heterozygote Advantage and Sickle-Cell Anemia
individuals heterozygous for HbS have protection from malaria with less chance for sickle cell crisis
Which of the following is not a characteristic of species?
individuals in different phases of development have different numbers of chromosomes
behavioral separation
individuals mate only with other individuals based on specific courtship rituals, songs, or other behaviors
hermaphrodites
individuals that produce both female and male gametes; can self-fertilize but do not achieve greater genetic variation
adaptations
inherited aspects of an individual that allow it to outcompete other members of the same population that lack the trait (or have a different version of the trait); traits that have evolved through the mechanism of natural selection
When female parental investment exceeds that of the male, males generally exhibit __?__ and male fitness is limited by access to females.
intrasexual selection
Although polar bears and brown bears are regarded as separate species, genetic evidence indicates that brown bears have acquired some polar bear DNA as a consequence of...?
introgression
DNA methylation
is a form of transcriptional regulation og gene expression
Sewall Wright was a pioneer in the study of the effects of inbreeding on the genetics of populations. His work led to the characterization of the value, F. The F statistic __?___.
is the frequency of gametes that are paired with other gametes that are identical by descent
geographic barrier
isolating barrier where extrinsic properties of landscape prevent gene flow; Allopatry
reproductive barrier
isolating barrier where features of organisms prevent interbreeding; effective even in sympatry
According to sexual selection theory, a male signal is likely to be honest if:
it is condition-dependent and it is costly to produce
key concept: mutations to proteins can affect... (4)
key concept: -cell structure -ability to catalyze enzymatic reactions -cell-cell signaling -ability to respond to other molecules
key concept: stability of DNA
key concept: because of DNA's __________, it forms the basis of a system that encodes and replicates information essential for life
key concept: gene expression and the environment
key concept: __________ is often influenced by signals from the environment, allowing organism to sometimes match to environmental circumstances
key concept: population subdivision, genetic drift, and gene flow
key concept: population subdivision enhances the effects of genetic drift, but gene flow counteracts subdivision by homogenizing allele frequencies
key concept: rare alleles are almost always carried in a heterozygous state
key concept: that explains that recessive alleles are invisible to selection and provides reason that selection cannot drive dominant allele to fixation
key concept: evolutionary history of the organism (in regard to genome)
key concept: the __________ of the organism is reflected in its genome diversity of noncoding elements
key concept: mutations to noncoding RNA
key concept: these can affect the translation and expression of genes
key concept: mutations
key concept: these can alter the structure of proteins
key concept: alleles and pleiotropic effects
key concept: when fitness effects oppose each other, environment determines direction of selection
Paleontology provided evidence that ____ Geologists recognized that _____
life changed change occurs gradually
Isochron
line on a graph of radioisotope ratios that connects points of the same age but derived from distinct mineral sources
teleosts
lineage of bony fish that comprises most living species of aquatic vertebrates; include goldfish, salmon, and tuna; can be distinguished from other fishes by unique traits, such as mobility of the premaxilla
synapsids
lineage of tetrapods that emerged 300 million years ago and gave rise to mammals; can be distinguishes from other tetrapods by the presence of a pair of openings in the skull behind the eyes known as the temporal fenestrae
Hemagglutinin 7 neuraminidase 9
long name for H7N9 flu strain
The "Grandmother Hypothesis", which offers an adaptive explanation for menopause in humans, suggests that...?
loss of fertility is associated with a shift in investment to grandchildren
which statement helps explain why male pipefish produce very few sperm:
male fitness is limited mostly by the number of eggs they can care for
number of mates that can be attained
male limitation of reproductive success
shorter lifespan
males have a ______ lifespan that females, generally
polygyny
males mate with multiple females
William Dallinger
man who used his special device to examine evolutionary change in temperature tolerance in protozoa over the course of his 7-year experiment
trilobites
marine arthropods that diversified during the Cambrian period and gradually died out during the Devonian period
K-T boundary
mass extinction event thought to be caused by asteroid impact
Pipefish and Seahorses demonstrate that...?
mate choice is not restricted to one gender
theorems
mathematical statements that have been proven based on previously established theorems and axioms
phenotypes
measurable aspects of organisms, such as morphology (structure), physiology, and behavior; genes interact with other genes and with the environment during the development of the phenotype
quantitative traits influenced by?
measurable phenotypes that vary among individuals over a given range to produce a continuous distribution of phenotypes -continuously varying -influenced by multiple genes &/or the environment
genetic distance
measure of how different populations are from each other genetically; can inform population geneticists about levels of inbreeding within a population or about the historic relationships between populations or species
chordates
members of a diverse phylum of animals that includes the vertebrates, lancelets, and tunicates; characteristics include notochord, pharyngeal gill slits, and post-anal tail
Reverend John Henslow
mentor of Charles Darwin; botanist; helped arrange Darwin's position on the HMS Beagle
Robert Fitzroy
mentor to Charles Darwin; meteorologist; captain of the HMS Beagle; fairly unstable depressive mental health
Robert Grant
mentor to Charles Darwin; studied invertebrate biology; advocated idea of unity of animal body plans; influenced ny Erasmus Darwin and Jean-Baptiste Lamarck
Murchison meteorite
meteorite that broke up in Australia in 1969 that demonstrated the same components in the same proportions as Miller-Urey, with several amino acids and with similar oily organic goo like used in Miller's apparatus; may have enriched the "prebiotic soup" that was present early in Earth's history
molecular clock
method used to determine time based on base-pair substitutions; uses the rates of molecular change to deduce the divergence time between two lineages in a phylogeny
Which of the following statements is correct? microRNAs bind DNA and block transcription microRNAs bind mRNA and block translation microRNAs bind ribosomal RNA and block translation all of the above
microRNAs binding mRNA and block translation
? occurs within a species and ? occurs above the species level.
microevolution; macroevolution
prokaryotes
microorganisms lacking a cell nucleus or any other membrane-bound organelles; comprise two distinct evolutionary groups, Bacteria and Archaea
jaw bones quadrate, articular, and angular of earlier chordates correspond to....
middle ear bones incus, malleus, and tympanic ring of later chordates (mammals) correspond to....
biomarkers
molecular evidence of life in the fossil record; can include fragments of DNA, molecules such as lipids, or specific isotopic ratios (ex. presence of okenane reveals purple sulfur bacteria 1.64 bya)
hormones
molecular signals that flow from cells in one part of the body to cells in other parts of the body; act directly or indirectly to alter expression of target genes
plasmids
molecules of DNA, found most often in bacteria, that can replicate independently of chromosomal DNA
Fossils allow us to learn about extinct species
morphology behavior-how animals mated, reproduced, and obtained food. development -fossils left behind of organisms at different ages
The placement of whales within the artiodactyls is supported by:
morphology of limb bones (e.g. the astragalus) in extinct whales DNA evidence
When you use a field guide to identify a species by its appearance, you are applying the _____ concept. morphospecies biological species ecological species evolutionary species
morphospecies
Dispersal explanation of biogeographical patterns
movement of populations from one region to another with limited return exchange
relationship btwn mutation and natural selection?
mutation creates diversity, natural selection acts on that diversity
gene duplication
mutation type that is very useful for creating novel abilities because it frees genes from purifying selection during mutation
somatic mutations
mutations that affect cells in the body ("soma") of an organism; these mutations affect all the daughter cells produced by the affected cell and can affect the phenotype of the individual; not passed down to offspring in animals but can be sometimes during vegetative reproduction
Female iguanas from the Galapagos exhibit mate choice—they prefer larger males. In contrast, the graph below (with data from two islands, Santa Fé and Genovesa) demonstrates that ___?___ favors males of intermediate size.
natural selection
what is the underlying process that drives biological evolution
natural selection
reinforcement
natural selection favors (increases) prezygotic isolation mechanisms that prevent the formation of hybrids with reduced fitness
evolutionary theory of aging
natural selection has not eliminated many harmful conditions and nonadaptive characteristics in older adults ex. opossum example
contrast evolution by natural selection and genetic drift
natural selection is non random and adaptive genetic drift is random and non adaptive
lively and dybdahl studied....
negative frequency-dependent selection; rare clones became common in the next generation
internal nodes
nodes that occur within a phylogeny and represent ancestral populations or species
a substitution that changes one of the first two bases in a codon...
nonsynonomus mutation; change the resulting amino acis
David Hume
notable opponent of natural theology; objected to the watch example by claiming it was a weak analogy; there was no empirical evidence for a creator; and that even if natural theology did show the need for a creator, that creator needn't be the God of the Bible
William Paley
notable proponent for the idea of natural theology by using the teleological argument (the watch on the heath example)
G-value paradox
observation that despite large differences in organismal complexity, multicellular eukaryotes tend to have very similar numbers of protein coding genes (or at least not correlated)
antagonistic pleiotropy
occurs when a mutation with beneficial effects for one trait also causes detrimental effects on other traits
viral reassortment
occurs when genetic material from different strains gets mixed into new combinations within a single individual; allows flu strains to infect new hosts (ex. from infecting birds to infecting humans)
parental conflict
occurs when parents have an evolutionary conflict of interest over the optimal strategy for parental care
epistasis
occurs when the effects of an allele at one genetic locus are modified by alleles at one or more other loci
Deep Time
old earth theory; the idea that our planet's history stretches back over a period of time so long that it is difficult for the human mind to imagine.
3.7 bya
oldest evidence of life dates back to this time; carbon contained in rocks with specific isotopic signatures; CONTROVERSIAL
428 mya
oldest fossil of fully terrestrial animal found from this time
2.1 bya
oldest fossils of multicellular life date back to this time
370 mya
oldest fossils of tetrapods found from this time
200,000 years ago
oldest human (H. sapiens) fossils are found at this time
3.45 bya
oldest stromatolite (bacteria) fossils date to this time
475 mya
oldest terrestrial plant fossils found from this time, followed by fungi and large forest ecosystems
Bacteria
one of the two prokaryotic domains of life; includes organisms such as E.coli and other familiar microbes
Archaea
one of the two prokaryotic domains of life; superficially resembles the other prokaryotic domain, but they are distinguished by a number of unique biochemical features
Richard Owen
opponent of Darwin; coined the term "dinosauria;" egotist and plagiarist
Fleeming Jenkin
opponent of Darwin; engineer; swamping argument of blending inheritance vs. natural selection (he believed that blending inheritance, the more accepted notion of the time, was contradictory of nat. selection)
St. George Jackson Mivart
opponent of Darwin; originally Huxley's protégé but reconsidered his position of natural selection
Lord Kelvin aka William Thomson
opponent of Darwin; used concept of heat conduction to estimate the age of the Earth
plutonism vs. neptunism
opposing idea that the earth's current terrain was created either through means of volcanic catastrophism or through means of oceanic catastrophism
nested hierarchy
ordering of species into a series of increasingly more inclusive clades according to the taxonomic distribution of synapomorphies
protostomes
organism type with digestive tract above nerve cord
deuterostomes
organism type with digestive tract below nerve cord
Tetrapods include:
organisms descended from ancestors with four limbs birds whales
The Edicaran fauna includes:
organisms that are not clearly related to any currently existing lineages
Turnover is...?
originations plus extinctions
Sympatric speciation requires...?
overlapping distributions (check?)
Oparin-Haldane hypothesis
oxidizing environment rich in CO2 and molecular nitrogen favors formation of aldehydes, but formation of amino acids becomes problematic; in this theory, first, biological building blocks formed from inorganic material, then building blocks polymerized into biological macromolecules, and finally macromolecules could form all other biological structures; abiogenesis theory
extrinsic postzygotic isolation is most likely when
parental populations are adapted to divergent environments
Early Cambrian era
period of paleozoic era between 542 mya --> 511 mya (chordates first appear here at 515 mya)
Aristotle
person sometimes cited as the original animal biologist, anatomist, etc; coined the Scala Naturae (with plants at the bottom)
Mary Anning
person who discovered fossils of several species of extinct marine reptiles, proving that extinction was a real thing that had happened
Georges Cuvier
person who largely developed paleontology, the study of fossils; advocated catastrophism; said that because fossils resemble but are not exactly the same as modern species, many past species are extinct
Jean-Baptiste Lamarck
person who proposed that... -complex species descended from simple organisms -simple organisms continually generated spontaneously -through selective use or disuse of organs, organisms could acquire or lose certain traits which are then passed on to their children and future generations, eventually changing the species (adaptation occurs through inheritance of acquired changes)
Georges-Louis Leclerc, Comte de Buffon
person who suggested that the Earth was probably not as young as the Bible would predict; it was likely much older; this man wanted to apply the laws of physics to understand the formation of the Earth and how life transformed as environment changed
Francisco Redi
person who used meat experiment with maggots to begin showing spontaneous generation wasn't true.
Charles Lyell
person who wrote "Principles of Geology" which emphasized uniformitarianism, deep time, and plutonism
genetic drift
phenomenon that might permit a population to traverse a fitness valley (in an adaptive landscape), moving from one fitness peak (local optimum) to another fitness peak (global optimum)
polyphenitic traits are an exampke of
phenotypic plasticity
The results from studies of __?__ bolster hypotheses about sexual asymmetries and sexual selection because the data demonstrate that the hypothesis is gender-neutral.
pipefish
mutation types (7)
point mutation, insertion, deletion, gene duplication, inversion, chromosome fusion, genome duplication
nodes
points in phylogeny where a lineage splits (a speciation event or other branching event, such as the formation of subspecies)
Sperm competition is common among higher vertebrates where selection favors males with large testes. In these situations, the female generally exhibits...?
polyandry
The Trivers-Willard hypothesis states that the mothers alter sex ration depending on condition. There will be more females when the mother is in _____ condition and more males when the mother is in____ condition.
poor, good
Hardy-Weinberg equilibrium
population frequencies do not changes if: -population is infinitely large -genotypes do not differ in fitness -there is no mutation -mating is random (random with respect to alleles at a particular locus) -there is no migration
Hardy winberg 5 assumptions
population is infinitely large genotypes do not differ in fitness no mutation random mating no migration
When taxonomists recognize subspecies, they are identifying: populations that are reproductively isolated from one another. populations with restricted enough gene flow to develop some population-specific traits, but that can still interbreed with members of other such populations. populations that will inevitably become separate species as reproductive isolation is nearly complete. populations with extremely restricted gene flow due to allopatric isolation. None of the other answer options is correct.
populations with restricted enough gene flow to develop some population-specific traits, but that can still interbreed with members of other such populations.
Comparative gene sequence data for a transcription factor with homologs in chimp and human are shown to have the following values in the relevant comparisons: dN = 0.242% (chimp:human), dS = 1.02% (chimp:human), pN = 0.169% (human:human) and pS = 0.47% (human:human). These data indicate that the transcription factor is experiencing __?__.
positive selection in humans
You observe two groups of freshwater fish that spawn at the same time of the year and in the same pond. After females lay their eggs on the pond bottom, males of both species attempt to fertilize them. After some investigation you realize that sperm from both species fertilize the eggs, but embryonic development stops shortly after fertilization when the eggs are fertilized by one species of males, but not by the other. This is an example of ______- zygotic reproductive isolation between the two species.
post-zygotic
you are studying a speciation in crickets
postmating-prezygotic
If two individuals from different species attempt to mate but fertilization fails to occur, this is likely the result of _____. However, if such a mating produces a zygote that fails to form a viable embryo, this is likely the result of _____.
pre-zygotic factors; post-zygotic factors
Biochemical recognition systems within the stigma of a flowering plant prevent the pollen from a different species from developing a pollen tube and fertilizing its eggs. This is an example of what kind of reproductive isolation? pre-zygotic, behavioral isolation pre-zygotic, temporal separation pre-zygotic, lock and key post-zygotic, temporal separation post-zygotic, ecological separation
pre-zygotic, lock and key
Two species of frog mate in the same pond. One breeds in early summer and one in late summer. This is an example of what kind of reproductive isolation? pre-zygotic, behavioral isolation pre-zygotic, temporal separation pre-zygotic, ecological separation post-zygotic, temporal separation post-zygotic, ecological separation
pre-zygotic, temporal separation
Reinforcement refers to the development of _____-zygotic factors and is typically more rapid in species living in _____.
pre-zygotic; sympatry
Which of the following would provide evidence for reinforcement
premating isolation between the two species is higher in areas where they are sympatric vs areas where they are allopatric; postzygotic isolation is strong in all crosses
Reinforcement
process by which diverging populations undergo natural selection in favor of traits that enhance pre-zygotic isolation, thereby preventing the production of less fit hybrid offspring
convergent evolution
process by which unrelated organisms independently evolve similarities when adapting to similar environments
adaptive radiation
process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches.
postzygotic barriers
production of hybrids is this type of reproductive barrier
John Perry
professor of engineering who had at one time served as Kelvin's assistant, was able to reconcile measurements of the geothermal gradient with the Earth being billions of years old by considering the planet to have a convecting, fluid mantle overlain by a relatively thin lid of solid rock. Calculations using Perry's model with a 50-kilometer-thick lid, along with modern estimates for the thermal diffusivity and freezing point of mantle rock, show that the range of estimates for the mean geothermal gradient (brown band on graph) is compatible with ages as great as 2 billion or 3 billion years (green line).
define haritability
proportions of total phenotypic variance that is attributed to genetic variation among individuals
most chemical reactions in the cells are preformed by
protein
opsin
protein associated with photosensitivity; very old, even found in prokaryotes and algae -animal type arose thru gene duplication -these link vertebrates to organisms living 650 million years ago
Promiscuous proteins
proteins capable of carrying out more than one function, such as catalyzing reactions of different substrates
repressors
proteins that bind to a sequence of DNA or RNA and inhibit the expression of one or more genes
transcription factors
proteins that bind to specific DNA sequences and act, in essence, like a light switch by turning all the sequences on or off simultaneously
crystallins
proteins usually associated with eye that arose from a heat-shock protein; arose by co-option/exaptation
A __?__ is termed a "transition."
pyrimidine to pyrimidine substitution
operational sex ratio
ratio of males to females capable of reproducing at a given time; reproduction of females leads to this being male-biased
genetic drift
reduces genetic variation and can lead to divergent populations
taxa (taxon)
refer to groups of organisms that a specific scientist judges to be cohesive units, such as species or orders
outgroup
reference used to infer what is ancestral and what is derived among the Ingroup.
bitrochleated
referring to something (usually bone) that has two articular points
lineage
refers to a chain of ancestors and their descendants; may be the successive generations of organisms in a single population, the members of an entire species during an interval of geological time, or a group of related species descending from a common ancestor
cryptic female choice
refers to a form of sexual selection that arises after mating, when females store and separate sperm from different males and thus bias which sperm they use to fertilize their eggs
gene control region
refers to an upstream section of DNA that includes the promoter region as well as other regulatory sequences that influence the transcription of DNA
phenotypic plasticity
refers to changes in the phenotype produced by a single genotype in different environments; tailors the organism to the environment
sexual selection
refers to differential reproductive success from the competition for fertilization, which can occur through competition among individuals of the same sex or through attraction of the opposite sex
allele
refers to one of any number of alternative forms of the DNA sequence of the same locus
base
refers to one of four nitrogen-containing molecules in DNA: adenine, guanine, cytosine, thymine (+ uracil in RNA)
gene tree
refers to the branched genealogical lineage of homologous alleles that traces their evolution back to an ancestral allele
turnover
refers to the disappearance (extinction) of some species and their replacement by others (origination) in studies of macroevolution; corresponds to the number of species eliminated and replaced per unit time
ploidy
refers to the number of copies of unique chromosomes in a cell (n). normal human somatic cells are diploid (2n); they have two copies of 23 chromosomes
population structure
refers to the occurrence of populations that are subdivided by geography, behavior, or other influences that prevent individuals from mixing completely; population subdivision leads to deviations from Hardy-Weinberg predictions.
reaction norm
refers to the pattern of phenotypic expression of a single genotype across a range of environments; depict how development maps the genotype into the phenotype as a function of the environment.
extinction
refers to the permanent loss of a species; it is marked by the death or failure of the last individual
genetic linkage
refers to the physical proximity of alleles at different loci. Genetic loci that are physically close to one another on the same chromosome are less likely to be separated by recombination during meiosis. Thus they are said to be in __________.
inbreeding coefficient (F)
refers to the probability that the two alleles at any locus in an individual will be identical because of common descent
QTL mapping identifies
regions of the genome associated with phenotypic variation & this is the first step towards elucidating genes responsible for phenotypic evolution
though simple mutations (ex. point) occur more often, the influence of the less common ones (ex. large duplications) is greater
relationship between mutation complexity and influence on phenotype
timing of reproduction barrier
reproductive barrier due to different spawning seasons for organisms
gametic incompatibility
reproductive barrier where sperm or pollen from one species fails to penetrate and fertilize the egg of another species
define fitness
reproductive success of an individual with aparticular phenotype
Darwin's pigeon research
research that used pigeon breeding to explain artificial selection to the readers of On the Origin of Species (based on the different varieties of domesticated pigeons)
Darwin's barnacles research
research that was known as Darwin's "rite of passage;" provided examples for his studies of transmutation
gene
segment of DNA whose nucleotides sequences code for proteins or RNA, or regulate the expression of other genes
stabilizing selection
selection that results when agents of selection act in opposing directions
artificial (cumulative) selection
selective breeding of plants and animals to promote the occurrence of desirable traits in offspring; persistent long-term breeding
gene flow can be reduced by...
separation of populations can, in time, be reduced by...
trans-acting elements
sequences of DNA that are located away from the focal gene (e.g., on another chromosome); these stretches of DNA generally code for a protein, microRNA, or other diffusible molecule that then influences expression of the focal gene
ecological situations that require rapid evolution are likely to favor...
sex is likely to be favored in ecological situations that requires ______ evolution
The drawing and data presented below illustrate __?__ in flowering plants.
sexual asymmetry
The relationship between phallus length and convolution of oviduct anatomy in ducks (see below) is regarded as an example of...?
sexual conflict through antagonistic co-evolution
Which of the following is not considered a potential benefit of sexual reproduction:
sexuals produce twice as many offspring as asexuals
enhancers
short sequences of DNA within the gene control region where activator proteins bind to initiate gene expression
Which of the following allowed scientists to determine whether early hominins were browsers and grazers or had diets comprised of either group?
shrubs and grasses differ in the type of photosynthesis they perform shrubs and grasses have different carbon isotopic signatures
Homologous trait
similar because of inheritance from a common ancestor
artificial selection
similar to natural selection, except that it results from human activity; when breeders nonrandomly choose individuals with economically favorable traits to use as breeding stock, they impose strong _____ on those traits
homologous trait
similar trait arising by common descent
analogous trait
similar trait not arising from common descent; similar due to convergent evolution
isotopic analysis of fossil teeth
since terrestrial animals drink freshwater (with lower O18/O16 ratio), and marine animals drink saltwater (with higher O18/O16 ratio), we can use ______ technique to distinguish between land animals and sea animals (and document entire transition!)
clades
single "branches" in the tree of life; each represents an organism and all of its descendants; a monophyletic group
define phenotypic plasticity
single genotype produces different phenotypes depending on the environment
Lagerstatten
sites with an abundant supply of unusually well-preserved fossils, often including soft tissues, from the same period of time
describe the isotopes
slatwater has higher oxygen isotopes and sea animals can de seen through the oxygen in bones
steep slope of isochron graph
slope of isochron graph that indicates older material
flat slope on isochron graph
slope of isochron graph that indicates younger material
heritability estimate
slope of regression for relationship between child and parent
Speciation due to genetic drift is typically a very _____ process.
slow
rate of evolution in different types of DNA (ordered slow to fast)
slowest: non-synonymous sites, synonymous sites, introns, pseudogenes: fastest
as mammals entered the water, what factor put some of the species at risk?
small populations
way to identify species: phylogenetic species concept
smallest possible group descending from a common ancestor and recognizable by unique, derived traits
way to identify species: biological species concept
species are groups of interbreeding populations that are reproductively isolated from other such groups
Phylogenetic analysis of phylogenetic bush
start: one node = ingroup -polarize characters into apomorphies & plesiomorphies
neutral theory of evolution
states that most genetic variation is due to the accumulation of neutral mutations that have attained high frequencies in a population via genetic drift (Kimura)
Bayesian method
statistical tool to determine relationships Looks at probability that a tree is correct given a specific model of molecular evolution (and a particular data set)
Maximum likelihood
statistical tool to determine relationships finds the most likely tree given a specific model of molecular evolution ***
cis-acting elements
stretches of DNA located near a gene - either immediately upstream (adjacent to the promoter region), downstream, or inside an intron - that influence the expression of that gene; these regions often code for binding sites for one or more transposable factors
The earliest generally accepted fossils of living organisms are:
stromatolites
the earlies fossils are
stromatolites
population genetics
study of distribution of alleles in populations and causes of allele frequency changes
biogeography
study of distribution of species across space and time
define quantitative genetics
study of genetic mechanisms of continuous phenotypic traits
paleontology
study of prehistoric life
quantitative genetics
study of the genetic mechanisms of continuous phenotypic traits and their underlying evolutionary mechanisms
ernest rutherford
suggested that kelvin's estimates for the age of the earth were too low because he had not known about radioactive heating
complex adaptations
suites of coexpressed traits that together experience selection for a common (often novel) function
In _____ speciation, there is gene flow between populations that are in the process of diverging into two or more species. In _____ speciation, there is no gene flow between populations that are in the process of diverging into two or more species.
sympatric; allopatric
The shift of some Rhagoletis from hawthorn fruit to apple fruit in the early 1800's is regarded as an example of both ecological speciation and...?
sympatry
Modern day mammals are descended most recently from what group:
synapsids
Imagine that a researcher discovers two new similar species of bats in the same geographic area. Amazingly, one of these species preys upon insects during the day. The other species—as one would expect—is nocturnal and only feeds during the night. These two bat species would be considered:
temporally separated
Baum and Smith and Huelsenbeck
tested Bayes theorem with 90 fair dice and 10 biased dice; found that P(biased) was nearly 2x greater than P(fair) outcome proved that bayesian interference could be used to sharpen probability through prediction of bias
If an organism has four copies of each chromosome, then it is: Please choose the correct answer from the following choices, and then select the submit answer button.
tetraploid versus. haploid/diploid/polyploid
What did Ernst Mayr say about Buffon?
that Buffon was not an evolutionist, yet he was the father of evolutionism
It has been noted that the genome size of some protozoans exceeds that in elephants. This is evidence of __?__.
the C-value paradox
The last epoch of the Cenozoic era was:
the Pleistocene
The graph at the right illustrates...?
the Red Queen effect
cost of size for competition
the _____ that the animal must be to compete for success, the more he must eat to compensate; used for both combat and for securing territory
historical contingency
the actualized trait will require further refinement from original mutation to be useful
Describe the evolution of whale teeth
the ancestors of all modern whales had teeth & produced small patches of baleen. In Mysticetes, baleen completely replaced teeth when the genes for building teeth were disabled.
Evolution occurs when:
the average value or trait in a population changes from one generation to the next
earths life span is based on
the biomarkers in rocks of that age
coelacanths
the closest living (extant) relatives of tetrapods
gene recruitment
the co-option of a particular gene or network for a totally different function as a result of mutation
last universal common ancestor (LUCA)
the common ancestor of all currently extant life, but not necessarily the first living thing
antagonistic pleiotropy
the condition that occurs when a mutation with beneficial effects for one trait also causes detrimental effects on other traits; ex. number of cervical vertebrae deviation from norm
the selection differential for a quantitative trait is ___
the difference between the mean for the trai in the original population and the mean of those individuals that reproduce; means there will be more change in the trait in the next generation
Which of the following statements about venom evolution is accurate?
the earliest venoms evolved before fangs and other parts of the venom delivery system
Anisogamy, as applied to reproductive investment, is best illustrated as...?
the eggs of a female kiwi are large, but the sperm of males are small
RNA polymerase
the enzyme that builds the single-stranded RNA molecule from the DNA template during transcription
sexual conflict
the evolution of phenotypic characteristics that confer a fitness benefit to one sex but a fitness cost to the other; antagonistic evolution ex. poor sad lady ducks
genetic recombination
the exchange of genetic material between paired chromosomes during meiosis; recombination can form new combinations of alleles and is an important source of heritable variation
Vicariance explanation of biogeographical patterns
the formation of geographic barriers to dispersal and gene flow, resulting in the separation of once continuously distributed populations
Leading edge expansion is an example of __?__.
the founder effect
The graph at left illustrates the phenomenon known as ___?___.
the founder effect
gene duplication
the generation of extra copies of a gene in a genome over evolutionary time; mechanism by which genomes can acquire new functions (diversification); extra copy can either lose its use, double the amount of expression, or diverge into a different path (and thus create an exaptation)
natural theology (teleological argument)
the idea that complexity is evident of design; basically the basis for intelligent design
metabolic origin for life
the idea that life started with simple metabolism and then acquired the ability to replicate (support: Krebs cycle reduction reactions occur spontaneously in a reducing environment)
On which point(s) would Charles Darwin and Georges Buffon have likely agreed:
the idea that species change over time
uniformitarianism
the idea that the natural laws observable around us now are also responsible for events in the past; one part of this view, for example, is the idea that the Earth has been shaped by the cumulative action of gradual processes like sediment deposition and erosion
convergent evolution
the independent origin of similar traits in separate evolutionary lineages
An example of an exaptation would be:
the lungs used by basal fish for breathing being used to control buoyancy in derived species with gills
cost of plumage for competition
the more ______ that the animal has to compete for success, the more it has to be maintained, and the more possibilities that predators can also spot it
Which of the following statements is accurate regarding antagonisitic pleitropy
the net fitness effect of an allele experiencing antagonistic pleiotropy may depend on the environment
background extinction
the normal rate of extinction for a taxon or biota
Effective population size may be different from actual population size because __?__.
the numbers of males and females able to reproduce is rarely equal
If two plant species with different numbers of chromosomes interbreed
the offspring might be able to produce asexually
A small population of a species colonizes an island where no member of the species is found. The colonizing population subsequently diverges from the ancestral population and becomes a new species. This is an example of...?
the peripheral isolation mode of allopatric speciation.
Scientists have argued that life likely existed as far back as 3.7 bya. They base this claim on:
the presence of biomarkers in rocks of that age
Although the interpretation is controversial, the dramatic fish kill recorded in the fossil record at the Tanis site in the Hell Creek formation of North Dakota (USA) has been linked to the K-Pg (KT) mass extinction due to...?
the presence of microtektites in the gill rakers
gene expression
the process by which information from a gene is transformed into a product
coalescence
the process by which, looking back through time, the genealogy of any pair of homologous alleles merges in a common ancestor
alternative splicing
the process of combining different subsets of exons together, yielding different mRNA transcripts from a single gene
RNA splicing
the process of modifying RNA after transcription but before translation, during which introns are removed and exons are joined together into a contiguous strand; can create multiple proteins from a single gene
vertical gene transfer
the process of receiving genetic material from an ancestor
transcription
the process that takes place when RNA polymerase reads a coding sequence of DNA and produces a complementary strand of RNA called messenger RNA (mRNA)
translation
the process that takes place when a strand of mRNA is decoded by a ribosome to produce a strand of amino acids that can then be folded to form a protein
heritability is
the proportion of phenotypic variance due to genetic differences
independent assortment
the random mixing of maternal and paternal copies of each chromosome during meiosis, resulting in the production of genetically unique gametes; ensures novel combinations
extrinsic mortality
the rate at which external events (predation, starvation) lead to death in a population
intrinsic mortality
the rate at which internal events (aging, disease, mutations) lead to death in a population
the synonymous sub rate is often assumed to represent
the rate of evolution by genetic drift
Absolute methods for dating rocks
the rates of radioactive decay
Georges Curvier's biggest contribution was:
the realization that extinctions were commonplace throughout history
the difference in beak size between offspring
the response to selection
The wide variety of finches Darwin observed in the Galápagos was thought-provoking because they appeared to have descended from _____ population. Today we regard this as an example of _____. Please choose the correct answer from the following choices, and then select the submit answer button.
the same; adaptive radiation
taxonomy
the science of describing, naming, and classifying species of living or fossil organisms
in 1977 before the drought
the selection differentail
One important feature that links extinct organisms such as Pakicetus and Indohyus to cetaceans is:
the shape of a bone in the middle ear
genetic polymorphism
the simultaneous occurrence of two or more variants of a particular DNA sequence in a population that produce two or more discrete phenotypes
relative fitness is caused by
the strength of selection
nucleotides
the structural units that link together to form DNA (and RNA)
amino acids
the structural units that, among other functions, link together to form proteins
stratigraphy
the study of layering in rock
population genetics
the study of the distribution of alleles within populations and the mechanisms that can cause allele frequencies to change over time
tips
the terminal ends of an evolutionary tree, representing species, molecules, or populations being compared
Panspermia
the theory that life on the earth originated passively from extra-terrestrial sources; either from microorganisms or from the chemical precursors of life present in outer space
Eukarya
the third domain of life; characterized by traits that include membrane-enclosed cell nuclei and mitochondria; includes animals, plants, fungi, and protists
optimality criterion
the tree choice with the most parsimony; objective measure used to decide how good the tree is
benefits of applying physics to paleontology
their technologies can be applied to fossils -ex. Scanning electron microscopy provides evidence of cellular structure. Structure of melanosomes suggests striking plumage -CAT scans help determine function of hadrosaur crest. Crest connected to nasal cavity (Sound generated by blowing air). Due to ear shape it was inferred that their ears were tuned to this frequency.
Leigh Van Valen
theorist behind the Red Queen Effect
neutral theory of evolution
theory by Kimura which states that most genetic variation is due to the accumulation of neutral mutations that have attained high frequencies in a population due to GENETIC DRIFT -Neutral substitutions should accrue in a clock-like fashion -Different types of DNA should evolve at different rates
game theory
theory that defines a framework of contests, strategies, and analytics into which Darwinian competition can be modeled; has helped to explain the basis of altruistic behaviors in Darwinian evolution.
Panspermia Hypothesis
theory that life was seeded on earth and other planets from outer space, a meteor or asteroid fell to earth and gave us new materials to work with like amino acids
grandmother hypothesis of menopause
theory that loss of fertility associated with shift in investment to grandchildren
mother hypothesis of menopause
theory that the risk of reproduction at older age selects for reduced fertility at those older ages; investment in current offspring
Genome alignments
these allowed scientists to discover new genes important for physiology and medicine
rubisco, citrate metabolism, defensin, or certain snake venoms
these are examples of neofunctionalization; how gene duplication and co-option of a promiscuous protein caused novel function
Costly display traits
these are often reliable indicators of male quality
gradients
these are very important to consider in theories about the acquisition of complex life processes
isolated populations
these become more genetically distinct due to their geography
homologous characteristics
these characteristics are similar in two or more species because they are inherited from a common ancestor
Bacterial symbionts
these often experience a reduction in genome size
small populations
these put certain species (like cetaceans) at risk for extinction because genetic drift can so ardently affect them
answer to Darwin's finch evolution
these species descended from a single species and then diversified, and they are genetically most related to a south american bird type
pedigrees vs. phylogenetic trees
these two types of diagrams are very similar, but _____ can be used to also reflect horizontal gene transfer, whereas ______ are meant to track more direct ancestral lines
Traits like the bright colors of the male collared lizard are considered honest indicators of male genetic quality because...?
they are costly for the males to produce
why are mutations neccessary
they are the ultimate source of genetic variance
Territorial male bluegill sunfish provide costly parental care by guarding eggs and fry until they are larger. Other males, called sneakers, adopt another st
they benifit from abandoning eggs that might not be theirs
The discovery of ribozymes was important because:
they can carry information they can catalyze reactions
Eukaryotes differ from archaea and bacteria because
they contain a nucleus they contain mitochondria
Which of the following would explain why viruses such as influenza evolve so rapidly:
they have a high mutation rate they have a high replication rate they can undergo viral reassortment
why is treatment of viruses difficult
they have a high replication rate
which of the following is true of QLT
they rely on recombination to create a wide ranfe of phenotypic variation
Taxonomic units only legitimate if
they represent a clade
postponing senescence
this can be done through calorie restriction (to switch on repair genes) or through trade-offs (tho this can cause lower fitness)
creation of refuges
this can slow the evolution of resistance (and now are required by law, for ex, with crops)
horizontal gene transfer
this complicates classification because it can choose to defy species barriers
speed of evolution
this depends on the amount of genetic variation and strength of selection
C12
this isotope of carbon will be found more often in organic matter compared to non-organic sources of carbon
uncertain paternity
this may explain why male parental care is rare
sociality
this promotes the evolution of larger brains by the necessity to form lasting alliances, compete for mates, and carry out complex communication
In Bittacus, the male offers the female "nuptial prey". The "nuptial prey" represents a resource for the female and provides a fitness benefit for the male __?___.
through the "purchase" of more time for the male to effectively deliver sperm
pre-mating barriers
timing of reproduction and pollinator isolation are this type of reproductive barriers
methodological naturalism
to study nature (i.e. the material world) as a part of a scientific enterprise, one can only make use of methods taht are open to human senses (sight, smell, taste, hearing, touch)
novel traits
traits that arise de novo (i.e., not inherited from an ancestor) within a lineage and have no obvious counterparts (homologs) in related lineages -can arise when existing genes are expressed in a new developmental context
Adaptation
traits that have evolved by natural selection
the presence of mRNA transcript of a gene in a cell means
transcription of the gene has occured
In co-speciation, two groups of organisms speciate in response to each other and in a coordinated manner.
true
if speciation were a result of genetic drift, then you would expect to see a bell-shaped distribution of most phenotypic characteristics
true
Why do some think darwin was a plagiarist?
two previous publication hint to natural selection Edward Blyth & patrick matthew & of course alfred russel wallace
frequency-dependent selection
type of selection where... -Production of each sex is favored when rare -Rare sex has more mating opportunities
mobile genetic elements
types of DNA that can move around in the genome; common examples include transposons ("jumping genes") and plasmids these help determine genome size
Josiah Wedgwood II
uncle to Charles Darwin; hunting companion and future father-in-law; endorsed Charles's Beagle expedition to Robert Darwin
fixed probability of decay
unstable isotopes have this feature which makes them useful for radiometric dating (high prob = rapid decay, low prob = slow decay)
Darwin recognized that __?__ existed in natural populations, but he didn't know its' source and referred to its consequences as a "condition of life."
variation
Evolutionary biologists study
variation in the expression of phenotypic traits
tetrapods
vertebrates with four limbs (or descended from them, like snakes); include mammals, birds, reptiles, and amphibians
aposmatism
warning coloration; favored only in areas where coral snakes co-occurq
steno
was one of the first to recognize that fossils wer the reamins of once living creatures and recognized the basic principles of stratigraphy
Nicolaus Steno:
was one of the first to recognize that fossils were the remains of once living organisms recognized that basic principles of stratigraphy
isotopic analysis of fossil teeth and fossil analysis of hindlimb loss/reduction
ways that we can document the transition of tetrapod animals from land to water
armaments
weaponry used to outcompete other individuals
50 mya
whales, bats, and primates emerge at this time
sexual monogamy
when one male pairs with one female and partners mate with each other exclusively
social monogamy
when one male pairs with one female and rears young together, but partner pair but may cheat
altruistic sperm
when sperm of the same male physically join together to swim faster, so only one sperm can actually fertilize the egg (maximizing indirect fitness); can discriminate their kin amongst others
Emma Wedgwood Darwin
wife of Charles Darwin (also his first cousin); devoted spouse, clerical and editorial assistant, nurse
the watch on the heath
william paley's argument for natural theology (complexity = design = must have a creator)
On the Origin of Species by Means of Natural Selection (1859) Charles Darwin
•Completed his 'Abstract' on Selection in less than 13 months •Intended to publish fully cited volumes later (but never did) -Descent with Modification -Struggle for Existence through Natural Selection
Different Influences on Phenotypic Variation
•Genotype •Additivity •Dominance •Epistasis •Environment
Stable vs unstable isotopes and their decay
•Many elements have stable and unstable isotopes •Unstable isotopes have a fixed probability of decay •Isotopes with high decay probabilities decay rapidly; isotopes with low decay probabilities decay slowly
What is the best evidence for panspermia
•Murchison meteorite--contained amino acids •LHB
Technology and fossils
•Technology allows scientists to gain insights into the natural history, behavior, and appearance of extinct organisms
When did transition to multicellular life begin?
•The transition to multicellular life began at least 2.1 billion years ago •Multicellularity evolved independently in a number of lineages
neutral theory by Kimara emphasizes
the much greater role of mutation pressure and random drift at the molecular level
a mutation that has risen to a high frequency through selective sweep shows a characteristic pattern of linkage with surrounding loci
the mutation experiences a small amount of recombination
viral reassortment
when genetics of two viruses mix, allowing progeny to acquire new characteristics & infect new hosts; can result in a strain that is deadly & highly infectious
The transition from single-celled to multi-celled organisms:
happened on multiple occasions
Origins of life and Francis Crick
he believed in directed panspermia (Earth was intentionally seeded by an intelligent extraterrestrial agent)
Darwin invested seven years in a survey of fossil and extant barnacles. He did this because
he wanted to study the diversity of a group of organisms which would become part of his larger study of natural selection
characters
heritable aspects of organisms that can be compared across taxa
Which of the following would increase the rate of evolution by natural selection
higher heritability
what do charles and jean agree on
species give rise to new species
narrow sense heritability reflects
specific, additive components of genetic variation to offspring
larger testes evolution
sperm competition drives this evolution in males
The earliest animal fossils appear similar to modern day:
sponges
disadvantages of sex
twofold cost, search cost, reduced relatedness, risk of sexually transmitted diseases
Carbon-14 dating
type of radiometric dating that is only really useful for about 6000 years back
what was found 2.5 bya?
unambiguous cyanobacterial fossils
Darwin early childhood
-Born into Darwin & Wedgwood wealth -Lost mother at an early age (raised by sisters) -Boarding School until age 16
Joseph Hooker
-Botanist and scientific colleague of Charles Darwin
The tree of life
-the phylogenetic tree that includes all organisms -how biologists use phylogeny to reconstruct the deep past
Phylogeny
A visual representation of the evolutionary history of populations, genes, or species; the study of the patterns of evolution
alkaline vents
Deep sea vents that release water that has a high pH, has a high mineral content and is warm rather than hot; an environment that may have been suitable for the origin of life.
Why can the fossil record never be complete?
most organisms do not fossilize because they are eaten before fossilization can occur
gene flow
movement of alleles from one population to another
The molecular clock used to date the emergence of the 2009 H1N1 strain would be inaccurate if:
mutations arose at different rates in different lineages
Radiometric dating estimates the earth to be
4.56 billion years old
? is characterized by scenarios where alpha greatly exceeds omega.
An adaptive radiation
the three evolutionary faunas
Cambrian, Paleozoic, Modern
Extrinsic mortality
Death rate due to environmental factors
Hadean
Earth's first eon
Ventral
Front or toward the front
Exaptation population
Gene is co-opted for a new use or function
Archosaurs arose during the:
Mesozoic
Disassortative Mating
Opposites attract
Darwin allies
Thomas Huxley asa gray joseph hooker charles lyell
F(st)
a measure of genetic distance between subpopulations
Plesiomorphy
ancestral trait
16. Which type of equilibrium is modeled in the following figure? a. Stable b. Unstable c. Mixed d. Neutral e. Complex
c. Mixed
define epistasis
interaction between alleles
branches
lineages evolving through time that connect successive speciation or other branching events
Synapomorphy
shared derived trait
Darwin family
•Both Families were vocal abolitionists -Social Conscience -Liberal
