BIO 171 Exam 4

How does unnecessary antibiotic prescription and use contribute to antibiotic resistance?

Bacteria adapt to the frequent presence of antibiotics and mutate resistances to them

How does balancing selection differ from stabilizing selection?

Balancing selection maintains genetic diversity in a population while stabilizing selection decreases genetic variation

Describe how antibiotic resistance results from directional natural selection and not stabilizing or disruptive natural selection. Why do we attribute antibiotic resistance to natural rather than artificial selection?

Because directional selection shifts the average value of a trait, it describes the shift of the population towards being entirely antibiotic resistance vs not. We do not select for the resistance trait intentionally

Why is the cessation of gene flow required to start speciation? How do you know that speciation has occurred? How can you transfer information about speciation events to a phylogenetic tree?

Because gene flow occurs through the mating and reproduction between species. The two populations will no longer be able to interbreed. These events can be indicated by the nodes on a tree

If evolution selects for fitness (i.e. offspring), why do so many male elephant seals have no offspring in their lifetimes? Why don't we see this same pattern in the female elephant seals?

Because the males compete with each other to see who will have more females to mate with. Females do not compete with the same intensity and they are choosier about their mates

Why is the fact that most human traits are polygenic and influenced by the environment relevant to our understanding of human evolution and race?

Because traits are inherited independently, there is no reason to think that physical traits for skin color or hair texture have anything to do with any other trait

In what situations might organisms that are small and/or slow have higher fitness than one that is larger or faster?

Birds in certain environments will have a higher fitness when small (beak size, greater speed)

What are some differences between trace fossils and body fossils? What are some examples of each of these two types of fossils?

Body fossils give us direct evidence; trace fossils give us indirect evidence. A body fossil would be an insect cast in amber, petrified wood, or a skeletal fossil of species. A trace fossil would be footprints or poop

evolution

Changes in allele frequency in a population over time

parsimony

Choosing the simplest hypothesis to account for a given set of observations. In phylogenetic reconstruction, opting for the tree requiring the fewest evolutionary steps

homologous

Describes characters that are similar in different species because of descent from a common ancestor; the noun form is homology

analogous

Describes similar characters that evolved independently in different groups as a result of similar selection pressures; the noun form is analogy

Genetic variation

Differences in genotype among individuals in a population

Why are different radioisotopes used to date fossils of differing ages?

Different isotopes take different amounts of time to decay (different half-lives)

Which domain is Plasmodium in?

Eukarya

If you measure allele frequencies of a gene (with two alleles) in a population at two time points, and you see that the frequency of the dominant allele has decreased and the frequency of the recessive allele has increased, what can you conclude?

Evolution of that gene has occurred

What does that data about zebra finch mate choice suggest about sexual selection in this species? How can this lead to runaway sexual selection?

Female mate choice is heavily influenced by the appearance of the males (9/10 attracted to more vibrant orange). The preference of the female will lead to a shift in the preferred phenotype, which could eventually lead to more extreme appearance in the species

What are the white cliffs of Dover made from?

Fossils

What evidence do we have that multiple species in Tribe Hominini were alive at the same time?

Fossils showed that 2 mya there were 3 different genera of hominins coexisting

How can you distinguish between genetic drift and gene flow? In both cases, why might the terms be better named as "allele drift" and "allele flow"?

Gene flow is movement between populations, while genetic drift is a change in allele frequency in the same population

Deleterious mutation

Genetic changes that are harmful to an organism

Neutral mutation

Genetic changes that have no effect or negligible effects on the organism, or whose effects are not associated with differences in survival or reproduction

Advantageous mutation

Genetic changes that improve their carriers' chances of survival or reproduction

In Wright's fruit fly bristle experiment, what would you expect to happen if the experiment went on for a thousand generations?

Genetic drift until full allele fixation/loss

How would the results differ if Wright started each vial with only 1 male and 1 female? What about if Wright started with 100 males and 100 females in each vial?

Genetic drift would hav a much larger effect on the smaller population of two flies than on the larger population of 200 flies

Trace the path of H. sapiens' colonization of the globe. What data support the Out of Africa hypothesis?

H sapiens evolved in Africa and spread to the other continents and formed different colonies. mtDNA data and data from y chromosomes support this idea

How did the founder effect impact the level of genetic diversity in different human populations?

H sapiens left Africa and spread throughout the globe, demonstrating gene flow and increasing the genetic diversity

What is heterozygote advantage? Do people with the AS genotype always have the highest fitness, all across the globe? Why or why not?

Heterozygous individuals have a higher fitness than both homozygous genotypes. They only have the highest fitness in areas with high threat of Malaria.

Is the likelihood of a mutation arising to a particular drug low or high compared to the number of TB cells that are circulating in a patient? How does combination therapy help?

High. Taking 4 antibiotics directed at resistance mechanisms helps prevent the development of a large resistant population

How are homologous traits different from analogous traits? How do analogous traits arise?

Homologous traits are similarities from a common ancestor. Analogous traits are similarities between organisms that evolved independently. They arise due to adaptation to similar environments

Neanderthals

In Europe, another human species lived and adapted to life in the cold climates of the last Ice Age.

outgroup

In phylogenetics, a group of organisms used as a point of reference for comparison with the groups of primary interest

How does polygenic inheritance differ from incomplete or codominant patterns of inheritance?

In polygenic inheritance multiple genes are involved to produce cumulative effects. In codominance and incomplete dominance, different alleles of a single gene affect the resulting trait

active TB

Infected, symptomatic and contagious

What information can be used to build a phylogenetic tree?

Informative, homologous characters (traits)

How does evolution select for more than one phenotype in male bluegill fishes? How could a male phenotype that does no parental care be as fit as the parental male that does engage in parental care? How does intersexual selection act in the bluegills?

Intrasexual selection can produce more than one successful strategy, especially for males

Is the tail of a peacock more likely to be a result of inter- or intrasexual selection? How do you know?

Intrasexual. The large elaborate tails are most likely a result of competing for a female's attention

How is it possible that directional natural selection can apply to both discrete and polygenic traits?

It can either shift frequency from one distinct phenotype to another (discrete), or it can shift the distribution of the range of phenotypes (polygenic)

Does genetic drift happen in large populations? Why or why not?

It does happen in large populations because it is always happening, but on a smaller scale

We say that genetic drift is "random". What is the biological meaning of that term?

It does not occur to the same thing/in the same place every time

What does the rpoB gene code for? What types of cells have the mutation in the rpoB gene that results in an RNA polymerase with a different shape? What are the consequences of producing an RNA polymerase with a different shape, for cells in the presence of the antibiotic Rifampin?

It encodes the β subunit of bacterial RNA polymerase and the homologous plastid-encoded RNA polymerase (PEP). Antibiotic-resistant bacterial cells have this mutation. Rifampin binds loosely and transcription by RNA polymerase becomes inefficient

What does an outgroup help you determine about trait mapping on a phylogenetic tree?

It helps us determine which traits are shared derived and which are ancestral

How does gene flow affect the fitness of a recipient population?

It increases the fitness by increasing the genetic variation

How do biologists now define evolution? What are the five mechanisms of evolution?

It is a change in allele frequency in a population over time 1. natural selection 2.sexual selection 3.genetic drift 4.gene flow 5.mutation

What does it mean for alleles to be fixed or lost?

It is fixed if the whole population has to have the allele. It is lost if none of the population has the allele

Why do we describe malaria as vector-borne but not zoonotic?

It is vector-borne because it is passed through the bite of a mosquito, but it is not zoonotic because it can pass from humans to mosquitos and it needs bot hosts to complete its life cycle

What does it mean when we say that two species are reproductively isolated from one another? If species are reproductively isolated, how is it possible for hybrids to form?

It means they cannot interbreed. Sometimes the isolation is not complete and species overlap

How does cycling antibiotics in hospitals help slow the spread of antibiotic resistance?

It reduces the likelihood of bacteria to develop adaptations against the antibiotics due to frequent use. Changing the environment for the bacteria and the mechanisms targeted will hopefully prevent its adaptation

How do you expect the wolf restoration on Isle Royale to affect the genetic diversity of the wolf pack on the island?

It should increase the genetic variation as it is a form of gene flow

Why would Darwin say "the sight of a peacock makes me sick"? Why would peacock have such heavy, large and conspicuous tails?

It's appearance, especially his tail, is not advantageous to its survival. The only reason for the tail is to attract a mate

What are some potential consequences of a future post-antibiotic era?

Its going to get increasingly harder to treat bacterial infections if antibiotic resistance keep persisting. We will see more frequent, longer hospital stays, higher medical costs, and increased mortality

protist

Kingdom composed of eukaryotes that are not classified as plants, animals, or fungi

Why might a physician decide to prescribe antibiotics for an infection that could be viral, rather than avoiding prescribing antibiotics, especially since antibiotic resistance is such a big problem?

Like for ear infections, they often do it just to "be safe" in case it is the rare case it is bacterial

In damselflies, if females showed a preference for males without a sperm scoop, what might happen over time?

Males will evolve to not have the sperm scoop

How is population genetics connected to Mendelian genetics? That is, how does the transmission of alleles from parent to offspring relate to transmission of alleles from the one generation to the next in a population?

Mendel's single cross with gametes produced by parents is much like the gametes produced by all members of a population

What factors can affect genetic variation in natural populations? Where does genetic variation come from? How much genetic variation is there in humans? More or less than that in fruit flies?

Mutation and recombination. Genetic variation comes from historical population sizes. Humans vary by about 0.1% in genomic sequence. It is much greater in flies at about 1%

What causes TB and why is it considered a re-emerging infectious disease? What is the connection between TB and HIV?

Mycobacterium tuberculosis. It is considered re-emerging because many ppl don't take the full course, crowded conditions have fostered the spread, and the bacteria itself is also complicated. Immune-compromised people are more susceptible to TB like those with HIV AIDS.

balancing

Natural selection that acts to maintain two or more alleles of a given gene in a population

derived trait

New feature that had not appeared in common ancestors

Is the opposable thumb a shared derived trait of all the primates? If not, what primate group does have an opposable thumb? Which primates do not have tails?

No it is a shared derived trait of Monkeys. Apes do not have tails

Are races in humans supported by data on genetic variation in humans? In which human populations do we see the largest amount of genetic variation?

No. DNA sequence variation shows no strict groupings of humans by "race". There is the largest amount of genetic variation in African populations

Is inbreeding an evolutionary process? Why or why not?

No. Inbreeding doesn't cause evolution

Do orangutans have earlobes? What does that mean for the taxonomic classification of orangutans?

No. They are in the Family Hominidae but not is Subfamily Homininae

In areas where Eastern and Western Meadowlarks live in sympatry, would you expect to find hybrids? Why or why not?

No. They have different courtship practices (different mating calls) so they would not mate with eachother

Why is the fossil record considered to be incomplete? What do we mean when we say that the fossil record has abundance, temporal, habitat, and taxonomic bias? Given these biases, what kinds of organisms would you imagine are under-represented in the fossil record?

Not every organism or species becomes a fossil (for example, it is hard for soft tissues to fossilize). -habitat bias: better record for aquatic organisms -taxonomic bias: better record for organisms w/ hard parts -temporal bias: better record for more recent organisms -abundance bias: better record for more common organisms. Organisms that are older, rarer, have soft tissue, and live on land are all likely under-represented.

convergent evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments

artificial selection

Selection by humans for breeding of useful traits from the natural variation among different organisms (dog breeding)

positive selection

Selection that increases the frequency of a beneficial allele

How does selection for sexually selected traits differ from traits that are selected for in natural selection?

Sexual selection is for the traits more successful at attracting and obtaining a mate, natural selection is for environmental factors

What occurs at nodes on phylogenetic trees? What happens in between nodes, along the branches?

Speciation event. evolution and mutation

Allopatric speciation

Speciation that occurs due to a physical/geographic separation

Instantaneous speciation

Speciation that occurs in a single generation

Population genetics

Study of allele frequency distribution and change under the influence of evolutionary processes

Homininae

Subfamily of African Apes containing humans, bonobos, chimpanzees and gorillas. Shared derived trait is earlobes

Where in the world is TB most prevalent? Where is multi-drug resistant TB most prevalent? Are these the same or different? Why?

TB, both drug-resistant and not, are most prevalent in Russia and China

What are sister taxa? How could you find sister taxa on a tree?

Taxa that have more in common with each other than with any other taxa. Their MRCA will not be shared with anyone else

Humans are equally related to bonobos and chimps; what does that suggest about the characteristics of the MRCA of humans, chimps and bonobos?

The MRCA of humans, bonobos, and chimps belongs to the Subfamily Homininae

What features distinguish Family Hominidae, Subfamily Homininae, and Tribe Hominini?

The Subfamily Homininae separates from Family Hominidae by having earlobes doesnt include orangutans. Tribe Hominini separates from Subfamily Homininae by being bipedal (only humans and human descendants)

What is the difference between allele and genotype frequencies? Why does it matter that we are considering diploid organisms in calculating genotype or allele frequencies?

The allele frequency tells you the probability of randomly drawing that allele from the population, while the genotype frequency is the number of a certain genotype in the total population. ****

Why is the presence of marsupial mammals on one side of Wallace's line and placental mammals on the other side of Wallace's line an important observation that supported descent with modification?

The animals evolved independently because the islands were further apart. Characteristic differences develop over time from a common ancestor

What is the problem with finding antibiotic resistant bacteria in meat? Why is finding microbes with multiple types of antibiotic resistance in meat of such great concern?

The bacteria and illnesses they may cause can spread to humans. It makes them more effective and a larger threat to us

What adaptations evolve in bacteria to result in antibiotic resistance?

The bacteria can either... -pump the antibiotic out of the cell -destroy the antibiotic -prevent the antibiotic from entering the cell -change the shape of the drug's target molecule

radioactive decay

The breakdown of a radioactive element, releasing particles and energy

What selective pressures may be acting to favor black squirrels in SE Michigan?

The cold. Black fur retains heat better than grey/brown fur during the cold months

What is the Modern Synthesis?

The combination of the principles of Mendelian genetics with evolutionary ideas from Wallace and Darwin

Modern Synthesis

The current theory of evolution, which combines Darwin's theory of natural selection and Mendelian genetics

Sympatric speciation

The formation of new species in populations that live in the same geographic area

What does a binomial taxonomic name tell you? Should two species that are in the same genus be more similar to each other than they are to a species in a different genus? Why?

The genus and species of the organism. Two species of the same genus should be more related to each other than to a species of different genus because it is the taxonomic rank more specific than family

In Endler's guppies, how might male patterns differ between high predation and low predation areas? Draw a graph to show this, using Endler's results in the slides.

The guppies in high predation areas will be duller and blend in. The guppies in low predation areas will be brighter and more flashy to attract mates

phylogeny

The history of descent with modification and the accumulation of change over time

Out of Africa hypothesis

The hypothesis that modern humans evolved in Africa and spread to other continents, replacing other Homo species without interbreeding with them

Bilateria

The monophyletic group of animals with bilateral symmetry

Gene Flow (resulting from migration)

The movement of alleles from one population to another through interbreeding between members of each population

Gene flow

The movement of alleles from one population to another through interbreeding between members of each population

Migration

The movement of organisms from one place to another, including the movement of individuals from one population to another. gene flow between populations

character states

The observed condition of a character, such as presence or absence of lungs or arrangement of petals

How does natural selection, an evolutionary mechanism posited by Darwin and Wallace, relate to descent with modification?

The organisms we have today are derived from a single common ancestor but are modified. They will have the most favorable traits of their ancestor and will modify the least favorable ones so they can optimize their fitness

If you want to determine if a trait is discrete or polygenic, what would you look for among phenotypes in the population? What are 3 examples of discrete and polygenic traits we've discussed in class?

The phenotypes would display a normal distribution -Discrete: yellow vs green peas, tongue rolling, blood type -Polygenic: height, eye color, skin and hair color

Dispersal

The process in which some individuals colonize a distant place far from the main source population

Natural selection

The process in which, when there is genetic variation in a population of organisms, the variants best suited for growth and reproduction in a given environment contribute disproportionately to future generations. Of all the evolutionary mechanisms, natural selection is the only one that leads to adaptations

natural selection

The process in which, when there is genetic variation in a population of organisms, the variants best suited for growth and reproduction in a given environment contribute disproportionately to future generations. Of all the evolutionary mechanisms, natural selection is the only one that leads to adaptations

Allele frequency

The proportion of a specified allele among all the alleles of a gene in a population

allele frequency

The proportion of a specified allele among all the alleles of a gene in a population

Genotype frequency

The proportion of a specified genotype among all the genotypes for a particular gene or set of genes in a population

geologic timescale

The series of time divisions that mark Earth's long history

half-life

The time it takes for an amount of a substance to reach half its original value. Radioactive half-life is the time it takes for half of the atoms in a given sample of a substance to decay

How is it possible that someone of Somali descent is more genetically similar to someone of European descent than to someone of Zimbabwean descent?

There is more variation within racial groups than between them

How does such a large amount of variation exist in organisms like Donax variabilis?

There is random mating, crossing over, and random fertilization (genetic diversity) within a species allowing for different traits

How do the founder effect and genetic bottlenecks relate to genetic drift?

They are both ways to get a smaller population, which would allow for greater influence of genetic drift

In the Canada Lynx video, why are the males interacting this way?

They are competing for each other for a mate

Why is the fossil record useful in helping us understand the history of life on Earth?

They are the only thing that gives us concrete evidence of evolution within a species and tells us where it lived and how it behaved

What kinds of inferences can paleontologists make by studying teeth of dinosaurs from the fossil record?

They can determine their rough age and diet

How do we use fossils to calibrate phylogenies?

They give us a starting point, showing us existence and evolution of an extinct species

What does it mean to say that an organism has an adaptation? Is that particular trait adaptive in all environments? What evolutionary mechanisms reliably produces adaptations?

They have a heritable trait that increases their survival and/or reproductive success. *****. Natural selection or sexual selection

Why do we classify speciation of apple and Hawthorn flies as sympatric rather than allopatric?

They live in the same geographical area

Why are antibiotics used in livestock? How does antibiotic use in livestock contribute to antibiotic resistance in humans?

They're often used as growth promoters. Resistant bacteria can arise in livestock then spread to humans

What kinds of research questions can be addressed using phylogenetic analysis?

Those regarding the evolutionary history of a group of taxa, the sequence of speciation events, or the nature of certain traits

What are vestigial structures and how do those structures relate to descent with modification?

Vestigial structures are structures not useful to the animal, but still retained from ancestor. One example is the fact that whale flippers have finger bones, which shows they shared a common ancestor with other organisms that have finger bones

How do the 3 requirements of evolution by natural selection apply to antibiotic resistance?

When bacteria are initially exposed to an antibiotic, those most susceptible to the antibiotic will die quickly, leaving any surviving bacteria to pass on their resistant features to succeeding generations

continuous trait

When the phenotype for a given trait can take on any value between two extremes. Ex. Height.

Do you think it is possible for genetic drift to counteract natural or sexual selection? If so, how?

Yes because it reduces genetic diversity

polytomy

a branch point from which more than two descendant groups emerge

Evolution

a change in allele/genotype frequencies in a population over one or more generations

malaria

a disease caused by Plasmodium (a parasitic protist) that feeds on hemoglobin

Australopithecus

a genus of early hominins that existed in Africa

monophyletic group

a group in which all members share a single common ancestor not shared with any other species or group of species

trace fossils

a main type of fossil that provides indirect evidence. Includes footprints, coprolites, burrows, tracks, and chemical signatures

modern human

a member of the species Homo sapiens, which includes all living humans

node

a point of branching in a phylogenic tree

branch

a related group of organisms in a phylogenic tree

homology

a similar characteristic due to common ancestor

What patterns on the phylogeny should you look for to see speciation by vicariance due to the separation of the Pacific and Caribbean seas?

a split from one branch into two

binomial name

a two part name consisting of a genus (capitalized) and species (not)

body fossils

a type of fossils that provides direct evidence. Includes bones or shells, organisms trapped in ice, insects trapped in amber, and petrified wood

When a person is exposed to TB, what is the difference between an active TB infection and a latent TB infection? How is latent TB treated compared to active TB?

active TB is the active sickness resulting from the infection. Latent TB is the bacterium residing dormant in the lungs until it becomes active (it may not) at a later time. latent TB treatment is usually just a shorter course of antibiotics (solo therapy vs combination therapy)

allele fixation versus loss

all members of a population will have this allele VERSUS all members of a population will NOT have this allele

What processes can result in genetic divergence between two populations undergoing speciation?

allopatric speciation and sympatric speciation

Chordates

an animal phylum that has a notochord

Rifampin

an antibiotic once used to treat TB but is now inaffective

Autopolyploidy

an individual that has more than two chromosome sets that are all derived from a single species

Mechanical isolation

anatomical differences between individuals prevent mating entirely

What is the fundamental asymmetry of sex? How is the fundamental asymmetry of sex related to inter- and intrasexual selection?

anisogamy. Females have fewer, larger gametes while males have many, smaller gametes. the asymmetry is what leads to male-male competition and female mate choice

What types of organisms do antibiotics kill?

bacteria only

Mycobacterium tuberculosis

bacteria that causes tuberculosis

Why are male traits most often under strong sexual selection?

because differences between the sexes in traits are often related to attracting and obtaining mates - usually a goal of the male of the species

shared derived trait

characteristic found in more than one, but not all, descendant forms and not in the common ancestor. Any trait that is found in all members of a clade but not in the outgroup

Denisovans

close relatives of neanderthals also interbred with humans

Intrasexual selection

competition within a single sex

Polyploidy

condition in which an organism has extra sets of chromosomes

How do the 3 different types of horizontal gene transfer work? How does horizontal gene transfer affect antibiotic resistance? How could a chicken living on an organic poultry farm that never is treated with antibiotics, have bacteria in its microbiome that is resistant to one or more antibiotics?

conjugation is transfer by a pilus, transformation is release from a dead cell that's picked up by a live cell, and transduction is transfer using a viral transport. Crowded conditions of chickens on poultry farms encourages spread of resistance between individuals

Sexual dimorphism

differences between the sexes in traits often related to attracting and obtaining a mate

Describe an example of directional, stabilizing, and disruptive selection.

directional: mice going from light to dark stabilizing: medium length tails disruptive: more white and red wheat than pink

How does disruptive selection relate to sympatric speciation?

disruptive = diversifying = divergent

Allele loss

elimination of an allele in a population

Does reproductive isolation start the process of speciation, or does reproductive isolation come at the end of speciation?

end

RNA polymerase

enzyme that links together the growing chain of RNA nucleotides during transcription using a DNA strand as a template

Intersexual selection

female mate choice

Tetraploid

four sets of chromosomes

How can you calculate the frequency of a dominant allele in a population for a single gene trait that exhibits codominance? What about a recessive allele?

frequency of a allele = (# of aa * 2) (# of Aa) / total # of alleles

Anisogamy

gametes of different sizes

Gametic isolation

gametes of two species meet but do not fuse

How do gametic and mechanical isolation differ?

gametic occurs after mating, mechanic prevents mating entirely

Why are genetic engineering approaches a challenge for scientists in the fight against malaria?

genetic engineering is difficult and expensive

Hominidae

great apes and humans

Great apes

group of large primates including chimpanzees, bonobos, gorillas and orangutans, and humans; they have no tail and have the shared derived trait of robust canine teeth

sister taxa (sister group)

groups that are more closely related to each other than either of them is to any other group

adaptation

heritable characteristic that increases an organism's ability to survive and reproduce in an environment

conjugation

horizontal gene transfer by means of a pilus

transformation

horizontal gene transfer in which a dead cell releases its genetic information and it is picked up by a living cell

transduction

horizontal gene transfer using a viral transport

What do the examples of the happy face spiders and Monarch and Viceroy Butterflies illustrate?

how difficult it is to recognize species boundaries in nature

Homo sapiens

humans

Tribe Hominini

humans and their ancestors

Hybrid inviability

hybrid embryos or juveniles die

Hybrid sterility

hybrid offspring live but are unable to reproduce

How do you determine if a population is in HWE for a particular gene? This question is asking specifically about how to approach a population genetics problem.

if p2 + q2 + 2pq = 1

How do you know whether or not a population is in Hardy-Weinberg equilibrium (HWE) for a given gene?

if the expected allele and genotype frequencies match the observed frequencies

How do immigration and emigration differ? How does each of these affect genetic variation of a population?

immigration is the movement into an area, while emigration is the movement out of an area. Immigration increases the variation while emigration decreases it

most recent common ancestor (MRCA)

in a phylogenetic tree, the MRCA is indicated by the deepest node from which all contemporary variants can be shown to have evolved

What is the difference between interbreeding and inbreeding?

inbreeding is mating between close relatives, while interbreeding is mating within the same species

What are the consequences of inbreeding?

increase in population of homozygous offspring. decrease in genetic variability

What do inter- and intra- mean? Can you think of a way to remember which is which?

inter means between 2 or more groups. intra means within the same group

Why does such a high rate of spinal deformity exist on Isle Royale in the wolf population?

interbreeding after dwindling populations

What is the difference between hybrid inviability and hybrid sterility?

inviability means the hybrid offspring dies, while sterility means they live but cannot reproduce

Postzygotic isolation

isolation that occurs after fertilization

Prezygotic isolation

isolation that occurs before fertilization

Why do scientists bother trying to determine if a population is in HWE for a particular gene, if populations rarely meet the conditions of HWE?

it acts as a null hypothesis that we can use to test for change

How can gene flow increase or decrease genetic variation of a population? How does gene flow homogenize populations?

it brings in new traits to a separate group or it removes extraneous traits. It can regulate the traits

How does an ice bridge in Lake Superior affect gene flow on Isle Royale?

it brings outside individuals to the island (old gray guy) or brings them back to the mainland

What is adaptive radiation and how is it represented on a phylogenetic tree?

it is a single ancestral species that rapidly diversify into many different species. its represented by many close branches fanning from a single branch

Why are homologous traits, rather than analogous traits, mostly used to build phylogenetic trees?

it is clearer when trying to determine which traits fit within a certain matrix and compare character states among all taxa

Why is fish > salamander > cat > human NOT evolution?

it is not a progression towards an ideal state (humans)

Why are mosquito nets a valuable strategy to fight malaria?

it prevents the vector mosquitos from actual contact with humans

If an error in meiosis occurs such that the gametes are diploid rather than haploid, why would fusion of two diploid gametes result in an entirely new species in one generation?

it would result in a tetraploid

Inbreeding

mating with close relatives

Homo erectus

meaning "upright man". extinct species of primitive hominid with upright stature but small brain

What are some reasons that recognizing a species in nature can be difficult?

members of the same species can look very different and members of different species can look nearly identical

polygenic (quantitative) inheritance

mode of inheritance in which the additive effect of two or more genes determines a single phenotypic character

horizontal gene transfer

movement of genes between different species of bacteria

Animals

multicellular heterotrophic organisms that lack cell walls. Includes sponges, cnidarians, and bilaterians

If positive selection is acting on one allele of a gene, what must be happening to other alleles of that same gene?

negative selection is acting on them

Based on current research, is it clear whether not taking a full course of antibiotics makes a person more or less likely to harbor resistant microbes?

no

If prezygotic isolating barriers have evolved, will hybrids be able to form?

no

latent TB

non-infectious, does not cause disease, occurs in 90% of infected people. can be activated later

Why do we need more than one concept of a species?

not every concept can apply to each type of organism

If postzygotic isolating barriers have evolved and hybrids form, does that mean that speciation is not complete?

not necessarily

Allele fixation

only one allele present in a population

continuous (polygenic) trait

phenotypes display a (bell-shaped) normal distribution

discrete trait

phenotypes fall into a few distinct classes

Which types of selection act on alleles? Which types of selection describe the effects of selection on the phenotypic distribution of traits?

positive and negative. directional, disruptive, and stabilizing

Sexual selection

process by which individuals that possess certain heritable traits are more successful at attracting and obtaining mates and thus reproduce at a higher rate relative to other individuals in the population

How does relative fitness differ from fitness? Why is it useful to calculate relative fitness?

relative fitness pertains to the population, fitness pertains to the individual. *****

What are two reasons that you might see a polytomy on a phylogenetic tree?

******

After one half life, how much radioisotope remains and how much decay product has built up? What happens after 2 and 3 half-lives?

-50% -25% -12.5%

Describe two ways in which the environment can interact with genetics to produce a particular phenotype.

-A field of a single wheat variety has variation in height, seed number, leaf shape, etc

What happens to the trait mean and genetic variation under directional, stabilizing, and disruptive selection?

-Directional: mean changes and genetic variation reduced -Stabilizing: mean stays the same and genetic variation reduced -Disruptive: mean stays the same and genetic variation in maintained

What is the broadest taxonomic classification for humans? What is the most specific taxonomic classification for humans?

-Domain -Species

How do Darwin and Wallace's 5 observations/realizations relate to their 2 big ideas?

-Fossils of extinct animals are found where similar animals live today: relates to natural selection of favorable traits -Islands near each other have similar but distinct animals living on them: size, shape, and other characteristics of organisms change over time and a wide variety of unique species comes from common ancestor (decent with modification) -Vestigial features: decent with modification -populations kept in check due to death of generations: natural selection

Homo

same

negative selection

selection that decreases the frequency of a deleterious allele

What part of the Plasmodium life cycle occurs in humans and which part occurs in mosquitoes?

sexual cycle in mosquitos; asexual cycle in humans

analogy

similarity that evolved independently in different organisms as a result of adaptation to similar environments

Is allopatric speciation faster or slower than sympatric speciation? Explain.

slower because sympatric speciation can occur through autopolyploidy

plasmid

small, circular piece of DNA located in the cytoplasm of many bacteria

Biological species concept

species are groups of naturally or potentially interbreeding natural populations that are reproductively isolated from another organism

Temporal isolation

species breed at different times

Ecological (spatial) isolation

species live in the same area but use different habitats, so they rarely encounter eachother

Behavioral isolation

species use different courtship signals

extant

still in existence

What are antibiotics, where do they come from, and how do antibiotics limit or stop bacterial growth?

substances traditionally produced by microorganisms that kill bacteria or inhibit their growth by... -blocking cell wall synthesis -blocking cell membrane synthesis -blocking protein synthesis (either translation or transcription) -blocking folic acid synthesis

transcription

synthesis of an RNA molecule from a DNA template

What are examples of temporal, ecological, and behavioral reproductive isolation?

temporal: friends ecological: garter snakes (aquatic and non) behavioral: meadowlarks with different songs

antibiotic resistance

the ability of bacteria to withstand the effects of an antibiotic

What types of calculations can you do regardless of whether or not a question tells you that the population is in HWE for a given gene? What types of calculations require knowing that a population is in HWE for a given gene?

the allele frequency and genotype frequency

What data suggests that apple and Hawthorn flies are undergoing speciation? How would we know if speciation between apple and Hawthorn flies was completed? What types of reproductive isolation would you expect will act in apple and Hawthorn flies?

the hosts they are found on (flies started using apples as hosts). There would be no flies that procreate on both apples and hawthorns. ecological and behavioral isolation

In sympatric speciation, how can there be a barrier to gene flow for organisms living in the same area?

the initial barrier is biological (genetic, ecological, or behavioral). mutation occurs that restrict or stop gene flow

gene x environment interaction

the interaction of a specific measured variation in the DNA and a specific measured aspect of the environment leading to a phenotype

relative fitness

the number of offspring of genotype 1 / the number of offspring of most fit genotype

fossil record

the only source of direct evidence about what prehistoric organisms looked like, where they lived, and when they existed

Vicariance

the physical splitting of a habitat

cranium

the portion of the skull that encloses the brain

paleontology

the study of fossils

How is a biological species defined?

they are groups of naturally or potentially interbreeding natural populations that are reproductively isolated from another organism

If a population is in HWE for a given gene, what predictions can you make about allele and genotype frequencies in the next generation?

they will remain constant

Why does p+q = 1?

they're probabilities. its math

reversal

to present the opposite of the normal order

polygenic trait

trait controlled by two or more genes

Anopheles mosquito

vector for malaria

What is the difference between allopatric speciation by vicariance and allopatric speciation by dispersal?

vicariance is the physical splitting of a habitat, while dispersal is the movement of members of a species to another geographic area

How have the recent improvements in our ability to extract and sequence DNA from fossils allowed us to apply the phylogenetic species concept to extinct species?

we can better determine between species and whether or not they evolved independently

How do we apply the principle of parsimony to determine which phylogenetic arrangement is most likely to be accurate?

we choose the tree supported by available data and fewest evolutionary changes

Interbreeding

when two members of the same species mate and produce offspring

Can one species have both inter- and intrasexual selection operating at the same time?

yes

Has resistance to anti-malarial drugs emerged in Plasmodium? If so, where?

yes. Artemisinin resistance in southeast Asian Countries

Give 2 examples of sexual dimorphism in nature. What causes sexual dimorphism?

-cardinals (males are vibrant red) -dung beetles (males have a large horn)

What characteristics are found in all vertebrates? Of these traits, which are the shared, derived traits of the vertebrates?

-cranium -vertebrae Both are shared derived traits

Arrange the following groups in order from broadest to most narrow: placental mammals, Subfamily Homininae, bilateria, animals, chordates, Family Hominidae, vertebrates, deuterostomes, tetrapods, eukaryotes, Tribe Hominini, mammals, primates

-eukaryotes -animals -bilateria -deuterosomes -chordates -vertebrates -tetrapods -mammals -placental mammals -primates -Family Hominidae -Subfamily Homininae -Tribe Hominini

Why has development of a vaccine for malaria been a challenge?

-high mutation rate -complex life cycle of the parasite (hard to target)

What characteristics of bacteria allow for antibiotic resistance to spread rapidly?

-high reproduction -high mutation rates -horizontal gene transfer -strong selective pressure

What are the factors that affect how quickly speciation occurs?

-if gene flow is cut off or at low levels between two separate populations -size of geographic barrier separating the two populations -dispersal abilities of the organisms -size of two populations (more genetic drift in smaller populations) -how different the two habitats are

What characteristics are found in all placental mammals? Of these traits, which are the shared, derived traits of the placental mammals?

-mammary glands -hair -placental gestation and birth The shared derived trait is the placental gestation and birth

What characteristics are found in all animals? Of these traits, which are the shared, derived traits of the animals?

-multicellular eukaryotes without a cell wall -gastrula stage during development -collagen protein -heterotrophic They are all shared derived traits except for being a multicellular eukaryote

Morphospecies concept

-species are defined by morphological characteristics -individuals that share many features are the same species

Phylogenetic species concept

-species defined by unique genetic history -species share smallest tips on the phylogenetic tree

What are the 5 evolutionary processes?

1. Genetic drift 2. Gene flow 3. Mutation 4. Natural Selection 5. Sexual selection

What are the two main outcomes of the Modern Synthesis?

1. It defined biological evolution as a change in allele frequencies in a population over one or more generations 2. It added mutation, gene flow, and genetic drift as additional processes that cause evolution

What are the 3 criteria for evolution by natural selection? Can an individual organism evolve by natural selection?

1. Variation in traits 2. Heritability 3. Differential reproductive success An individual organism cannot evolve by natural selection, it happens through reproduction

What are the 3 main steps in the general model of speciation?

1. an initial barrier to gene flow occurs/emerges due to separation in space, time, or behavior 2. genetic makeup of each population changes through selection, genetic drift, and/or mutation 3. reproductive isolating mechanisms evolve, resulting in new species according to BSC using a wide variety of mechanisms

What are the 3 factors that influence the speed at which evolution by natural selection occurs? Be sure to explain why this is the case for each factor.

1. generation time of the organism 2. strength of selection 3. starting frequency of selected allele

What are the conditions required for a population to be in HWE, and how do these conditions correspond to evolutionary processes?

1. population is very large (no genetic drift affecting gene under study) 2. population is closed (no migration or gene flow) 3. no mutations is random with respect to trait under study 4. mating is random with respect to the trait (no sexual selection and no inbreeding at gene under study) 5. all genotypes in population have equal chance of surviving and reproducing (no natural selection at gene under study)

tuberculosis

A bacterial infection caused by Mycobacterium tuberculosis that affects the lungs and airways

Deuterostomes

A bilaterian in which the blastopore, the first opening to the internal cavity of the developing embryo, becomes the anus. The taxonomic name is Deuterostomia and includes humans and other chordates

mammal

A class of vertebrates distinguished by body hair and mammary glands from which they feed their young

heterozygote advantage

A form of balancing selection in which the heterozygote's fitness is higher than that of either of the homozygotes, resulting in selection that ensures that both alleles remain in the population at intermediate frequencies

disruptive natural selection

A form of selection that operates in favor of extremes and against intermediate forms, selecting against the mean

Sexual Selection

A form of selection that promotes traits that increase an individual's access to reproductive opportunities

directional natural selection

A form of selection that results in a shift of the mean value of a trait in a population over time

stabilizing natural selection

A form of selection that selects against extremes and therefore maintains the status quo

What is a monophyletic group and how could you find one on a phylogenetic tree?

A group in which all members share a single common ancestor not shared with any other species or group of species. they will have. trait that is unique from the other organisms/groups in the tree

genus

A group of closely related species. First part of binomial naming system

character

A heritable feature that varies among individuals

Founder effect

A large population as a subset of individuals that go establish a new population

primates

A member of the order of mammals that includes humans, distinguished by a number of molecular and morphological features, including relatively large brains, nails rather than claws, front-facing eyes, and, in some species, an opposable thumb

taxon

A named taxonomic group at any rank, such as a species, a genus, or a family

Plasmodium

A parasitic protist that causes malaria

Adaptive radiation

A period of unusually rapid evolutionary diversification in which natural selection accelerates the rate of speciation within a group, with new species adapted for specific niches

Genetic drift

A random change in the frequency of an allele due to the statistical effects of finite population size

Hardy Weinberg Equilibrium

A state in which allele and genotype frequencies do not change over time, implying the absence of evolutionary forces. It also specifies a mathematical relationship between allele frequencies and genotype frequencies

vertebrates

A subphylum of Chordata, distinguished by a bony cranium that protects the brain and (unless lost through evolution), a vertebral column; also known as craniates

ancestral trait

A trait shared by all members of a group through a common ancestor. Any trait tat is shared between the outgroup and all members that are found in all members of a clade

What is an isotope of an element? What is the difference between a parent radioisotope and its decay product?

A version of an element with a different number of neutrons. A parent isotope will be considered a different substance as it decays

fitness

Ability of an organism to survive and reproduce in its environment

Gene pool

All the alleles present in all individuals in a population or species

Population

All the individuals of a given species that live and reproduce in a particular place; one of several interbreeding groups of organisms of the same species living in the same geographical area

Why do you need to know about allele frequencies in order to determine if genetic drift is occurring? What does it mean to say that an allele is fixed or lost?

Allele frequencies have to show a change. An allele is fixed if all individuals have it. An allele is lost if no individuals have it

Categorize the following variables as either an allele frequency or a genotype frequency: p, p2, q, q2, 2pq.

Allele: p and q Genotype: p2, q2, and 2pq

How do fossils form? What kinds of organisms are most likely to be fossilized? What kinds of organisms are least likely to be fossilized?

An animal dies and sinks to the bottom of the ocean/lake or is buried by mud and sediments. as it decomposes, its skeleton is eventually replaced completely by minerals and solidifies into stone

Trade-off

An exchange in which something is gained at the expense of something lost (attractive to mate vs. predator avoidance)

Bottleneck

An extreme, usually temporary, reduction in population size that may result in marked loss of genetic diversity and, in the process, genetic drift

How do you determine if a trait is ancestral or shared derived? Where do you map traits on a tree?

Ancestral traits are shared between the outgroup and all members of the clade, while shared derived are found in all members of the clade but not in the outgroup.*****

What anatomical features are found in bipedal species of primates?

Angling and narrowing of the stance, narrowing and arching of the feet, curving of the spine into s shape, and attachment at the base of the skull instead of top

polymorphism

Any genetic difference among individuals that is present in multiple individuals in a population

Mutation

Any heritable change in the genetic material, usually a change in the nucleotide sequence of a gene

How do natural and artificial selection differ?

Artificial selection is based on human priorities, natural selection is based on adaptation to environment and mutation