Biology Evolution Ch.13

why is embryology importance evidence of evolution

it allows us to see embryological similarities and differences between the early stages of related organisms (ex: all chordates have a gill slit during development)

what is comparative anatomy/ why is it important evidence of evolution

it compares different body parts of different animals

what is Batesian mimicry

non-harmful animal resembles a harmful animal

what is sexual selection

non-random mating between males and females, traits selected may be favorable for reproduction but not for survival

what are the two theories of macroevolution

phyletic gradualism and punctuated equilibrium

what is cladogenesis

the splitting apart of evolutionary lineages; the formation of new clades

Darwin's finches and adaptive radiation

the studied finches originated from the same ancestor from the mainland, as the finches flew to each small island, they grew apart from their ancestors and became different species that "radiated" away from the main branch of original finches.

what is paleontology

the study of fossils through actual remains of an animal or their traces

why is biochemical comparison of DNA important evidence for evolution

it allows for DNA sequence comparisons to see conserved DNA sequences and common conserved pathways

what is convergent evolution

unrelated species adapt to similar environments, becoming more alike (analogous structures)

what was Lamark's theory of evolution based on

use and disuse & the inheritance of acquired traits

what did Lamark say about use and disuse

used body parts will develop and unused ones are weakened, leading to evolution

examples of vestigial structures

-Wings of ostrich, homologous to wings of eagles. -Appendix of humans, homologous to cecum of cows

what are the four requirements for natural selection

1. demand for resources exceeds supply, which results in competition for survival (fittest survive to pass on genes) 2. difference in levels of fitness due to variation in traits, differentiating the ability to compete and survive 3. variation in traits must be genetically-influenced to be passed onto offspring 4. variations in traits must be significant for reproduction and/or survival, genes improving reproductive success/survival are favored and increase over generations and vice versa

evolution of chordates

1. notochord (first seen in lancelets and tunicates) 2. head (first seen in hagfish) 3. vertebral column (first seen in jawless fish (also known as Class Agnatha, e.g. lampreys) 4. jaw and mineralized skeleton (first seen in chondrichthyes, e.g. sharks) 5. lungs/lung derivatives (first seen in ray-finned fish) 6. lobed fins 7. limbs with digits (amphibians) 8. amniotic eggs (reptiles) 9. production of milk (mammals).

All of the following would disrupt genetic equilibrium EXCEPT one. Which is the EXCEPTION? A. Polyploidy B. Isolated population C. Genetic drift D. Inbreeding E. Natural selection

B. isolated population Genetic (Hardy-Weinberg) equilibrium is a condition where there are no changes in allele frequencies (evolution). For genetic equilibrium, the population will need to be Large, mate Randomly, and experience no Mutations, natural selection, or Migration. Remember these conditions using Large, Random M&M (read & like "n"). This question asks us to find the choice that would not disrupt genetic equilibrium. Isolated populations do not migrate. Therefore, choice [B] does not disrupt genetic equilibrium, and is our answer.

2 types of mimicry

Batesian and Mullerian

example of sympatric speciation

Centuries ago, some members of a maggot fly population began laying their eggs on apples instead of hawthorns. Now there are two types of flies that can no longer produce viable offspring: one that lays eggs on hawthorns and the other on apples... A scenario in which two groups within the same species are gradually becoming different species and the speciation is occurs without the presence of a geographical barrier

who proposed the three theories of evolution

Cuvier, Lamarck, and Darwin

honorable mention evolution theorists and their theories

Gause - competitive exclusion principle = two species are not able to occupy the same niche while also maintaining their population levels. In the long run, the species that is more adapted to the niche will outcompete and dominate the other species. Malthus - principle of population = the human population increases geometrically (ie., 2, 4, 16, 132...), while food production increases arithmetically (ie., 2, 4, 6, 8...). This means that food production will not be able to keep up with growth in the human population, resulting in disease, famine, war, and calamity.

two types of genetic drift

bottleneck effect and founder effect

example of Batesian mimicry

Two different species of butterflies look nearly identical, but only one species is poisonous when eaten.

what is a phylogenetic tree

a branched diagram that shows inferred evolutionary relationships between different taxa

what is an internal node of a phylogenetic tree

a branching point on a cladogram that represents the splitting/divergence of a single group into two descendant groups

what is the Hardy-Weinburg formula

a calculation of frequency during genetic equilibrium, with no change in gene frequencies, and if both equations hold true then the population is under the Hardy-Weinberg equillibrium

what are mutations for causing microevolution

a change in DNA that can be dormant until environmental change allows it to flourish

what is a clade

a cluster with an ancestor and all its decendents

what is a cladogram

a type of phylogenetic tree that shows inferred evolutionary relationships among various biological species

what is a specific type of allopatric speciation

adaptive radiation

what is genetic drift for causing microevolution

allele frequencies change by change, creating larger effects on smaller populations

what are 2 types of speciation

allopatric and sympatric speciation

what is a monophyletic tree

an ancestor and all its descendants

what is a paraphyletic tree

an ancestor and some but not all of its descendants

what is polytomy

an internal node of a phylogenetic tree that leads to more than two tips

what are 3 types of sympatric speciation

balanced polymorphism, polyploidy, and hybridization

what is postzygotic isolation

barriers to organism success after the zygote has formed

why is Lamark's ideas on inheritance of acquired traits INCORRECT

because acquired traits are generally not heritable

what does evolution increase

biodiversity

what is an example of stabilizing selection

birth weight

what is an example of difference in levels of fitness due to trait variation

black peppered moths favored over white moths to live during the Industrial Revolution (lots of soot/ash in the environment gave better camouflage for the peppered moths)

what is crypsis

camouflage + the inclusion of olfactory/smell or auditory methods of concealment (scent masking, silencing)

what are 4 types of coevolution

camouflage, crypsis, aposematic coloration, mimicry

what did Cuvier say about catastrophism

catastrophes lead to mass extinction of species in the area; different populations in different areas were shaped by catastrophes that occurred because random organisms that survived would repopulate the area

what was Cuvier's theory of evolution based on

catastrophism

for genetic variation, sexual reproduction is

crossing over, independent assortment and random joining of gametes

what is camouflage

cryptic coloration; matching appearance to the environment to avoid detection, and it's strictly a visual method of concealment

what is behavioral isolation

different courtship rituals

what is balanced polymorphism for sympatric speciation

different phenotypes are isolated within the same area

what are the 4 main patterns of evolution

divergent, convergent, parallel, coevolution

What is phyletic gradualism?

evolution happened gradually via accumulation of small intermediary changes

when the Hardy-Weinberg conditions are met, what happens

evolution occurs

what is mimicry

evolution to resemble another species

for genetic variation, mutation must not be...

fatal

what are the female and male preferences in sexual selection

females favor high quality partners and males prefer a high quantity of partners to increase their number of offspring

what are ichnofossils

fossilized traces of organisms but not the organisms themselves

what are the 5 types of evidence of evolution

fossils, biogeographic spread of species, embryology, comparative anatomy, and biochemical comparison of DNA

what is gamete isolation

gametes do not recognize/fertilize each other (ex: zona pellucida on mammalian oocytes)

what factors can cause microevolution

genetic drift, non-random mating, mutations, natural selection, and gene flow

5 types of prezygotic isolation

habitat, temporal, behavioral, mechanical, and gamete

macroevolutional species are reproductively isolated. what is that?

isolation via prezygotic and postzygotic isolating mechanisms that result in a lack of gene flow between species

what are allele frequencies

heritable traits

what are genetically-influenced traits

heritable traits

3 types of advantages from balanced polymorphism

heterozygote, hybrid, and minority advantages

Example of Hardy-Weinberg Equilibrium equation: In a population of rabbits, brown fur color is dominant and white fur color is recessive. 91% of the population is brown and 9% is white. What is the heterozygous frequency?

heterozygous frequency = 2pq in p^2 + 2pq + q^2 = 1 white fur = recessive = bb = 9% = 0.09 homozygous recessive (bb) frequency = q^2 = 0.09 q = 0.3 p + q = 1 p + 0.3 = 1 p = 0.7 2pq = 2(0.7)(0.3) = 2(0.21) = 0.42 x 100 = 42%

what is conserved DNA

high similarity DNA, which means theres higher relatedness in the organisms

what is convergent evolution also known as

homoplasy

Example of Hardy-Weinberg Equilibrium equation: Assume a population is in Hardy-Weinberg equilibrium. If 25% of the population is homozygous recessive, what is the allele frequency of the dominant allele?

homozygous recessive = q^2 in p^2 + 2pq + q^2 = 1 q^2 = .25 -> q = 0.5 p + q = 1 p = 1 - 0.5 = 0.5 x 100 = 50% (p= dominate allele, both for the homozygous and heterozygous presence)

what is speciation

how species form, starting with reproductive isolation, which leads to interruption of gene flow between populations that gradually develop into two species

what are the 3 types of postzygotic isolation

hybrid mortality, hybrid sterility, hybrid F2 breakdown

what is survival of the fittest

individuals with the greatest fitness have the greatest success and pass on more DNA to future generations, compared to less fit parents

is punctuated equilibrium accurate

it is likely to be true because it is supported by fossil evidence

why is biogeographic evidence important for evolution

it shows the spread of different species around the world which can be analyzed through their similarities and differences

the evolution of fish, from earliest to latest ancestor?

jawless fish -> cartilaginous fish -> lobe-finned fish

requirements for the Hardy-Weinberg equilibrium

large population to minimize genetic drift, random mating, no mutation, no natural selection, no migration (gene flow) so the population must be isolated

what is macroevolution

long-term evolution that occurs at a level at or higher than species

what is stabilizing selection

mainstream (average) is favored

for genetic variation, balanced polymorphism...

maintains a variety of phenotypes within a population

what is mechanical isolation

male/female genitalia are not compatible.

What is prezygotic isolation

mechanisms are barriers that prevent fertilization and zygote formation from occurring between species

what is gene flow for causing microevolution

migration (non-random) moving alleles between populations, leading to variation through mixing

preferred phylogenetic tree

minimal evolutionary reversals, convergent evolution, and parallel evolution

phylogenetic trees can be...

monophyletic or paraphyletic

what is polytomy also known as

multifurcation

for genetic variation, polyploidy is

multiple copies of alleles introducing more variety and preserving different alleles. they can also mask effects of harmful recessive alleles.

what are the sources of genetic variation

mutation, sexual reproduction, balanced polymorphism, polyploidy

what was Darwin's theory of evolution about

natural selection

what is natural selection for causing microevolution

no luck is involved

is phyletic gradualism accurate

not likely to be true because it is not supported by fossil evidence

what is habitat isolation

occupying different habitats

what is directional selection

one extreme favored

Hardy-Weinburg equations

p + q = 1 p^2 + 2pq + q^2 = 1

p + q = 1 variables

p = frequency of dominant allele q = frequency of recessive allele

p^2 + 2pq + q^2 = 1 variables

p = frequency of homozygous dominant pq = frequency of heterozygous q = frequency of homozygous recessive

Two organisms from different species mate, and the offspring of their offspring have reduced fitness. This is an example of...

postzygotic isolation, specifically hybrid f2 breakdown if the original organisms are the F1 hybrids that can reproduce and create the F2 offspring with reduced fitness

what are the 2 types of macroevolution

prezygotic isolation and postzygotic evolution

what are vestigial structures in comparative anatomy

structures that serve no purpose but are homologous to functional structures in other organisms

genetic diversity happens during meiosis stages...

prophase I (chromosome cross-over) and metaphase/anaphase I (chromosomes assort randomly and are pulled to the poles to create the chromosome makeup for the 2 future daughter cells)

what is minority advantage

rare phenotypes that offer higher fitness, cycling between high and low frequency

what is disruptive selection

rare traits are favored, mainstream is not

what is embryology

study of embryos and their development

what is temporal isolation

reproducing at different times/seasons

what is polyploidy for sympatric speciation

results from nondisjunction during meiosis (two 3n organisms, usually sterile, meet and are reproductively compatible)

what is artificial selection

selection carried out by humans to selectively breed for specific traits (ex: dog breeding)

besides natural, what are two other types of selection

sexual and artificial

what is non-random mating for causing microevolution

sexual selection, outbreeding, inbreeding

what is punctuated equillibrium

short spurts of evolutionary changes during periods of stasis

what is an example of heterozygote advantage

sickle cell anemia

what is parsimony

simpler explanations of evolution are more likely to be correct

what is an example of disruptive selection

snails living in low and high vegetation areas

what is hybridization for sympatric speciation

some hybrids are more fit than purebreds

what is allopatric speciation

speciation that occurs due to a geographical barrier

what is adaptive radiation

speciation that occurs when many species arise from one ancestor as they adapt differently from their environments. species can specialize to fill different niches within the same environment. may or may not have a geographical barrier involved (ex: Darwin's finches on Galapagos Island)

what is sympatric speciation

speciation that occurs without geographic isolation

what is parallel evolution

species diverge from a common ancestor but undergo similar changes

what are the three types of natural selection

stabilizing, directional , and disruptive selection

what are analogous structures in comparative anatomy

structures that have the same function but not have a common ancestor (ex: bird wings and bat wings)

what are homologous structures in comparative anatomy

structures that may or may not perform the same function but have a common ancestor (ex: forearm of the bird and forearm of the human)

differences between sympatric, adaptive, and allopatric speciation

sympatric = WITHOUT geographical barriers adaptive = with OR without geographical barriers allopatric = WITH geographical barriers

what is an example of a common conserved pathway

the Krebs cycle

what is fitness

the ability to survive and produce viable and fertile offspring

what does natural selection lead to

the evolution of the POPULATION, not individuals

what is microevolution

the process when gene frequencies change within a population over generations (favorable genes increase, unfavorable decrease)

what is evolution

the gradual development and change of heritable traits in populations over successive generations

what is anagenesis

the gradual evolution of interbreeding population without splitting

what is natural selection

the gradual, non-random process where allele frequencies change as a result of environmental interaction

what is the individual with the most fitness in a population

the individual with the greatest amount of offspring

what is an example of directional selection

the longest giraffe neck allows access to the most leaves

what did Lamark say about inheritance of acquired traits

traits acquired through use and disuse are passed onto offspring (ex: giraffe's stretching neck will cause its neck to develop and produce long-necked offspring)

what is Mullerian mimicry

two poisonous animals resemble each other to warn their predator

what is coevolution

two species impart selective pressure on each other

what is hybrid advantage

two strains of organisms produce more superior offspring

what is aposematic coloration

warning coloration; vibrant coloration in poisonous animals to warn predators

why is paleontology importance evidence of evolution

we can observe the development of species through time by comparing deepest fossils to shallowest

what is the founder effect

when some individuals migrate away from a population and the genetic frequencies change because of the new lack of diversity

what is divergent evolution

when species diverge from a common ancestor

when do neutral variations become a beneficial kind of balanced polymophism

when the environment changes

what is hybrid sterility

when the hybrid zygote is infertile

what is hybrid mortality/inviability

when the hybrid zygote is non-viable and does not survive past the embryonic stage, often due to different chromosome numbers

what is hybrid f2 breakfown

when the offspring of hybrids have decreased fitness

what is the bottleneck effect

with a smaller gene pool, some alleles may be lost by chance (ex: natural disaster killing a majority of the population)