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BIO 303 EXAM 2
| Question | Answer |
|---|---|
| ________ is the major source of variation | mutation |
| genetics of mutations provided supporting evidence for.. | natural selection |
| different types of genetic mutations | 1. Point 2. insertion 3. deletion 4. gene duplication 5. inversion 6. chromosome fusion 7. genome duplication |
| somatic mutations | affect cells in the body of organism-->not heritable |
| germ-line mutations | affect gametes-->heritable and relevant to evolution |
| insertion | small string of bases (called indels) are inserted into genome |
| deletion | indel is deleted from the genome |
| gene duplications are caused by.. | crossovers |
| ex of gene duplication | opsin gene in primates-->allows for color vision |
| when a phenotype provides an essential adaption, natural selection permits only mutations that ________ the adaptation | improve |
| natural selection eliminates ______ mutations from the genotype | harmful |
| if the phenotype no longer provides _______, natural selection no longer eliminates harmful mutation and the gene fossilizes | adaptation |
| Natural selection does NOT encourage.. | poor fitness |
| Hardy Weinburg Equation | p^2+2pq+q^2=1 |
| Hardy-Weinburg serves as the fundamental _____ ______ in population genetics | null hypothesis |
| genetic drift causes ________ in finite populations | evolution |
| genetic drift results from.. | sampling error |
| sampling error | higher with smaller sample; new, small sample of population not accurate representation of whole population |
| bottlenecks cause.. | genetic drift and reduces genetic variation |
| rare alleles are likely to be lost during.. | bottleneck |
| founder effect | new population started by small number of individuals |
| founder effect causes.. | genetic drift |
| the founder effect is a type of.. | bottleneck |
| even brief bottlenecks can lead to ______ _______ in genetic diversity that can persist for generations | drastic reduction |
| dominance | dominant allele masks presence of recessive in heterozygote |
| the ______ frequency is reached through tug of war between negative selection and new mutation | equilibrium |
| equilibrium frequency explains the persistence of rare, ________ mutations in populations | deleterious |
| selection occurs when genotypyes differ in.. | fitness |
| outcome of selection depends on.. | frequency of allele and effects on fitness |
| population size influences power of.. | drift and selection |
| drift is more powerful in a ______ population | small |
| selection is more powerful in a _______ population | large |
| Inbreeding Coefficient | As (F) increases, fitness declines, and the amount of deleterious genes increases |
| Inbreeding coefficient is often the probability.. | that two alleles are identical by descent |
| with a higher inbreeding coefficient, rare, __________ genes are more likely to be seen in homozygous combination | deleterious |
| why do some orchids produce chemicals that attract male wasps | classic mimicry; the chemicals smell like wasp pheromones, so the wasp deposits sperm and picks up pollen from that plant |
| Negative frequency-dependent selection | just like negative feedback; whatever phenotype becomes more abundant, selection acts on that to continue the balance in numbers of each color |
| in negative frequency-dependent selection, reproductive success in inversely proportional to.. | morph |
| species | consist of interbreeding populations that evolve independently of other species; smallest evolutionarily independent unit |
| species exist when they are _______ _______ from one another bc of a lack of gene flow | genetically isolated |
| cryptic species | look the same but are not related |
| speciation | evolutionary process by which new species arise; causes one evolutionary lineage to split into two or more lineages |
| genetic isolation leads to.. | speciation |
| speciation begins when gene flow is ______ and the population becomes genetically isolated | disrupted |
| speciation is all about.. | barriers |
| forms of genetic isolation | 1. physical isolation 2. mutational isolation |
| physical genetic isolation | dispersal and vicariance |
| mutational genetic isolation | genome duplication results in polyploidy; polyploidy causes instant reproductive isolation without physical isolation-->mate choice |
| divergence mechanisms | 1. genetic drift 2. natural selection 3. sexual selection |
| dispersal | large, whole population breaks into smaller, isolated groups via migration |
| vicariance | large, whole population breaks into smaller, isolated groups via disturbance/separation of environment |
| behavioral isolation | two species courting females from same lek; two different calls, two different dances, two different colors on throat skin that prevent females from choosing male of wrong species |
| if there is heritable variation in a trait that affects the ability to _______ ________, then variants conducive to success will become more common over time | obtain mates |
| if sexual selection causes differences between sexes, it will have to act of the sexes.. | differently |
| sexually dimorphic traits | result from sexual selections; 1. ornaments and 2. armaments |
| ornaments | attractive traits that increase mating success |
| armaments | weaponry used to outcompete other individuals |
| mate-mate competition leads to extreme _______ in reproductive success | variance |
| mates may compete for.. | territory |
| direct benefits of female choice | benefits the female directly |
| indirect benefits of female choice | benefits that affect the genetic quality of female's offspring |
| fitness | the reproductive success of an individual with a particular phenotype |
| components of fitness | 1. survival to reproductive age 2. mating success 3. fecundity |
| fecundity | # offspring produced |
| relative fitness | fitness of a genotype standardized by comparison to other genotypes |
| selection coefficients | If S=0 fitness is the same between two genotypes; If S=1, one genotype is completely lethal |
| _____ rates for any given gene are low | mutation |
| how many new mutations are estimated to occur in humans? | 9.8 billion |
| genetic mutations are the source for ______ and drift to act | selection |
| selection | differential reproductive success that happens for a reason (in response to the current environment) |
| genetic drift | differential reproductive success that just happens |
| genetic drift can result in the change of ______ frequencies in populations resulting from sampling error in drawing gametes from gene pool | allele |
| genetic drift can result in _____-________ evolution | non-adaptive |
| _______ ______ does not lead to adaptation | genetic drift |
| what populations are more influenced by genetic drift? | small |
| genetic drift results in a loss of.. | heterozygosity |
| in natural selection, small ______ in fitness can lead to large changes over the long term | advantages |
| drift reduces ______ _______ in a population | variation |
| in genetic drift, _________ and lost at a faster rate in small populations | alleles |
| 5 assumptions of Hardy-Weinburg | 1. There is no selection 2. There are no mutations 3. There is no migration 4. There are no chance events 5. Mates are chosen at random |
| hardy-weinburg basically leads a species to.. | extinction |
| fundamental conclusions of hardy-weinburg | 1. allele frequency in a population will not change generation after generation 2. if the allele frequencies in a population are given by p and q, the genotype frequencies will be given by p^2, 2pq, and q^2 |
| hardy-weinburg equation definition | a situation in which allele and genotype frequencies in an ideal population do not change from one generation to the next |
| when alleles are not in equilibrium, ______ is occurring | evolution |
| Coevolutionary arms race (escalation) | species interact antagonistically in a way that results in each species exerting reciprocal directional selection on the other |
| examples of anti-predator adaptations | 1. toxins, spines, armor 2. warning coloration 3. cryptic coloration 4. mimicry 5. flash coloration 6. behavioral modification |
| predator adaptations | 1. mimicry 2. cryptic coloration 3. speed 4. acute sense |
| Batesian Mimicry | occurs when harmless species resemble harmful or distasteful species, deriving protection from predators |
| Mullerian Mimicry | occurs when several harmful or distasteful species resemble each other in appearance, facilitating the learned avoidance of predators |
| adaptations | traits or integrated suites of traits that increase the fitness of the possessor is called an adaptation |
| adaptionist program | evolutionary biologists who do research to demonstrate adaptive traits in organisms |
| not all phenotypes are necessarily.. | adaptive |
| coevolution | reciprocal evolutionary change between interacting species, driven by natural selection |
| reciprocal selection | selection that occurs in two species due to their interactions with one another. |
| what is the critical prerequisite of coevolution | reciprocal selection |
| three species concepts | 1. morphospecies 2. biological scpecies 3. phylogenetic |
| morphospecies concept | species designation and identification is based on the morphological differences between population |
| what is the primary way fossils are assigned to species | morphospecies concept |
| what species concept works very poorly in explaining fungi, bacteria, and archaea | morphospecies concept |
| biological species concept | species are groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups-->when populations fail to hybridize in nature, producing inviable hybrids |
| phylogenetic species concept | species are the smallest possible groups whose members are descended from a common ancestor and who all possess defining or derived characteristics that distinguish them from other such groups |
| reinforcement | results when hybrid offspring have low fitness and natural selection results in assortative mating and prezygotic isolation |
| prezygotic isolation | divergence in traits between populations that prevents fertilization from occurring |
| types of prezygotic isolation | 1. mechanical isolation 2. behavioral isolation 3. temporal isolation 4. gamete incompatibility |
| mechanical isolation | parts don't fit |
| behavioral isolation | different mating dances |
| temporal isolation | different breeding seasons |
| hybridization | occassionally hybridization of fertile young can occur and lead to the formation of new species |
| who typically has a larger parental investment in each offspring than fathers | mothers |
| parental investment | the energy and time expended in both constructing an offspring and caring for it |
| parental investment is all about.. | fitness |
| as parental investment increases.. | the survival and reproductive success of the offspring receiving it increases |
| the parent that invests more time and energy into offspring typically had reproductive success that is limited by.. | resources and time |
| the parent that invests the least time and energy typically has reproductive success that is limited by.. | number of mates |
| in some species, sexual selection may not.. | act on one gender at all |
| the ______ of sexual selection often differs between sexes | intensity |
| sexual selection | differential reproductive success due to variation among individuals to find mates |
| population genetics | study of the distribution of alleles within populations and the mechanisms that can cause allele frequencies to change over time |
| theorum | mathematical statements that have been proven based on previously established theorums and axioms-->use deductive reasoning |
| fixed allele | an allele that remains in a population when all of the alternative alleles have disappeared |
| average excess of fitness | the difference between the average fitness of individuals bearing the allele and the average fitness of the population as a whole |
| pleiotropy | the condition when a mutation in a single gene affects the expression of more than one different phenotypic trait |
| antagonist pleiotropy | occurs when a mutation with beneficial effects for 1 trait also causes detrimental effects on other traits |
| negative selection | selection that decreases the frequency of alleles within a population |
| positive selection | type of selection that increases allele frequency in a population |
| epistasis | occurs when the effect of an allele @ one genetic locus are modified by alleles at one or more loci |
| additive allele | describes allele that yields twice the phenotypic effect when 2 copies are present at a given locus than occurs when only one copy is present-->not influenced |
| inbreeding depression | a reduction in the average fitness of inbred individuals relative to that of outbred individuals |
| landscape genetics | research that combines population genetics, landscape ecology, and spatial stats |
| population structure | populations that are subdivided by geography, behavior, or other influences that prevent individuals from mixing completely |
| genetic distance | measure of how different populations are from each other genetically |
| gene flow | migration of alleles from one population to another |
| geographic mosaic theory of coevolution | proposes the geographic structure of populations is central to the dynamics of coevolution --> direction and intensity of coevolution varies from population to population |
| diversifying coevolution | refers to an increase in genetic diversity caused by the heterogeneity of coevolutionary processes across the range of ecological |
| endosymbionts | mututalistic organisms that live within the body or cells of another organisms |
| retrovirus | RNA virus that uses an enzyme called reverse transcriptase to become part of the host's DNA--> i.e. AIDS |
Created by:
asexton_21