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97 Cards in this Set
- Front
- Back
What is the reasoning behind the McDonald-Kreitman Test? |
If neutrality holds, there should be a positive correlation between the heterozygosity at a locus and its rate of evolution (rate of substitution) |
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Consider a deleterious recessive allele that is lethal when homozygous. If the mutation rate at this locus is 10^-e, the equilibrium allele frequency would be |
0.001 |
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Which of the following is the definition of fitness according to evolutionary biolgoy |
The average lifetime contribution of individuals with a particular genotype to a population |
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If selection pressures vary over time and/or space |
genetic variation is not necessarily mantained |
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Sewall Wright's metaphor of an "adaptive landscape" that includes "peaks" and "valleys" is used widely in evolutionary biology. What might cause a population to move away from a fitness peak for multiple generations? |
Genetic drift |
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Which of the following is NOT a component of fitness according to evolutionary biology |
Mutation |
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In inverse (negative) frequency-dependent selection |
rare alleles are advantageous |
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The end result of positive frequency-dependent for a population depends strongly on |
the initial frequencies of alleles in the population |
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which of the following is the result of a recent selective sweep |
decreased variation and high levels of linkage disequilibrium at nearby sites |
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When the ratio of non-synonymous differences to synonymous differences (Dn/Ds) for homologous genes in a pair of species is compared, historical patterns of selection can be inferred. Which of the following provides the strongest evidence of directional selection? |
Dn/Ds=1.5 |
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Local populationsof the grasshopper Vandiemenella viatica are monomorphic for different chromosomal fusions and inversions. Grasshoppers that are heterozygous for different chromosomal rearrangements have reduced fitness. What might explain the fact that each population is fixed for a different rearrangement |
Genetic drift in small populations |
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The Figure shows the proportion of warfarin-resistant rats in a population of rats in Wales...According to the graph... |
Directional selection of warfarin resistance occurred during the warfarin poisoning program, but rats that were not resistant to warfarin increased in frequency after the poisoning program ended. |
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As long as no other factors intervene, the results of directional selection are that |
a character state with even a minuscule advantage can be fixed by natural selection |
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Why did 'industrial melanism' in the peppered moth, Biston betularia, help to convince researchers that the intensity of natural selection can be very strong |
The dark-colored allele increased in frequency very rapidly in multiple populations and later decreased rapidly after the environment changed. |
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The color of a species of snail is determined by a single autosomal locus. AA homozygotes are red. AB heterozygotes are pink and BB homozygotes are white. Genotypic fitnesses are as follows: wAA = 0.5, wAB = 1.0, wBB = 0.75. At equilibrium... |
both alleles segregate, and allele B is more common than allele A |
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Imagine a species distributed over a large geographic range containing a gradual environmental gradient and having different genotypes with greater fitness at opposite ends of the range. Which of the following patterns would you expect to find for the frequencies of genes over the entire range in the absence of gene flow |
There will be a step cline |
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Which of the following statements about natural selection is true? |
It can have an evolutionary effect only if phenotypic differences are heritable. |
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The proportion of phenotypic variance that is due to additive genetic difference among individuals is referred to as |
narrow-sense heritability |
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A character that is insensitive to alteration by environmental factors is |
environmentally canalized |
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The phenotypic effect of synergistic interactions among loci is referred to as |
epistatsis |
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Heritability estimates often inaccurately predict the change in a trait over many generations of artificial selection because the effects of |
Linkage disequilibrium New genetic mutations A change in the genetic variance Natural selection |
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Which of the ollowing represents the phenotypic variance (Vp) in a phenotypic trait |
Vg + Ve |
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Which of the following would likely cause the greatest mean evolutionary rates of morphological characters in a large population with a constant mutation rate? |
Directional selection |
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When the effect of the environment on a phenotype differs from one genotype to another in a population and the reaction norms of the genotypes are parallel |
an interaction is NOT needed in the components of phenotypic variance (Vg and Ve) |
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What is meant by "Evolution may proceed along 'genetic lines of least resistance'" |
Characters with little genetic variation will constrain the rate of natural selection, correlated characters may increase in fitness less rapidly, they can evolve only along the greatest axis of variation |
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QTL mapping is a method for detecting loci that contribute to quantitative trait variation. This method relies on the association between phenotypic difference and molecular markers. A QTL typically refers to a |
chromosome region that may include many genes |
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Anthropogenic climate change is taking place at such fast rate that many speices will fail to adapt quickly enough to avoid extinction. Which of the following may constrain evolution in response to human induced climate change |
1. Lack of heritable genetic variation for relevant traits 2. Genetic correlations between relevant traits and other traits that conflict with the direction of selection 3. Loss of genetic variation in relevant traits by genetic drift in dwindling populations 4. Lack of new mutations that allow adaptation to new climate conditions |
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The hypothesis that functionally related characters should be genetically correlated is called |
phenotypic intergration |
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Genetic correlations can have two causes ____ and ____ |
linkage disequilibrium pleiotropy |
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Stabilizing selection is often observed in nature because of |
trade-offs |
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The response of a quantitative character to selection depends on the heritability of the character and the selection differential. Response to selection will be greatest when heritability is ___ and selection is ___ |
0.75; 4 |
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In correlated selection, selection favors some combination of character states over others, usually because the characters |
are functionally related |
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George William's hypothesis--That senescence evolved because alleles that are advantageous early in life (e.g., those that increase reproductive effort) will be selected for even if they are deleterious later in life--is contingent on the existence of |
antagonistic pleiotropy: an allele that has a beneficial effect on on trait may have a deleterious effect on another |
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Which of the following environmental conditions is LEAST likely to select for an iteroparous life-history strategy |
Early reproduction |
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Which of the following situations would represent a trade-off between survival and reproduction |
1. Mating activity and egg production reduce the longevity of both sexes 2. survival to greater age comes at the expensive of early reproduction 3. Production of more inflorescences in the first season reduces productive vegetative growth in the second season 4. The production of many offspring results in smaller offspring |
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If new mutant strategy appears in a population that has adopted an evolutionary stable strategy (ESS), which of the following will result? |
The mutant strategy will not be able to increase in numbers in the population under the influence of natural selection |
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In ESS models, fitness is |
frequency dependent |
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When referring to the capacity of a population to grow, r equals the |
per capita rate of increase |
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Protogyny (hermaphroditism in which females switch to being males at some point in life) is favored when |
at large body size, male fitness increases more rapidly than female fitness does. |
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Which life-history strategy would maximize an individual's fitness compared with other possible strategies (and taking into account the existence of interactions with other individuals) |
Evolutionary stable strategy |
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Postreproductive survival, which is not generally favored by natural selection, may in fact be favored when |
postreproductive individuals provide parental care |
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According to life-history theory, species in which parents can provide only limited parental investment are also likely to have which of the following characteristics |
A negative correlation between offspring number and offspring size |
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What is the most likely explanation for the very low fecundity (offspring produced at each reproductive event" of species such as whales, humans, and elephants |
High investment in parental care |
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A life-history strategy where females reproduce more than once is called |
iteroparity |
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The two most accepted hypotheses for the evolution of senescence are based on the principle that |
The selective advantage of high probability of survival declines with age |
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because increased fecundity means increased fitness, we might expect to observe the evolution of ever-increasing fecundity, but this is not the case. Which of the following offers a plausible reason for lower than expected fecundity? |
There are allocation trade-offs between fecundity and other traits. |
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which of the following does NOT represent a life history trait |
Defense against predation |
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Whicho of the following statements is FALSE |
variation in matting success is generally greater in females than in males. |
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When the gain in reproductive success is a decelerating function of allocation to one sex or the other |
fitness of hermaphrodite exceeds that of a unisexual individual |
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Diocey ( separate males and females), and self-incompatibility promote |
outcrossing |
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Which of the following is NOT a form of asexual reproduction |
hermaphrodism |
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Mate preference by the opposite sex generally favors |
attractive and stimualtory features |
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Differences in the number of mates or in the reproductive capacity of individuals of one sex can be explained by the concept of |
sexual selection |
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What is the "twofold" cost of sexual reproduction |
Given equal fecundity, sexually reproducing females will produce only half the number of female offspring of asexually reproducing females |
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If a male that produces a larger quantity of sperm sires more offspring, sexual selection has been mediated by |
sperm competition |
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The effects of recombination on the rate of evolution are greatest in |
a large sexual population |
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Mutation rates are expected to evolve to the minimal achievable level because |
natural selection eliminates alleles that increase mutation rate, as most mutations are deleterious and recombination decouples them from beneficial mutants. |
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Which of the following has NOT been presented as a hypothesis to explain sexual selection by mate choice |
Scramble competition |
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Female swordtails prefer males fitted with plastic swords not only in sword-bearing species but also in species lacking swords. Females of the swordless species even prefer sword-bearing species over their own. This phenomenon is an example of |
sensory bias |
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Which type of sexual reproduction involves the development of offspring from an unfertilized egg |
Apomixis |
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Which of the following is NOT a hypothesized advantage of sexual reproduction |
it reduces the chances of producing defective offspring. |
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Which of the following sexual selection hypotheses would apply to a species in which females have evolved resistance to male inducements to mate, and their resistance selects for traits that enable males to overcome this resistance |
Chase-away sexual selection |
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Coyne and Orr's studies of reproductive isolation and genetic divergence between pairs of Drosophila populations and species showed that |
among recently diverged populations, premating isolation tends to be stronger than postmating isolation |
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(figure: gene tree population crested auklet/least auklet) What is the name of the phenomenon depicted in the figure |
Incomplete lineage sorting- failure of gene copies to coalesce within the duration of the species (the lineages coalesce in an ancestral species) |
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the notion that a species is a single lineage of populations or organisms thta maintains a separate identity from other lineages is called the |
evolutionary species concept: it has it's own evolutionary tendencies and historical fate |
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The difference between primary and secondary hybrid zones is that primary (sympatric) hybrid zones _____ while secondary (allopatric) hybrid zones _____ |
Primary: formed in situ as natural selection alters allele frequencies in continuously distributed populations Secondary: arise when two formerly allopatric species come in contact again |
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Suppose that two populations sharing many of the same gene lineages become reproductively isolated from each other over time, different lineages are lost in each population and eventually these populations may speciate. Which of the following describes how genetic lineages change over time in this hypothetical scenario |
polyphyly--->paraphyly--->monophyly |
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Even though species typically are defined by their reproductive isolation, the propensity of organisms to interbreed or to produce fertile offspring cannot always be determined experimentally. In the absence of experimentation, evolutionary biologist can infer reproductive isolation by measuring |
1.differences in phenotypic characters 2. whether loci are in Hardy-Weinberg equilibrium 3. total similarity of genetic markers 4. Whether independent genetic markers are in linkage disequilibrium or not |
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The biological species concept has been widely adopted, but it also has some practical difficulties. Which of the following is NOT one of these difficulties |
The concept is poorly defined |
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According to the biological species concept, speciation consists of the evolution of biological barriers to gene flow. The most important distinction is between ____ and ____ barriers |
prezygotic: before fertilization, prevent fertilization, and viable offspring postzygotic: after fertilization |
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refer to figure (Chromosome star)Which of the following is a likely outcome of this rearrangement |
Likelihood of anueploidy in the offspring of F1 individuals |
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Which of the following ideas is central to the biological species concept |
Reproductive Isolation |
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Which of the following terms refers to a variant of species that is associated with a particular type of habitat ( usually used with botanical literature) |
Ecotype |
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which of the following is NOT one of the possible fates of a hybrid zone? |
Extinction of all populations due to hybridization |
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In many groups of insects, the genitalia of related species differ in morphology, such as these three drosophila species below. One explanation for the difference is that this trait is not highly constrained... Another explanation involves: |
The "lock and key" hypothesis |
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Reproductive isolation as a result of Dobzhansky-Muller incompatibility is cause by |
the inability of tow or more loci from different lineages to function well together. |
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What class of barrier to gene flow would we be observing if we noted that the offspring of a lion and a tiger (liger!) are awkward, gangly beast that have poor survival in the wild?
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postzygotic barrier-offspring survived |
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Is the mind of a newborn human a blank slate (tabula ras)
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No, because the human mind has evolved over evolutionary time and shares some characteristics with the minds of other primates |
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What is theistic evolution |
The belief that God established natural laws (such as natural selection) and the let the universe run on its own, without further supernatural intervention. |
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What is the scientific basis for the research on model organisms (yeast, mice) that is funded by the National Institute of Health, with the aim of furthering our understanding of human disease |
Common ancestry |
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A scientific theory is |
a conceptrual framework that describes a large body of observations |
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Which of the following statements about evolutionary science is TRUE |
The fact that evolutionary biologists disagree about the number of matter does not mean that Darwin is wrong
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The release of natural enemies of a pest into the wild is called |
biological control |
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It is important to store "germ plasm" banks of different crop strains because |
genetic diversity is essential for a population's long-term success |
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In Dover, Pennsylvania, a 2005 court case resulted in a decision against the teaching of intelligent design in schools, Central to the judge's ruling was the concept that |
intelligent design is not a science |
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Which of the following is NOT a good justification for the teaching of evoultion |
To disprove religious texts |
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Evolution is an important foundation in which of the following fields |
1. Medicine 2. Psychology 3. Sociology 4. Anthropology |
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Which of the following DOES NOT provide strong evidence for the process of evoultion |
The complexity of biological organisms suggest that they have been specially designed |
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The most important feature of scientific hypotheses is that they |
are testable |
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Which of the following is NOT contested by evolutionary biologists |
The evolution of adaptive characteristics by the action of natural selection on random mutations |
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Which of the following would be a likely response of an evolutionary biologist to the claim that the "orderliness of the universe" is evidence of intelligent design |
The appearance of design to the universe is an emergent property of random process (mutation) and an non-random process (natural selection) |
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How might a vaccine develop benefit from evolutionary biology |
Epidemic strains can be predicted by looking for positive selection in virulence genes. |
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What conditions select for iteroparity |
1. High adult survival rates 2. Low rates of population increase 3. Young that require parental care 4. Very long lifespans |
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What characters represent a life-history trait? |
1. Age at sexual maturity 2. Adult body size 3. Age-specific fecundity 4. Time to first reproduciton |
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What Hypotheses explain sexual selection |
1. Direct benefits: selection of superior provider 2. Antagonistic coevolution: the ability to counteract the other sexes resistance to mating 3. Indirect benefits: runaway sexual selection, good genes model 4. Sensory bias |
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What are the difficulties with the biological species concept |
1. the concept cannot be applied to extinct species 2. many populations are allopatric 3. the concept does not apply to clonal organisms 4. testing reproductive isolation in the lab is not always feasible. |
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What are the possible fates of a hybrid zone |
1. persistence for an indefinite period of time 2. full reproductive isolation between populations 3. Merging of the semi-species into a single species 4. Evolution of some hybrids into a third species. |