Evolution Test 2
polymorphism
A locus at which different individuals in a population carry different alleles is known as a(n) ________.
When Bradshaw and colleagues investigated the quantitative trait loci (QTL) of two species of Mimulus (Mimulus cardinalis and Mimulus lewisii), they used marker loci as a way to map the QTLs. Their results are shown in the accompanying figure. According to these results,
All of the above
Haploid genotypes involving two loci, such as AB, Ab, aB, and ab, are known as an organism's ________.
Haplotype
migration
In an evolutionary sense, ________ is the transfer of alleles from one population to another.
d
Suppose a founding population carries an allelic frequency not typical of the original population. Which of the following effects would most likely lead to homogenization? A) genetic drift within the founding population B) random mating within the founding population C) no mutations within either population D) migration between the original and founding populations E) None of the above.
founder effect
Suppose a large population exists on a continent, and a new population is formed by the migration of a few individuals to an island some distance away. The fact that the alleles being carried to this island are not going to be a complete and representative set, as compared to the continental population, is a case of genetic drift known as the ________. [two words]
The probability that two mutually exclusive events will occur is calculate by
adding the probability of each individual event
The effects of inbreeding depression has been documented in
both plants and animals
in the study of Gigord and colleagues using Elderflower orchids, the allele frequencies of yellow and purple flowers varied such that when the yellow allele started to become rare, the reproductive success of purple flowers decreased and the reproductive success of yellow-flowered individuals increased in a process known as?
frequency-dependent selection
The total variation in a trait is known as the _____ _____
phentotypic variation
In experiments by Greene and colleagues (1987) with the tephritid fly Zonosemata vittigera and the jumping spider Phidippus apacheanus, the purpose for gluing housefly wings onto the bodies of the tephritid fly was to ________.
test for effect of wing markings in preventing predation
When Clausen and colleagues grew genetically identical individuals of the yarrow plant at different elevations, the results are shown in the accompanying figure. This observation verifies that
the genotypes of yarrow plants interacts with environmental influences to produce the phenotype
Heritability measures _____
the portion of the total variation in a trait that is due to variation in genes
In experiments with Caenorhabditis elegans by Anderson and colleagues (2011), the relationship between physiological performance and temperature was measured. This type of measurement is termed a ________.
thermal performance curve
hitchhiking (or selective sweep)
A phenomenon known as ________ [one or two words] occurs under conditions where a strong selection pressure acts on a particular change in an amino acid, which results in the corresponding increase in frequency of a closely linked neutral (or even mildly deleterious) mutation.
background selection
A phenomenon known as ________ [two words] occurs under conditions where a selection pressure works against deleterious mutations, resulting in the corresponding decrease in the frequency of a closely linked neutral mutation.
d
Although most of the mechanisms of evolution are nonrandom, the one that is absolutely random is ________. A) sexual selection B) natural selection C) artificial selection D) genetic drift
c
At present, the neutral theory of molecular evolution ________. A) is strongly supported by significant amounts of empirical evidence B) has been disproven, as neutral mutations have not been shown to have been fixed in populations C) is inclusive, as enough data has not yet been evaluated D) seems to work in some species but not others
c
Gene flow through migration ________. A) has no effect on allele frequencies of populations B) can go only in one direction C) may have the largest impact on small populations, such as those on islands D) maintains the Hardy-Weinberg equilibrium
The null hypothesis, which demonstrates that evolution is not occurring from generation to generation is known as the ________________ model
Hardy-Weinberg
c
In terms of the Hardy-Weinberg equilibrium, genetic drift results from a violation of ________. A) the random mating assumption B) the lack of natural selection assumption C) the infinite population size assumption D) the lack of mutation assumption E) the lack of migration assumption
The explanation for the accumulation of deleterious alleles in asexual populations over time, with the resulting genetic load, is known as _____
Muller's ratchet
c
The assumptions of the Hardy-Weinberg equilibrium principle include all of the following except ________. A) random mating B) no migration C) limited population size D) All of these are assumptions of Hardy-Weinberg.
c
The effects of inbreeding depression has been documented in ________. A) plants only B) animals only C) both plants and animals D) This is a hypothetical construct and has yet to be documented.
genetic drift
The fact that blind luck (more technically known as sampling error) can account for changes in allelic frequencies in populations is the evolutionary mechanism called ________. [two words]
a
The neutral theory of molecular evolution, as developed by Kimura, posits that ________. A) functionally neutral mutations that become fixed in populations occur in much larger numbers than those that become fixed by natural selection B) functionally neutral mutations never become fixed in populations without some element of selection also acting on them C) functionally neutral mutations are not subject to genetic drift D) functionally neutral mutations contribute very little to changes at the molecular level
sampling error
The random discrepancy between theoretical predictions and actual outcomes is called ________. [two words]
inbreeding depression
The survival and fertility rates of the offspring of related individuals are commonly reduced. This is known as ________. [two words]
b
There are occasions when theoretical expectations do not match with actual outcomes, as you see in the case of zygote formation leading to genetic drift. This discrepancy is known as ________. A) sampling bias B) sampling error C) nonrandom mating D) random mutations
d
Unusually high rates of rare heritable traits, such as achromatopsia in the Pingelapese people, is often due to ________. A) genetic drift B) natural selection C) hitchhiking D) the founder effect E) None of the above.
The fraction known as the broad-sense heritability (where VG = genetic variation, VP = phenotypic variation, and VE = environmental variation) is expressed by
VG/VP and VG/VG + VE (A and B are both accurate)
coalescence
When we track alleles from lineages backwards in time, we see them ultimately fuse into one lineage. The result is a gene tree, which is produced by a process called ________.
a
With enough time and in the absence of other evolutionary mechanisms, genetic drift will ________. A) reduce the genetic variation in a population B) increase the genetic variation in a population C) have no effect on the genetic variation of a population D) None of the above.
inbreeding
________, the most common type of nonrandom mating, will not change allelic frequencies, but it will change genotypic frequencies toward homozygosity.
Certain loci that are in linkage disequilibrium with alleles of interest can be used as markers, which can then be useful in reconstructing the history of those alleles in populations. One such marker/allele is describe in your text, where the allele in question has an insertion mutation, rendering an enzyme (glucocerbrosidase, or GBA) nonfunctional. The decay curve for linkage disequilibrium between this marker (named D1S305) and the nonfunctional GBA allele is shown in the accompanying figure. The orange lines show the present level of linkage disequilibrium and the inferred number of generaitons elapses since the most recent common ancestor. Assuming an average generation time of 25 years, how many years total will be require for the linkage disequilibrium to reach 0.2?
about 2500 years total
A principle advantage of sexual reproduction is that it
all of the above
if a population is in Hardy-Weinberg equilibrium, which of the following statements is correct?
allele frequencies must remain the same from generation to generation
An advantage to studying linkage disequilibrium is that
both A and C (it provides another tool enabling the reconstruction of the history of genes and populations AND it can be used to identify alleles that have been recently selected by natural selection)
In experiments by Greene and colleagues (1987) with the tephritid fly Zonosemata vittigera and the jumping spider Phidippus apacheanus, carefully controlled experiments demonstrated that ________.
both wing-waving by the tephritid fly was sufficient to prevent predation
when we track alleles from lineages backwards in time, we see them ultimately fuse into one lineage. the result is a gene tree, which is produced by a process called
coalescence
In cases where selection consistently favors a higher (or lower) value of a trait or phenotype, the result over time is a change in the average value of a trait in the population. This mode of selection is known as ________.
directional selection
Data on survival of juvenile black-bellied seedcrackers as a function of beak size is shown in the accompanying figure. Given the relative survival rates of juvenile birds in terms of both the lower mandible width and length, this is a clear example of _____
disruptive selection
Variation among individuals that is due to factors other than genetic factors is called ________.
environmental variation
variation among individuals that is due to factors other than genetic factors is called ____
environmental variation
suppose a large population exists on a continent, and a new population is formed by the migration of a few individuals to an island some distance away. the fact that the alleles being carried to this island are not going to be a complete and representative set, as compared to the continental population, is a case of genetic drift known as the?
founder effect
Besides selection on multilocus genotypes, there are two other mechanisms that can create linkage disequilibrium. What are they?
genetic drift and population admixture
which of the following can produce linkage disequilibrium?
genetic drift, selection on genotypes of more than one locus, and mixing two disparate populations, each of which is in linkage equilibrium (all of the above)
The creation of new combinations of alleles, as a consequence of sexual reproduction with meiosis is called
genetic recombination
The principle advantage of sexual reproduction is that it 'reshuffles the genetic deck.' The creation of new combinations of alleles during sexual reproduction-complete with outbreeding and meiosis and crossing over-is called _____
genetic recombination
To demonstrate the response of several Daphnia genotypes across a wide range of environments, Luc De Meester (1996) measured the change in phototactic behavior of Daphnia sampled from lakes that contained different numbers of predatory fish. Some genotypes altered their behavior in the presence versus absence of fish. The variation in response is termed ________.
genotype by environment interaction
_____refers to the fraction of the total variation in a trait that is due to variation in genes.
heritability
It becomes possible to predict evolutionary changes in a population after we have measured two attributes affecting the population in question. What two measures allow us to make such predictions?
heritable variation; strength of selection
Alleles that are relatively new to a population and have been subject to positive natural selection are characterized by having
high frequency and high linkage disequilibrium
To learn the location of and determine the role that QTLs have on phenotypes, researchers look for associations between a marker locus genotype and phenotype. Examples of research focusing on such methods have been conducted on
human personality traits, human disease such as Crohn's disease, the speed of thoroughbred race horses(All of the above)
When genotypes at one locus of a chromosome are independent of genotypes at another locus of the same chromosome, the two loci are
in linkage equilibrium
If there is a nonrandom association between the genotypes at two loci on a chromosome, the loci are said to be in
linkage disequilibrium
When considering two loci on a chromosome, the loci are said to be in ________________ when the genotype at one locus is independent of the other
linkage equilibrium
Bush and colleagues (2010) photographed body and head lice on several cockatoos and compared the ________ of the lice on the bird's bodies and heads.
luminosity
in an evolutionary sense, _____ is the transfer of alleles from one population to another.
migration
Suppose a founding population carries an allelic frequency not typical of the original population. Which of the following effects would most likely lead to homogenization?
migration between the original and founding populations
the point at which the rate that a deleterious allele is being eliminated from a population by natural selection is in equilibrium with the rate at which the deleterious allele is being replaced by a new mutation is termed?
mutation-selection balance
Determining the best-fit line for a data set by utilizing the least-squares linear regression, the slope of the resulting line represents a useful estimate known as the ________, [two words] for which we use the symbol h2.
narrow-sense heritability
Determining the slope of the best-fit line for a data set of midparent versus midoffspring values by utilizing least-squares linear regression generates an estimate of heritability known as the ______
narrow-sense heritability
Type A snakes are unbanned, Type B are strongly banded, and types C and D are intermediates. Given that natural selection favors unbanded snakes on the islands, how can you account for the presence/perpetuation of banded snakes on the islands?
natural selection favors banded snakes on the mainland, which occasionally migrate to the islands
which of the following choices is NOT a potential disadvantage to sexual reproduction
none of the above
Continuously variable traits typically have a _____ _____ otherwise known as a "bell-curve."
normal distribution
In the mating of an Aa female and an Aa male, the genotypic outcome predicted by a Punnett square is
one-quarter AA, one-quarter aa, and one-half Aa
In large populations, the Hardy-Weinberg equilibrium principle can be used to determine whether evolution is occurring. For instances where allelic frequencies are indicated by p and q, the resultant genotypic frequencies are indicated by which of the following equations?
p2+2pq+q2
The mode of reproduction in which females produce genetically identical offspring from unfertilized eggs is known as _____
parthenogenesis
When a locus is discovered to be in linkage disequilibrium with nearby markers, and this allele is found to occur in high frequency, it is logical to assume that this allele has been favored by ______ _____
positive selection
The abbreviation QTL stands for ________, [three words] which are those genes that influence nonqualitative traits.
quantitative trait loci
Traits that are conditioned by multiple loci and form continuously variable phenotypes that are conditioned by both the genotypes and environmental influences are most appropriately termed _____
quantitative traits
The experimental work of Edward East in 1916, shown in the accompanying figure, confirmed that _____
quantitative traits are established by the combined influence of Mendelian alleles at multiple loci
With enough time and in the absence of other evolutionary mechanisms, genetic drift will
reduce the genetic variation in a population
if there were a high allele frequency for the CCR5-32 coreceptor, and the rate of infection with HIV was high as well, one would expect the frequency of the CCR5-32 coreceptor allele to?
rise quickly and confer resistance on a large part of the population
The authors of your textbook described two ways in which the strength of selection can be measured. What are these two ways?
selection differential; selection gradient
which of the following reduces linkage disequilibrium by disrupting overrepresented haplotypes and by generating new ones
sexual reproduction, genetic recombination, crossing over(all of the above)
In populations where individuals with intermediate values of a trait have the highest fitness, the average value of the trait does not change over time, but the variation tends to be reduced. This set of circumstances is known as ________. [two words]
stabilizing selection
If genetic drift is not accompanied by natural selection, mutation, or migration, than the frequencies of alleles will "wander" between 0 and 1. Using the accompanying figure what is an accurate statement?
the effects of genetic drift more immediate, and more pronounced, on small population sizes
