Evolution Final

What is h for complete dominance?

0

What is meant by "non-trivial" in seeking an equilibrium in population genetics?

0 < p < 1

The rate of mutation to a recessive lethal allele is 0.000001. What is the equilibrium frequency this allele? Hint: lethal alleles cause death (lowest fitness).

0.001

Suppose you are studying a rare human genetic disease and find that the mutation rate for the disease causing allele is µ = 0.00012, and selection against the allele is s = 0.7. What would be the estimated equilibrium frequency for this recessive deleterious allele?

0.013

Consider a locus with two alleles, A1 and A2. If the rate of mutation of A1 to A2 is 0.0000025 and the rate of mutation from A2 to A1 is 0.0000010, what will be the equilibrium frequency of the A1 allele?

0.2857

What is h in the additive case?

0.5

Which one of these is the equilibrium frequency of the allele A2 ?

0.5

Human populations are polymorphic for the gene coding for myoglobin, with two alleles, A1 and A2. Tomoya Takata and his colleagues (Takata et al. 2002) found that in a small Japanese population, the frequency of the A1 allele was 0.755. If the population is in Hardy-Weinberg equilibrium, what are the frequencies of the A1A1, A1A2, and A2A2 genotypes, respectively?

0.57, 0.37, 0.06

In a population of birds, wing feather pigmentation is determined by a single gene with two incompletely dominant alleles, A1 and A2. Suppose genotype A1A1 confers dark brown wings, genotype A1A2 is light brown, and genotype A2A2 is light beige. In a population of 1000 birds, 350 have dark brown wings, 500 have light brown wings, and 150 have light beige wings. What is the A1 allele frequency in this population?

0.60

How many degrees of freedom should be used when testing for Hardy-Weinberg using the Chi Square test with 1 gene and 2 alleles?

1

What is the probability of rolling a 1 or a 6 on a die?

1/6 + 1/6 = 1/3

Consider a population that is in Hardy-Weinberg equilibrium at a locus with two alleles, A and a, at frequencies of p and q, respectively. Assuming the population remains in Hardy-Weinberg equilibrium, what is the expected frequency of Aa heterozygotes after 100 generations?

2pq

At an X-linked locus which has 2 alleles, how many different genotypes could there be in a population, maximum?

5

What is h for the underdominance case?

<0

Considering the phylogenetic evidence of feather evolution, all of the following might have been original functions of feathers EXCEPT

flight

According to the textbook, one strategy in conservation biology, when funding and other resources are limited, is:

focus attention on the hot spots, where new species appear more often, to maintain biodiversity.

What does it mean to say that Hardy-Weinberg is a mixed equilibrium?

frequencies of genotypes and alleles have different dynamics

Which of the following is Carolus Linnaeus (1707-1778) responsible for?

having the insight that organisms can be organized into a hierarchical system of classification without having a theoretical explanation for why these patterns should exist

An adaptation refers to a __________.

hereditary trait that makes organisms more fit in their environment and that has arisen as a result of the action of natural selection

The penguin's wing is used to swim. The hawk's wing is used to fly. These two wing types are:

homologous.

Charles Darwin's tree of life metaphor was used to describe:

how a common ancestral species has diverged into many species, with the various branches illustrating the relationships among species and groups of species.

Aristotle's scala naturae was a linear classification system that influenced Western thinkers for thousands of years (some would argue it still does). In this classification system, each species occupied a link in a chain that became increasingly complex. Also, the scala naturae:

included rocks and minerals. ranked organisms by degree of perfection. is refered to in English as the Great Chain of Being. is a hierarchy.

In order for traits to evolve by natural selection, individuals must experience differential reproductive success. This means that

individuals with certain traits are more successful than others in the population at surviving and reproducing.

Which of the following is an advantage of parsimony analysis?

it is conceptually simple

Which of these lines depicts the allele frequency of a recessive, advantageous allele?

line B

Which one of the lines on this graph represents the relationship between p and f[A2A2]?

line a

Consistency Index (C.I.) is:

lower when there is a lot of homoplasy.

What is w in population genetics?

mean fitness of the population

What does the "m" stand for in the formula for C.I.?

minimum number of changes for any conceivable topology

In sickle cell anemia, a point mutation leads to a replacement of one amino acid in a hemoglobin molecule, in a unit responsible for transportation of oxygen. This and any other mutation in a gene that causes a change in the amino acid sequence in a polypeptide chain is known as a __________ mutation.

missense

Lamarck's theory included:

multiple instances of spontaneous generation. transformational change (as opposed to variational). the Great Chain of Being. inheritance of acquired characteristics.

Although they serve no known current functions, vestigial traits may persist in some organisms for all of the following reasons EXCEPT that

natural selection cannot act to eliminate traits

The height of a yarrow plant (Achillea millefolium) depends on its genotype and the altitude at which it is raised. Suppose that one of the genotypes produces plants that are tall at low and high elevations and short at medium elevations. In this case, we would say that the genotype codes for the __________ in the yarrow plant.

norm of reaction for height

If the two sister species on the phylogenetic tree shown differ from the other two species in a single character state (e.g., dark or light fur), how many character state changes (evolutionary events) are needed to explain this pattern?

one

Sometimes, the probability of an event NOT happening is analyzed in population genetics models. What is that?

one minus the probability of the event actually happening

Most computer programs for reconstructing large phylogenies

only check a very small fraction of possible trees

An exaptation is a trait

originally selected for one function but later co-opted for a different function

Which are the most famous substitutions in population genetics? Select all the two that are correct. Students should know these by heart.

p + q = 1 p2 + 2pq + q2 = 1

What allele frequencies result in the highest frequency of heterozygotes in a population at Hardy-Weinberg equilibrium?

p = q = 0.5

Fr. Braverman's student Iggy worked on a one-locus, two-allele population genetics derivation. He used the traditional symbols, such that p = frequency [A1]. But he could not get all the way to the end of the derivation. Here is where he left off. Continue the derivation until you obtain p^. ∆p = 1 - q - s2

p^ = s2

Which of these represents the equilibrium for overdominance?

p^=t/s+t

The figure shows the relationship between femur diameter and body mass for a wide range of animals. This figure highlights the surprising finding that there are no organisms with large bodies and thin legs. What type of constraint has caused this?

physical constraint on bone strength

Consider the group shown here exclusively made up of these taxa: B, C, F, G. What is its "phyly"?

polyphyletic

Natural selection is a process by which the characteristics of a(n) __________ will change over time.

population

What is the unit of evolution?

population

What evolutionary process or processes tend to decrease the variation betweenseparate populations?

positive, directional natural selection (leading to local adaptation)

Long-term evolution experiments in laboratory populations of E. coli are valuable for all of the following reasons EXCEPT that they allow researchers to

precisely replicate natural populations of E. coli evolving in the wild.

An ancestral trait is characterized by:

presence in the common ancestor of a given tree.

The word "uniformitarianism" contains "uniform." What is uniform in this concept?

present and past

What is the definition of fitness?

reproductive success

This is a table of relative fitnesses for the genotypes shown. Which of these rows shows values consistent with the additive case of incomplete dominance?

row e

One example of studying natural selection in the field comes from decades of work on life history strategies in the guppy, Poecilia reticulata. A species' life history strategy refers to the __________.

schedule and manner of investment in survivorship and reproduction over the lifetime of an individual

One constraint on what natural selection can achieve comes from the fact that it lacks foresight. This means that Correct Answer

selection favors changes that are immediately beneficial, not changes that may be useful sometime in the future.

Synapomorphy

shared derived character

Give an example of a phenotype which is maintained in the population by overdominance (balancing selection).

sickle-cell anemia in regions of the world where malaria is present

What kind of equilibrium does overdominance produce?

stable

As opposed to uniformitarianism, the approach known as catastrophism explains that Earth's geological features are a result of

sudden, cataclysmic, and large-scale geological events.

Where does the 2 come from in "2pq"?

the addition rule of probability

James Hutton, a Scottish geologist and naturalist, argued that the earth was formed an inconceivably long time ago, based on:

the alignment of rock strata, the geological processes of erosion and sedimentation, and fossil data

What is the fundamental idea behind parsimony?

the best phylogeny is the one that both explains the observed character data and posits the fewest evolutionary changes for a group of taxa

When the Hardy-Weinberg assumptions are met, but the genotypic frequencies are not yet in Hardy-Weinberg Equilibrium:

the genotype frequencies take one generation of random mating to reach Hardy-Weinberg equilibrium.

A paraphyletic group contains:

the group's most recent common ancestor but not all of its descendants.

Long-branch attraction is

the inferring of too close a relationship between rapidly evolving species or populations.

The oldfield mouse study is a textbook example of hypothesis testing among natural selection (adaptation) studies. Which of the following is NOT correct regarding the main findings of this study?

Coat color in the oldfield mouse does not seem to have any adaptive value.

What does a phylogenetic tree's topology represent?

the qualitative relationships among taxa

Building on the ideas first proposed by James Hutton, Charles Lyell aimed to explain Earth's geological features using an approach known as uniformitarianism, which hypothesized that:

the same geological processes currently observable operate over very long periods of time in a slow and gradual manner.

What is "s" in population genetics?

the selection coefficient

What is s in population genetics?

the selection coefficient

Consider two events that are mutually exclusive, that is, if one occurs, the other cannot occur. The probability that either one will occur is ________, and the probability that both will occur is ________.

the sum of their probabilities; zero

German biologist Willi Hennig (1913-1976) established the modern approach to classification in his book Phylogenetic Systematics, where he described how to classify organisms according to which of the following?

their evolutionary histories

Robert Chambers, a Scottish geologist and author of Vestiges of the Natural History of Creation, is often overlooked for recognizing which critical aspect of evolutionary biology?

thinking of evolution in terms of populations and not individuals

Homologous traits are found in two or more species because

those traits have been inherited from a common ancestor.

How many different unrooted tree arrangements are possible for a phylogenetic tree relating four species?

three

Why do you need to use a statistical test (e.g., the chi-square test) to compare the observed genotype frequencies in a population to those expected under Hardy-Weinberg equilibrium

to assess whether the deviation of observed from expected frequencies is likely due to chance

What is the purpose of log transforming an axis of a graph?

to help visualize patterns by spreading otherwise clustered data points

The figure indicates a ________ between the number and size of offspring that a female guppy can produce.

trade-off

Based on the phylogenetic tree, which of the following is most closely related to mammals?

turtles

A mouse population contains hybrids between New Zealand Black (NZB) and New Zealand White (NZW) mice. NZW homozygotes are healthy, but NZB homozygotes experience autoimmune disease. NZB/NZW heterozygotes experience even more severe autoimmune disease (so much so that they are used as a model for the human autoimmune disease lupus). This situation is an example of __________.

underdominance

What are the requirements for natural selection on a trait?

variation of the trait in a population the trait must be heritable differential reproductive success due to some variants

To be an adaptation, a trait must:

was the result of natural selection makes organisms more fit in their environment be heritable

The figure shown demonstrates a type of equilibrium in which the marble __________.

will remain at its present location if it is not perturbed, but if it is perturbed, it will move even further from that location

According to the figure above,

yarrow plant with genotype 4 grow largest at medium elevation

Which of these represents an equilibrium?

∆p=0

What is the strategy for solving for equilibrium under overdominance and underdominance?

Look at the equation for parts that can be ignored since they cannot produce a ∆p = 0 under biologically realistic and non-trivial conditions.

The verbal model explaining the evolution of the sex ratio starts with what premise?

Male births are less common than female.

Archbishop James Ussher famously used the Old Testament of the Bible to estimate the date of creation as October 23, 4004 B.C.E. What is the significance of this in the history of the idea of evolution?

Many thinkers were working on this question, including Isaac Newton. The age of the earth proved critical to Darwin's theory of evolution.

Which of the following is NOT an assumption of the Hardy-Weinberg model?

Mating in the population is not random with respect to the locus in question.

Which of the following is an assumption of the Hardy-Weinberg model?

Mating is random with respect to genotype

One inputs character and taxa data into ___________ and then can run an exhastive search for the most parsimonious tree with _____________. Group of answer choices

Mesquite; PAUP

Which of the following best summarizes the process of evolution by natural selection?

Mutations that improve the fitness of individuals will tend to increase in frequency over time.

Why was it informative for researchers studying evolution of oldfield mouse coat color to find the genes responsible for the light coat color of many beach populations?

Natural selection can only result in evolutionary change if variation in the trait of interest has a heritable, genetic component.

The textbook presents in Box 1.1 a quantitative model about the sex ratio. What does it conclude?

Natural selection moves the sex ratio to 1:1.

The textbook examines in detail a study of the natural populations of guppies (Poecilia reticulata) in the waterfalls of Trinidad and Tobago. Upstream of such waterfalls, guppies typically face only mild predation pressure from one small species of fish. Downstream of the waterfalls, however, populations of guppies often are under severe predation pressure from voracious predators such as the pike cichlid. What life history strategy would be favored by natural selection in the upstream waterfalls?

Natural selection should favor females that can produce offspring that are relatively large and grow quickly.

In the guppies (Poecilia reticulata) of Trinidad and Tobago, natural selection may act differently in different locations of the waterfalls. Upstream of such waterfalls, guppies typically face only mild predation pressure from one small species of fish. Downstream of the waterfalls, however, populations of guppies often are under severe predation pressure from voracious predators such as the pike cichlid. What life history strategy would be favored by natural selection in the downstream waterfalls?

Natural selection should favor females that produce as many offspring as possible, rather than producing larger but fewer offspring.

Is the evolution of pesticide resistance in insects considered artificial selection?

No, but it is anthropogenic.

What would you advise to researchers in the following situation? A researcher is interested in the role of natural selection on the American toad as a way to study the effect of climate change. She intends on using the Hardy-Weinberg Equilibrium as a null hypothesis. If rejected, she could infer the evolutionary force at work. She samples 20 toads from Camden, New Jersey, and 20 toads from Philadelphia, Pennsylvania. The individuals are genotyped at one locus. Should the data from both groups be combined to test for Hardy-Weinberg?

No, do not combine, because the assumption of random mating is violated. If Hardy-Weinberg is rejected, she will not know if the cause is natural selection or nonrandom mating.

Aristotle's scala naturae was a linear classification system that influenced Western thinkers for thousands of years (some would argue it still does). In this classification system, each species occupied a link in a chain that became increasingly complex. Scala naturae did not recognize the shared degrees of complexity among organisms or the ability of species and taxa to change. Which of the following is an example demonstrating that organisms have shared degrees of complexity?

Nostoc (a cyanobacterium) and Helianthus (sunflowers, a vascular plant) have chloroplasts and conduct photosynthesis.

In developing his sex ratio theory, Sir Ronald A. Fisher assumed that sex ratio is under genetic control. Why is this an important assumption?

Only traits under genetic control can evolve by natural selection.

The figure illustrates an evolutionary trade-off in binocular vision in birds. Which of the following is NOT true regarding the trade-off in this case?

Ostriches have better binocular vision than owls because their eyes are set on opposite sides of their head.

The probability of two independent events occurring simultaneously is:

Pr(E1 and E2) = P1 x P2

Charles and Mary Brown found, in more than 30 years of studying cliff swallows (Petrochelidon pyrrhonota), that the number of swallow roadkill had significantly decreased and the average wing length of swallows in the population at large had decreased as well (Brown and Brown 2013). Which of the following scenarios could have resulted in these changes?

Swallows with shorter wings are more likely to survive in the face of oncoming vehicles, resulting in the population evolving shorter wings on average and dying less often as the result of road kill.

Which of these is variational change, analogous to variational evolution?

The San Lomita Earthquake of 1989 destroyed many buildings, except those built with earthquake-resistant provisions.

Which of these describes the mixed equilibrium of Hardy-Weinberg?

The allele frequencies are a neutral equilibrium, and the the genotypic frequencies are a stable equilibrium.

What makes a character parsimony-informative?

The character can distinguish among different hypotheses.

What were Charles Darwin's two fundamental insights about the process of evolution?

The environment selects on variation in the traits of individual organisms, and all species have descended from one or a few common ancestors.

What is special creation?

The idea that each species was created in its current form by God.

Charles Darwin believed that cranial sutures present in modern birds, reptiles, and mammals evolved prior to the evolutionary split between these three groups (see Figure 3.26). What is the best explanation for the evolution of this complex trait?

The original selective advantage of cranial sutures was probably to allow the rigid protective cranium to expand with a growing brain, and this function is retained.

What is the difference between the situations shown in the red and yellow lines?

The red line shows a dominant allele; the yellow line shows a recessive allele.

How does hypothesis-testing apply to inferring phylogenetic trees using parsimony?

The tree (hypothesis) with the most support is chosen.

The graph shows the distribution of fitness effects of Bacteriophage f1 mutants. Note that values greater than 1.0 indicate beneficial mutations, whereas values less than 1.0 indicate deleterious mutations. What is the best conclusion from this study?

The vast majority of the mutations had a deleterious effect, but some were beneficial.

What did David Reznick and his coworkers do to test whether the life history strategies of the guppies (Poecilia reticulata) were indeed adaptations to their selection pressures in the upstream and downstream waterfalls of Trinidad and Tobago?

They transplanted guppies from high-predation sites below a waterfall to low-predation sites above a waterfall to test whether descendants of transplanted individuals evolved adaptations to their new selection.

In the scenario depicted in the figure, what will happen to the allele frequencies on the island? Assume there is no selection or mutation, mating is random, and the population sizes are large.

They will become more similar to those on the mainland.

Many models of the evolutionary consequences of mutation assume that the rate of back mutation is negligible. When is this a reasonable assumption?

When we are considering a protein where forward mutation leads to a nonfunctional protein and back mutation leads to a functional protein.

Among animals, the blue whale has the largest brain size. Should humans attempt to communicate with them? Group of answer choices

Yes, but their brain size might only be large due to their large body size.

Anaximander's contribution to the history of the idea of evolution was:

a mechanical paradigm of the world.

What does a species' life history strategy refer to?

a schedule and manner of investment in survivorship and reproduction over the lifetime of an individual

Vestigial traits:

actually support Charles Darwin's theory of evolution.

In the interaction between predators and prey, we frequently observe prey becoming increasingly good at escaping predators, and predators increasingly good at capturing prey. This is an example of __________.

an evolutionary arms race

What is a scientific hypothesis?

an explanation of a phenomenon based on natural processes

According to the phylogenetic tree shown, fungi are most closely related to which of the following?

animals

Antibiotic resistance evolves quickly because

antibiotics impose strong selection for resistance.

Suppose you are trying to build a phylogenetic tree using parsimony. You are workign with 5 taxa and 5 characters. The results are in the following table. Each letter codes for a different character state. Which characters are parsimony-informative?

b only

Which of these graphs illustrates phenotypic plasticity?

c (the one that criss crosses)

In the figure, the hierarchically arrayed groups indicated by the shaded gray boxes are called ________ by modern evolutionary systematists.

clades

Evolutionary change in one species that affects the selective conditions for a second species is known as which of the following?

coevolution

Bats and hummingbirds both have wings and can fly. This is due to:

convergent evolution.

A mutation resulting in deletion of a protein-coding gene will most likely have a ___________ effect on fitness.

deleterious

Charles Darwin's definition of evolution

descent with modification

When a researcher finds genotypic frequencies in a sample from a population to be about the same as those predicted by the Hardy-Weinberg equilibrium, what is the appropriate language for discussing this result?

Hardy-Weinberg Equilibrium cannot be rejected

What was Yule's mistake?

He thought frequencies in a population were also a stable equilibrium, just like the genotypic frequencies.

What is the difference between a rooted and unrooted tree?

A rooted tree shows "directionality," meaning movement from past to present.

In what way is artificial selection different from natural selection?

Artificial selection relies on humans choosing which traits are beneficial

Suppose that you collected genotype frequency data from a natural population. If you found that the expected genotype frequencies differed significantly from your observed genotype frequencies, which of the following could you conclude?

At least one evolutionary process is operating in this population.

In their experiment in 1943 using E. coli, Salvador Luria and Max Delbrück tested two alternative hypotheses. The random mutation hypothesis and the acquired inherited resistance hypothesis make different predictions about the distribution of resistant mutants that will be observed upon exposure to bacteriophage (viruses that can infect and kill E. coli). Which of the following predictions, if proven, would support the acquired inherited resistance hypothesis?

At the time of exposure to the phage, all E. coli cells will be phage-sensitive. The process of exposure to the phage will induce phage resistance in a small fraction of the bacterial cells.

The figure shows the wing length of cliff swallows that died as road kill and of the population at large. What do these data indicate about natural selection acting on wing length in cliff swallows?

Birds with longer wings are more likely to die as road kill, so natural selection favors birds with shorter wings.

What was one of the ideas that separated Charles Darwin's On the Origin of Species as a complete, scientific explanation for evolution when compared to all other previous attempts?

Darwin articulated a mechanistic explanation for change in species over time and the match between organisms and the environment.

How did Charles Lyell and his writings influence Charles Darwin?

Darwin took ideas from geology and applied them to living things

Humans have 23 pairs of chromosomes and chimps have 24 pairs. How has this difference best been explained?

Humans have one chromosome that is the result of a fusion of two chromosomes in our ancestors.

What is different between a rooted and unrooted tree?

Direction on a rooted tree indicates the passage of time

Which of the following examples best illustrates the concept of spontaneous generation?

During flooding, frogs spontaneously arise from mud.

The exquisite complexity of traits such as the vertebrate eye seems to pose a problem for evolution by natural selection. How do evolutionary biologists think that complex eyes evolved?

Eyes evolved in gradual steps, each of which was fully functional and adaptive in improving visual acuity.

The figure shows the relationships among featherless and feathered dinosaurs and birds. Based on this phylogeny, what can you say about the evolution of feathers?

Feathers are an exaptation for flight

If testes size is correlated with number of sperm produced, under what condition is larger testes size more likely to be evolutionarily advantageous?

Females mate with multiple males.

Following an intense drought in 2000 to 2004, descendant populations of Brassica rapa flowered much earlier in the season than those from predrought populations. Researchers agreed that this could be a result of strong selection during these four years. For natural selection to act on flowering time in B. rapa, all of the following must be true, except

Flowering times must differ depending on the environment in which a plant is grown.