BIO 2700 (Evolution) Final Study Guide

C. three

(Fill in the blank) If you were to apply the phylogenetic species concept to groups A-D identified in the figure below, you would conclude that there are _____ species. A. one B. two C. three D. four

B. False

A behavioral biologist was interested in the role of relatedness on survivorship in a small population of zebra finches. To examine this problem, he looked at the relationship of hatchling survival to relatedness and observed the relationship in the figure below. From this study you should conclude that there is no relationship between inbreeding and fitness. A. True B. False

A. Inbreeding increases the frequency of homozygotes for deleterious, recessive alleles.

A behavioral biologist was interested in the role of relatedness on survivorship in a small population of zebra finches. To examine this problem, he looked at the relationship of hatchling survival to relatedness and observed the relationship in the figure below. Given your knowledge of inbreeding coefficients, which of the following is the most likely explanation for the observed pattern? A. Inbreeding increases the frequency of homozygotes for deleterious, recessive alleles. B. Inbreeding prevents selection from favoring heterozygotes. C. Inbreeding increases the rate of mutation, producing more deleterious alleles. D. Chance variation associated with sampling error.

B. Patient A likely contracted HIV from the doctor, but patient B likely did not.

A doctor and two of his patients are discovered to be HIV positive. It is suspected that the patients may have been accidentally infected by the doctor. A phylogenetic study of the HIV within these three individuals, as well as six random HIV positive citizens of the city in which they live is conducted (see figure below). What conclusions would you draw from this? A. Both patients likely contracted HIV from the doctor. B. Patient A likely contracted HIV from the doctor, but patient B likely did not. C. Patient B likely contracted HIV from the doctor, but patient A likely did not. D. Neither patient likely contracted HIV from the doctor.

B. species with dispersal of fruit have reduced rates of extinction (longer persistence times) relative to those that do not disperse their fruit.

A plant paleontologist has been studying extinction rates in fruiting plants. They were able to identify plants that are term-76dispersed by animals and those that are not dispersed at all, just dropping their fruit near the base of the plant. Using this information, they examined the fossil to determine how long species would persist before going extinct. These were then separated by whether or not fruits were dispersed (Figures A and B below). Based on this result, one can conclude that: A. dispersal of fruit has no impact on species persistence in the fossil record. B. species with dispersal of fruit have reduced rates of extinction (longer persistence times) relative to those that do not disperse their fruit. C. species with dispersal of fruit have increased rates of extinction (shorter persistence times) relative to those that do not disperse their fruit. D. this comparison provides no information on persistence time of species.

B. 1, 2

A researcher set up 200 independent experimental populations of mice, each consisting of 16 mice (8 males and 8 females) that were all heterozygous for a brown and white allele for coat color. All lines were kept in separate cages and never intermixed throughout the experiment. The lines were maintained by randomly selecting and transferring 8 male and 8 female offspring from one cage into a new cage to start the next generation (we can ignore natural selection), maintaining all 200 lines independently. If this experiment were allowed to run for a very long time (to equilibrium) and mutation cannot occur, the number of genotypes in any individual population at equilibrium would be ____________ while the total number of genotypes found in our sample of 200 cages would be ____________. A. 1, 1 B. 1, 2 C. 2, 1 D. 2, 2

A. Population 1,

A. Population 1,We have tested for selection at one locus with two alleles in four different populations, with the results portrayed below. Assuming all other Hardy-Weinberg assumptions are in effect, selection has the LEAST impact in: A. Population 1, B. Population 2, C. Population 3, D. Population 4.

B. False

Adaptation is the process by which organisms identify and produce needed genetic variants that allow them to the survive in the environment that they live in. A. True B. False

A. True

Adaptive potential of a species is directly related to levels of genetic variation because the more genetic variation an organism has, the more opportunities there are to develop adaptations to changing environments. A. True B. False

C. The small number of flu cases in 2020-21 made it a difficult to predict what flu viruses to vaccinate against in 2021-2022.

After an unusually mild flu season in 2020-21, there has been a resurgence of the flu this year (2021-2022). A recent report indicated that the flu vaccine is only 16% effective this year, whereas it is normally 40-60% effective. Which of the following is likely the best explanation for the poor performance of the flu vaccine this year? A. Flu vaccines don't work. B. The flu virus is evolving more rapidly this year than in previous years. C. The small number of flu cases in 2020-21 made it a difficult to predict what flu viruses to vaccinate against in 2021-2022. D. All of the above are true.

B. False

All variation in phenotypic traits that has a genetic basis is adaptive. A. True B. False

A. True

An organisms' physical appearance can be influenced by genetic factors, the environment, and the interaction between genes and the environment. A. True B. False

B. frequency dependent selection

Bacteria are generally haploid organisms that reproduce asexually. A strain of Heliobacter pylori (the haploid bacterium that often causes ulcers) is found to have low levels of genetic variation at a locus encoding a membrane protein. If we assume this variation is maintained by selection, the most likely explanation from the list below would be: A. directional selection B. frequency dependent selection C. selection favoring heterozygotes D. selection against heterozygotes

C. inductive reasoning

Bettas, a small aquarium fish, can breathe air. Since we know that a betta is a fish, we conclude that all fish can breathe air. This statement is an example of: A. hypothesis testing. B. deductive reasoning. C. inductive reasoning. D. lack of reason.

B. differences in phenotype must be genetically based for natural selection to be effective.

Both phenotype and genotype are important to evolutionary biologists because: A. genotypes can only be inferred by directly examining phenotypes. B. differences in phenotype must be genetically based for natural selection to be effective. C. genotypes are the sole factor in determining phenotypes. D. All of the above statements are true.

B. False

Darwin's knowledge of how traits were inherited was a key component in his formulation of the theory of evolution by natural selection. A. True B. False

D. All of the above

Each of the different species concepts has clear pitfalls, making choice of a single concept difficult. We have applied the biological species concept in this class, a definition based on reproductive isolation between distinct species. Which of the following would be limitations of this concept? A. It is of little use when defining fossil species. B. It cannot be applied to species that use asexual reproduction. C. It can be subjective, particularly when considering allopatric taxa. D. All of the above

D. The taxonomy (e.g., assignment to families) accurately reflects evolutionary history of these taxa.

Early studies of DNA sequences from humans (family Hominidae) and other primates (placed in the family Pongidae) provided the rooted phylogenetic tree below. Which of the following conclusions is NOT consistent with this result? A. Based on this study, we cannot identify precise relationships among human, gorilla, and chimps. B. Orangutan is the most divergent lineage of the taxa studied. C. Hominidae represent a monophyletic group. D. The taxonomy (e.g., assignment to families) accurately reflects evolutionary history of these taxa.

A. True

Even though mutation is a weak evolutionary force and selection can be very powerful, mutation can maintain harmful alleles in natural populations. A. True B. False

B. False

For animals, speciation CANNOT occur in the absence of geographic isolation. A. True B. False

D. All of the above are true.

Gene duplications have been important in the process of evolution because: A. extra copies of a gene provide more places for mutations to occur. B. extra copies of a gene are free to evolve new functions. C. extra copies of a gene can move to different locations in the genome, becoming involved in different linkage groups. D. All of the above are true.

B. it reduces the impact of drift by effectively increasing size of subpopulations,

Gene flow among finite subpopulations is important because: A. it prevents drift from occurring. B. it reduces the impact of drift by effectively increasing size of subpopulations, C. it reduces the impact of drift by effectively decreasing size of subpopulations, D. it has no impact on subpopulations.

A. True

Gene flow is a powerful evolutionary force that can overcome the effects of natural selection and drift in certain circumstances. A. True B. False

D. random sampling of a finite number of gametes each generation.

Genetic drift results from: A. the randomness of mutation. B. independent assortment of alleles within the effectively infinite number of gametes produced each generation. C. transmission of favorable alleles each generation. D. random sampling of a finite number of gametes each generation.

D. Decrease genetic variability within populations but increase genetic variability between populations.

Genetic drift will tend to: A. Increase genetic variability both within and between populations. B. Decrease genetic variability both within and between populations. C. Increase genetic variability within populations but decrease genetic variability between populations. D. Decrease genetic variability within populations but increase genetic variability between populations.

B. Dispersal among these three land masses after their separation produced this pattern and timing of divergence.

Gondwana is the southern supercontinent that was hypothesized to have broken apart due to continental drift. Africa was hypothesized to have separated first, about 100 mya, with South American separating from Australia and New Zealand about 35 mya. The freshwater fish family Galaxiidae has representative species that are found in southern Africa (AF), South America (SA), and Australia (AU); therefore, they provide a valuable test of this hypothesis. Molecular studies were used to generate the phylogenetic tree and divergence time estimates in the figure below. Based on these results you would conclude that: A. Vicariance associated with the break-up of Gondwana produced this pattern and timing of divergence. B. Dispersal among these three land masses after their separation produced this pattern and timing of divergence. C. Both vicariance associated with the break-up of Gondwana and dispersal after separation played a role in explaining producing this pattern. D. This approach cannot be used to test biogeographic hypotheses.

B. HIV evolves more rapidly than our ability to eradicate it.

HIV is a significant human health concern, causing AIDS. It has been difficult to develop treatments for this disease because: A. Humans don't make antibody to HIV. B. HIV evolves more rapidly than our ability to eradicate it. C. HIV does not respond to drug treatments. D. All of the above statements are true.

D. All of the above statements are true.

Hardy-Weinberg equilibrium is important to evolutionary biologists because: A. it demonstrated that application of Mendel's principles to the population level could result in unchanging allele and genotype frequencies over time. B. it provides a framework for quantifying the impact of specific factors like mutation, selection, and genetic drift that cause evolutionary change. C. it provides a null hypothesis, allowing for tests of evolutionary forces in the lab and nature. D. All of the above statements are true.

A. True

Homeotic genes (e.g., HOX and HOM) are important regulatory genes that have increased in number during the evolution of animals and have likely been important for major morphological innovations in this group. A. True B. False

D. All of the above are possible explanations.

In a species of bird, cost of reproduction is higher for females than males. You would expect these females would be selective and choose their mates based on: A. what they look like because that is an indicator of superior genetic quality. B. the direct benefits (e.g., gifts of food) provided by the male. C. specific traits that they may be genetically programmed to select for in males. D. All of the above are possible explanations.

C. They need to search for another target gene as this locus is not exhibiting signs of positive selection.

In their studies of the evolution of corn, scientists noticed that a specific variant of corn kernels seemed to be resistant to the action of corn worms. They mapped this variation to several regions, but decided to focus on a single gene locus on chromosome 3 and sequenced the region containing this locus to contrast expected (dashed line) and observed patterns of variation (solid line) under the neutral model (results in figure below). Based on this result, the scientists should conclude that: A. Resistance to corn worms is not genetic. B. This locus is under positive selection and responsible for resistance to corn worms. C. They need to search for another target gene as this locus is not exhibiting signs of positive selection. D. These experiments tell us nothing about selection.

A. genotypic fitness may vary across environments.

It is important to consider the environmental context of variation because: A. genotypic fitness may vary across environments. B. organisms can acquire heritable change by responding to their environment. C. the use of mathematical models to study selection requires it. D. my professor told me I had to.

B. Lake Michigan

Lake trout were once common throughout the Great Lakes. Overfishing has resulted in a reduction in the number of populations, and it is now heavily managed to maintain its existence. Managers want to develop a hatchery stock of lake trout for use in recolonizing populations that have been lost. Scientists collected samples of 20 individuals from each of three Great Lakes (Michigan, Superior, and Huron) and characterized levels of morphological and genetic differences among populations. The phylogenetic tree below is based on genetic data, with the different boxes indicating geographic sources of samples. Given this information and our discussions on conservation, which stock would you select for hatchery propagation? A. Lake Huron B. Lake Michigan C. Lake Superior D. They are all the same so it doesn't matter

D. 3

Lake trout were once common throughout the Great Lakes. Overfishing has resulted in a reduction in the number of populations, and it is now heavily managed to maintain its existence. Scientists collected samples of 20 individuals from each of three Great Lakes (Michigan, Superior, and Huron) and characterized levels of morphological and genetic differences among populations. The phylogenetic tree below is based on genetic data, with the different boxes indicating geographic sources of samples. Given this information you would conclude that there are _____ evolutionarily significant units. A. 0 B. 1 C. 2 D. 3

A. a preadaptation due to the action of natural selection favoring this modification.

Mammary glands in mammals are modified sweat glands. This evolutionary transformation is an example of: A. a preadaptation due to the action of natural selection favoring this modification. B. convergent evolution of sweat glands and mammary glands. C. neutral evolution. D. genetic drift.

B. Low levels of gene flow will allow populations to become genetically different, requiring special protection for these genetically distinct forms.

Most fishes native to the Colorado River of the western United States are endangered, mainly due to excessive water use and introduction of nonnative fishes. Biologists have expressed particular interest in evolutionary parameters to assist in their efforts to protect and maintain these species. Management of these fishes requires knowledge of gene flow because: A. High levels of gene flow will allow populations to become genetically different, requiring special protection for these genetically distinct forms. B. Low levels of gene flow will allow populations to become genetically different, requiring special protection for these genetically distinct forms. C. Increased gene flow causes mutation rates to increase, creating more variability. D. High gene flow increases the probability that inbreeding will occur in local populations.

B. it is the ultimate source of all variation.

Mutation is important to the evolutionary process because: A. it usually causes rapid shifts in allele frequency. B. it is the ultimate source of all variation. C. it always generates superior genotypes, allowing selection to rapidly attain the most fit genotype. D. All of the above are true statements.

A. individuals with favored genotypes leave more progeny.

One implication of Darwin's theory of evolution by natural selection is that species become adapted to their environment. This happens because: A. individuals with favored genotypes leave more progeny. B. environmental variation induces phenotypic changes that improve competitive efficiency. C. mutation is directed to create variants necessary for a species' survival. D. It does not happen. Species do not become better adapted to their environment.

B. False

Organisms that have not changed over 100s of millions of years are not evolving. A. True B. False

C. Evolutionary independence

Regardless of your definition of species, which of the following must happen for speciation to occur? A. Hybridization B. Geographic isolation C. Evolutionary independence D. Polyploidy

A. premating factors are enhanced by selection against inferior hybrid progeny when related species co-occur.

Reproductive isolation is important to evolutionary biologists as it is responsible for the barriers that create and maintain biodiversity. Scientists studied the evolution of reproductive isolation by characterizing the amount of pre- and postmating reproductive isolation within and among many species pairs of Drosophila that are allopatric or sympatric. Results from these studies (see figure below) are consistent with the hypothesis that: A. premating factors are enhanced by selection against inferior hybrid progeny when related species co-occur. B. mutation rates are higher in sympatry than allopatry. C. genetic drift is stronger in allopatry, preventing the evolution of premating isolation. D. selection favors the evolution of postmating reproductive isolation in sympatry.

C. premating reproductive isolation is greater between sympatric pairs of species.

Reproductive isolation is important to evolutionary biologists as it is responsible for the barriers that create and maintain biodiversity. Scientists studied the evolution of reproductive isolation by characterizing the amount of pre- and postmating reproductive isolation within and among many species pairs of Drosophila that are allopatric or sympatric. These scientists found that (results of their studies are presented in the figure below): A. there is no difference in levels of premating and postmating isolation between allopatric and sympatric pairs of species. B. postmating reproductive isolation is always greater than premating isolation. C. premating reproductive isolation is greater between sympatric pairs of species. D. premating reproductive isolation is greater between allopatric pairs of species.

D. All of the above models have been proposed and observed in nature.

Scientist have generated models where the evolution of reproductive isolation (speciation in our terms) can occur without geographic isolation. They propose that this can occur when: A. environments change within part of the range of a species, with local selection causing divergence and the evolution of reproductive isolation. B. a species has narrow dietary requirements, preferring specific types of food. New food resources become available and some members of the population take advantage of it and diverge to become different species. C. Failures in meiosis can cause the doubling of chromosome numbers (polyploidy), leading to the production of individuals that are reproductively isolated from their parental species because they do not have the same number of chromosomes. D. All of the above models have been proposed and observed in nature.

B. False

Scientists do not address the existence of a god or gods because they want to avoid confrontations with religious zealots. A.True B. False

A. Larger islands have more species.

Scientists examined the number of species found on various Caribbean islands (map below). When they plotted species diversity against island size (graph below) they found that: A. Larger islands have more species. B. Smaller islands have more species. C. All islands have the same number of species. D. There is no relationship between island size and number of species.

C. the recessive allele is favored.

Selection is most effective at eliminating alleles when: A. the dominant allele has the highest fitness. B. all genotypes have the same fitness. C. the recessive allele is favored. D. the heterozygote is favored.

C. Selective sweeps reduce levels of neutral variation near the target of selection, but not other places in the genome.

Selective sweeps occur due to the influence of positive selection favoring a specific mutation. Which of the following statements describes how this phenomenon influences neutral variation? A. Selective sweeps eliminate all neutral variation in the genome. B. Selective sweeps reduce levels of neutral variation distant from the target of selection, but not other places in the genome. C. Selective sweeps reduce levels of neutral variation near the target of selection, but not other places in the genome. D. Neutral variation cannot be influenced by the action of positive selection.

D. Increased gene flow from more fit populations would drive all populations to the highest peak quickly.

Sewall Wright proposed the shifting balance theory to describe how evolution occurs within and among populations within a species. The description of how selection operates is provided by an adaptive topography, a complex plot of fitness across multilocus genotypes that is composed of a series of peaks and valleys (see figure below). If a population achieved the highest fitness (like peak B in the figure below), Wright predicted that: A. Landscapes only impacted local populations, with no influence on other populations. B. Drift would drive all populations to the highest peak quickly, C. Mutation would drive all populations to the highest peak quickly, D. Increased gene flow from more fit populations would drive all populations to the highest peak quickly.

C. Drift

Sewall Wright proposed the shifting balance theory to describe how evolution occurs within and among populations within a species. The description of how selection operates is provided by an adaptive topography, a complex plot of fitness across multilocus genotypes that is composed of a series of peaks and valleys (see figure below). Which of the following forces would allow a population to move from fitness peak A to peak B, crossing the valley between? A. Disruptive selection B. Balancing selection C. Drift D. Assortative mating

A. True

Sexual reproduction is more costly than asexual reproduction because it requires two sexes in sexually reproducing forms, decreasing reproductive potential for the species. A. True B.False

A. True

Sexual selection is a form of natural selection that is focused on traits that are specifically associated with reproductive success. A. True B. False

B. the genetic code is redundant.

Some mutations are synonymous because: A. they do not cause selection to occur. B. the genetic code is redundant. c. they cause amino acid replacements. D. they insert premature stop codons in the sequence

B. Broadly distributed species are more likely to have reduced levels of genetic variation.

Species with broader geographic distributions are less likely to go extinct than are those with small, narrow geographic distributions. Which is NOT a likely reason for this observation? A. Broadly distributed species are more likely to be adapted to a diversity of environments. B. Broadly distributed species are more likely to have reduced levels of genetic variation. C. Broadly distributed species are more likely to have larger populations sizes. D. All of the above are valid statements that are consistent with this observation.

B. False

The Hardy-Weinberg equation describes the allele and genotype frequencies that will be found in an evolving population of organisms. A. True B. False

B. False

The bill and webbed feet shared by platypus (a monotreme mammal) and ducks are homologous (left and right, respectively, in the figure below). A. True B. False

A. True

The concept of effective population size is important because it provides an adjustment for the number of individuals that are actually contributing to the next generation, important information when incorporating population size in models of evolution. A. True B. False

D. All of the above are important to conservation biologists.

The distribution of genetic variation is important to conservation biologists because: A. they allow us to quantify levels of gene exchange among populations and identify independent lineages for conservation. B. low levels of genetic variation may be significant, identifying a reduced ability to fight disease and adapt to changing environments. C. evolutionary theory predicts that rates of evolution are positively correlated with levels of genetic variation. D. All of the above are important to conservation biologists.

D. similarity of ecological niches in shaping phenotypic variation

The existence of marsupial and placental mammals that exhibit similar phenotypes (e.g., cat-, dog-, and mice-like organisms) identifies the importance of _____________ in the evolution of these phenotypically similar marsupial and placental mammals. A. shared ancestry of the genetic variation for these traits B. genetic drift C. gene flow D. similarity of ecological niches in shaping phenotypic variation

D. parapatric speciation requires selection for different environments, allopatric does not.

The final result of allopatric and parapatric models of speciation is similar, yet the processes involved in each of these models are quite different. Some major difference between these models are: A. allopatric speciation requires the formation of premating reproductive isolation, parapatric does not. B. parapatric speciation requires the formation of premating reproductive isolation, allopatric does not. C. allopatric speciation requires selection for different environments, parapatric does not. D. parapatric speciation requires selection for different environments, allopatric does not.

B. episodes of mass extinction (defined as a loss of > 60% of the biota in 1 million years) are relatively rare in the fossil record.

The graph below illustrates the percent of extinction that has occurred in one million year intervals over the 500 million year fossil record. The % extinction in one million year intervals is presented on the x axis while the proportion (frequency) of one million year intervals with that level of extinction are provided on the y axis. Based on this information you would conclude that: A. episodes of mass extinction (defined as a loss of > 60% of the biota in 1 million years) account for the vast majority of the extinctions that have occurred. B. episodes of mass extinction (defined as a loss of > 60% of the biota in 1 million years) are relatively rare in the fossil record. C. Background extinctions (<60% loss of biota per 1 million years) have been relatively rare. D. Extinction has been generally irrelevant for the evolution of biodiversity.

B. False

The human population (approximately 5.5 billion people) does not experience genetic drift. A. True B. False

B. False

The maximum parsimony tree is the tree which requires the maximum number of steps. A. True B. False

C. directional selection and drift

The number of alleles and their frequency in a population are determined by the interaction of evolutionary forces. Which combination of forces below will NOT result in the maintenance of multiple alleles within a population for long periods of time? A. mutation and drift B. overdominance and drift C. directional selection and drift D. mutation and directional selection

A. True

The process of domestication results in a bottleneck because only specific individuals and phenotypic variants are used to produce a crop that includes the specific traits of interest. A. True B. False

A. True

The process of speciation is important because it generates isolated lineages that evolve independently, increasing levels of adaptation. A. True B. False

C. Both of the above.

The relationship of island size to the number of species (depicted in the figure below) could be important because: A. Island size could affect colonization rate. B. Island size could affect extinction rate. C. Both of the above. D. Neither of the above.

A. patterns of variation would remain the same over a long period of time.

The three-spined stickleback is a small fish found in coastal streams of the western United States and Canada. These fishes are common where found, ranging from headwater reaches of streams to the ocean. Biologists noted considerable variation in the number of bony plates along the sides of these fish, so they collected a series of samples along a single stream. Results of their study are plotted in the figure below. If the observed pattern of plate number variation were caused by balance between selection in different environments (e.g., salt vs. freshwater downstream and upstream, respectively) and gene flow, you would predict that: A. patterns of variation would remain the same over a long period of time. B. plate number would eventually become homogenous across populations, with all populations eventually becoming indistinguishable. C. plate number would vary randomly among sampling localities across sampling years. D. all individuals would eventually have nine plates.

B. plate number would eventually become homogenous across populations, with all populations eventually becoming indistinguishable.

The three-spined stickleback is a small fish found in coastal streams of the western United States and Canada. These fishes are common where found, ranging from headwater reaches of streams to the ocean. Biologists noted considerable variation in the number of bony plates along the sides of these fish, so they collected a series of samples along a single stream. Results of their study are plotted in the figure below. If the observed pattern of plate number variation were caused by recent initiation of gene flow among formerly isolated populations (assume there is no selection), you would predict that: A. patterns of variation would remain the same over a long period of time. B. plate number would eventually become homogenous across populations, with all populations eventually becoming indistinguishable. C. plate number would vary randomly among sampling localities across sampling years. D. all individuals would eventually have nine plates.

C. Amphibians

The tree below provides the phylogenetic relationships of vertebrates. In this tree, which of the following groups is NOT paraphyletic? A. Jawless fishes B. Bony fishes C. Amphibians D. Reptiles

B. Cospeciation may occur at some levels; however, lice often shift bird hosts.

The two trees below provide the relationships for many different kinds of birds (left tree) and their lice (right tree). From these results you would conclude that: A. Cospeciation of lice and their host bird species has been important throughout the entire history of this group. B. Cospeciation may occur at some levels; however, lice often shift bird hosts. C. Cospeciation never occurs in this group. D. This data does not allow us to examine cospeciation.

D. All of them

Three different sequence characters (A-C) are mapped onto the rooted tree for taxa 1-4 (see below), showing where changes occurred. For which character(s) is "a" homologous? A. A B. B C. C D. All of them

A. A

Three genes (A, B, C) are part of a regulatory network controlling the expression of gene D (see pathway below). Which of the genes influences the expression of the most genes in the pathway? A. A B. B C. C D. D

C. B, C

Three simulation replicates were established to study genetic drift (no mutation or selection included in the model), where population size was constant within each experiment but varied among the three simulations. Based on these results (figure below), you would conclude that smallest sample size was used to generate Figure ____ and the largest for Figure _____. A. A, B B. A, C C. B, C D. Not enough information provided to allow you answer this question.

D. All jawless fishes are equally related to tetrapods.

Using the phylogenetic tree below, which of the following statements about relationships among vertebrates is NOT correct? A. Coelacanths are more closely related to tetrapods than to ray-finned fishes. B. Mammals and birds are equally related to frogs. C. All bony fishes are more closely related to tetrapods than are sharks and rays related to tetrapods. D. All jawless fishes are equally related to tetrapods.

B. average population fitness (Wbar) varies with allele frequency.

We have tested for selection at one locus with two alleles in four different populations, with the results portrayed below. Assuming all other Hardy-Weinberg assumptions are in effect, graphs for each of these populations describe how: A. frequency of an allele changes over time. B. average population fitness (Wbar) varies with allele frequency. C. allele frequency varies from one generation to the next. D. mutation causes change in allele frequency.

D. Populations 1, 2, and 4.

We have tested for selection at one locus with two alleles in four different populations, with the results portrayed below. Assuming all other Hardy-Weinberg assumptions are in effect, you might expect to find more than one allele at equilibrium in ______________. A. Populations 1 and 2, B. Populations 2 and 3, C. Populations 2 and 4, D. Populations 1, 2, and 4.

C. 3

We use historical patterns of change to test for various hypotheses of evolution. The tree below represents several of these predictions, depicting morphological change (x-axis) in groups of organisms over time (y-axis). Letters (A-C) identify evolutionary lineages and numbers (1-3) identify specific branches. If a lineage was experiencing stasis, you would expect it to look like branch: A. 1 B. 2 C. 3 D. none of them

C. C

We use historical patterns of change to test for various hypotheses of evolution. The tree below represents several of these predictions, depicting morphological change (x-axis) in groups of organisms over time (y-axis). Letters (A-C) identify evolutionary lineages and numbers (1-3) identify specific branches. Which of the three lineages is consistent with an adaptive radiation? A. A B. B C. C D. none of them

A. Relative fitness is more important than absolute fitness.

When considering fitness in terms of allele frequency change, A. Relative fitness is more important than absolute fitness. B. Absolute fitness is more important than relative fitness. C. Relative and absolute fitness are equally important. D. Fitness has no relationship to changes in allele frequency.

D. All of the above

When natural selection is operating, which of the following is likely to be involved? A. Heritable characteristics B. Differences in survival C. Differences in reproductive success D. All of the above

D. All of the above contribute to macroevolution

Which of the following evolutionary forces do NOT contribute to macroevolution? A. natural selection B. genetic drift C. mutation D. All of the above contribute to macroevolution

D. all of the above can explain gaps in the fossil record.

Which of the following explains gaps in the fossil record? A. Conditions for fossilization are not constant over time. B. Conditions for fossilization are not constant everywhere. C. Geological processes may destroy fossils. D. all of the above can explain gaps in the fossil record.

D. all of the above are important.

Which of the following features can influence how natural selection operates within a population of organisms? A. the external environment they live in B.other species they interact with C. their genetic makeup D. all of the above are important.

D. All of the above are implications of the theory of evolution.

Which of the following is NOT an implication of evolution: A. Organisms have descended from a common ancestor, allowing us to view life as a hierarchical array of groups. B. Life as we know it has been around for a long time. C. Evolutionary phenomena can be explained by natural laws. D. All of the above are implications of the theory of evolution.

D. Single stranded RNA is easier to construct from constituent elements than double stranded DNA

Which of the following is NOT evidence that RNA may have preceded DNA in the development of early forms of life? A. DNA cannot replicate without both proteins and RNA B. RNA is highly conserved across all domains of life C. Energy in cells is stored in ribonucleoside triphosphates D. Single stranded RNA is easier to construct from constituent elements than double stranded DNA

C. individuals must produce as many offspring as the environment can support

Which of the following is NOT required for evolution by natural selection to occur? A. individuals in populations must vary B. individual variation must be heritable C. individuals must produce as many offspring as the environment can support D.there must be differential survival among individuals

A. random genetic drift

Which of the following is most likely to lead to genetic differences among populations? A. random genetic drift B. gene flow C. selection favoring the heterozygote D. random mating

D. constancy of allele frequency over time

Which of the following is the least likely outcome of genetic drift? A. fixation of an allele B. extinction of an allele C loss of heterozygosity D. constancy of allele frequency over time

A. Allopatric

Which of the following modes of speciation do not require selection? A. Allopatric B. Parapatric C. Sympatric D. All require selection

A. independent assortment of alleles on different chromosomes

Which of the following processes can generate genetic variation? A. independent assortment of alleles on different chromosomes B. random segregation of alleles at a single locus C. selection favoring recessive homozygotes D. All of the above processes can generate genetic variation.

D. Exaggerated traits lower an individual's overall fitness.

Which of the following statements about extremely exaggerated traits in sexual selection is false? A. Exaggerated traits may take a lot of energy to grow and maintain. B. Exaggerated traits can make an individual more susceptible to predation. C. Exaggerated traits are found more often in males than in females. D. Exaggerated traits lower an individual's overall fitness.

B. Regulatory genes do not produce protein products.

Which of the following statements about regulatory genes is NOT correct. A. Regulatory gene products bind to specific regions of DNA. B. Regulatory genes do not produce protein products. C. Regulatory genes can influence the rate at which other genes are expressed. D. Mutations in regulatory genes can lead to major morphological changes.

C. The sex that invests more in reproduction is more likely to select their mates more carefully.

Which of the following statements about sexual selection is true? A. The biggest, strongest individuals always win the battle for mates. B. Sexual dimorphism is genetically hard-wired, and selection plays no role when individuals of the two sexes look different. C. The sex that invests more in reproduction is more likely to select their mates more carefully. D. All of the above statements are correct.

D. Conifers are more closely related to ferns than cycads are to ferns.

Which of the following statements about the phylogeny (figure below) is NOT true? A. Angiosperms and gnetophytes are equally related to ferns. B. Conifers are more distantly related to angiosperms than are gnetophytes to angiosperms. C. Conifers are more closely related to angiosperms than are cycads. D. Conifers are more closely related to ferns than cycads are to ferns.

B. Disease genes are always extra genes found only in people with that disease.

Which of the following statements is FALSE? A. Alleles are different forms of the same gene. B. Disease genes are always extra genes found only in people with that disease. C. Chance events play a large role in determining the fate of a new mutation. D. Heterozygotes contain multiple forms of the same gene.

D. given enough time, both processes result in the elimination of heterozygotes and increased relatedness of individuals within populations.

While inbreeding and genetic drift are different processes, they can individually have similar impacts on a population. Which of the following statements correctly describes the impacts of these processes within a population? A. both processes cause change in allele frequencies B. both processes maintain variation within populations C. both processes produce increased heterozygosity D. given enough time, both processes result in the elimination of heterozygotes and increased relatedness of individuals within populations.

B. size is more heritable than fat content.

With Americans becoming more aware of health issues, people are eating more pork (the other white meat) so pig farming has become a booming industry. After graduation from the genetics program from a large agriculture school, you are hired to run the selective breeding program at a pig farm. Two traits of significance to the pig farmers are size and fat content (see figure below). Given this information, you would conclude that: A. fat content is more heritable than size. B. size is more heritable than fat content. C. fat content and size show equal, high levels of heritability. D. neither trait is heritable.

A. Focus on size as that trait will respond to selection more quickly than fat content.

With Americans becoming more aware of health issues, people are eating more pork (the other white meat) so pig farming has become a booming industry. After graduation from the genetics program from a large agriculture school, you are hired to run the selective breeding program at a pig farm. Two traits of significance to the pig farmers are size and fat content (see figure below). Your board of directors is pushing you to produce a profitable product quickly. Given this data, you would recommend: A. Focus on size as that trait will respond to selection more quickly than fat content. B. Focus on fat content as that trait will respond to selection more quickly than size. C. Develop strains for both traits as they will respond equally well to selection. D. Find another trait as neither will respond well to selection.

D. There is no benefit for individuals of either sex to change sex.

You are exploring the rainforest in South America and discover some unusual birds where reproductive success varies with size of an individual (see figure below). Given our discussion of sex change in sexual organisms, you would predict that: A. Males would eventually change sex to become female as they grew larger. B. Females would eventually change sex to become male as they grew larger. C. All individuals would eventually change sex as they grew larger. D. There is no benefit for individuals of either sex to change sex.

A. it is more likely to be transmitted by a vector (like a mosquito) than directly between infected people.

You are medical doctor working on infectious diseases and discover a new bacterium that is extremely virulent, causing great harm to the human population where you work. You are trying to identify its mode of transmission so that you can attempt to develop a means of reducing its impacts on the population. You would predict that: A. it is more likely to be transmitted by a vector (like a mosquito) than directly between infected people. B. it is more likely to be transmitted directly between infected people than by a vector (like a mosquito). C. it is more likely to be transmitted directly between infected people than through the water supply. D. It is not possible to make such predictions.