Bio 280 Final Review EVERYTHING

If p = 0.8, what is the frequency of heterozygotes in a population, assuming Hardy-Weinberg equilibrium? a. 0.2 b. 0.64 c. 0.16 d. 0.32 e. none of the above

0.32

In a population of butterflies that has two alleles at a locus for spots, no spots (N) and spots (S), there are 20 individuals with the NN genotype, 40 with the NS genotype, and 40 with the SS genotype. What is the frequency of N in the population? a. 0.4 b. 0.2 c. 0.6 d. 0.8 e. none of the above

0.4

Which of the following could result in a polyphenism? a. A mutation creates a deleterious version of an allele that is then passed on to an organism's offspring. b. A change in an environmental cue switches the production of one phenotype to an alternate phenotype. c. The cumulative action of multiple genes produces variation among individuals over a given range. d. A combination of alleles on a single gene produces two or more discrete phenotypes in a population.

A change in an environmental cue switches the production of one phenotype to an alternate phenotype.

Which of the following is NOT one of the conditions required for evolution by natural selection to occur? a. Differences in phenotypic traits must be at least partially inheritable. b. Phenotypic traits must vary among members of a population. c. The phenotypic traits of individuals affect their likelihood of surviving and reproducing. d. A population must live in an environment that causes and increased rate of mutation.

A population must live in an environment that causes and increased rate of mutation.

How do trade-offs and constraints limit the extent of adaptive evolution? Describe some examples of trade-offs and constraints.

A trade-off is when a trait increases the fitness of an individual in one way, but reduces fitness in another. For example, take the bluegill fish. When this fish has a large reproductive organ, females find this more attractive and therefore reproduce more with them. However, it is more difficult for these fish to swim when they have large reproductive organs, making them more vulnerable to predators. Some constraints that limit the extent of adaptive evolution are historical, genetic, physiological, mechanical, and developmental. Look at an image of a pig flying. This is extremely unlikely for several reasons. Firstly, the historical constraints show that a pig did not descend from an animal with wings, so genetically, there is no opportunity for the genome to mutate to present a set of wings. Also, mechanically, the wings to support a pig would be incredibly large and unpractical for survival.

Which of the following statements is correct? a. All cells in a multicellular organism's body contain the same genes. b. All cells in a multicellular organism's body express the same genes. c. All cells in a multicellular organism's body contain the same proteins. d. All are correct.

All cells in a multicellular organism's body contain the same genes.

What is an adaptation? What is the process of adaptation?

An adaptation is a particular outcome of natural selection as well as a process of natural selection. The process of adaptation is that an organism can become better suited to its environment, not because of a mutation in the genotype, but a change in the phenotype because of the environment they live in. To provide an example, some plants, like succulents, have adapted to hot, dry climates because they began storing water in their leaves. An adaptation can also be behavioral, which doesn't have to do with the phenotype.

What is an equilibrium population? What are the conditions required for a population to remain at evolutionary equilibrium? Why is the concept of an equilibrium population useful?

An equilibrium population is used as a guideline to understand evolution. In an equilibrium population, evolution is stagnant and allele and genotype frequencies are unchanged over time regardless of sexual recombination. To stay in equilibrium, there cannot be any mutations, mating must be random, there must be an infinite population size, no gene flow, and therefore no selection. This idea allows scientists to understand evolution and the criterium required for it to occur.

Describe some examples of rapid evolution in response to human-caused environmental changes, and explain how this evolutionary change affects people.

An example of rapid evolution is antibiotic resistance. This arises when an individual gets sick with bacteria, some of which are resistant to bacteria. The person takes antibiotics and the bacteria that are resistant survive and multiply. Then, the entire infection becomes a resistant strain. This happens because antibiotics are prescribed even when they aren't always required. Some farm animals also get antibiotics so that they don't get sick, and it goes into human food and then gets ingested. This affects people because it makes resistant strains of bacteria difficult to kill. Because of this, certain individuals, if not strong enough, could die from illnesses because they can't kill the bacteria. Another example is pesticide resistance. Similar to antibiotic resistance, pesticides are used to eradicate insects on crops. A specific example of this is bt crops. In these crops, a gene is transferred from the Bacillus T into corn and when they eat the corn a protein produced by the bt gene kills the insect. However, over time, the insects get resistant. So this affects farmers because they have to pay more attention to their placement of crops. They start creating refuges where non-bt crops are planted next to bt crops and this allows for resistant and non-resistant insects to mate, hopefully decreasing or slowing down the rate of evolution.

What is artificial selection, and what is its relevance to the theory of evolution by natural selection? Describe some observational and experimental evidence of the effects of artificial selection.

Artificial selection is selection, not by nature, but by humans. This concept allows us to understand and see natural selection firsthand. Take, for instance, Yoo's artificial selection experiment on flies. They took several populations of flies and removed a random sample of 250 from each population. From there, they selected the 50 with the most bristles and began a population with those. They repeated this for 86 generations and found that the bristle number increased overall. This study creates an "environment" that selects flies with a higher bristle number. It is essentially a simulation of natural selection.

Describe some intellectual developments in the 17th and 18th centuries that helped set the stage for the later development of the theory of evolution. Name some of the key figures associated with these developments.

At the beginning of the 17th century, people began thinking that humans might have prehistory; that things weren't always the way they are now. Hobbes and Locke were two individuals that introduced the "radical" idea that there were pre-civilized humans. Later on, ideas arose that perhaps the earth had changed as well. We see this in Burnett's book Sacred History of Earth in 1691, where he talks about how the earth was a layer of crust over water, and then it cracked and God created the world. Another intellectual development was the meaning of fossils and the concept of extinction. Scientists thought fossils looked like animals and soon realized they are preserved remnants of them. They began wondering if these animals still existed and later discovered that different layers of earth had fossils during different times. The comparison of fossils and modern organisms truly made them think that organisms changed over time. Natural Theology was a popular belief that due to the complexity of each organism and how they fit so perfectly with their environment, they have to have been designed by a greater being. Because of this belief introduced by John Ray in 1691, people began close inspections of nature and the diversity of life. In the 18th century, we find the Enlightenment. This begins with the growth of materialist philosophy and reasoning where society looks to logic and reason instead of the Bible and bishops. This allowed for scientists to become unshackled from making their discoveries align with the Biblical world. The history of the earth is discovered in different stages by Comte de Buffon and the scientific community develops a new way of classification for organisms. Linneaus develops a nested hierarchy for organisms in his book System of Nature in 1735. This is the classification system we still use today. These developments created the framework for the theories of evolution to follow in the 19th century.

Why did Melander suggest that farmers apply pesticides "poorly" to deal with the San Jose scale insect? a. Because some susceptible scales would survive, keeping susceptible genes in the scale population b. Because most scale insects do not respond to pesticides c. Because this would kill a smaller population of resistant scales d. Because few resistant scales would survive, keeping resistant genes out of the scale population

Because some susceptible scales would survive, keeping susceptible genes in the scale population

How did Alfred Wallace make a living? a. As a college professor b. By selling plant and animal specimens c. As a curator at a natural history museum d. From fees for public speaking

By selling plant and animal specimens

Which of the following examples illustrates phenotypic plasticity?

Children with access to adequate nutrition can grow taller than children who are malnourished.

Describe Darwin's four postulates and the logic by which the postulates, if true, must inevitably lead to evolution by natural selection. Describe evidence in support of each of the postulates (be sure to include evidence from the Grant's study of medium ground finch beak size on Daphne Major).

Darwin's four postulates are: 1. Individuals in a population vary 2. Traits are passed from parents to offspring (heredity) 3. Individuals vary in success at surviving and reproducing (differential reproductive success) 4. Survival and reproduction are not determined by chance We see evidence that these postulates are true in the Grants' study of medium ground finch beak size on Daphne Major. To support the first postulate, the Grants do find different-sized beaks on the island. For the second postulate, they notice that the bigger the parents' beaks, the bigger the offsprings' beaks. To support the third, we need to address the concept of biotic potential. This is the maximum rate that a population could grow if everything was perfect (no limited resources and everyone was fertile). We know that this isn't true because the population numbers are not as high as they could be if the population had reached biotic potential, so we know that there is variation in success at reproducing. We also know that there are limited resources, like food and shelter. Because of this, we know that there is competition, and not every individual will receive enough resources to survive. And finally, for the fourth postulate, we see this firsthand with the drought that occurred on the island. The drought prevented small seeds from growing so all of those plants died and what remained were eaten. All of the seeds that were left for the birds to eat were bigger and harder, so individuals with small beaks weren't able to eat them. However, birds with larger beaks were able to eat them and they were able to survive because they receive the resources they needed to live, while those with smaller beaks didn't.

Compare and contrast directional selection, stabilizing selection, and disruptive selection. Describe an example of each.

Directional Selection is when selection for a trait goes toward a certain extreme. For example, in the Grants' study of finches, the larger-beaked birds survived and the smaller-beaked birds didn't, therefore shifting the average beak length upward. Stabilizing selection is when selection for a trait stays around the middle of a distribution (around the average). For example, birth weight is stabilized because the mortality rate increases when a child is too big or too small. So, there are less variation and more individuals with a birth weight that isn't extreme. Disruptive selection is when selection for a trait goes toward the extremes. Say, for example, if large and small organisms survived in their environment more than medium-sized organisms, this would be disruptive selection.

Describe the important general characteristics of mutations, with respect to their effect on evolution.

Even though mutation rates seem rare, the human genome is so large, that there are quite a lot of mutations that occur. Because of this, they allow plenty of genetic variation in populations. If a mutation proves beneficial for an organism, it will be acted upon by natural selection. Without mutations, there will be no genetic variation for evolution to occur. In addition, mutations are deleterious, which means that they are harmful to organisms. When mutations build up over time, the average fitness of an organism decreases. So, due to natural selection, the detrimental mutations will be selected against and either canceled or remain recessive in the gene pool. Because mutations are random, there is no way to determine whether they will be beneficial or detrimental to an organism until acted upon by natural selection, continuing the evolution of an organism.

What is evolution? Describe both the overall pattern and the process.

Evolution is both a pattern and a process. It is a pattern of evolutionary history by which all organisms are related by common ancestry and have changed over time. It is a process of evolutionary mechanisms by which populations descend, with modification, from pre-existing populations; the genetic make-up of a population changes from one generation to the next.

Describe some experimental evidence of natural selection in the wild.

Experimental evidence of natural selection in the wild is the experimental test of Anolis sagrei from Staniel Cay, where they have large trees and shrubs. In this experiment, scientists found 14 lizard-free islands without trees and had only small shrubs to release a dozen lizards. After 15 years, the scientists came back to find that the lizards had shorter legs and were more slender. Why was this? They found that when the lizards crawled on large branches, long, thick legs would help the lizards escape rapidly. However, on small branches, long, thick legs reduced the agility required to escape. Because of this, there was a natural selection for shorter, more slender legs.

In a comparison of winter-white and winter-brown snowshoes, a. FST in the polymorphic zone is generally very high. b. FST for the chromosomal region containing the Agouti gene is very high. c. In winter-brown hares, expression of Agouti increased in the fall. d. FST did not identify any genes responsible for coat color.

FST for the chromosomal region containing the Agouti gene is very high.

Describe and explain frequency-dependent selection and describe an example.

Frequency-dependent selection is when the fitness of a phenotype depends on its frequency of occurrence. For example, if we look at the mimicry between color patterns of different poisonous and non-poisonous butterflies, we can see that if there isn't enough frequency of similar color patterns in the non-poisonous butterflies, it won't be selected for.

Which of the following is NOT a potential agent of natural selection? a. Fishing by humans b. A parasite c. Genetic drift d. A flood

Genetic Drift

What effects is genetic drift expected to have on allele frequencies? How are these effects expected to differ in populations of different sizes? Describe some experimental evidence that these predicted effects actually occur in populations.

Genetic drift has two effects on allele frequencies: fixation or they get lost, thus decreasing the genetic variation of a population. This process is more easily noticed in smaller populations than larger populations because it can have a bigger detrimental effect. This is because the smaller a population, the less variation it has a vice versa. This is heavily displayed in the Buri experiment where there were 107 populations that all were heterogeneous for the eye color gene bw75. From each of these populations, 8 females and 8 males were selected by chance and started new populations. These steps were repeated for several generations. By the time almost all of the populations reached generation 19, they were either fixed or lost the bw75.

Describe the expected effects of genetic drift on genetic variability in populations. Explain your conclusions.

Genetic drift is expected to reduce the genetic diversity of a population. An individual with a beneficial or detrimental mutation appears in a population it may remain in the population or go randomly or due to natural selection. Genetic drift can randomly select or not select the mutation, which usually would be eliminated because genetic drift tends to reduce genetic diversity.

What is genetic drift? How and why does it occur? How is sampling error involved?

Genetic drift is the random changes of allele frequency in a population. This happens when reproduction is random which results in a change in allele frequencies or increased genetic variation. The reason for this is sample error. To elaborate, in a scenario where a natural disaster occurred, like a flood, that only allowed a random subset of the population to survive, there was no trait that was selected for that allowed them to survive. It was purely random. This is an example of sampling error because those that survived do not represent the population as a whole. The reproduction will continue in this population and allele frequencies will continue to change.

Define the following terms: locus, allele, gene pool, substitution.

Locus: A particular location on a chromosome where a gene occurs Allele: different variants of a particular gene on the locus Gene Pool: All of the alleles at a particular locus, or all of the alleles from all individuals in a population Substitution: Occurs when one allele that has previously existed in a population gets replaced

Why are mutations crucial for evolution? a. Mutations in germline cells that affect large parts of the genome are very common. b. Mutations in somatic cells can affect an organism's health. c. Mutations are the ultimate source of genetic variation in populations. d. Mutations can change the DNA sequence without affecting the protein it codes for.

Mutations are the ultimate source of genetic variation in populations.

Many plant species are hermaphroditic and run the risk of self-mating. Some species carry self-incompatibility alleles that can prevent this from occurring. If a pollen grain with self-incompatibility allele S1 lands on a stigma that also carries the S1 allele the pollen will not germinate and fertilization does not occur. Thus, this mechanism not only prevents selfing, but also has the unfortunate effect of preventing mating with any other plant that carries the same allele. However, if the pollen lands on a stigma of a plant with a different allele, fertilization occurs. Imagine a population of plants in which the allele frequency of S1=0.9 and the allele frequency of S2=0.1. All other things being equal, individuals with the ____ allele will have higher fitness on average. This is an example of______. a. S1; positive selection b. S2; positive selection c. S1; negative frequency-dependent selection d. S2; negative frequency-dependent selection

S2; negative frequency-dependent selection

Compare and contrast somatic mutations and germline mutations, with respect to their potential impact on evolution.

Somatic mutations are mutations that happen anywhere in the body that isn't an egg or sperm. These mutations can cause certain events to happen to an individual, like cancer, for example. Germline mutations, however, are mutations that happen in the egg or sperm that carry out to offspring. If there is an advantageous mutation in a germline cell, it can be selected for by natural selection and make an impact on evolution. While a somatic mutation could be beneficial or detrimental to the individual, it cannot be acted upon by natural selection. Because of this, germline mutations cause a much larger impact on evolution than somatic mutations.

On which of the following points would Charles Darwin and Jean-Baptiste Lamarck have agreed? a. Adaptation occurs when individuals change to adapt to their environment. b. Life is spontaneously generated all the time. c. Species give rise to new species d. Simple organisms have existed for a shorter period of time than complex organisms.

Species give rise to new species

Which of the following ideas was NOT accepted by Jean-Batiste Lamarck? a. Bacteria represent some of the youngest species on earth. b. Species arise spontaneously. c. Species go extinct d. Characteristics acquired during an organism's lifetime can be inherited by offspring.

Species go extinct

What is biotic potential and how is it related to development of the theory of evolution by natural section?

The biotic potential is the maximum rate a population could grow if everything was perfect (no limited resources and everyone was fertile). This is related to the development of the theory of evolution by natural selection because when it is calculated, we see that it is impossible (or very unlikely) to reach. Darwin calculated this with two elephants and discovered that the population would reach 19 million in 750 years, so we know that elephants have not reached this. Biotic potential allows us to understand the variation in success at surviving and reproducing by demonstrating what it would be if there were no variation. This concept is the main part of the third postulate of Darwin's logic of evolution by natural selection.

Describe the comparative method and explain how and why it is used

The comparative method takes certain traits of organisms from different species and compares them to test hypotheses about adaptive evolution. An example of this is found in the study comparing the testes of males of Megachiroptera and males of other species. The hypothesis was that it was an adaptation in response to sperm competition. This is another way to find evidence for adaptive evolution.

Which of the following can be concluded from the Grant's long-term study of the medium ground finch on Daphne Major? a. The strength of selection was constant over time. b. The direction of selection varied over time. c. Beak size generally became larger over time. d. Beak size remained unchanged except during drought years.

The direction of selection varied over time.

What is the founder effect? What are population bottlenecks? What are the expected effects of the founder effect and population bottlenecks?

The founder effect is a process that can contribute to genetic drift. Any existing population can have a group that diverts and forms a new population. This is the founder population. Population bottleneck is another process that can lead to genetic drift. This happens when a catastrophic event endangers a population and they recover, as long as the survivors are random. The expected effects of the founder effect and population bottlenecks is that genetic diversity is decreased.

What is the evidence that evolution has occurred? Describe evidence for the common descent of organisms and evidence that species have changed over time. In your description, list categories of evidence and then examples within each category. Also, explain your logic (i.e., how, exactly, does the evidence you describe demonstrate that evolution has occurred?).

The four categories, biogeography, homology, vestigial traits, and fossils are evidence that evolution has occurred. Biogeography is the science of how species are distributed geographically across the globe. To provide an example, oceanic islands that develop from volcanoes lack native reptiles, amphibians, land mammals, and freshwater fish, even though they are animals that need land to survive. In many cases, we see many taxa that are diverse and endemic, meaning they are the only population of that species in the world. In other words, they are found there and only there. Scientists have observed that the only species that are similar to these endemic species are located on the nearest mainlands. Knowing this, we can reason that a common ancestor of species on the mainland and the island, several generations ago, was able to make its way to the island and create a population. Evolutionary mechanisms and the isolating environment of the island allowed the species to evolve and "branch off" from their common ancestor to become a new species. Darwin was able to see this in the several different species of mockingbirds on the Galapagos Islands. One was able to make its way to the archipelago and start a population. Homology is the similarity found between two species to a common ancestor. One example of this is the fact that all living things have the same genetic code, so all organisms must have descended from one common ancestor. In a more complex example, we see some of the same bones in the same order in diverse vertebrates, but with different functions. In the human and chicken embryos, gill pouches and tails are observed. In most humans, these parts serve no function and grow into the body, however, in chickens, tails are still useful. Because humans and chickens have both of these traits, as does a common ancestor, we can assume that evolutionary mechanisms made way for humans and chickens to become their own species but kept certain common traits. Vestigial traits are traits that have lost their original function but still persist. A popular example of this is found in whales, and boa constrictors, and their pelvic bones. Even though they lack hind legs, they have a pelvic bone that remains in their bodies. In earlier generations, land mammals must have evolved to lose their hind legs and kept their pelvic bones even though they're not useful. Another example is of the wings on an ostrich. We see that their wings cannot support the size and weight of their bodies. Although they have these wings, they are not used to make them fly, instead, they are used to make them look aggressive. This demonstrates evolution has occurred because their traits and functions do not always coincide with other animals like them; they aren't "designed" to fit perfectly with their environments. And lastly, fossils of extinct organisms prove evolution has occurred. The phrase "the law of succession" is used when one finds a fossil in a certain area and it resembles certain creatures in the same area. Knowing fossils take several years to form, we can reason that the similar modern organisms descended from the extinct organism in the fossil because they appear similar even though both don't exist at the same time. We can also look at a fossil series that show different versions of animals before the current version. We can see with each animal which traits disappeared and which appeared showing the lineage of the species.

On which point(s) would Charles Darwin and Georges Buffon have likely disagreed? a. The idea that Earth was formed according to the laws of physics. b. The idea that all life shares a common ancestor. c. The idea that species change over time. d. They would have agreed on all of these points.

The idea that all life shares a common ancestor.

Describe the main current method for estimating mutation rates. What is a typical estimated mutation rate? How much genetic variation is such a mutation rate expected to generate? Explain.

The main current method for estimating mutation rates is the comparison of generations through whole-genome sequencing. Mutation rates provide plenty of genetic variation in populations even though they seem so rare. However, because the human genome is so expansive, the typical estimated mutation rate of 1.1 x 10^-8 per base pair per generation means that many mutations will occur, thus generating lots of genetic variation in populations.

Assuming that a deleterious allele is maintained in a population by mutation-selection balance, which scenario below describes the case where you would expect the equilibrium frequency of the allele to be highest? a. The mutation rate is low; the allele is highly deleterious. b. The mutation rate is low; the allele is slightly deleterious. c. The mutation rate is high; the allele is highly deleterious. d. The mutation rate is high; the allele is slightly deleterious.

The mutation rate is high; the allele is slightly deleterious.

Describe the neutral theory of molecular evolution, explain why it is plausible, and describe some of its predictions.

The neutral theory of molecular evolution is that most variation at the molecular levels does not affect fitness. In other words, alternative alleles at a locus are neutral with respect to evolution. Most mutations don't present phenotypes or remain recessive before they're selected for or against in a population. The frequency of the few that remain, do not usually increase the individuals' fitness either way. Some predictions are that the substitution rate is equal to the migration rate, regardless of population size, which means substitution, evolution, rate is constant. This makes it so we have the use of molecular clocks, which means we can look at the substitution rate and determine how much time has elapsed.

What is the response to selection (R)? What is the selection differential (S)? What is heritability (h2)? How are these quantities measured and assessed?

The response to selection is an equation that depends on the heritability and selection differential to calculate the increase or decrease of a trait when two individuals produce offspring. The selection differential is a measure of how successful an individual is, this can be measured by a difference of means. The heritability is of a trait is how often it will get passed down to offspring. It is measured by the additive genetic variance divided by the phenotypic variance. When we multiply the heritability and the selection differential we get the response to selection.

Which of the following statements about genome size is false? a. The complexity and size of genomes vary widely between taxa. b. The genome includes all coding and noncoding regions of an organism's DNA. c. There is a correlation between genome size and gene number across species. d. Protein-coding genes make up a tiny portion of the genome in many eukaryotes.

There is a correlation between genome size and gene number across species.

Which of the following is the best evidence for a genetic bottleneck in northern elephant seals? a. Dominant males mate with multiple females. b. They have low genetic variation within a mitochondrial DNA sequence that has a high mutation rate. c. Their populations increased rapidly after hunting was restricted. d. all of the above

They have low genetic variation within a mitochondrial DNA sequence that has a high mutation rate.

Mutations in the GDF9 gene in sheep have been linked to changes in female fecundity. The relative fitnesses of the different genotypes in the population are +/ - = 1.0, +/+ = 0.7, -/ - = 0.1. Which statement below is correct? a. This is an example of heterozygote advantage; genetic variation will be maintained over time. b. This is an example of negative frequency-dependent selection; genetic variation will be maintained over time. c. This is an example of heterozygote advantage; genetic variation will be lost over time. d. This is an example of negative frequency-dependent selection; genetic variation will be lost over time.

This is an example of heterozygote advantage; genetic variation will be maintained over time.

Name some early 19th century thinkers who directly influenced Darwin's thinking and describe their ideas.

William Paley - Revived the idea of Natural Theology where organisms were created by design. Jean Baptiste Lamarck - One of the first transmutationists (things can be transferred from one to another). He developed the first full theory of evolution from ancestors, but not from a common ancestor. He believed that organisms progressed from simplicity to complexity. His most famous theory is the inheritance of acquired characteristics. The example Lamarck uses to explain his theory is that if a giraffe were to stretch its neck constantly to reach to food and its offspring inherited the stretched neck, over time, the giraffe's neck would be as long as it is today. Thomas Malthus - Developed the concept "struggle for existence." He realized that there was a fixed amount of resources that were needed by a growing population, so there would be competition among the species for these limited resources. Charles Lyell - Developed the concept of uniformitarianism. The geological processes we observe today are the only processes that have ever existed. These include processes like erosion, sedimentation, wind, etc. He realized the age of the earth is extremely old considering how gradual these processes are. He also realized that the fossil record is incomplete and that we haven't found everything that has ever existed.

How do gene frequencies behave in Hardy-Weinberg equilibrium? a. Allele frequencies stay the same from generation to generation. b. Genotype frequencies stay the same from generation to generation. c. Genotype frequencies depart from expected frequencies. d. a and b e. a, b, and c

a and b

You are studying snails and find that individuals have shells that either coil to the right or the left. Which of the following is a plausible explanation(s) for this variation? a. Different alleles at a single locus produce the different phenotypes. b. Individuals are genetically identical but certain environmental conditions trigger the production of each coil type. c. This is a quantitative trait and many loci contribute to the phenotypic differences d. All of the above are correct e. a and b are correct

a and b are correct

Which of the following statements is central to the idea of uniformitarianism? a. Natural laws that are observable today also operated in the past. b. Catastrophic events such as floods and volcanoes have played the primary role in shaping the earth's existing features. c. Geological change happens gradually for the most part. d. a and c are correct.

a and c are correct.

Tasmanian devils once inhabited most of present day Australia, but only an isolated population on the island of Tasmania has survived to present day. Which of the following processes has likely affected Tasmanian devils as a result of this history? a. a higher mutation rate b. stronger natural selection c. a genetic bottleneck d. gene flow

a genetic bottleneck

Which of the following could NOT be described as a phenotype? a. a sequence of nucleotides b. a molecule produced by a gene c. a developmental process d. a morphological structure

a sequence of nucleotides

a) Describe some types of mutation that can create new alleles in a population. b) Describe some types of mutation than can create new genes in a population.

a) Point mutations can create new alleles in a population. One of these mutations is a nonsense mutation, which is where a single nucleotide is changed and results in an early stop codon during translation. This can cause a protein to be much shorter than it should be, therefore changing the way it folds and functions. Another mutation is a missense mutation, which is when a different amino acid is coded for. The amino acid that is coded for is much different than the original, again, changing the shape and function of the protein. Insertions and deletions are mutations that cause frameshifts and completely change a protein from its original. b) Retrotransposition can create new genes in a population. This happens when, instead of being translated, the mRNA is sent back to the nucleus. Then, it is reverse transcribed and inserted back into the sequence in a new location. This allows for the genome to be copied several times, where mutations can occur and create new genes. Another process is unequal crossing over. When this happens, the tetrad is mispaired at meiotic synapsis, leaving two unequal chromosomes (one with a deletion and one with a duplication). And lastly, nondisjunction can create new genes because the chromatids do not separate and remain in one daughter cell while the other daughter cell gets neither chromatid.

William Smith a. created the first geological map b. devised a system of taxonomy still in use today c. was the first to establish the fact of extinction d. first proposed the idea of natural selection

a. created the first geological map

Duplication is a type of mutation that alters DNA by copying a segment. Which of the following segments of DNA can be duplicated? a. a region of a gene b. a whole gene c. an entire genome d. all of the above

all of the above

Researchers have provided evidence in support of Batesian mimicry by demonstrating that a. predators learn to avoid unpalatable prey b. predators that avoid unpalatable prey also avoid species that mimic such prey c. mimic species evolve mimicking appearance only where the model species is present d. all of the above

all of the above

Which of the following could be considered part of the environment that could influence gene expression? a. signals from other cells b. contact with neighboring cells c. products from other genes d. all of the above

all of the above

Mutations can affect an organism's phenotype without altering the protein-coding sequence by influencing a. when a protein is made. b. where a protein is made. c. the amount of protein made. d. all of the above a

all of the above a

The effectiveness of selection on an allele depends in part on a. the frequency of the allele. b. the magnitude of average excess fitness. c. the average fitness of the population. d. all of the above.

all of the above.

Which of the following would be a useful proxy for fitness? a. probability of survival to reproductive age b. number of offspring produced by an individual during a specific season c. probability of survival of offspring d. all of the above.

all of the above.

In the Hardy-Weinberg equation, q is a. an allele frequency. b. a genotype frequency c. the frequency of heterozygotes. d. the frequency of dominant alleles.

an allele frequency.

Although the Ester1 allele confers a selective advantage to mosquitoes exposed to DDT on the coast of France, carriers of Ester1 in inland populations are more likely to be caught by spiders and other predators. This is an example of a. positive selection. b. antagonistic pleiotropy. c. genetic drift. d. average excess of fitness.

antagonistic pleiotropy.

Alleles a. are found at genetic loci. b. are always dominant or recessive. c. are alternative forms of a phenotype. d. are found in germline tissue only

are found at genetic loci.

Bates hypothesized that mimicry must be the result of evolution by natural selection, because mimics and the model species they resemble a. are found in the same place b. are closely related c. are genetically dissimilar d. are both quite common

are found in the same place

Homologous traits a. always perform the same function in different species. b. always perform a different function in different species. c. are inherited from a common ancestor. d. are defined on the basis of function, not ancestry.

are inherited from a common ancestor.

Trans-acting regulatory elements a. are typically adjacent to genes they regulate b. are typically far away from genes they regulate c. never code for transcription factors d. never code for microRNAs

are typically far away from genes they regulate

Wallace is credited with originating the scientific study of a. biogeography b. mimicry c. island geology d. animal behavior

biogeography

Horizontal gene transfer a. can occur via the transfer of plasmids. b. cannot be beneficial to the organism. c. is more common in eukaryotes than prokaryotes. d. does not affect evolution.

can occur via the transfer of plasmids.

Genetic recombination occurs during meiosis when a. genetic material is duplicated. b. chromosomes are paired. c. sister chromatids are segregated. d. haploid gametes are formed.

chromosomes are paired.

Several studies have revealed that the Eda gene fulfills three necessary conditions for evolution by selection. Which is not one of these conditions? a. functional importance of armor for survival b. extensive among-individual difference in phenotype c. inherited genetic variation underlying phenotype differences d. genetic fixation at the Eda gene

d. genetic fixation at the Eda gene

During his voyage on the Beagle, Darwin did NOT visit a. the Galapagos Islands b. Tahiti c. Tierra del Fuego d. the Hawaiian Islands

d. the Hawaiian Islands

Gene flow a. decreases genetic differences between populations b. increases genetic differences between populations c. cannot influence adaptive evolution d. occurs only when individuals move from one population to another

decreases genetic differences between populations

Carlos Linnaeus a. devised a system of taxonomy that is still used today. b. accepted the idea that most of life's diversity arose through the process of evolution. c. did not believe that life's diversity reflected a divine plan. d. lived in the 19th century.

devised a system of taxonomy that is still used today.

Organisms vary considerably in genome size. Which of the following explains most of this variation? a. differences in the number of protein-coding genes b. differences in the number of ribosomal RNA genes c. differences in the number of pseudogenes d. differences in the number of mobile genetic elements

differences in the number of mobile genetic elements

If a population of gallflies occurred in an area where birds were present but parasitoid wasps were absent, which type of selection is most likely to affect gall size? a. stabilizing b. negative frequency-dependent c. directional d. disruptive

directional

At Cambridge, Darwin pursued a degree in ___________ and was mentored by ________. a. botany, Paley and Huxley b. divinity, Henslow and Sedgewick c. geology, Lyell and Cuvier d. biology, Fitzroy and Humboldt

divinity, Henslow and Sedgewick

Henry Walter Bates spent _________ years exploring ______________, returning to England in ______________. a. fifteen, Tierra del Fuego and the Galapagos, 1835 b. eleven, the Amazon basin, 1859 c. seven, the Peruvian rainforest, 1871 d. ten, Mexico and Central America, 1899

eleven, the Amazon basin, 1859

The "refuge" strategy proposed by Tabashnik to slow the evolution of Bt resistance relies on a. the fact that Bt resistance has no cost. b. gene flow between refuge and resistant populations. c. natural selection producing the same outcome in both refuge and pesticide-treated populations. d. lack of natural selection in the refuge populations.

gene flow between refuge and resistant populations.

Which of the following is involved in pre-transcriptional gene regulation? a. histones b. microRNA c. DNA methylation d. alternative splicing

histones

Studies of mice inhabiting Gulf and Atlantic coastal areas showed a. both have darker coats than inland mice. b. coat color differences in the two populations of coastal mice were caused by mutations to the same gene. c. in coastal habitats, lighter mice were less likely to be preyed upon than darker mice d. in coastal habitats, darker mice were larger than lighter mice

in coastal habitats, lighter mice were less likely to be preyed upon than darker mice

Inbreeding a. increases heterozygosity in populations. b. creates deleterious recessive alleles. c. increases homozygosity in populations. d. All are correct

increases homozygosity in populations.

A mature RNA transcript differs from a primary RNA transcript because a. exons are spliced out of the mature transcript. b. introns are spliced out of the mature transcript. c. exons are added to the mature transcript. d. introns are added to the mature transcript.

introns are spliced out of the mature transcript.

DNA methylation a. is a form of transcriptional regulation of gene expression. b. is a form of post-translational regulation of gene expression. c. is a form of post-transcriptional regulation of gene expression. d. does not regulate gene expression

is a form of transcriptional regulation of gene expression.

Wallace's "Sarawak Law" states that a. eastern Indonesian islands contain different species than do western Indonesian islands b. life and the Earth evolve together c. Sarawak contains unusually distinctive species d. natural selection is the main mechanisms of evolution

life and the Earth evolve together

In population evolving by genetic drift only, the frequency of a given allele is most likely to ______________ after one-hundred generations of evolution. a. increase b. decrease c. stay the same d. none of the above; it is impossible to identify to most likely outcome of this random process

none of the above; it is impossible to identify to most likely outcome of this random process

Polyphenic traits are an example of a. phenotypic plasticity. b. quantitative trait loci. c. genetic polymorphism. d. dominant traits.

phenotypic plasticity.

Polyphenic traits are an example of a. phenotypic plasticity. b. quantitative trait loci. c. simple genetic polymorphism. d. dominant traits.

phenotypic plasticity.

Most chemical reactions in a cell are performed by: a. DNA b. RNA c. proteins d. amino acids

proteins

Genetic drift a. will always lead to higher fitness of individuals in the population. b. reduces genetic variation within a population. c. increases genetic similarity between populations. d. occurs only in small populations.

reduces genetic variation within a population.

Wallace and Darwin a. argued bitterly over which one of them originated the theory of evolution by natural selection b. were both born into wealth and privilege c. separately and independently came to the same conclusions about the mechanism of evolution d. both traveled extensively in the Amazon basin of South America

separately and independently came to the same conclusions about the mechanism of evolution

Natural selection favors gallflies that produce intermediate gall sizes. This is an example of a. stabilizing selection b. sexual selection c. disruptive selection d. directional selection

stabilizing selection

In the Hardy-Weinberg equation, what does 2pq refer to? a. the frequency of heterozygotes in a population b. the frequency of both alleles in a population c. the frequency of homozygotes in a population d. none of the above

the frequency of heterozygotes in a population

A mutation that has risen to high frequency through a selective sweep shows a characteristic pattern of linkage with surrounding loci. Which of the following contribute(s) to this pattern: a. the allele drifted to high frequency, which took a long time b. the mutation experienced a large amount of recombination c. the mutation experienced a small amount of recombination

the mutation experienced a small amount of recombination

The difference in beak size between offspring of finches that survived the drought on Daphne Major and the population average before the drought is: a. the response to selection (R) b. the selection differential (S) c. heritability d. the mutation rate

the response to selection (R)

In 1977, before the drought on Daphne major, the average beak depth in the finch population was 9.2 mm. Breeding parents that survived the drought had an average beak depth of 9.7 mm. The difference between these values represents: a. the response to selection (R) b. the selection differential (S) c. heritability d. the mutation rate

the selection differential (S)

One important feature that links extinct organisms such as Pakicetus and Indohyusto cetaceans is a. the shape of a bone in the middle ear b. the presence of forelimb flippers. c. the lack of hindlegs. d. peg-like teeth.

the shape of a bone in the middle ear

A polymorphism is a. multiple discrete phenotypes arising from a genotype, depending on the environment. b. the simultaneous occurrence of two or more discrete phenotypes within a population. c. a measurable phenotype that varies among individuals over a given range of values. d. a change in the phenotype produced by a single genotype in different environments.

the simultaneous occurrence of two or more discrete phenotypes within a population.

Bates hypothesized that mimics benefit from their mimicry because a. it improves their camouflage b. they can mate with the model species they resemble c. they resemble unpalatable species d. all of the above

they resemble unpalatable species

The presence of an mRNA transcript of a gene in a cell means a. translation of the gene has occurred. b. transcription of the gene has occurred. c. replication of the gene has occurred. d. recombination of the gene has occurred.

transcription of the gene has occurred.

The "Wallace Line" separates a. the two halves of the island of New Guinea b. Asia from Europe c. mammals from other vertebrates d. two species assemblages with distinct evolutionary histories

two species assemblages with distinct evolutionary histories

Bates ______________Darwin. a. was a bitter rival of b. was a friend and supporter of c. never met or corresponded with d. was employed as an assistant to

was a friend and supporter of

The voyage of the Beagle ended in 1832, and Darwin subsequently developed his theory of natural selection, which he a. published in 1839 as part of his book about the voyage of the Beagle b. wrote up in an 1842 essay that he shared only with a few confidants c. kept completely secret until the publication of Origin of Species in 1859

wrote up in an 1842 essay that he shared only with a few confidants