BIOL 102 Chapter 22: Darwin and Evolution

Which of the following statements best describes evolution?

Populations change genetically from one generation to the next.

Which of the following statements is most accurate in comparing scientific theories and scientific hypotheses?

Scientific theories are supported by, and make sense of, many observations, whereas scientific hypotheses are narrow, testable ideas.

A challenge to traditional (pre-1860) ideas about species came from embryology, when it was discovered that _____. See Concept 22.3 (Page)

embryos of dissimilar organisms, such as sharks and humans, resemble each other

Which of the following statements best describes the effect of natural selection on a population?

improved match between a population and its environment

Which of the following factors contribute to limiting the capacity of organisms to overreproduce?

inability of individuals to tolerate the physical conditions, lack of food, and mortality from predators

James Hutton and Charles Lyell provided which of the following ideas that paved the way for Darwin's thinking?

the surface features of Earth were formed slowly and gradually and the geological processes are still at work

What does it mean that organisms have a nearly universal genetic code?

A specific DNA sequence encodes the same information in one species as it would in nearly any other.

Are changes to an organism's physical environment likely to result in an evolutionary change?

A trait that is favorable in one environment can be less successful or even harmful in another environment. Thus, if a feature of the environment changes, selective pressures may change as well.

Which of the following statements about vestigial structures is accurate?

A vestigial structure in species A can be homologous to a functional structure in species B.

Which term describes a trait that increases an individual's ability to survive in a particular environment?

Adaptation

Why do anatomical and molecular features often fit a similar nested pattern?

All life within a group shares some features with its ancestor and adds its own features, resulting in a nested pattern.

Which of the following observations most strongly supports the common origin of all life on Earth?

All organisms use essentially the same genetic code.

Which of the following statements best defines artificial selection?

Artificial selection is a process in which humans decide which plants and/or animals will and will not breed.

The cow Bos primigenius (which is farmed for meat and milk) has a smaller brain and larger eyes than closely related species of wild ungulates. Which of the following statements best describes the process that led to differences between domesticated/farmed cows and their wild relatives?

Artificial selection resulted in changes in the lineage leading to domesticated cows because humans wanted animals with high milk output and high muscle content.

What happened in the soapberry bug population in central Florida when the bugs began to feed on seeds from the goldenrain tree fruits which are much closer to the fruit surface?

Bugs with shorter beaks had more access to food, allowing them to produce more offspring.

Cotton-topped tamarins are small primates with tufts of long white hair on their heads. While studying these creatures, a scientist noticed that males with longer hair get more opportunities to mate and that they father more offspring than males with shorter hair. Which of the following possible studies would be the best design for testing if longer hair is an adaptive trait? Assume that hair length is a trait that is inherited.

Capture a group of males with long hair at random, and cut the hair very short in half of the males; then, compare the number of matings of males with their hair left unchanged vs. males with shortened hair.

Which of the following statements best describes Darwin's theory of evolution by natural selection?

Darwin's theory emphasized that populations vary and change over time.

What is the meaning of Darwin's expression "descent with modification"?

Descent with modification refers to evolutionary change over time.

Which of the following statements about evolutionary trees is accurate?

Evolutionary trees are considered evolutionary hypotheses.

Which term describes the ability of a trait to be passed on to offspring?

Heritability

Identify the four postulates of natural selection.

Individuals in a population vary in the traits they possess. Some trait differences are heritable. Individuals with certain traits are more likely to survive and reproduce. Survival and reproductive success are variable among individuals in a population.

Which of these conditions do NOT occur in populations evolving due to natural selection?

Individuals pass on most traits that they acquire during their lifetime. Submit

It has been observed that organisms on many islands are different from, but closely related to, similar forms found on the nearest continent. Which of the following possible conclusions is best derived from this observation?

Island forms are descended from mainland forms.

Which of the following statements is accurate about an organ described as vestigial?

It must be homologous to some feature in an ancestor.

Which of the following statements best describes Linnaeus' method of classifying organisms?

Linnaeus grouped organisms into increasingly more inclusive categories.

Fossils of Thrinaxodon, a species that lived during the Triassic period, have been found in both South Africa and Antarctica. Thrinaxodon had a reptile-like skeleton and laid eggs, but small depressions on the front of its skull suggest it had whiskers and, therefore, fur. Thrinaxodon may have been endothermic (able to generate its own internal heat). Which of the following statements is likely most accurate about Thrinaxodon?

Mammals evolved from a relative of Thrinaxodon.

Identify the pair of homologous structures.

Maple leaf and oak leaf

Which of the following statements best represents a conclusion that Cuvier made when he considered the fossils found in the vicinity of Paris?

Multiple catastrophes caused extinctions and then species from other areas repopulated emptied areas.

Which of the following statements about natural selection is true?

Natural selection favors individuals that reproduce more than others.

The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data?

Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.

Which of the following statements is most consistent with data obtained from the fossil record?

Older strata carry fossils that differ greatly from living organisms.

Within six months of effectively using methicillin to treat S. aureus infections in a community, all new S. aureus infections were caused by a resistant strain (MRSA). How can this best be explained?

Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.

Which of the following observations helped Darwin shape his concept of descent with modification?

South American temperate plants are more similar to South American tropical plants than to European temperate ones.

Currently, two living elephant species (X and Y) are classified in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which of the following statements would be accurate?

Species X and Y share a greater number of homologies with each other than either does with species Z.

Which of the following is an observation or inference on which natural selection is based?

Species produce more offspring than the environment can support.

In 1959, doctors began using the powerful antibiotic methicillin to treat infections of Staphylococcus aureus, but within two years, methicillin-resistant strains of S. aureus (MRSA) appeared. How did the resistant strains of S. aureus emerge?

Staphylococcus aureus bacteria that were able to synthesize cell walls using a protein that was not affected by methicillin survived the methicillin treatments and reproduced at higher rates than did other individuals. Over time, these resistant individuals became increasingly common.

Members of two different species possess a similar-looking structure that they use in a similar way to perform about the same function. Which of the following observations would suggest that the relationship more likely represents homology than convergent evolution?

The embryological development of the two structures are similar.

There are a group of 13 related species of birds on a group of about 20 isolated oceanic islands. These species are grouped into four subgroups, with subgroup 1 evolving first (3 species), subgroup 2 evolving second (1 species), subgroup 3 evolving third (5 species), and subgroup 4 evolving last (6 species). If subgroup 4 evolved most recently, then which of the following statements is the most logical prediction?

The genomes of subgroup 4 should be more similar to each other than to the genomes of subgroup 3.

Continental drift (plate tectonics) has moved continents around the globe. Which of the following predictions would be most likely?

The most recently separated continents will have the most closely related species.

Claytonia virginica is a plant with flowers that vary from white, to pale pink, to bright pink. Slugs prefer to eat pink-flowering over white-flowering plants (due to chemical differences between the two), and plants experiencing severe herbivory are more likely to die. The bees that pollinate this plant also prefer pink over white flowers, so that Claytonia with pink flowers produce more seeds than Claytonia with white flowers. A researcher observes that the percentage of different flower colors remains stable in the study population from year to year. Given no other information, if the researcher removes all slugs from the study population, what do you predict will most likely happen to the percentage of flower colors in the population over time?

The percentage of pink flowers will increase over time.

A group of small fish live in a lake with a uniformly light-brown sandy bottom. Most of the fish are light brown, but about 10 are mottled. This fish species is often prey for large birds that live on the shore. A construction company dumps a load of gravel in the bottom of the lake, giving it a mottled appearance. Which of these statements presents the most accurate prediction of what will happen to this fish population?

The proportion of mottled fish will increase over time.

Hypothesize why the percentage of mosquitoes resistant to DDT rose rapidly.

The rapid rise in the percentage of mosquitoes resistant to DDT was most likely caused by natural selection in which mosquitoes resistant to DDT could survive and reproduce, while other mosquitoes could not.

DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Instead, DDT is now largely ineffective against many insects. Which of the following possible actions would have had the best chance of preventing this evolution of DDT resistance?

The use of DDT should have been interspersed with the use of other pesticides that have a different mode of action.

Starting from the wild mustard Brassica oleracea, plant breeders have created the strains known as Brussels sprouts, broccoli, kale, and cabbage. Which of the following statements is correct with regard to the wild mustard?

There is enough heritable variation in the wild mustard to permit these different varieties.

Why do dark-colored rock pocket mice on dark lava flows have white bellies?

There is no selection for dark bellies by visual predators.

A species of mouse that is preyed on by owls (which can see color) at dawn and dusk varies in coat color between dark and light brown. Under which of the following conditions will NO evolution occur if climate change results in the soil color becoming darker?

There is no variability in the genes that control coat color.

If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, what would be most likely to happen in environments that lack antibiotics?

These bacteria would be outcompeted and replaced by bacteria that have lost the antibiotic resistance genes. Submit

Why did dark-colored rock pocket mice first appear in a population of light-colored rock pocket mice?

They have a genetic mutation that affects their fur color.

Which of the following statements is accurate if we view evolution both as a pattern and a process?

To study evolution as a pattern we draw on information from many other scientific fields, while to study evolution as a process we study factors that cause changes in populations. Submit

A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; however, after several years, the farmer sees more and more pigweed growing once again in the fields. Which of the following statements best explains the return of pigweed to the farmer's fields?

Triazine-resistant weeds were more likely to survive and reproduce than were non-resistant individuals.

Over long periods of time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?

Under particular circumstances that persisted for long periods, natural selection reduced each of these structures because they presented greater costs than benefits. Submit

Which one of the following researchers developed a theory of evolution that was very similar to Charles Darwin's?

Wallace

Mutations are always __________.

a change in an individual's DNA

Which of the following observations would provide evidence supporting Lamarck's proposed evolutionary mechanism of "inheritance of acquired characteristics"?

a decrease in tail length in dogs after 20 generations of dogs that had their tails docked (cut off) as puppies

An adaptation is __________.

a trait that gives an organism a reproductive advantage in the current environment

Which of the following factors would most likely cause an increase in population size of a prey animal?

an improvement in eyesight

Given what we know about evolutionary biology, which of the following places would be the most likely to have the highest number of species that are unique to the area (that is, that had evolved in that place). Assume that the conditions have existed for at least a few million years.

an isolated group of ocean islands

Of the following anatomical structures, which is most homologous to the bones in the wings of a bird?

bones in the flippers of a whale

Darwin used the phrase "descent with modification" to explain which of the following ideas?

both the unity and diversity of life

Which of the following characteristics is most likely an adaptation?

bright colors of prairie flowers

Varieties of Staphylococcus aureus that are resistant to the drug methicillin __________.

developed in response to the use of methicillin were strongly selected for as methicillin became widely used to treat bacterial infections

Emerald ash borers are beetles whose larvae eat the leaves of ash trees. Without treatment of the trees, the beetles usually kill all ash trees in an area within 10 years. Which of the following events would provide the best possible avenue for saving the ash trees?

discovery of a gene in ash trees that prevents feeding by emerald ash borers and subsequent breeding of more ash trees with this chemical

Which of the following observations helped Darwin agree with Lyell that Earth was more than a few thousand years old?

experiencing an earthquake and seeing fossils of ocean organisms high in the Andes

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, which develop from similar embryonic tissues. These structural similarities are an example of ________.

homology

DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that

humans and chimpanzees share a relatively recent common ancestor

Antibiotic resistance in bacteria is an increasingly dangerous public health problem. Which of the following strategies would be most likely to reduce public health problems?

increased funding for research into finding new antibiotics with new mechanisms of action

After a drought in 1977, researchers hypothesized that on the Galapagos Island Daphne Major, medium ground finches with large, deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus cistoides fruits. A tourist company sets up reliable feeding stations with a variety of bird seeds (different types and sizes) so that tourists can get a better look at the finches. Which of the following events is now most likely to occur to finch beaks on this island?

increased variation in beak size and shape over time

A heritable trait is one that

is determined at least in part by genes passed from parents to offspring.

The theory of evolution through natural selection is considered a scientific theory because __________.

it is supported by a massive body of evidence from many disciplines it is broad enough in scope to explain many observations it is general enough to provide many testable hypotheses

Which of the following observations led to Darwin's major inferences?

members of a population vary in their heritable traits although organisms can produce huge numbers of offspring, many of these offspring do not survive

Imagine that you are an explorer who has discovered an isolated land mass in the middle of the Pacific Ocean. You find a predator that resembles a North American wolf except that it lays eggs. You name it the "mid-ocean wolf." The physical similarity between the mid-ocean wolf and the North American wolf is most likely due to which of the following factors?

natural selection that favors similar traits for organisms with similar ecological roles

From his observations of organisms in the Galapagos Islands, Darwin reasoned that __________.

organisms had adapted to new environments, giving rise to new species

In a hypothetical environment, fishes called pike-cichlids locate their prey by sight and eat small, immature algae-eating fish. Thus, the population of algae-eaters experiences predatory pressure from pike-cichlids. Which of the following possible changes is LEAST likely to occur in the algae-eater population in future generations?

production of fewer offspring by algae-eaters

Charles Darwin __________.

proposed natural selection as the mechanism of evolution

A biologist observes that a particular plant species is found in a forest but not in a nearby meadow. She hypothesizes that the plants could grow in the meadow but are not found there because their seeds have yet to land in the meadow. Which of the following would be the most appropriate way to scientifically evaluate this hypothesis?

scattering seeds in several areas of the meadow and observing whether they start to grow

Which of the following ideas of Charles Darwin was most derived from his reading of Malthus's essay on human population growth?

the ability of all species to over reproduce

Which of the following is an example of the pattern of evolution?

the fossil record of the evolution of modern cetaceans Submit