Question 1

Fossils found in deeper layers are ________ than fossils found in more shallow layers.

Accepted Answer

The deeper the layer in the earth, the older the fossils found within it, since layers of sedimentary rock are deposited one on top of the other over time. Therefore, fossils found in deeper layers are older than those found in more shallow layers.

Question 2

Natural selection

Accepted Answer

Natural selection is the principle cause of evolutionary change. It is a mechanism of evolution where individuals with certain advantageous traits are more likely to survive and reproduce, passing on their genes to the next generation, causing the frequency of those traits to increase over time.

Option A is incorrect as while natural selection can lead to the extinction of some species, it is not its principle cause.

Option C is incorrect as natural selection occurs in all cells, not just gametes.

Option D is incorrect as genetic drift is a separate mechanism of evolution, not a requirement for natural selection.

Question 3

What is biological evolution?

Accepted Answer

Biological evolution refers to the change in inherited characteristics of a group of organisms over generations. It involves the process of natural selection, genetic drift, and other mechanisms that drive changes in populations over time.

Question 4

Breeding programs for farm-raised chickens result in a variety of unusual colors and feathers.Is this an example of evolution?

Accepted Answer

The change in chicken coloration is a genetic change in the population over time, which is an example of evolution. While the breeding programs are human-controlled and do not involve natural selection, the resulting genetic changes still represent evolutionary changes in the population. Additionally, the time scale for evolution is not limited to long periods of time, as it can occur relatively quickly in response to selective pressures.

Question 5

The fossil record

Accepted Answer

The fossil record shows evidence of gradual changes in species over time, as well as the appearance of major new groups of organisms that arose from previously existing organisms, such as the emergence of mammals from reptiles. It does not prove that all known species appeared at the same time or that humans date back to the first indications of life, and it is not artificially created by evolutionary biologists.

Question 6

One of the reasons scientists have had so much difficulty finding a cure for HIV/AIDS is that the HIV virus is quick to evolve resistance to the drugs used to treat it.What is the most likely mechanism for this type of evolution?

Accepted Answer

The most likely mechanism for the evolution of drug resistance in HIV is that certain versions of the virus persist longer in the presence of a drug than others. Those viruses may survive drug treatment and pass their genes to their offspring, creating a population of drug-resistant viruses. This is known as selective pressure, and it allows the virus to rapidly evolve resistance to drugs.

Question 7

A group of scientists proposed that mammals with fur that contrasts with their background are hunted more by predators than mammals with fur that blends in with their background.After running several experiments,the scientists found that dark mice were attacked 25 percent of the time in a dark habitat and 75 percent of the time in a light habitat.The light-colored mice were attacked 25 percent of the time in a light habitat and 75 percent of the time in a dark habitat.These data

Accepted Answer

The data support the hypothesis because the dark-colored mice were attacked more in light habitats and the light-colored mice were attacked more in dark habitats, which is consistent with the idea that mammals with fur that contrasts with their background are hunted more by predators.

Question 8

Which of the following statements regarding the evolutionary history of an organism is FALSE?

Accepted Answer

Predictions of evolutionary relatedness based on DNA usually agree with those based on anatomical evidence, rather than contradicting them. This statement is therefore false.

Question 9

Bears have thinner bones than whales.Hippopotami have intermediate bone thickness.What hypothesis does this support?

Accepted Answer

The fact that hippopotami have intermediate bone thickness between bears and whales suggests that they spend part of their time in water (like whales) and part on land (like bears). This supports hypothesis C.

Question 10

Evolution is

Accepted Answer

Evolution is strongly supported by scientific evidence, including genetic and molecular biology, ecological observations, and the fossil record. It is one of the most well-supported theories in science.

Question 11

Which of the following statements about evolution is true?

Accepted Answer

Evolution is a process of change in allele frequencies in a population over time. This change can result in the addition or loss of traits in existing organisms through natural selection, genetic drift, mutation, and gene flow. Therefore, option C is the correct statement. Options A, B, and D are incorrect because they are too narrow or untrue.

Question 12

The fossils of Pakicetus,Ambulocetus,Rodhocetus,and Dorudon are examples of ________,demonstrating the fifteen million years of evolution between Indohyus and Balaena (modern baleen whale).

Accepted Answer

The fossils of Pakicetus, Ambulocetus, Rodhocetus, and Dorudon are transitional fossils, as they demonstrate the evolution of whales over fifteen million years from their land-dwelling ancestor Indohyus to the modern baleen whale Balaena. These fossils show the intermediate stages of whale evolution, making them key pieces of evidence for the theory of evolution.

Question 13

Equus (horses)have a single toe on their hoof,while Hyracotherium (the ancestor to horses)had four toes.Which of the following evidence would support this conclusion?

Accepted Answer

A transition fossil with three toes would provide evidence that the ancestor to horses had multiple toes, while the current horse (Equus) only has one toe. Option A is not sufficient evidence as it only shows one toe, but does not necessarily show the transition from multiple toes to one toe. Option B does not align with the current understanding of horse evolution. Option D shows that some members of the ancestor species already had one toe, but it doesn't show the transition from multiple toes to a single toe.

Question 14

Two fossils are found in a hillside.Fossil A was found in an upper layer and fossil B was found in a lower layer.Which of the following statements is true?

Accepted Answer

Fossil B was found in a lower layer, which means it is older than fossil A found in an upper layer. Therefore, B is likely the oldest of these fossils. There is no information provided about the evolutionary relationship between the two fossils.

Question 15

Cultivation of corn over thousands of years has resulted in a modern corncob that looks very different from the tiny ancestral cob.Does this support the concept of evolution?

Accepted Answer

The changes in corn through artificial selection by humans over time is an example of evolution, demonstrating that evolutionary changes can occur under human influence, which is a form of selection pressure, similar to natural selection but with human preferences guiding the selection process.

Question 16

Natural selection tends to

Accepted Answer

Natural selection favors individuals with traits that enhance their survival and reproduction, leading to an increase in the commonality of those traits within a population. This phenomenon is known as adaptation. Thus, Choice A is the correct option. Conversely, natural selection may decrease the number of individuals in a population, but this is not its primary effect. Also, genetic drift is a random process that can lead to changes in the frequency of certain alleles within a population, but it is not driven by natural selection. Finally, natural selection increases the likelihood of adaptation, rather than decreasing it.

Question 17

Peppered moths are generally light in color and blend into the trunks of the trees on which they live.Populations of peppered moths found in areas where soot has blackened the tree trunks are dark in color.This example demonstrates

Accepted Answer

This is an example of natural selection because the dark coloration in the peppered moths is advantageous in areas with blackened tree trunks, making them less visible to predators and increasing their chances of survival and reproduction.

Question 18

Humans simulate the process of natural selection when they use ________ to develop new varieties of crop plants that better meet the needs of farmers.

Accepted Answer

Artificial selection involves humans deliberately choosing and breeding only those individuals with desirable traits in order to create new varieties of crops that better meet the needs of farmers. Gene flow, habitat changes, and continental drift are all natural processes that occur without human intervention and are not directly involved in the development of new crop varieties through artificial selection.

Question 19

Neanderthal fossils

Accepted Answer

Neanderthal fossils are older than modern human fossils and are usually found in layers below them, indicating an evolutionary timeline in which modern humans evolved from a common ancestor with Neanderthals.

Question 20

The result of ________ over evolutionary time spans is that alleles that allow organisms to survive and reproduce at a higher rate than other individuals become more common in the population.

Accepted Answer

Natural selection is the process by which organisms with advantageous traits are more likely to survive and reproduce, passing these traits on to their offspring. Over time, this can result in certain alleles becoming more common in the population, as individuals with those alleles are more successful at passing them on. Artificial selection and gene flow can also influence allele frequency, but do not occur naturally over evolutionary time spans. Homology refers to the similarity of traits between different species, and is not directly related to allele frequency or evolution.

Quiz 11: Evidence for Evolution