Question 1

For natural selection to occur, variation must exist. This is true because without variation
A) there is no way for change to occur between generations.
B) the one trait that exists is always advantageous, and change is not necessary.
C) there is no competition among individuals.
D) traits are never inherited by offspring.

Accepted Answer

Natural selection depends on variation because it relies on differences in traits among individuals to determine which ones are better adapted to their environment and more likely to survive and reproduce. Without variation, there would be no opportunity for one trait to become more or less common over time, as all individuals would be the same. Choice B is incorrect because not all traits are always advantageous, and even advantageous traits can become less so if the environment changes. Choice C is incorrect because competition can still occur even if all individuals are the same. Choice D is incorrect because traits are always inherited by offspring, even if they are not visibly different from those of their parents.

Question 2

Which of the following is an example of stabilizing selection on size?
A) Both small and large individuals survive, but medium individuals die off.
B) Only large individuals survive, thus stabilizing the species in the next generation.
C) The proportion of small and large individuals remains the same.
D) Large and small individuals are selected against to a similar degree.

Accepted Answer

Stabilizing selection favors the average individuals in a population by selecting against extremes. In this case, both large and small individuals being selected against means that the average or medium-sized individuals are favored, which is a classic example of stabilizing selection.

Question 3

Which of the following postulates makes up Darwin's theory of adaptation?
A) The total resources in a given environment tends to expand as the number of individuals using those resources increases.
B) Only noninherited variation has a long-term impact on evolutionary change.
C) Regardless of variation in parents, genetic mixing makes offspring very similar to each other across a species.
D) Individuals vary in ways that sometimes affect survival or reproduction.

Accepted Answer

Darwin's theory of adaptation is based on the postulate that individuals vary in ways that sometimes affect survival or reproduction. This variation can lead to differential reproductive success and natural selection, which over time can result in adaptations to the environment. The other options do not accurately describe Darwin's theory of adaptation.

Question 4

Charles Darwin is known for his revolutionary argument that
A) plants and animals are not designed by God and do not change over time.
B) plants and animals change slowly over time.
C) fossil plants and animals changed, but existing plants and animals do not.
D) plants and animals are created by chance and then evolve through divine intervention.

Accepted Answer

Charles Darwin is known for his theory of evolution, which argues that plants and animals change slowly over time through natural selection. He argued that those with advantageous traits are more likely to survive and reproduce, passing on those traits to future generations. This theory revolutionized the scientific understanding of life on Earth and is still widely accepted today. Therefore, choice B is the correct answer.

Question 5

Adaptations are defined as the components of an individual organism that
A) allow it to survive and reproduce.
B) allow it to evolve more rapidly.
C) occur by random chance alone.
D) absolutely never change.

Accepted Answer

Adaptations are traits or characteristics that provide an organism with an advantage in surviving and reproducing in its environment. These adaptations can be behavioral or physical and are shaped by natural selection. Ultimately, adaptations allow organisms to better compete for resources, avoid predators, find mates, and increase their chances of passing on their genes to the next generation. Therefore, option A is the best choice as it accurately captures the purpose of adaptations.

Question 6

Natural selection usually acts upon and produces adaptations at the level of the
A) gene.
B) individual.
C) group.
D) species.

Accepted Answer

Natural selection acts upon and produces adaptations at the level of the individual, not the gene, group, or species. Individuals with advantageous traits are more likely to survive and reproduce, passing those traits on to their offspring. Over time, this can lead to the evolution of new species with unique adaptations that allow them to thrive in their environments.

Question 7

Influential nineteenth-century scientists like Charles Darwin concluded that the complex adaptations we see in plants and animals are problematic and require a special explanation because
A) a divine creator designed them.
B) it is very unlikely that they arose by random chance alone.
C) they occur in most plants and animals.
D) they have no real function.

Accepted Answer

Charles Darwin and other nineteenth-century scientists believed that the complex adaptations seen in plants and animals were unlikely to have arisen by random chance alone, and therefore required a special explanation. This observation ultimately led Darwin to propose natural selection as the mechanism for evolution.

Question 8

During 1976 on the Galápagos Island of Daphne Major, Peter and Rosemary Grant found evidence of natural selection by adaptation when they observed that
A) finches with shallow beaks were less likely to survive and reproduce than finches with deep beaks.
B) finch beak size had no effect on survival rates.
C) many more small seeds were available for the finches to eat.
D) more finches with deep beaks died than finches with shallow beaks.

Accepted Answer

Peter and Rosemary Grant observed that finches with shallow beaks were less likely to survive and reproduce than finches with deep beaks. This suggests that natural selection favored beak depth as an adaptation for accessing different types of food sources.

Question 9

Charles Darwin, when developing his theory of adaptation by natural selection, incorporated the observation that
A) offspring are adapted to avoid resembling their parents in order to avoid mate confusion.
B) offspring tend to resemble their parents.
C) all competition between individuals within a species is over mates.
D) variation in offspring is shaped by the behavior of the parents during their lifetimes.

Accepted Answer

Darwin observed that offspring tend to resemble their parents, which led him to propose that natural selection acts on inherited traits.

Question 10

While on the Galápagos, Darwin observed variation among finches. These observations
A) helped lead Dárwin to move away from the concept of species as unchanging entities.
B) caused Darwin to assert that the ability of a population to expand is infinite.
C) confused Darwin, but he was later informed by the Grants, who were experts on birds, what he was seeing.
D) led to Darwin's formulation of the theory of natural selection, which he published while still in the Galápagos.

Accepted Answer

Darwin's observation of variation among finches on the Galápagos Islands was a key factor that led him away from the traditional view of species as unchanging entities and towards his theory of evolution by natural selection.

Question 11

After a drought, a scientist collects dead birds and finds that most of the individuals that did not survive to adulthood have either small or large beaks. Given this pattern, how do you expect selection is likely acting on the population?
A) Selection will not change the mean beak size.
B) Selection will make the mean beak size in the population smaller.
C) Selection will make the mean beak size in the population larger.
D) The entire population will die out.

Accepted Answer

The pattern suggests stabilizing selection, where individuals with extreme traits (very small or very large beaks) are less likely to survive, favoring those with intermediate traits. This maintains the mean beak size in the population.

Question 12

A key observation that Charles Darwin incorporated into his theory of adaptation by natural selection was that
A) any given environment can support only a certain number of individuals.
B) adaptations appear to arise fully formed every now and then, as a key driver of evolution.
C) individuals within a species tend to cooperate for the survival of the species.
D) no matter how limiting the resources in a given environment are, individuals can always find a way to survive.

Accepted Answer

Darwin observed that in any given environment, there is a finite amount of resources available to support a population. This led him to conclude that individuals within a population must compete with each other for survival, and only those individuals that are better adapted to their environment will survive and reproduce. This process of natural selection leads to the evolution of new traits and ultimately to the formation of new species.

Question 13

Even though natural selection was named after the artificial selection that plant and animal breeders use, it really refers to the
A) survival of the physically fit.
B) reproduction of traits from generation to generation.
C) selective retention of variation in a population.
D) variable ability of species to survive and reproduce.

Accepted Answer

Natural selection refers to the selective retention of variation in a population, meaning that certain traits or characteristics are favored and passed on to future generations based on their ability to survive and reproduce in their environment. While survival and reproduction are important aspects of natural selection, they are not the defining factors. Additionally, the term "natural" refers to the fact that the selection is occurring without human intervention, as opposed to artificial selection which is deliberately guided by breeders.

Question 14

When the Daphne Major finches reach a point where the costs of having a beak larger than average size outweigh the benefits, beak size will begin to stay the same, and the population will achieve a(n) ________ state.
A) direction
B) trend
C) equilibrium
D) drift

Accepted Answer

Equilibrium is the state where the population has reached a balance between competing pressures, in this case, the advantages and disadvantages of having a beak larger than average size. Once the costs outweigh the benefits, there will be no selective pressure for larger beaks, and the population will stabilize at a certain beak size, creating an equilibrium state.

Question 15

Why did natural selection act on the medium ground finch on Daphne Major?
A) Birds with medium beak sizes experienced higher mortality.
B) A drought changed the environment where the finches lived.
C) Offspring of finches with small beaks did not survive the juvenile period.
D) The population reached equilibrium.

Accepted Answer

A drought changed the environment on Daphne Major, leading to a decrease in the availability of small, soft-shelled seeds that the smaller-beaked finches traditionally fed upon. This caused the medium and large-beaked finches to have a selective advantage, as they were better able to crack the tougher seeds that were now more abundant. As a result, natural selection acted on the medium ground finch (and other finch species on the island) to favor those with larger beaks.

Question 16

What is the significance of the human eye in the history of research on evolution?
A) William Paley proved that since the human eye was clearly designed for seeing, it was evidence for a heavenly designer.
B) Human eyes are far more advanced than the eyes of other mammals and are an example of rapid, recent evolution.
C) Differences between human eyes and other animals' eyes are explained as different adaptations shaped by natural selection.
D) Since the human eye is made of soft tissue, and has no fossil record, the study of the eye does not inform evolutionary thinking.

Accepted Answer

The study of the human eye has been important in understanding evolution because it demonstrates how adaptations through natural selection have shaped the development of different species. While there may be some design features to the eye, the complex differences between human eyes and those of other animals can be explained as adaptations that have developed over time. The eye is one example of how evolution can shape the form and function of an organism.

Question 17

Which of the following is an example of directional selection on size?
A) Both small and large individuals survive.
B) Only large individuals survive.
C) The proportion of small and large individuals remains the same.
D) Neither small nor large individuals survive.

Accepted Answer

Directional selection on size occurs when one extreme of a size range has a higher fitness than the other. In this case, only large individuals survive, which means that individuals that are smaller than the selected range do not survive and reproduce, while individuals that are larger than the selected range have higher fitness and reproduce more. This results in a shift of the population towards larger sizes over time.

Question 18

Darwin originally went to school to become a ________ but ended up at ________ and after graduation studied ________.
A) doctor; Cambridge; natural history
B) ship's captain; Portsmouth navy yard; sailing
C) preacher; University of Edinburgh; religion
D) doctor; Harvard University; genetics

Accepted Answer

Charles Darwin originally went to the University of Edinburgh to become a doctor but soon realized that he had no interest in the medical profession. He then went to Cambridge University where he studied natural history and after graduation traveled on the HMS Beagle for five years observing and collecting specimens which led him to develop his theory of evolution by natural selection.

Question 19

If a population is in stasis, then
A) the population is in its natural state.
B) natural selection is not acting on the population.
C) the most common type of individual is consistently favored by stabilizing selection.
D) the most common type of individual is consistently favored by disruptive selection.

Accepted Answer

Stasis refers to a period of little or no evolutionary change in a population. Stabilizing selection is a type of natural selection that favors the most common phenotype, leading to a reduction in genetic variation and potentially contributing to stasis in a population. Therefore, the most common type of individual is consistently favored by stabilizing selection in stasis populations.

Question 20

Species are populations of
A) unrelated individuals that are best adapted to their environment.
B) individuals that maintain a fixed set of characteristics.
C) individuals that may vary and that may or may not change through time.
D) individuals that cannot be modified or go extinct.

Accepted Answer

Species are populations of individuals that may vary among themselves and can change over time due to natural selection, genetic drift, mutations, and other evolutionary forces. This variability and potential for change are key aspects of biological species.

Quiz 1: Adaptation by Natural Selection

For natural selection to occur, variation must exist. This is true because without variation

Which of the following is an example of stabilizing selection on size?

Which of the following postulates makes up Darwin's theory of adaptation?

Charles Darwin is known for his revolutionary argument that

Adaptations are defined as the components of an individual organism that

Natural selection usually acts upon and produces adaptations at the level of the

Influential nineteenth-century scientists like Charles Darwin concluded that the complex adaptations we see in plants and animals are problematic and require a special explanation because

During 1976 on the Galápagos Island of Daphne Major, Peter and Rosemary Grant found evidence of natural selection by adaptation when they observed that

Charles Darwin, when developing his theory of adaptation by natural selection, incorporated the observation that

While on the Galápagos, Darwin observed variation among finches. These observations

After a drought, a scientist collects dead birds and finds that most of the individuals that did not survive to adulthood have either small or large beaks. Given this pattern, how do you expect selection is likely acting on the population?

A key observation that Charles Darwin incorporated into his theory of adaptation by natural selection was that

Even though natural selection was named after the artificial selection that plant and animal breeders use, it really refers to the

When the Daphne Major finches reach a point where the costs of having a beak larger than average size outweigh the benefits, beak size will begin to stay the same, and the population will achieve a(n) ________ state.

Why did natural selection act on the medium ground finch on Daphne Major?

What is the significance of the human eye in the history of research on evolution?

Which of the following is an example of directional selection on size?

Darwin originally went to school to become a but ended up at and after graduation studied .

If a population is in stasis, then

Species are populations of