Question 1

The cow Bos primigenius (which is bred for meat and milk) has a smaller brain and larger eyes than closely related wild species of ungulates. These traits most likely arose by ________.

Accepted Answer

A)  natural selection, because these traits evolved in the population over time 
B)  natural selection, because these traits were not consciously selected by humans 
C)  artificial selection, because changes in these traits co-occurred with human selection for high milk output and high muscle content 
D)  artificial selection, because these animals differ from their close relatives and common ancestor

Question 2

Pseudogenes are ________.

Accepted Answer

A)  composed of RNA, rather than DNA 
B)  the same things as introns 
C)  unrelated genes that code for the same gene product 
D)  nonfunctional vestigial genes

Question 3

Scientific theories ________.

Accepted Answer

A)  are nearly the same things as hypotheses 
B)  are supported by, and make sense of, many observations 
C)  cannot be tested because the described events occurred only once 
D)  are predictions of future events

Question 4

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?

Accepted Answer

A)  Forelimb evolution was adaptive in people and bats, but not in whales. 
B)  Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy. 
C)  Genes mutate faster in whales than in humans or bats. 
D)  Whales are not properly classified as mammals.

Question 5

Which of these conditions are always true of populations evolving due to natural selection?
Condition 1: The population must vary in traits that are heritable.
Condition 2: Some heritable traits must increase reproductive success.
Condition 3: Individuals pass on most traits that they acquire during their lifetime.

Accepted Answer

A)  Condition 1 only 
B)  Condition 2 only 
C)  Conditions 1 and 2 
D)  Conditions 2 and 3

Question 6

The Linnaeus classification system grouped organisms by ________.

Accepted Answer

A)  linear hierarchy of the scala naturae 
B)  increasingly more general categories 
C)  increasingly more complex categories 
D)  environmental location

Question 7

Given what we know about evolutionary biology, we expect to find the largest number of endemic species in which of the following geological features, which have existed for at least a few million years?

Accepted Answer

A)  an isolated ocean island in the tropics 
B)  an extensive mountain range 
C)  a grassland in the center of a large continent, with extreme climatic conditions 
D)  a shallow estuary on a warm-water coast

Question 8

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that ________.

Accepted Answer

A)  island forms are descended from mainland forms 
B)  common environments are inhabited by the same organisms 
C)  island forms and mainland forms have identical gene pools 
D)  the island forms and mainland forms are converging

Question 9

After the drought of 1977, researchers hypothesized that on the Galápagos 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 these events is now most likely to occur to finch beaks on this island?

Accepted Answer

A)  evolution of yet larger, deeper beaks over time, until all birds have relatively large, deep beaks 
B)  evolution of smaller, pointier beaks over time, until all birds have relatively small, pointy beaks 
C)  increased variation in beak size and shape over time 
D)  no change in beak size and shape over time

Question 10

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 warm-blooded. The fossils of Thrinaxodon are consistent with the hypothesis that ________.

Accepted Answer

A)  fossils found in a given area look like the modern species in that same area 
B)  the environment where it lived was very warm 
C)  mammals evolved from a reptilian ancestor 
D)  Antarctica and South Africa separated after Thrinaxodon went extinct

Question 11

The following questions refer to the evolutionary tree in the figure below.
The horizontal axis of the cladogram depicted below is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V-Z) represent various common ancestors. Let's say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.
 
-Which of the five species, labeled V-Z, is the common ancestor of the fewest number of species?

Accepted Answer

A)  V 
B)  W 
C)  Y 
D)  Z

Question 12

Which one of the following observations did Darwin first make during his discovery of evolution?

Accepted Answer

A)  The ability of individuals to survive and reproduce is not equal. 
B)  There is variation in inherited traits. 
C)  Individuals who reproduce more leave more offspring. 
D)  The unequal ability to reproduce leads to the accumulation of favorable traits in a population.

Question 13

When Cuvier considered the fossils found in the vicinity of Paris, he concluded that the extinction of species ________.

Accepted Answer

A)  does not occur, but evolution does occur 
B)  and the evolution of species both occur 
C)  and the evolution of species do not occur 
D)  occurs, but that there is no evolution

Question 14

Currently, two of the living elephant species (X and Y) are placed in the genus Loxodonta, and a third surviving species (Z) is placed in the genus Elephas. Assuming this classification reflects evolutionary relatedness, which of the following is the most accurate phylogenetic tree?

Accepted Answer

A)   
B)   
C)   
D)

Question 15

Which of the following statements describe evolution?

Accepted Answer

A)  Individuals evolve in response to their environment. 
B)  The match between organism and their environment decreases. 
C)  Natural selection chooses the most popular trait. 
D)  Quick changes occur in an individual's phenotype.

Question 16

What must be true of any organ described as vestigial?

Accepted Answer

A)  It must be analogous to some feature in an ancestor. 
B)  It must be homologous to some feature in an ancestor. 
C)  It must be both homologous and analogous to some feature in an ancestor. 
D)  It need be neither homologous nor analogous to some feature in an ancestor.

Question 17

Currently, two extant elephant species (X and Y) are classified in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which statement should be true?

Accepted Answer

A)  Species X and Y are not related to species Z. 
B)  Species X and Y share a greater number of homologies with each other than either does with species Z. 
C)  Species X and Y share a common ancestor that is alive today. 
D)  Species X and Y are the result of artificial selection.

Question 18

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

Accepted Answer

A)  Species diversity declines farther from the equator. 
B)  Fewer species live on islands than on the nearest continents. 
C)  Birds live on islands located farther from the mainland than the birds' maximum nonstop flight distance. 
D)  South American temperate plants are more similar to the tropical plants of South America than to the temperate plants of Europe.

Question 19

The following questions refer to the figure below, which shows an outcrop of sedimentary rock whose strata are labeled A-D.

If x indicates the location of fossils of two closely related species, then fossils of their most-recent common ancestor are most likely to occur in which stratum?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D

Question 20

Which pair of scientists below would probably have agreed with the process that is depicted by this tree?

Accepted Answer

A)  Cuvier and Lamarck 
B)  Darwin and Wallace 
C)  Aristotle and Lyell 
D)  Wallace and Linnaeus

Exam 22: Descent with Modification: A Darwinian View of Life