Chapter 8

Question 1

Darwin’s observations while traveling on the Beagle helped him develop which theory?

Answer 1

that species change over time

Question 2

The phenotype of an organism is:

Answer 2

its physical characteristics

Question 3

Why is it that creationism can never be accepted as a scientific explanation of the origin of life?

Answer 3

Because the ideas of creationism cannot be tested through experiment and observation.

Question 4

Disruptive selection occurs when:

Answer 4

individuals with extreme values of a trait have greater fitness than individuals with intermediate values of the trait.

Question 5

Which of the following is NOT a mechanism of genetic change in populations?

a) biogeography
b) migration
c) mutation
d) genetic drift
e) natural selection

Answer 5

biogeography

Question 6

A population’s environment sometimes changes too quickly for natural selection to adapt the individuals in the population to the environment. In these situations:

Answer 6

the individuals’ instincts can no longer be trusted to elicit behavior that maximizes reproductive success.

Question 7

Name some sources of evidence demonstrating the occurrence of evolution:

Answer 7

biogeography, molecular biology, comparative anatomy/embryology, the fossil record

Question 8

Which of the following best describes the difference between artificial and natural selection?

Answer 8

Natural selection can act without the input of humans; artificial selection requires some human input.

Question 9

While on the voyage of the HMS Beagle, Darwin:

Answer 9

nurtured his love of studying nature, exploring plant and animal diversity, and collecting fossils.

Question 10

Evolution is define as:

Answer 10

a change in the frequency of alleles in a population over time.

Question 11

Evolution only occurs via:

Answer 11

natural selection, genetic drift, migration, or mutation.

Question 12

Most mutations:

Answer 12

are random, meaning they are unrelated to how useful or harmful they might be to the organism in which they occur.

Question 13

Which of the following choices is NOT a useful characteristic of cytochrome C for sequence comparisons across different species?

a) It is large enough to contain useful phylogenetic information.
b) It is highly conserved.
c) It has the same function across species.
d) It is useful for establishing the evolutionary relationships between all kingdoms of life.
e) It is not likely to be subject to lateral transfer.

Answer 13

It is useful for establishing the evolutionary relationships between all kingdoms of life.

Question 14

Two types of polygamy are:

Answer 14

polygyny and polyandry

Question 15

The average time to death from starvation in a fruit fly is about 20 hours. Selecting for increased starvation resistance in fruit flies:

Answer 15

can produce populations in which the average time to death from starvation is 160 hours

Question 16

While on the Beagle, Darwin was intrigued by glyptodonts because:

Answer 16

glyptodont fossils resembled a species that currently existed, but were much, much larger

Question 17

Genetic drift will have the greatest effects for populations:

Answer 17

that are very small

Question 18

The 14 species of Darwin’s finches on the Galapagos Islands mainly differ in:

Answer 18

bill size

Question 19

Human birth weight is a classic example of the results of:

Answer 19

stabilizing selection

Question 20

For a population to evolve through natural selection:

Answer 20

its members must possess inheritable variation

Question 21

Which of the following is NOT an important reason that natural selection does not lead to perfect organisms?

Answer 21

Artificial selection, that is, selection by humans for improvement of animal and plants for human use, is the only way that perfect organisms can evolve.

Question 22

Based on the information given, which of the organisms described below most likely has the lowest fitness?

Answer 22

a sterile organism that lives twice as long as the average longevity in its population

Question 23

Which of the following statements about the relationship between humans and evolution is FALSE?

Answer 23

Because evolutionary processes are operating today just as they have been since life first appeared on Earth, humans have not influenced evolutionary processes

Question 24

The amount of time that has passed since two species last shared a common ancestor:

Answer 24

is revealed by the degree of similarity in sections of their DNA

Question 25

Anatomical homology in vertebrate forelimbs is considered to be evidence for evolution because:

Answer 25

similarities among vertebrate forelimbs suggest that they evolved from a common ancestor

Question 26

Convergent evolution can occur only when two species:

Answer 26

evolve under similar selecting forces

Question 27

When first used in medicine in the 1940s, penicillin was uniformly effective in killing the bacterium Staphyloccocus aureus. Today, ____________________ has led to an increase in antibiotic-resistant alleles, and humans are increasingly at risk from untreatable Staphyloccocus aureus infections.

Answer 27

natural selection in Staphyloccocus aureus populations