Chapter 27

Question 1

According to Lamarck, which variable would have the greatest influence on the evolution of an organism?

Answer 1

the environment

Question 2

Lamarck’s proposal of the inheritance of acquired characteristics included the idea that

Answer 2

the continual stretching of giraffe’s necks to reach leaves led to longer necks in offspring.

Question 3

When he arrived at the Galápagos Islands, Darwin did not observe the amazing tool-using “woodpecker finch” that can modify twigs to pry out grubs. Because there are no true woodpeckers on the Galápagos Islands, this behavior allows this finch to exploit an untapped food source. However, not all members of this species exhibit this behavior, which is probably learned from watching other finches. T or F? Young isolated at hatching will not know how to do this.

Answer 3

True

Question 4

When he arrived at the Galápagos Islands, Darwin did not observe the amazing tool-using “woodpecker finch” that can modify twigs to pry out grubs. Because there are no true woodpeckers on the Galápagos Islands, this behavior allows this finch to exploit an untapped food source. However, not all members of this species exhibit this behavior, which is probably learned from watching other finches. T or F? It is probably not “hardwired” in the brain as a behavior passed on genetically.

Answer 4

True

Question 5

When he arrived at the Galápagos Islands, Darwin did not observe the amazing tool-using “woodpecker finch” that can modify twigs to pry out grubs. Because there are no true woodpeckers on the Galápagos Islands, this behavior allows this finch to exploit an untapped food source. However, not all members of this species exhibit this behavior, which is probably learned from watching other finches. T or F? There must be a great advantage to reaching this food source for this learned behavior to be repeated by most descendants each generation.

Answer 5

True

Question 6

When he arrived at the Galápagos Islands, Darwin did not observe the amazing tool-using “woodpecker finch” that can modify twigs to pry out grubs. Because there are no true woodpeckers on the Galápagos Islands, this behavior allows this finch to exploit an untapped food source. However, not all members of this species exhibit this behavior, which is probably learned from watching other finches. T or F? This “learned” behavior will not lead to evolutionary change in the woodpecker population.

Answer 6

False

Question 7

Which piece of evidence did Darwin observe during his 5-year journey aboard the HMS Beagle?

Answer 7

A South American species of finch is most likely the ancestor of the Galápagos Island finches.

Question 8

What evidence would be studied by a biogeographer?

Answer 8

continental drift or the movement of tectonic plates over time, ocean currents and wind patterns, ranges of animals and ability to migrate

Question 9

Which evidence for evolution uses impressions of plants and animals pressed into sedimentary rock?

Answer 9

fossil record

Question 10

Anatomical features that are fully developed and functional in one group of organisms but reduced and functionless in a similar group are termed

Answer 10

vestigial

Question 11

the requirements of the Hardy-Weinberg equilibrium

Answer 11

no net mutations, no net migration of alleles into or out of the population, no selection of one genotype over another

Question 12

If the Hardy-Weinberg equilibrium is met, what is the net effect?

Answer 12

no evolution because the alleles in the population remain the same

Question 13

The founder effect is…

Answer 13

a form genetic drift, It produces a high frequency of some rare alleles in a small isolated population, Founding members contain a tiny fraction of the alleles found in the original population.

Question 14

When only a few individuals survive unfavorable times, thereby losing the majority of genotypes in the next generation, it is called

Answer 14

a bottleneck effect

Question 15

genetic drift can lead to…

Answer 15

an allele becoming fixed in a population when its alternative allele is lost from the population

Question 16

A random alteration in the sequence of DNA nucleotides that provides a new variant of the gene is

Answer 16

gene mutation

Question 17

Movement of alleles between populations such as by the migration of breeding individuals is called

Answer 17

gene flow

Question 18

What contributes to evolution?

Answer 18

mutations
gene flow
genetic drift

Question 19

Inbreeding within a population is an example of

Answer 19

nonrandom mating

Question 20

Disruptive selection is described in the text with the case of British land snails. In the grassy fields, the light-banded snails escape bird predators. In the darker forest, the dark snails survive and the light-banded snails are eaten. As long as the snails continue to cruise across the British landscape mating at the same season and having access to each other, why doesn’t this “disruptive selection” eventually lead to two separate species?

Answer 20

There is no reproductive isolation to prevent gene flow.

Question 21

Which type of natural selection occurs when an intermediate phenotype is favored?

Answer 21

stabilizing selection

Question 22

Which type of natural selection increases the frequency of one extreme phenotype?

Answer 22

directional

Question 23

The model of speciation that requires some time with geographic barriers between two populations, allowing evolution of reproductive isolation, is

Answer 23

allopatric speciation

Question 24

During sympatric speciation

Answer 24

reproductive isolation between certain subpopulations occurs

Question 25

During allopatric speciation

Answer 25

a geographic separation occurs between subpopulations

Question 26

The fin of a tuna and the flipper of a dolphin are

Answer 26

analogous structures

Question 27

Lizards on a small island are more likely to have to mate with close relatives. The form of microevolution is

Answer 27

the founder effect

Question 28

Cheetahs are very genetically similar, meaning there is not a lot of genetic diversity in their gene pool. It appears that at least 2 times in the last 10,000 years cheetah populations crashed to very low numbers. The present day low genetic diversity is due to _____________.

Answer 28

the bottleneck effect

Question 29

A population of mice live in a grassy area near a stream. Some individuals have alleles that give them white fir while others have alleles for brown fur. A family of hawks move in and nest nearby. The hawks catch the white mice at a higher rate because those mice do not blend in to the surroundings so well. This changes the genetic makeup of the population and a higher percentage of the next generation of mice have brown fur. This is an example of _______.

Answer 29

Natural Selection

Question 30

A population of mice live in a grassy area near a stream. Some individuals have alleles that give them white fir while other have alleles for brown fur. One day the stream floods killing a higher percentage of mice with the brown alleles basically at random. This changes the genetic makeup of the population and a higher percentage of the next generation of mice have white fur. This is an example of

Answer 30

Genetic Drift

Question 31

A population of mice live in a grassy area near a stream. Some individuals have alleles that give them white fir while others have alleles for brown fur. One day a mouse is born in which an allele for brown fur has change and causes the mouse to be tan. This is an example of

Answer 31

Mutation

Question 32

In Arkansas, the gray tree frog breeds in March, while the closely related species Harpers frog breeds at the end of May. This is an example of a ___________________ isolating mechanism.

Answer 32

temporal

Question 33

Two species of peas are visited by the same species of bee. Each species of pea has its stamens positioned to place pollen on different parts of the bee’s body. Upon visiting other flowers, the pollen from the bee can only get on the female parts of the same species. This is an example of a ___________________ isolating mechanism.

Answer 33

mechanical

Question 34

In peacock spiders, a male displays before a female. If the male is of the wrong species then the female will reject him because he does not do the correct courtship display or have the correct color patterns. This is an example of a ___________________ isolating mechanism.

Answer 34

behavioral

Question 35

Red-legged frogs and Bullfrogs can interbreed in the lab. However, Red-legged frogs only breed in fast-moving streams and Bullfrogs only breed in ponds. This is an example of a _______________ isolating mechanism.

Answer 35

habitat

Question 36

allopatric speciation

Answer 36

populations become separated by geographic barrier and gene flow is no longer possible

Question 37

sympatric speciation

Answer 37

a single population divides into two isolated groups without being geographically isolated