Chapter 9 Definitions

Question 1

What is the net movement of alleles from one population to another due to the migration of individuals?

Answer 1

Gene Flow

Question 2

What is mating among individuals on the basis of mate selection for a particular phenotype or due to inbreeding?

Answer 2

Non-random Mating

Question 3

What is the change in frequencies of alleles due to chance events in a breeding population?

Answer 3

Genetic Drift

Question 4

What is a change in a gene pool that occurs when a few individuals start a new isolated population?

Answer 4

Founder Effect

Question 5

What is changes in gene distribution that result from a rapid decrease in population size

Answer 5

Bottleneck Effect

Question 6

What is natural selection that favours intermediate phenotypes and acts against extreme variants

Answer 6

Stabilizing Selection

Question 7

What is natural selection that favours the phenotypes at one extreme over another, resulting in the distribution curve of phenotypes shifting in the direction of that extreme

Answer 7

Directional Selection

Question 8

Natural selection that favours the extremes of a range of phenotypes rather than intermediate phenotypes; this type of selection can result in the elimination of intermediate phenotypes

Answer 8

Disruptive (diversifying) selection

Question 9

What is natural selection for mating based, in general, on competition between males and choices made by females

Answer 9

Sexual Selection

Question 10

What is the net movement of alleles from one population to another due to the migration of individuals?

Answer 10

Gene Flow

Question 11

What is mating among individuals on the basis of mate selection for a particular phenotype or due to inbreeding?

Answer 11

Non-random Mating

Question 12

What is the change in frequencies of alleles due to chance events in a breeding population?

Answer 12

Genetic Drift

Question 13

What is a change in a gene pool that occurs when a few individuals start a new isolated population?

Answer 13

Founder Effect

Question 14

What is changes in gene distribution that result from a rapid decrease in population size?

Answer 14

Bottleneck Effect

Question 15

What is natural selection that favours intermediate phenotypes and acts against extreme variants?

Answer 15

Stabilizing Selection

Question 16

What is natural selection that favours the phenotypes at one extreme over another, resulting in the distribution curve of phenotypes shifting in the direction of that extreme?

Answer 16

Directional Selection

Question 17

Natural selection that favours the extremes of a range of phenotypes rather than intermediate phenotypes; this type of selection can result in the elimination of intermediate phenotypes?

Answer 17

Disruptive (diversifying) selection

Question 18

What is natural selection for mating based, in general, on competition between males and choices made by females?

Answer 18

Sexual Selection

Question 19

What is the formation of new species from existing species?

Answer 19

Speciation

Question 20

What is a barrier that either impedes mating between species of prevents fertilization of the eggs if individuals from different species attempt to mate; also called pre-fertilization barrier?

Answer 20

Pre-zygotic isolating mechanism

Question 21

What is a barrier that prevents hybrid zygotes from developing into viable, fertile individuals; also called post-fertilization barrier?

Answer 21

Post-zygotic isolating mechanism

Question 22

What is speciation in which populations within the same geographical areas diverge and become reproductively isolated?

Answer 22

Sympatric speciation

Question 23

What is speciation in which a population is split into two or more isolated groups by a geographical barrier; also called geographical speciation?

Answer 23

Allopatric speciation

Question 24

What is the ecological role and physical distribution of a species in its environment?

Answer 24

Ecological niche

Question 25

What is the diversification of a common ancestral species into a variety of differently adapted species?

Answer 25

Adaptive radiation

Question 26

What is the pattern of evolution in which species that were once similar to an ancestral species diverge, or become increasingly distinct?

Answer 26

Divergent evolution

Question 27

What is a pattern of evolution in which similar traits arise because different species have independently adapted to similar environmental conditions?

Answer 27

Convergent evolution

Question 28

What is a model of evolution that views evolutionary change as slow and steady, before and after a divergence?

Answer 28

Gradualism

Question 29

What is a model of evolution that views evolutionary history as long periods of stasis, or equilibrium, that are interrupted by periods of divergence?

Answer 29

Punctuated equilibrium