Chapter 9 Definitions Flashcards
What is the net movement of alleles from one population to another due to the migration of individuals?
Gene Flow
What is mating among individuals on the basis of mate selection for a particular phenotype or due to inbreeding?
Non-random Mating
What is the change in frequencies of alleles due to chance events in a breeding population?
Genetic Drift
What is a change in a gene pool that occurs when a few individuals start a new isolated population?
Founder Effect
What is changes in gene distribution that result from a rapid decrease in population size
Bottleneck Effect
What is natural selection that favours intermediate phenotypes and acts against extreme variants
Stabilizing Selection
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
Directional Selection
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
Disruptive (diversifying) selection
What is natural selection for mating based, in general, on competition between males and choices made by females
Sexual Selection
What is the net movement of alleles from one population to another due to the migration of individuals?
Gene Flow
What is mating among individuals on the basis of mate selection for a particular phenotype or due to inbreeding?
Non-random Mating
What is the change in frequencies of alleles due to chance events in a breeding population?
Genetic Drift
What is a change in a gene pool that occurs when a few individuals start a new isolated population?
Founder Effect
What is changes in gene distribution that result from a rapid decrease in population size?
Bottleneck Effect
What is natural selection that favours intermediate phenotypes and acts against extreme variants?
Stabilizing Selection
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?
Directional Selection
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?
Disruptive (diversifying) selection
What is natural selection for mating based, in general, on competition between males and choices made by females?
Sexual Selection
What is the formation of new species from existing species?
Speciation
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?
Pre-zygotic isolating mechanism
What is a barrier that prevents hybrid zygotes from developing into viable, fertile individuals; also called post-fertilization barrier?
Post-zygotic isolating mechanism
What is speciation in which populations within the same geographical areas diverge and become reproductively isolated?
Sympatric speciation
What is speciation in which a population is split into two or more isolated groups by a geographical barrier; also called geographical speciation?
Allopatric speciation
What is the ecological role and physical distribution of a species in its environment?
Ecological niche
What is the diversification of a common ancestral species into a variety of differently adapted species?
Adaptive radiation
What is the pattern of evolution in which species that were once similar to an ancestral species diverge, or become increasingly distinct?
Divergent evolution
What is a pattern of evolution in which similar traits arise because different species have independently adapted to similar environmental conditions?
Convergent evolution
What is a model of evolution that views evolutionary change as slow and steady, before and after a divergence?
Gradualism
What is a model of evolution that views evolutionary history as long periods of stasis, or equilibrium, that are interrupted by periods of divergence?
Punctuated equilibrium
