Evolution and Natural Selection

Evolution that occurs in a relatively short time when one species gives rise to many species in response to the creation of a new habitat or another ecological opportunity

• Genetic Drift

• Sympatric Speciation

• Punctuated Equilibrium

• Adaptive Radiation

Structures in different species that are similar because of common ancestry

• Homologous Structures

• Biogeography

• Analogous Structures

• Vestigial Structures

The theory that evolution occurs slowly but steadily

• Gradualism

• Evolution

• Punctuated Equilibrium

• Biogeography

More primitive features, such as teeth and tails, that do appear in ancestral forms

• Vestigial Structures

• Ancestral Traits

• Derived Traits

• Analogous Structures

A species evolves into a new species without a physical barrier

• Sympatric Speciation

• Adaptive Radiation

• Genetic Drift

• Disruptive Selection

When allelic frequencies remain constant, a population is in genetic equilibrium

• Hardy-Weinberg Principle

• Punctuated Equilibrium

• Stabilizing Selection

• Founder Effect

Operates to eliminate extreme expressions of a trait when the average expression leads to higher fitness

• Disruptive Selection

• Directional Selection

• Stabilizing Selection

A physical barrier divides one population into two or more populations

• Allopatric Speciation

• Adaptive Radiation

• Genetic Drift

• Disruptive Selection

A measure of the relative contribution that an individual trait makes to the next generation

• Evolution

• Mimicry

• Fitness

• Natural Selection

Increases the expression of the extreme versions of a trait in a population

• Disruptive Selection

• Directional Selection

• Stabilizing Selection