Chapter 16: Evolution of Populations

Combined genetic information of all the members of a particular population.

Number of times an allele occurs in a gene pool compared with the number of times other alleles occur.

Trait controlled by a single gene.

Trait controlled by two or more genes.

Form of natural selection in which the entire curve moves; occurs when individuals at one end of a distribution curve have higher fitness than individuals near the middle.

Form of natural selection by which the center of the curve remains in its current position; occurs when individuals near the center of a distribution curve have higher fitness than individuals at either end.

Form of natural selection in which a single curve splits into two; occurs when individuals at the upper and lower ends of a distribution curve have higher fitness than individuals near the middle.

Random change in allele frequencies that occurs in small populations.

Change in allele frequencies as a result of the migration of a small subgroup of a population.

Principle that allele frequencies in a population will remain constant unless one or more factors cause the frequencies to change.

Situation in which allele frequencies remain constant.

Formation of a new species.

Separation of species or populations so that they cannot interbreed and produce fertile offspring.

Form of reproductive isolation in which two populations have differences in courtship rituals or other types of behavior that prevent them from interbreeding.

Form of reproductive isolation in which two populations are separated physically by geographic barriers such as rivers, mountains, or stretches of water.