Genetic Variation and Natural Selection

Flashcards based on lecture notes about genetic variation and natural selection.

Genetic Variation

The number and relative frequency of alleles present in a particular population

Directional Selection

Natural selection pattern that changes the average phenotype of a population in one direction, reducing genetic diversity

Allele frequencies changes

Alleles become fixed at a frequency of 1.0, while deleterious alleles become lost at a frequency of 0.0

Stabilizing Selection

Natural selection pattern that reduces both extremes in a population, reducing genetic variation but without changing the average.

Disruptive Selection

Natural selection pattern that eliminates phenotypes near the average value and favors extreme phenotypes, increasing genetic variation.

Speciation

The formation of new species, in which disruptive selection can play a role

Heterozygous Advantage

Heterozygous individuals have higher fitness than homozygous individuals