Lect 21 - population genetics and natural selection

Flashcards covering key concepts from the Population Genetics and Natural Selection lecture.

Hardy-Weinberg equation

p2 + 2pq + q2 = 1. Used to predict genotypes in a population.

What does 'p' represent?

Frequency of the dominant allele in the Hardy-Weinberg equation.

What does 'q' represent?

Frequency of the recessive allele in the Hardy-Weinberg equation.

What factors can change allele frequencies?

Non-random mating, assortative mating, inbreeding, random genetic drift, bottleneck effect, founder effect, natural selection, gene flow/migration, and mutation.

What is random genetic drift?

A random change in allele frequencies due to sampling error over generations.

What is the bottleneck effect?

Population reduction event resulting in some alleles being lost or becoming rare.

What is the founder effect?

Small group of individuals become isolated from a larger population leading to reduced genetic variation.

What is natural selection?

Individuals with favorable heritable traits are more likely to survive and reproduce.

What is stabilizing selection?

Reduces variation but does not change the mean.

What is directional selection?

Changes the mean value towards one extreme.

What is disruptive selection?

Favors the two extremes producing two peaks.

What is sexual selection?

Individuals' traits increase their chances of attracting mates and successfully reproducing.

What is a cline?

The gradual geographic change in genetic/phenotypic composition.