Unit 3 - Ch. 23: Population And Evolutionary Genetics Flashcards
What is population genetics?
The study of allele distribution and change in populations over time.
What is a gene pool?
The total set of alleles in a population
What is microevolution?
Small-scale changes in allele frequency across generations
What is the Hardy-Weinberg equation?
• p + q = 1 (alleles)
• p² + 2pq + q² = 1 (genotypes)
What conditions are required for Hardy-Weinberg equilibrium?
No mutation, drift, selection, migration; random mating
What does it mean if a population is in Hardy-Weinberg equilibrium?
Allele and genotype frequencies are not changing
What is the selection coefficient?
A measure of how much less fit a genotype is, compared to the fittest one (1 - W)
What is directional selection?
Favors one extreme phenotype
What is stabilizing selection?
Favors intermediate phenotypes
What is disruptive selection?
Favors both extremes over the intermediate
What is genetic drift?
Random changes in allele frequency, more significant in small populations
What is the founder effect?
When a new population is started by a small group, leading to reduced genetic variation
What is the bottleneck effect?
Drastic reduction in population size, followed by rebound, often leading to drift
What is gene flow (migration)?
The movement of alleles between populations—increases genetic similarity
