Fundamentals of Population Genetics

Population genetics explores genetic variation within populations and involves the forces of evolution. It combines Darwinian theory with Mendelian inheritance to understand genetic patterns across generations.

A gene pool comprises all alleles in a population. Greater genetic diversity, measured by allele frequency, can indicate a healthier population, more resilient to changes.

This principle provides a baseline for non-evolving populations, predicting allele frequencies when five conditions are met: no mutation, random mating, no selection, large population size, and no gene flow.

Genetic drift is random allele frequency changes, more pronounced in small populations. It can lead to the founder effect or bottleneck effect, drastically shaping genetic diversity.

Gene flow, the transfer of alleles between populations, increases genetic variation. It can prevent speciation by homogenizing genetic differences that might have led to new species.

Mutations are the original source of genetic variation, introducing new alleles into the population. While often neutral, their accumulation underlies many evolutionary changes.

Natural selection acts on phenotypic variation, influencing allele frequencies. It can lead to adaptive evolution, where advantageous traits become more common in the population over generations.