Population genetics
A branch of evolutionary biology responsible for investigating processes that cause changes in allele and genotype frequencies in populations based upon Mendelian inheritance.
Four different forces can influence the frequencies: natural selection, mutation, gene flow (migration), and genetic drift.
A population can be defined as a group of interbreeding individuals and their offspring
For human genetics the populations will consist only of the human species.
The Hardy-Weinberg principle is a widely used principle to determine a and genotype frequencies.