Population genetics principle was given by ?

Population genetics is a subfield of genetics that deals with genetic differences within and between populations, and is a pa of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and population structure Population genetics began as a reconciliation of Mendelian inheritance and biostatistics models. Natural selection will only cause evolution if there is enough genetic variation in a population. Before the discovery of Mendelian genetics, one common hypothesis was blending inheritance. But with blending inheritance, genetic variance would be rapidly lost, making evolution by natural or sexual selection implausible. The Hardy-Weinberg principle provides the solution to how variation is maintained in a population with Mendelian inheritance. According to this principle, the frequencies of alleles (variations in a gene) will remain constant in the absence of selection, mutation, migration and genetic drift. Ref : https://en.m.wikipedia.org/wiki/Population_genetics