The sum total of allelic frequencies of a gene in a population is

The sum total of allelic frequencies of a gene in a population is 1.

p²+2pq+q²=1

The Hardy-Weinberg equilibrium describes the relationship between allelic and genotype frequencies in a non-evolving population. Allelic frequencies are represented as p and q, and from these, you can calculate genotype frequencies (e.g., p² for homozygous AA individuals). The sum of genotype frequencies equals 1, representing the total genetic variation. Deviations from this equilibrium signal evolutionary changes, such as genetic drift or natural selection, in a population. It serves as a fundamental concept in population genetics for understanding how genetic variation evolves over time.