Crow and Kimura rescue the abstract concept of F-statistics from pure math and make it biological. "F" measures the probability that two alleles are identical by descent. It is the currency of relatedness. When you read their derivation, you realize that every mating is, to some tiny degree, incestuous—and that this dictates the entire genetic load of a species.
For a more in-depth understanding of population genetics theory, we recommend: an introduction to population genetics theory pdf
The theoretical foundation of this field was laid in the early 20th century. Three brilliant scientists successfully merged Darwin’s theory of natural selection with Mendel's laws of inheritance: Crow and Kimura rescue the abstract concept of