Who is Ronald A. Fisher from The Selfish Gene and what is their importance?

Born in 1890, Ronald Fisher grew up to become a statistician, geneticist, and evolutionary biologist. Fisher had to compensate for his very bad eyesight by imagining complicated problems in his head. His brilliantly developed math mind helps him arrive at many "firsts", but Dawkins is most interested in his way of calculating exactly what proportion of genes are passed into a population.

Fisher's formula mathematically shows how related an individual is likely to be to its parent, child, or brother. He also studies why populations have a 50-50 sex ratio. Dawkins admires these mathematical explanations of Darwinian theory.

Unfortunately, Fisher was convinced that it is correct to shape human populations. ... fixing things so that only the most intelligent and noble survive. This is called eugenics, and it was responsible for much cruelty during World War II.