Dec. 21, 1889 – March 3, 1988.
From the ever eloquent Today In Science History:
Wright was an American geneticist who was one of the founders of modern theoretical population genetics. He researched the effects of inbreeding and crossbreeding with guinea pigs, and later on the effects of gene action on inherited characteristics. He adopted statistical techniques to develop evolutionary theory.
Wright is best known for his concept of genetic drift, called the Sewell Wright effect - that when small populations of a species are isolated, out of pure chance the few individuals who carry certain relatively rare genes may fail to transmit them. The genes may therefore disappear and their loss may lead to the emergence of new species, although natural selection has played no part in the process.
Check out genetic drift at The Biology Project at The University of Arizona.
Learn more about Wright HERE. Image from HERE