What is Sewall Wright?
'''Sewall Green Wright''' (21 December 1889 – 3 March 1988) was an [[United States|American]] [[Genetics|geneticist]]. He was a founder of [[population genetics]], and contributed to [[evolution]]ary [[theory]]. He also did original work in [[statistics]] in a field called [[path analysis (statistics)|path analysis]]. With [[R.A. Fisher]] and [[J.B.S. Haldane]], he was a founder of theoretical population genetics. He is the discoverer of the [[inbreeding]] [[coefficient]] and of methods of computing it in [[pedigree]]s. He extended this work to populations, calculating the degree of inbreeding of members of populations as a result of random [[genetic drift]]. Together with Fisher, he pioneered methods for calculating the distribution of [[gene]] [[frequency|frequencies]] among populations as a result of the interaction of [[natural selection]], [[mutation]], migration and genetic drift. The work of Fisher, Wright, and Haldane on theoretical population genetics was a major step in the development of the [[modern evolutionary synthesis]] of genetics with evolution. Wright also made contributions to mammalian genetics and biochemical genetics.<ref>Provine, William B. 1986. ''Sewall Wright and evolutionary biology''. Chicago.</ref> == Genetic drift == What appears to happen in [[evolution]] is that the rate of change in any organism varies a lot. There seem to be times when change is rapid, and times when almost no change occurs. Wright tried to explain ''stasis'', which is when no visible change occurs. His explanation was that organisms come to occupy ''adaptive peaks''. In order to evolve to another, higher peak, the species would first have to pass through a valley of maladaptive intermediate stages. In other words, they get stuck on one peak, and can't get to another because getting there would make them less competitive. Wright though getting to another peak might be possible. It might happen by [[genetic drift]] if the population is small enough. If a species was divided into small populations, some cou