At the age of seven, in 1897, he wrote his first "book", entitled Wonders of Nature,[5] and he published his last paper in 1988:[9] he can be claimed, therefore, to be the scientist with the longest career of science writing.

Wright's astonishing maturity at the age of seven may be judged from the following excerpt quoted in the obituary:[5] Have you ever examined the gizzard of a fowl?

[10][11][12] Wright received his Ph.D. from Harvard University, where he worked at the Bussey Institute with the pioneering mammalian geneticist William Ernest Castle investigating the inheritance of coat colors in mammals.

[16][17] For his work on genetics of evolutionary processes, Wright was awarded the Daniel Giraud Elliot Medal from the National Academy of Sciences in 1945.

He was the chief developer of the mathematical theory of genetic drift,[27] which is sometimes known as the Sewall Wright effect,[29] cumulative stochastic changes in gene frequencies that arise from random births, deaths, and Mendelian segregations in reproduction.

Wright was convinced that the interaction of genetic drift and the other evolutionary forces was important in the process of adaptation.

Natural selection would lead to a population climbing the nearest peak, while genetic drift would cause random wandering.

[35] In order to evolve to another, higher peak, the species would first have to pass through a valley of maladaptive intermediate stages.

Wright had a long-standing and bitter debate about this with R. A. Fisher, who felt that most populations in nature were too large for these effects of genetic drift to be important.

Wright strongly influenced Jay Lush, who was the most influential figure in introducing quantitative genetics into animal and plant breeding.

His main project was to investigate the inbreeding that had occurred in the artificial selection that resulted in the leading breeds of livestock used in American beef production.

The concentrated study of these two groups of mammals eventually led to the Shifting Balance Theory and the concept of "surfaces of selective value" in 1932.

[citation needed] The creation of the statistical coefficient of determination has been attributed to Sewall Wright and was first published in 1921.

[39] This metric is commonly employed to evaluate regression analyses in computational statistics and machine learning.

He found a union of concept in Charles Hartshorne, who became a lifelong friend and philosophical collaborator.

Their work was essential to the contributions of Dobzhansky, Mayr, Simpson, Julian Huxley, and Stebbins.