Encyclopedia of Evolution.pdf - Online Reading Center

0 Wright, Sewall
the USDA, studying the genetics of animal breeding. This is
where he first began to study the effects of inbreeding and the
changes that can occur in small populations.
He is best remembered for developing the theoretical
framework for understanding genetic drift, in which random
events in small populations can alter the direction of breeding
and of evolution. A related area of study was inbreeding,
in which recessive mutations can show up more frequently in
small than in large populations, and this is therefore a major
problem in endangered species (see extinction; Mendelian
genetics; population genetics). He is considered one of
the three scientists who laid the theoretical foundation for the
modern synthesis (see also Fisher, R. A.; Haldane, J. B.
S.). His views contrasted sharply with those of the other two,
who emphasized the role of natural selection in maintaining
genetic variation in natural populations. Wright’s empha-
sis upon evolutionary events in small populations, however,
allied him more closely with the Japanese evolutionary geneticist
Motō Kimura, who claimed that most genetic variation
in populations was neutral in its effects on the organisms.
Wright continued to make major contributions to science
well after his mandatory retirement from the University of
Chicago at age 65. His major work, Evolution and the Genetics
of Populations, was four volumes in length, the final volume
of which was released when he was 98 years old. Wright
won many scientific awards. His first paper was published in
1912, his last in 1988, a span of 76 years. He died March 3,
1988.
Further Reading
Provine, William B. Sewall Wright and Evolutionary Biology. Chicago:
University of Chicago Press, 1986.