Sewall G. Wright
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Sewall G. Wright
Sewall Green Wright was born on December 21, 1889 to Philip Green and Elizabeth Quincy Sewall Wright. He was one of three gifted brothers, and from an early age he had a love and talent for math’s and biology. Wright attended Galesburg High School, where he graduated in 1906 to enrol in Lombard College to study mathematics. He was fortunate to be influenced greatly by a Professor Wilhelmine Entemann Key, one of the first women to receive a PhD, in the world of biology, and this would set him on the road to eventually becoming one of the most influential founders of evolutionary theory in living memory. This marriage of mathematics and biology, following from his PhD study in Harvard, where he investigated the inheritance of coat colours in the animals, set him on a long a fruitful career in the world of genetics. He was laid to rest at the age of 99 on March 3rd, 1988.
Scientific achievements and credits
His publication on ‘systems of mating’ assured him a place in history as one of the founder members of population genetics, which eventually lead to the advent of modern evolutionary synthesis or Neo Darwinism. His writings on mathematical population genetics, inbreeding and evolutionary theory are hugely influential to the field of genetics, as well as his inbreeding coefficient, which is a standard part of genetics today. He is also credited as the lead theorist on genetic drift, which later became known as the Sewall Wright effect, a stochastic effect that arises from the role of random sampling in reproduction. The application of this theory lead to him formulating his theory on how evolution occurs. This was hugely influential in the evolution of evolution theory itself, and paved the way for latter day geneticists. Wright also gave a way to visualise the relationship between genotype or phenotype and success in replication called fitness landscapes. His method of path analysis is used in disciplines as far reaching as social science. He was even a hugely influential reviewer of manuscripts, and was one of the most common reviewers for Genetics. Such was his reputation that he was often accredited with reviews he did not even write.
Wright and Philosophy
Wright was one of the few geneticists of his time to venture into the moral and professional minefield that is philosophy. He found a union of concept in Charles Hartshorne, who became a life long friend and philosophical collaborator. He proposed an explanation for stasis whereby he suggested organisms come to occupy adaptive peaks. This meant that organisms would come to maintain a certain morphology or physiology simply due to the fact any other would result in a drop in fitness. In order to evolve, the species would first have to pass through maladaptive intermediate stages. Wright furthered this in his shifting balance theory, which spoke of how species are broken up into semi - isolated subunits called demes that are adapted to local situations. Evolutionary change occurs when these populations evolve in a direction of lowered fitness due to sampling error and selection, and then move in a differing direction to a higher state of evolution, and for whatever reason, expand. He had a long standing debate with Ronald Fisher about this, who believed in his own Large population size theory.
More metaphysically, Wright also believed that the birth of the consciousness, was not due to a mysterious property of increasing complexity, but rather an inherent property, therefore implying these properties were in the most elementary particles.
His legacy
Wright's effect on genetics over the near century that he lived is iconic. Coined Darwins successor, he paved the way forward into Neo-Darwinism with the help of fellow legends Ronald Fisher and J. B. S. Haldane. He also was one of the pioneers in the marriage of philosophy and biology, showing us that not only the theories of evolution were important, but also the ramifications that they had on society and its structure.
References
Perspectives: Anecdotal, Historical and Critical Commentaries on Genetics. Edited by JF Crow and WF Dove.
1: Sewall Wright and Physiological Genetics 2: Sewall Wright’s ‘Systems of Mating’
Metaphysics and the Origin of Species: Michael T. Ghiselin
