Difference between revisions of "Sewall Wright" - New World Encyclopedia
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| − | '''Sewall Green Wright''' (December 21, 1889 – March 3, 1988) was an American [[geneticist]] who was one of three major pioneers in the wedding of [[genetics]] to [[evolutionary theory]] known as the [[modern evolutionary synthesis]] ([[neodarwinism]]). This triumvirate—Sewall Wright, [[R. A. Fisher]], and [[J. B. S. Haldane]—helped to establish theoretical population genetics early in the 20th century, which was a major step in the melding of classical Darwinism with the rediscovered | + | '''Sewall Green Wright''' (December 21, 1889 – March 3, 1988) was an American [[geneticist]] who was one of three major pioneers in the wedding of [[genetics]] to [[evolutionary theory]] known as the [[modern evolutionary synthesis]] ([[neodarwinism]]). This triumvirate—Sewall Wright, [[R. A. Fisher]], and [[J. B. S. Haldane]—helped to establish theoretical population genetics early in the 20th century, which was a major step in the melding of classical [[Darwinism]] with the rediscovered [[Mendel]]ian genetics, fusing two very different and formerly divided research traditions, the Darwinian naturalists and the experimental geneticists. |
| − | + | Wright was the discoverer of the [[inbreeding coefficient]] and of methods of computing it in pedigrees. He extended this work to populations, computing the amount of inbreeding of members of populations as a result of random [[genetic drift]], and he and Fisher pioneered methods for computing the distribution of [[gene frequencies]] among populations as a result of the interaction of [[natural selection]], [[mutation]], migration, and genetic drift. Wright also is known for his work on [[path analysis (statistics)|path analysis]]. | |
| − | He was a Unitarian, and attended church | + | :He was a Unitarian, and attended church |
| − | Contrary to the popular conception of an either-or dichotomy between evolution and belief in God—either evolutionary theory is correct or belief in God is correct—Ronald Fisher successfully juxtaposed the two viewpoints (Orr 1999). Fisher was a deeply devout Anglican and a leader in evolutionary theory. Orr (1999) finds it surprising that so few evolutionists seem to know that many of the brightest stars of evolutionary biology, such as Fisher and Theodosius Dobzhansky, were ardent believers in God—almost as if an "unconscious censorship" is going on because the facts are "a bit too embarrassing." | + | :Contrary to the popular conception of an either-or dichotomy between evolution and belief in God—either evolutionary theory is correct or belief in God is correct—Ronald Fisher successfully juxtaposed the two viewpoints (Orr 1999). Fisher was a deeply devout Anglican and a leader in evolutionary theory. Orr (1999) finds it surprising that so few evolutionists seem to know that many of the brightest stars of evolutionary biology, such as Fisher and Theodosius Dobzhansky, were ardent believers in God—almost as if an "unconscious censorship" is going on because the facts are "a bit too embarrassing." |
:Nonetheless, many of the century’s leading scientists–including some of the brightest stars of evolutionary biology, that most allegedly atheistic of all sciences–were deeply religious. Among the fathers of the so-called modern synthesis, Theodosius Dobzhansky was a Christian and something of an amateur theologian; Sir Ronald Fisher was a deeply devout Anglican who, between founding modern statistics and population genetics, penned articles for church magazines; and J.B. S. Haldane was an unabashed mystic.5 While surprising, there’s one fact more surprising still–few evolutionists know any of this. The reason cannot be that biologists care only about these men’s science, as any evolutionist can rattle off a dozen anecdotes about each. Rather it seems clear that a kind of unconscious censorship goes on. These facts are a bit too out of whack and a bit too embarrassing. And so they get dropped. The result is that scientists live with an absurdly pat view of the history of science and religion–a view which, to Gould, promotes a false confidence in the incommensurability of the two. (orr) | :Nonetheless, many of the century’s leading scientists–including some of the brightest stars of evolutionary biology, that most allegedly atheistic of all sciences–were deeply religious. Among the fathers of the so-called modern synthesis, Theodosius Dobzhansky was a Christian and something of an amateur theologian; Sir Ronald Fisher was a deeply devout Anglican who, between founding modern statistics and population genetics, penned articles for church magazines; and J.B. S. Haldane was an unabashed mystic.5 While surprising, there’s one fact more surprising still–few evolutionists know any of this. The reason cannot be that biologists care only about these men’s science, as any evolutionist can rattle off a dozen anecdotes about each. Rather it seems clear that a kind of unconscious censorship goes on. These facts are a bit too out of whack and a bit too embarrassing. And so they get dropped. The result is that scientists live with an absurdly pat view of the history of science and religion–a view which, to Gould, promotes a false confidence in the incommensurability of the two. (orr) | ||
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Sewall Wright was born in [[Melrose, Massachusetts|Melrose]], [[Massachusetts]] to Philip Green Wright and Elizabeth Quincy Sewall Wright. His parents were first cousins, an interesting fact in light of Wright's later research on [[inbreeding]]. The family moved three years later after Philip accepted a teaching job at [[Lombard College]], a [[Universalist]] college in Galesburg, Illinois. | Sewall Wright was born in [[Melrose, Massachusetts|Melrose]], [[Massachusetts]] to Philip Green Wright and Elizabeth Quincy Sewall Wright. His parents were first cousins, an interesting fact in light of Wright's later research on [[inbreeding]]. The family moved three years later after Philip accepted a teaching job at [[Lombard College]], a [[Universalist]] college in Galesburg, Illinois. | ||
| − | + | Sewall Wright was the oldest of three gifted brothers—the others being the [[aeronautical engineer]] [[Theodore Paul Wright]] and the [[political scientist]] [[Quincy Wright]]. | |
| − | + | From an early age Wright had a love and talent for [[mathematics]] and [[biology]]. As a child, Wright also helped his father print and publish an early book of poems by his father's student [[Carl Sandburg]]. | |
| + | Sewall Wright attended [[Galesburg High School]] and graduated in 1906. He then enrolled in [[Lombard College]] where his father taught, to study [[mathematics]]. He was influenced greatly by Professor Wilhelmine Entemann Key, one of the first women to receive a [[Doctorate|Ph.D.]] in [[biology]]. 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 [[mammal]]s. He worked for the [[U.S. Department of Agriculture]] until 1925, when he joined the Department of Zoology at the [[University of Chicago]]. He remained there until his retirement in 1955, when he moved to the [[University of Wisconsin–Madison]]. | ||
| − | Wright married Louise Lane Williams (1895–1975) | + | Wright received many honors in his long career, including the [[National Medal of Science]] (1966), the [[Balzan Prize]] (1984), and the [[Darwin Medal]] of the [[Royal Society]] (1980). He was a member of the [[United States National Academy of Sciences|National Academy of Sciences]] and a [[Foreign Member of the Royal Society]]. For his work on genetics of evolutionary processes-, Wright was awarded the [[Daniel Giraud Elliot Medal]] from the National Academy of Sciences in 1945.<ref name=Elliot>National Academy of Sciences, [http://www.nasonline.org/site/PageServer?pagename=AWARDS_elliot "Daniel Giraud Elliot Medal,"] ''National Academy of Sciences''. Retrieved July 30, 2011.</ref> |
| + | |||
| + | |||
| + | Wright married Louise Lane Williams (1895–1975)in 1921. They had three children: Richard, Robert, and Elizabeth. | ||
==Scientific achievements and credits== | ==Scientific achievements and credits== | ||
| − | + | Sewall Wright's papers on [[inbreeding]], [[mating system]]s, and [[genetic drift]] make him a principal founder of [[population genetics|theoretical population genetics]], along with [[R. A. Fisher]] and [[J. B. S. Haldane]]. Their theoretical work is the origin of the [[modern evolutionary synthesis]] or neodarwinian synthesis. Wright was the inventor/discoverer of the [[inbreeding coefficient]] and [[F-statistics]], standard tools in population genetics. He was the chief developer of the mathematical theory | |
of [[genetic drift]], which is sometimes known as the Sewall Wright effect, cumulative stochastic changes in [[gene frequency|gene frequencies]] that arise from random births, deaths, and Mendelian segregations in reproduction. In this work he also introduced the concept of [[effective population size]]. Wright was convinced that the interaction of [[genetic drift]] and the other evolutionary forces was important in the process of adaptation. He described the relationship between genotype or phenotype and [[Fitness (biology)|fitness]] as [[fitness surface]]s or fitness landscapes. On | of [[genetic drift]], which is sometimes known as the Sewall Wright effect, cumulative stochastic changes in [[gene frequency|gene frequencies]] that arise from random births, deaths, and Mendelian segregations in reproduction. In this work he also introduced the concept of [[effective population size]]. Wright was convinced that the interaction of [[genetic drift]] and the other evolutionary forces was important in the process of adaptation. He described the relationship between genotype or phenotype and [[Fitness (biology)|fitness]] as [[fitness surface]]s or fitness landscapes. On | ||
these landscapes mean population fitness was the height, plotted against horizontal axes representing the [[allele frequency|allele frequencies]] or the average phenotypes of the population. [[Natural selection]] would lead to a population climbing the nearest peak, while [[genetic drift]] would cause random wandering. | these landscapes mean population fitness was the height, plotted against horizontal axes representing the [[allele frequency|allele frequencies]] or the average phenotypes of the population. [[Natural selection]] would lead to a population climbing the nearest peak, while [[genetic drift]] would cause random wandering. | ||
Revision as of 03:39, 30 July 2011
Sewall Green Wright (December 21, 1889 – March 3, 1988) was an American geneticist who was one of three major pioneers in the wedding of genetics to evolutionary theory known as the modern evolutionary synthesis (neodarwinism). This triumvirate—Sewall Wright, R. A. Fisher, and [[J. B. S. Haldane]—helped to establish theoretical population genetics early in the 20th century, which was a major step in the melding of classical Darwinism with the rediscovered Mendelian genetics, fusing two very different and formerly divided research traditions, the Darwinian naturalists and the experimental geneticists.
Wright was the discoverer of the inbreeding coefficient and of methods of computing it in pedigrees. He extended this work to populations, computing the amount of inbreeding of members of populations as a result of random genetic drift, and he and Fisher pioneered methods for computing the distribution of gene frequencies among populations as a result of the interaction of natural selection, mutation, migration, and genetic drift. Wright also is known for his work on path analysis.
- He was a Unitarian, and attended church
- Contrary to the popular conception of an either-or dichotomy between evolution and belief in God—either evolutionary theory is correct or belief in God is correct—Ronald Fisher successfully juxtaposed the two viewpoints (Orr 1999). Fisher was a deeply devout Anglican and a leader in evolutionary theory. Orr (1999) finds it surprising that so few evolutionists seem to know that many of the brightest stars of evolutionary biology, such as Fisher and Theodosius Dobzhansky, were ardent believers in God—almost as if an "unconscious censorship" is going on because the facts are "a bit too embarrassing."
- Nonetheless, many of the century’s leading scientists–including some of the brightest stars of evolutionary biology, that most allegedly atheistic of all sciences–were deeply religious. Among the fathers of the so-called modern synthesis, Theodosius Dobzhansky was a Christian and something of an amateur theologian; Sir Ronald Fisher was a deeply devout Anglican who, between founding modern statistics and population genetics, penned articles for church magazines; and J.B. S. Haldane was an unabashed mystic.5 While surprising, there’s one fact more surprising still–few evolutionists know any of this. The reason cannot be that biologists care only about these men’s science, as any evolutionist can rattle off a dozen anecdotes about each. Rather it seems clear that a kind of unconscious censorship goes on. These facts are a bit too out of whack and a bit too embarrassing. And so they get dropped. The result is that scientists live with an absurdly pat view of the history of science and religion–a view which, to Gould, promotes a false confidence in the incommensurability of the two. (orr)
- Orr, H. A. 1999. Gould on God: Can religion and science be happily reconciled? Boston Review October/November. Retrieved May 17, 2007.
Biography
Sewall Wright was born in Melrose, Massachusetts to Philip Green Wright and Elizabeth Quincy Sewall Wright. His parents were first cousins, an interesting fact in light of Wright's later research on inbreeding. The family moved three years later after Philip accepted a teaching job at Lombard College, a Universalist college in Galesburg, Illinois.
Sewall Wright was the oldest of three gifted brothers—the others being the aeronautical engineer Theodore Paul Wright and the political scientist Quincy Wright.
From an early age Wright had a love and talent for mathematics and biology. As a child, Wright also helped his father print and publish an early book of poems by his father's student Carl Sandburg.
Sewall Wright attended Galesburg High School and graduated in 1906. He then enrolled in Lombard College where his father taught, to study mathematics. He was influenced greatly by Professor Wilhelmine Entemann Key, one of the first women to receive a Ph.D. in biology. 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. He worked for the U.S. Department of Agriculture until 1925, when he joined the Department of Zoology at the University of Chicago. He remained there until his retirement in 1955, when he moved to the University of Wisconsin–Madison.
Wright received many honors in his long career, including the National Medal of Science (1966), the Balzan Prize (1984), and the Darwin Medal of the Royal Society (1980). He was a member of the National Academy of Sciences and a Foreign Member of the Royal Society. For his work on genetics of evolutionary processes-, Wright was awarded the Daniel Giraud Elliot Medal from the National Academy of Sciences in 1945.[1]
Wright married Louise Lane Williams (1895–1975)in 1921. They had three children: Richard, Robert, and Elizabeth.
Scientific achievements and credits
Sewall Wright's papers on inbreeding, mating systems, and genetic drift make him a principal founder of theoretical population genetics, along with R. A. Fisher and J. B. S. Haldane. Their theoretical work is the origin of the modern evolutionary synthesis or neodarwinian synthesis. Wright was the inventor/discoverer of the inbreeding coefficient and F-statistics, standard tools in population genetics. He was the chief developer of the mathematical theory of genetic drift, which is sometimes known as the Sewall Wright effect, cumulative stochastic changes in gene frequencies that arise from random births, deaths, and Mendelian segregations in reproduction. In this work he also introduced the concept of effective population size. Wright was convinced that the interaction of genetic drift and the other evolutionary forces was important in the process of adaptation. He described the relationship between genotype or phenotype and fitness as fitness surfaces or fitness landscapes. On these landscapes mean population fitness was the height, plotted against horizontal axes representing the allele frequencies or the average phenotypes of the population. Natural selection would lead to a population climbing the nearest peak, while genetic drift would cause random wandering.
- Gould (2002) stated that Dobzhansky's 1937 book was one of the "founding documents for the second phase of the Synthesis," and was "a direct and primary inspiration for the books that followed." (Gould considered the first phase to be the construction of population genetics by R. A. Fisher, J. B. S. Haldane, and Sewall Wright.
- Dobzhansky returned to Columbia University from 1940 to 1962. He worked for ten years, until 1945, with Sewall Wright, a mathematically inclined evolutionary biologist, with whom Dobzhansky first collaborated with in 1936.
Wright's explanation for stasis 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. This could happen by genetic drift if the population is small enough. If a species was divided into small populations, some could find higher peaks. If there was some gene flow between the populations, these adaptations could spread to the rest of the species. This was Wright's shifting balance theory of evolution. There has been much skepticism among evolutionary biologists as to whether these rather delicate conditions hold often in natural populations. 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. Wright's statistical method of path analysis, which he invented in 1921 and which was one of the first methods using a graphical model, is still widely used in social science. He was a hugely influential reviewer of manuscripts, as one of the most frequent reviewers for Genetics. Such was his reputation that he was often credited with reviews that he did not write.
From 1915 to 1925 Wright was employed by the Animal Husbandry Division of the U.S. Bureau of Animal Husbandry. 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. He also performed experiments with 80,000 guinea pigs in the study of physiological genetics. Further more he analyzed characters of some 40,000 guinea pigs in 23 strains of brother-sister matings against a random-bred stock. (Wright 1922a-c). 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. (Wright 1988 Pg 122 American Naturalist)
He did major work on the genetics of guinea pigs, and many of his students became influential in the development of mammalian genetics. He appreciated as early as 1917 that genes acted by controlling enzymes.
An anecdote about Wright, disclaimed by Wright himself, describes a lecture during which Wright tucked an unruly guinea pig under his armpit, where he usually held a chalkboard eraser: according to the anecdote, at the conclusion of the lecture, Wright absent-mindedly began to erase the blackboard using the guinea pig.
Wright and philosophy
Wright was one of the few geneticists of his time to venture into philosophy. He found a union of concept in Charles Hartshorne, who became a lifelong friend and philosophical collaborator. Wright 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.
Legacy
Wright and Fisher, along with J.B.S. Haldane, were the key figures in the modern synthesis that brought genetics and evolution together. Their work was essential to the contributions of Dobzhansky, Mayr, Simpson, Julian Huxley, and Stebbins. The modern synthesis was the most important development in evolutionary biology after Darwin. Wright also had a major effect on the development of mammalian genetics and biochemical genetics.
An interesting anecdote about Sewall Wright and Barbara McClintock. [2]
ReferencesISBN links support NWE through referral fees
- ↑ National Academy of Sciences, "Daniel Giraud Elliot Medal," National Academy of Sciences. Retrieved July 30, 2011.
- ↑ http://www.estherlederberg.com/Anecdotes.html; see anecdote #25
- [[James F. Crow|]] (1988). Sewall Wright (1889-1988). Genetics 119 (1): 1–4.
- (1987). Sewall Wright and physiological genetics. Genetics 115 (1): 1–2.
- Ghiselin, Michael T. (1997) Metaphysics and the Origin of Species. NY: SUNY Press.
- [[William G. Hill|]] (1996). Sewall Wright's 'Systems of Mating'. Genetics 143 (4): 1499–506.
- Provine, William (1986). Sewall Wright and Evolutionary Biology. University of Chicago Press. ISBN 0-226-68473-3.
- (1932). The roles of mutation, inbreeding, crossbreeding and selection in evolution. Proc. 6th Int. Cong. Genet 1: 356–366.
- Wright, Sewall (1986). Evolution: Selected papers. University of Chicago Press. ISBN 0-226-91053-9.
- Gould, S. J. 2002. The Structure of Evolutionary Theory. Cambridge, MA: The Belknap Press of Harvard University Press.
- Hull, D. L. 1988. Science as a Process: An Evolutionary Account of the Social and Conceptual Development of Science. Chicago: The University of Chicago Press.
Bibliography
Books by Wright
- Wright, Sewall (1984). Evolution and the Genetics of Populations: Genetics and Biometric Foundations v. 1 (Genetic & Biometric Foundations); New Edition. University of Chicago Press. ISBN 0-226-91038-5.
- Wright, Sewall (1984). Evolution and the Genetics of Populations: Genetics and Biometric Foundations v. 2 (Theory of Gene Frequencies); New Edition. University of Chicago Press. ISBN 0-226-91039-3.
- Wright, Sewall (1984). Evolution and the Genetics of Populations: Genetics and Biometric Foundations v. 3 (Experimental Results and Evolutionary Deductions); New Edition. University of Chicago Press. ISBN 0-226-91040-7.
- Wright, Sewall (1984). Evolution and the Genetics of Populations: Genetics and Biometric Foundations v. 4 (Variability within and Among Natural Populations); New Edition. University of Chicago Press. ISBN 0-226-91041-5.
External links
- Sewall Wright: Darwin's Successor—Evolutionary Theorist by Edric Lescouflair and James F. Crow
- Sewall Wright Papers at the American Philosophical Society
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|---|---|---|---|
| Key concepts: Hardy-Weinberg law | genetic linkage | linkage disequilibrium | Fisher's fundamental theorem | neutral theory | |||
| Selection: natural | sexual | artificial | ecological | |||
| Effects of selection on genomic variation: genetic hitchhiking | background selection | |||
| Genetic drift: small population size | population bottleneck | founder effect | coalescence | |||
| Founders: R.A. Fisher | J. B. S. Haldane | Sewall Wright | |||
| Related topics: evolution | microevolution | evolutionary game theory | fitness landscape | genetic genealogy | |||
| List of evolutionary biology topics |
Template:Winners of the National Medal of Science
| Persondata | |
|---|---|
| NAME | Wright, Sewall Green |
| ALTERNATIVE NAMES | |
| SHORT DESCRIPTION | |
| DATE OF BIRTH | December 21, 1889 |
| PLACE OF BIRTH | Melrose, Massachusetts |
| DATE OF DEATH | March 3, 1988 |
| PLACE OF DEATH | Madison, Wisconsin |
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