# Sewall Wright

> American geneticist (1889-1988)

**Wikidata**: [Q221061](https://www.wikidata.org/wiki/Q221061)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Sewall_Wright)  
**Source**: https://4ort.xyz/entity/sewall-wright

## Summary

Sewall Wright was born on December 21, 1889, in Melrose [1][2][3][4][5][6] and died on March 3, 1988, in Madison [3][1][2][4][6]. He was the son of Elizabeth Quincy Wright [7] and pursued his education at Galesburg High School, Lombard College, the University of Illinois system, and Harvard University [1][8]. Wright worked as a biologist, geneticist, statistician, and university teacher , with his primary field of study being population genetics .His professional career included employment with the United States Department of Agriculture from 1915 to 1925, the University of Chicago from 1926 to 1955, and the University of Wisconsin–Madison from 1955 to 1960 [1][8]. He received numerous accolades, including the Balzan Prize, Thomas Hunt Morgan Medal, National Medal of Science, Darwin Medal, Kimber Genetics Award, and Josiah Willard Gibbs Lectureship, among others [9][10][8][11][12]. Wright was also a member of the Royal Society, National Academy of Sciences, American Academy of Arts and Sciences, and American Philosophical Society [13][8].

## Summary
Sewall Wright was an American geneticist, statistician, and biologist who made foundational contributions to population genetics and evolutionary theory. He is best known for developing the concept of genetic drift and the shifting balance theory of evolution.

## Biography
- Born: December 21, 1889
- Nationality: United States
- Education: University of Illinois, Harvard University, University of Wisconsin–Madison
- Known for: Population genetics, genetic drift, shifting balance theory
- Employer(s): University of Chicago, University of Wisconsin–Madison, United States Department of Agriculture
- Field(s): Genetics, statistics, evolutionary biology

## Contributions
Sewall Wright developed the mathematical theory of population genetics, including the concept of genetic drift and the inbreeding coefficient. He created the shifting balance theory of evolution, which explains how populations can cross adaptive valleys through genetic drift and selection. Wright published numerous influential papers on population structure, gene frequency, and evolutionary processes, including his seminal work "Evolution in Mendelian Populations" (1931). He also contributed to the development of path analysis in statistics and made significant advances in understanding the effects of inbreeding and crossbreeding on genetic diversity.

## FAQs
What is Sewall Wright most famous for?
Sewall Wright is most famous for developing the concept of genetic drift and the shifting balance theory of evolution, which revolutionized our understanding of how populations evolve and adapt.

Where did Sewall Wright work?
Sewall Wright worked at the University of Chicago, University of Wisconsin–Madison, and the United States Department of Agriculture throughout his career.

What awards did Sewall Wright receive?
Sewall Wright received numerous prestigious awards including the National Medal of Science, Darwin Medal, Thomas Hunt Morgan Medal, Kimber Genetics Award, and the Balzan Prize for his contributions to genetics and evolutionary biology.

How did Sewall Wright influence modern genetics?
Sewall Wright's mathematical models and theories provided the foundation for modern population genetics, influencing how scientists understand genetic variation, evolution, and the role of chance in evolutionary processes.

## Why They Matter
Sewall Wright's work fundamentally transformed our understanding of evolution by introducing mathematical rigor to population genetics. His concept of genetic drift demonstrated that random changes in gene frequencies could drive evolutionary change, challenging the prevailing view that natural selection was the sole mechanism of evolution. The shifting balance theory provided a framework for understanding how populations could evolve complex adaptations through a combination of genetic drift, selection, and gene flow. Wright's contributions continue to influence fields ranging from conservation biology to medical genetics, and his mathematical models remain essential tools for understanding genetic variation in populations.

## Notable For
- Developing the concept of genetic drift in population genetics
- Creating the shifting balance theory of evolution
- Introducing path analysis in statistics
- Publishing "Evolution in Mendelian Populations" (1931)
- Receiving the National Medal of Science
- Being awarded the Darwin Medal by the Royal Society
- Contributing to the modern synthesis of evolutionary theory
- Developing mathematical models for inbreeding and crossbreeding
- Influencing the field of quantitative genetics
- Being a member of the National Academy of Sciences

## Body
### Early Life and Education
Sewall Green Wright was born on December 21, 1889, in the United States. He pursued his education at several prestigious institutions, including the University of Illinois, Harvard University, and the University of Wisconsin–Madison. His academic background in mathematics and biology provided the foundation for his groundbreaking work in population genetics.

### Academic Career
Wright's academic career spanned several decades and institutions. He held positions at the University of Chicago, where he conducted much of his foundational research in population genetics. Later, he moved to the University of Wisconsin–Madison, where he continued his research and teaching. Wright also worked with the United States Department of Agriculture, applying his genetic theories to practical problems in agriculture and animal breeding.

### Major Theoretical Contributions
Wright's most significant contribution to science was the development of the mathematical theory of population genetics. He introduced the concept of genetic drift, which describes how random changes in gene frequencies can occur in small populations, independent of natural selection. This was a revolutionary idea that challenged the prevailing view that natural selection was the only mechanism of evolution.

He also developed the inbreeding coefficient, a mathematical measure of the probability that two alleles at any locus in an individual are identical by descent. This concept became fundamental to understanding the genetic consequences of inbreeding in populations.

### The Shifting Balance Theory
Perhaps Wright's most influential contribution was the shifting balance theory of evolution. This theory proposed that populations could cross adaptive valleys through a combination of genetic drift, selection, and gene flow. According to this theory, populations could evolve complex adaptations by first drifting away from local optima, then being pulled toward new adaptive peaks through selection and gene flow from other populations.

### Statistical Innovations
Beyond genetics, Wright made significant contributions to statistics. He developed path analysis, a method for describing the directed dependencies among a set of variables. This technique became widely used in genetics, sociology, and other fields for understanding causal relationships.

### Publications and Research
Wright published extensively throughout his career, with his most influential work being "Evolution in Mendelian Populations" (1931). This paper laid out the mathematical foundations of population genetics and introduced many of the concepts that would become central to the field. He continued publishing influential papers throughout his career, including work on the effects of inbreeding and crossbreeding on genetic diversity.

### Awards and Recognition
Wright's contributions were widely recognized by the scientific community. He received the National Medal of Science, the highest scientific honor in the United States. He was also awarded the Darwin Medal by the Royal Society, the Thomas Hunt Morgan Medal, and the Kimber Genetics Award. In 1992, he received the ASN Award for Distinguished Achievement in the Conceptual Unification of the Biological Sciences.

### Professional Affiliations
Wright was a member of numerous prestigious scientific organizations. He was elected to the National Academy of Sciences, the American Academy of Arts and Sciences, the American Philosophical Society, and the Royal Society. He was also a member of the Econometric Society and the Institute of Mathematical Statistics.

### Legacy and Influence
Sewall Wright's work continues to influence modern genetics and evolutionary biology. His mathematical models and theories provide the foundation for understanding genetic variation in populations, and his concepts are taught in genetics courses worldwide. The field of population genetics, which he helped establish, remains a vibrant area of research with applications in conservation biology, medical genetics, and evolutionary studies.

### Later Years and Death
Wright continued his research and writing well into his later years. He died on March 3, 1988, at the age of 98, leaving behind a legacy that transformed our understanding of evolution and genetics. His work bridged the gap between Mendelian genetics and Darwinian evolution, helping to establish the modern synthesis of evolutionary theory.

## References

1. BnF authorities
2. Geni.com
3. MacTutor History of Mathematics archive
4. Sewall Wright and his Role in the Development of Genetics of Populations
5. [Source](https://genetics-gsa.org/awards/thomas-hunt-morgan-medal/)
6. [Source](https://docs.google.com/spreadsheets/d/1dsunM9ukGLgaW3HdG9cvJ_QKd7pWjGI0qi_fCb1ROD4/pubhtml?gid=216486814&single=true)
7. [Source](https://www.nasonline.org/programs/awards/evolution-earth-and-life.html)
8. [Source](https://www.uchicago.edu/who-we-are/global-impact/accolades/gordon-j-laing-award)
9. [Source](https://www.econometricsociety.org/society/organization-and-governance/fellows/memoriam)
10. Complete List of Royal Society Fellows 1660-2007
11. Scientific Legacy Database
12. Mathematics Genealogy Project
13. [The Academic Family Tree](https://academictree.org/flytree/peopleinfo.php?pid=31868)
14. International Standard Name Identifier
15. Virtual International Authority File
16. NNDB
17. SNAC
18. Gran Enciclopèdia Catalana
19. Croatian Encyclopedia
20. Freebase Data Dumps. 2013
21. Treccani's Enciclopedia on line
22. National Library of Israel Names and Subjects Authority File
23. Catalogo of the National Library of India