Dear SMBE Members,
On the morning of July 4, 2021, population geneticist Richard “Dick” Lewontin passed away at the age of 92, just three days after his high-school sweetheart and wife of 73 years, Mary Jane. Both had been in poor health. Lewontin was an emeritus Professor in the Department of Organismic & Evolutionary Biology and Curator in the Museum of Comparative Zoology at Harvard University.
Lewontin has left an indelible imprint on the field of evolutionary biology through his research, writing, and mentorship.
After finishing his undergraduate degree at Harvard, Lewontin trained under the supervision of the famous Drosophila geneticist Theodosius Dobzhansky at Columbia. Dobzhansky was often away collecting flies, which provided Lewontin freedom and independence. But, when Dobzhansky was back in the lab, they purportedly argued intensely about population genetics, an activity both parties enjoyed immensely.
Fresh after earning his PhD from Columbia, he moved to North Carolina State University, where he remained for just 4 years (1954-1958) before moving, first to the University of Rochester, and then to the University of Chicago. In his early work, Lewontin was known for bringing a mathematical modeling approach to the field of genetics. While most population genetics was focused on a single gene, his early work with Ken-Ichi Kojima essentially founded two-locus theory and introduced the term “linkage disequilibrium” to describe the statistical association between the variation at each of a pair of genes. This work laid the foundation for now commonly used, association-mapping approaches.
However, the primary reason Lewontin moved to Chicago was because he recognized the exciting work of biochemist Jack Hubby, a new faculty member, who was pioneering the method of gel electrophoresis. As Lewontin put it: Hubby had a method but no question, and he had a question but no method. Together, they published two ground-breaking papers in Genetics: Hubby & Lewontin (1966) and Lewontin & Hubby (1966). The first focused on the method by which one could assay genetic variation via gel electrophoresis, and the second applied this method to assess genetic variation in a population of Drosophila pseudoobscura. Lewontin complained – even decades later – how the latter paper was more highly cited, and Hubby wasn’t adequately recognized for his contributions. Nonetheless, together, these papers laid the foundation for the field of molecular evolution, by (1) demonstrating the surprisingly high amount of genetic variation (heterozygosity) in natural populations and (2) setting the stage for the still ongoing debate about how much of this variation was due to natural selection and how much was due to chance. See Charlesworth et al. (2016) for more detail. As a direct consequence of these studies, Motoo Kimura and his colleagues developed the neutral theory, which tries to explain in quantitative terms the observed pattern of genetic variation expected in the absence of any form of natural selection. Thus, effectively, these papers set the agenda, for both empirical and theoretical population genetics, for the ensuing decades and to the current era of population genomics.
In 1973, Lewontin was lured to Harvard University and the Museum of Comparative Zoology (MCZ) to serve as a “Curator of Population Genetics”, a new position designed for him. He was offered the entire third floor of the MCZ, which he had renovated to his specifications. Most notably, in the center was an expa
Continue Reading →