| Richard Lewontin | |
|---|---|
| Born | 29 March 1929 New York |
| Nationality | United States |
| Fields | Genetics, Evolutionary biology, Population genetics |
| Institutions | Harvard |
| Alma mater | Columbia University |
| Doctoral advisor | Theodosius Dobzhansky |
| Known for | Evolutionary biology, Population genetics |
Richard Charles "Dick" Lewontin (born March 29, 1929) is an American evolutionary biologist, geneticist and social commentator. A leader in developing the mathematical basis of population genetics and evolutionary theory, he pioneered the application of techniques from molecular biology such as gel electrophoresis to questions of genetic variation and evolution.
In a pair of 1966 papers co-authored with J.L. Hubby in the journal Genetics, Lewontin helped set the stage for the modern field of molecular evolution.
In 1979 he and Stephen Jay Gould introduced the term "spandrel" into evolutionary theory.
Lewontin strongly opposes genetic determinism, especially as allegedly expressed by sociobiology and evolutionary psychology.
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Lewontin was born in New York City to Jewish parents. Lewontin attended Forest Hills High School and the École Libre des Hautes Études in New York. In 1951, he obtained a bachelor's degree in biology from Harvard University. In 1952, he received a master's degree in mathematical statistics followed by a doctorate in zoology in 1954, both from Columbia University where he was a student of Theodosius Dobzhansky. Lewontin held faculty positions at North Carolina State University, the University of Rochester, and the University of Chicago. In 1973 Lewontin served as Alexander Agassiz Professor of Zoology and Professor of Biology at Harvard until 1998, and as of 2003 was the Alexander Agassiz Research Professor at Harvard. Lewontin has worked with and had great influence on many philosophers of biology, including William C. Wimsatt, Elliott Sober, Philip Kitcher, Elisabeth Lloyd, Peter Godfrey-Smith, Sahotra Sarkar, and Robert Brandon, often inviting them to work in his lab.
Lewontin has worked in both theoretical and experimental population genetics. A hallmark of his work has been an interest in new technology. He was the first person to do a computer simulation of the behavior of a single locus (previous simulation work having been of models with multiple loci). In 1960 he and Ken-Ichi Kojima were the first population geneticists to give the equations for change of haplotype frequencies with interacting natural selection at two loci.[1] This set off a wave of theoretical work on two-locus selection in the 1960s and 1970s. Their paper gave a theoretical derivation of the equilibria expected, and also investigated the dynamics of the model by computer iteration. Lewontin later introduced the D' measure of linkage disequilibrium.[2] (An achievement that he would be less happy to claim is that he introduced the name "linkage disequilibrium" itself, one about which many population geneticists have been unenthusiastic).
In 1966, he and Jack Hubby published a paper that revolutionized population genetics.[3] They used protein gel electrophoresis to survey dozens of loci in Drosophila pseudoobscura, and reported that a large fraction of the loci were polymorphic, and that at the average locus there was about a 15% chance that the individual was heterozygous. (Harry Harris reported similar results for humans at about the same time).[4] Previous work with gel electrophoresis had been reports of variation in single loci and did not give any sense of how common variation was.
Lewontin and Hubby's paper also discussed the possible explanation of the high levels of variability by either balancing selection or neutral mutation. Although they did not commit themselves to advocating neutrality, this was the first clear statement of the neutral theory for levels of variability within species. Lewontin and Hubby's paper had great impact—the discovery of high levels of molecular variability gave population geneticists ample material to work on, and gave them access to variation at single loci. The possible theoretical explanations of this rampant polymorphism became the focus of most population genetics work thereafter. Martin Kreitman was later to do a pioneering survey of population-level variability in DNA sequences while a Ph.D. student in Lewontin's lab.[5]
In a landmark paper, Richard Lewontin identified that most of the variation (80-85%) within human populations is found within local geographic groups and differences attributable to traditional "race" groups are a minor part of human genetic variability (1-15%).[6] In a 2003 paper, A.W.F. Edwards criticized Lewontin's conclusion that race is an invalid taxonomic construct (because the probability of racial misclassification of an individual based on variation in a single genetic locus is approximately 30%), terming it Lewontin's Fallacy.
In 1975, when E. O. Wilson's book Sociobiology proposed evolutionary explanations for human social behaviors, a number of biologists responded negatively, including Lewontin, S.J. Gould, Ruth Hubbard, and others.[7]
Lewontin and his late Harvard colleague Stephen Jay Gould introduced the term spandrel to evolutionary biology, inspired by the architectural term "spandrel", in an influential 1979 paper "The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme." "Spandrels" were described as features of an organism that exist as a necessary consequence of other (perhaps adaptive) features, but do not directly improve fitness (and thus are not necessarily adaptive).[8] The relative frequency of spandrels versus adaptations continues to stir controversy in evolutionary biology.
Lewontin was an early proponent of a hierarchy of levels of selection in his article "The Units of Selection". He has been a major influence on philosophers of biology, notably William C. Wimsatt (who taught with Lewontin and Richard Levins at the University of Chicago), Robert Brandon and Elisabeth Lloyd (who studied with Lewontin as graduate students), Philip Kitcher, and Elliot Sober. Lewontin briefly argued for the historical nature of biological causality in "Is Nature Probable or Capricious?"
In "Organism and Environment" in Scientia, and in more popular form in the last chapter of Biology as Ideology, Lewontin argued that while traditional Darwinism has portrayed the organism as passive recipient of environmental influences, a correct understanding should emphasize the organism as an active constructor of its own environment. Niches are not pre-formed, empty receptacles into which organisms are inserted, but are defined and created by organisms. The organism-environment relationship is reciprocal and dialectical. M.W. Feldman, K.N. Laland, and F.J. Odling-Smee among others have developed Lewontin's conception in more detailed models.
In an adaptationist view of evolution, the organism is a function of both the organism and environment while the environment is only a function of itself. The environment is seen as autonomous and unshaped by the organism. Lewontin instead believed in a constructivist view where the organism is a function of the organism and environment with the environment being a function of the organism and environment as well. This means that the organism shapes the environment as the environment shapes the organism. The organism shapes the environment for future generations.[9]
Lewontin has long been a critic of traditional neo-Darwinian approaches to adaptation. In his article "Adaptation" in the Italian Enciclopedia Einaudi, and in a toned-down version in Scientific American, he emphasized the need to give an engineering characterization of adaptation separate from measurement of number of offspring, rather than simply assuming organs or organisms are at adaptive optima.[10] Lewontin has claimed that his more general, technical criticism of adaptationism grew out of his recognition that the fallacies of sociobiology reflect fundamentally flawed assumptions of adaptiveness of all traits in much of the modern evolutionary synthesis.
Lewontin accused neo-Darwinists of telling “Just So” stories when they try to show how natural selection explains such novelties as long-necked giraffes.[11]
Along with others, such as Gould, Lewontin has been a persistent critic of some themes in neo-Darwinism; specifically, he has criticised proponents of sociobiology and evolutionary psychology such as Edward O. Wilson and Richard Dawkins, who attempt to explain animal behaviour and social structures in terms of evolutionary advantage or strategy—this has been controversial when applied to humans, because some see it as genetic determinism. Lewontin, in his writing, calls for what he considers a more nuanced view of evolution, which he claims requires a more careful understanding of the context of the whole organism as well as the environment.
Such concerns about what he views as the oversimplification of genetics led Lewontin to be a frequent commentator in debates, and he has lectured widely to promote his views on evolutionary biology and science. In books such as Not in Our Genes (co-authored with Steven Rose and Leon J. Kamin) and numerous articles, Lewontin has questioned much of the claimed heritability of human behavioral traits such as intelligence as measured by IQ tests, promoted by books such as The Bell Curve.
Lewontin has been criticized by some academics for a rejection of sociobiology for non-scientific reasons. Some credit this rejection to political beliefs (Wilson 1995). Lewontin has at times identified himself as Marxist or at least left-leaning (Levins and Lewontin 1985). Others (Kitcher 1985) have countered that Lewontin's criticisms of sociobiology are genuine scientific concerns about the discipline and claim that attacking Lewontin's motives amount to an ad hominem argument.
Lewontin has also written on the economics of agribusiness. He has contended that hybrid corn was developed and propagated not because of its superior quality, but because it allowed agribusiness corporations to force farmers to buy new seed each year rather than plant seed produced by their previous crop of corn. Lewontin testified in an unsuccessful suit in California challenging the state's financing of research to develop automatic tomato pickers, favoring the profits of agribusiness over the employment of farm workers.
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