Richard Charles Lewontin (March 29, 1929 – July 4, 2021[3]) was an American evolutionary biologist, mathematician, geneticist, and social commentator.

In a pair of seminal 1966 papers co-authored with J. L. Hubby in the journal Genetics,[4][5] Lewontin helped set the stage for the modern field of molecular evolution.

From a sociological perspective, Lewontin strongly opposed genetic determinism[6] and neodarwinism as expressed in the fields of sociobiology and evolutionary psychology.

Previously, as a member of Science for the People, he denounced the involvement of prominent scientists in Pentagon programs aimed at developing weapons for the Vietnam War.

Lewontin and Hubby's paper also discussed the possible explanation of the high levels of variability by either balancing selection or neutral mutation.

[14] That is, it appears that a majority of genetic variation is found within groups only if a single locus is used, but the reverse is true if analyzing a multiplicity of loci.

Edwards' paper was commented on by Jonathan Marks, who argued that "the point of the theory of race was to discover large clusters of people that are principally homogeneous within and heterogeneous between, contrasting groups.

[18] In 1975, when E. O. Wilson's book Sociobiology proposed evolutionary explanations for human social behaviors, biologists including Lewontin, his Harvard colleagues Stephen Jay Gould and Ruth Hubbard responded negatively.

The subsequent 5–20 years consequently saw some of the most novel and rigorous methods to quantify selection in the wild and lab, test for selection phylogenetically, and reconcile the effects of other evolutionary processes (e.g., drift, gene flow, development, historical contingency); all of which resulted in a sort-of renaissance in evolutionary biology.

[24] Lewontin said 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.

In his writing, Lewontin suggests a more nuanced view of evolution is needed, which requires a more careful understanding of the context of the whole organism as well as the environment.

[26] Such concerns about what he viewed as the oversimplification of genetics led Lewontin to be a frequent participant in debates, and an active life as a public intellectual.

In the book Not in Our Genes (co-authored with Steven Rose and Leon J. Kamin) and numerous articles, Lewontin questioned much of the claimed heritability of human behavioral traits, such as intelligence as measured by IQ tests.

Lewontin testified in an unsuccessful suit in California challenging the state's financing of research to develop automatic tomato pickers.