Lewontin 1972

[Jacquelyne Betance]

The Apportionment of Human Diversity" is a 1972 paper on racial categorisation by American evolutionary biologist Richard Lewontin.[1] In it, Lewontin presented an analysis of genetic diversity amongst people from different conventionally-defined races. His main finding, that there is more genetic variation within these populations than between them,[2] is considered a landmark in the study of human genetic variation and contributed to the abandonment of race as a scientific concept.[3][4][5]

And so I thought, 'Well, we've got enough of this data, let's see what it tells us about the differences between human groups'. And so I just looked into the literature, and that literature was in books and so on. [...] One day I was going to give a lecture, I think it was in Carbondale, Illinois, or somewhere south. I was working in Chicago at the time. So I took a couple of these books with me and a pad of paper, and a table of logarithms which I needed for this purpose, and a little hand calculator, and I sat on this bus trip for three or four hours looking at the books, picking out the data, looking it up in the table of logarithms, doing a calculation, and writing it down in tables. And when I got back after the round trip I had all the data I needed to write the paper about how much human genetic variation there was, and so I did it.

Lewontin had been interested in using quantitative methods to assess taxonomic categories for some time before 1972. Over a decade earlier, palaeontologist George Gaylord Simpson had invited him to co-author a second edition of his textbook Quantitative Zoology (1960), and Lewontin added a chapter on the analysis of variance. In it, he illustrated how this approach could be used distinguish geographically distinct races with the example of Drosophila persimilis, a species of fruit fly. Though the method was similar to that he would later apply to human genetic variation, he reached the opposite conclusion: there was much greater genetic variance between geographic populations than between individual fruit flies, so there was a reasonable basis for distinguishing taxonomic races.[8] Foreshadowing his later work on human genetic variation, he also emphasised that, because there will always be measurable differences between any two populations, it is the degree of difference compared to other axes of variation that will determine whether a grouping is biologically significant.[8] "The Apportionment of Human Diversity" was published in an volume dedicated to Simpson, perhaps prompting Lewontin to recall this previous work.[8]

Lewontin performed a statistical analysis of the fixation index (FST) in populations drawn from seven classically-defined "races" (Caucasian, African, Mongoloid, South Asian Aborigines, Amerinds, Oceanians, and Australian Aborigines). At that time, direct sequence data from the human genome was not sufficiently available, so he instead used 17 indirect markers, including blood group proteins. Lewontin found that the majority of the total genetic variation between humans (i.e., of the 0.1% of DNA that varies between individuals), 85.4%, is found within populations, 8.3% of the variation is found between populations within a "race", and only 6.3% was found to account for the racial classification. Numerous later studies have confirmed his findings.[9] Based on this analysis, Lewontin concluded, "Since such racial classification is now seen to be of virtually no genetic or taxonomic significance either, no justification can be offered for its continuance."[page needed]

Fifty years after its publication, the paper was found to be frequently referenced in social media.[13] In particular, Twitter users associated with far-right politics commonly used the term "Lewontin's fallacy" (referencing A. W. F. Edwards' 2003 critique of Lewontin, "Human Genetic Diversity: Lewontin's Fallacy") as a rhetorical device to dismiss scientific arguments against biological race.[13] Commenting on the enduring significance afforded to Lewontin's paper in far-right and white nationalist discourse, geneticists Jedidiah Carlson and Kelley Harris proposed that "rejection of Lewontin's interpretation has become a tenet of white nationalist ideology".[13]

In 2022, a special issue of the journal Philosophical Transactions of the Royal Society B: Biological Sciences was published with the theme "Celebrating 50 years since Lewontin's apportionment of human diversity",[14] and a section of the book Remapping Race in a Global Context was devoted to discussing Lewontin's paper and defending it against Edwards' critique.[15]

Richard Lewontin, a geneticist and evolutionary biologist at Harvard University, died on July 4 at the age of 92, according to an obituary. Mary Jane Lewontin, his wife of more than 70 years, died three days prior on July 1. Lewontin studied genetic diversity within populations and helped develop the use of protein gel electrophoresis to examine this at a molecular level.

In 1966, at the University of Chicago, Lewontin and John Hubby published two papers that pioneered the use of protein gel electrophoresis to study genetic variation within populations of wild fruit flies. Not only did the technique lay the groundwork for the field of molecular genetics, but it revealed a surprising amount of genetic diversity within the population.

He also wrote a seminal 1972 paper in which he argued there is more genetic variation within members of a population of humans than there is between members of different groups, undermining the idea that there is a genetic basis for the idea of race.

Lewontin won numerous awards and honors, including a the Sewall Wright Award in 1994, honorary lifetime membership in the American Society of Naturalists, the 2015 Crafoord Prize in Biosciences, and the 2017 Thomas Hunt Morgan Medal from the Genetics Society of America.

In 1972, world-famous biologist Richard Lewontin published an analysis of human classification. Using alleles for 17 genes related to blood type (a state of the art technique at the time), he found that 85.4% of variability existed within racial populations, 8.3% of variation between groups within racial groups, and 6.3% of variation was between racial groups (Lewontin, 1972, pp. 396-397). Because so much of the variation was at the individual level, Lewontin concluded that,

Human racial classification is of no social value and is positively destructive of social and human relations. Since such racial classification is now seen to be of virtually no genetic or taxonomic significance either, no justification can be offered for its continuance

In statistical terms, Lewontin (1972) calculated an effect size, and the 6.3% of variation between racial groups is equivalent to an eta-squared effect size of .063. Likewise, the 8.3% of variation between groups within a racial group is equivalent to an eta-squared value .083. The eta-squared effect size is a measure of the total sample variance that can be explained by average group differences in the independent variable (Warne, 2021).

The reality is that the majority of variation will be due to individual-level differences every time eta-squared is less than .50. which I have pointed out before. There is nothing damning about this fact. In the social sciences the vast majority of eta-squared values are less than .50, and a high level of individual-level of variation is never of any concern. Lewontin (1972) stated a trivial statistical fact as if it were a profound truth.

As if that were not enough of a problem, Lewontin then came to the conclusion that because group membership explained comparatively little variation that racial classifications were unjustified and not useful.

Detterman, D. K. (2016). Education and intelligence: Pity the poor teacher because student characteristics are more significant than teachers or schools. The Spanish Journal of Psychology, 19, Article E93.

The Genetics Society of America (GSA) is pleased to announce that Richard C. Lewontin, PhD is the 2017 recipient of the Thomas Hunt Morgan Medal for lifetime achievement in the field of genetics. This award recognizes Lewontin's extensive impact on our understanding of evolution, a broad and deep influence that has shaped the field. An unprecedented 160 distinguished biologists co-signed a letter of support to nominate Lewontin for the Morgan Medal. Lewontin is the Alexander Agassiz Professor of Zoology in the Museum of Comparative Zoology, Emeritus and a Professor of Biology Emeritus in the Department of Organismic and Evolutionary Biology at Harvard University.

"While Richard Lewontin's research contributions to genetics have been immensely impactful, it is the rich vitality of his conceptual legacy that is impossible to overstate," says Andrew Clark, PhD (Cornell University).

In the 1960s, Lewontin worked on models that show how physical linkage between two genetic loci affect changes in allele and haplotype frequency during evolution. This work set the stage for today's wealth of studies that use linkage disequilibrium to make inferences about evolutionary change and relatedness.

In 1966, Lewontin and John Hubby published a pair of papers that revolutionized evolutionary biology. Their survey of differences in protein electrophoresis between individual wild fruit flies was the first to show that molecular variation was widespread in nature, and they were among the first to articulate the likelihood such variation might have little effect on the organism's evolutionary fitness. The study inspired a huge number of empirical population genetic studies and theoretical work to explain the findings. The 1966 papers were honored last year as among the most significant ever published in the 100-year history of the journal GENETICS.

Lewontin also contributed to the field of human genetics, showing in 1972 that the majority of human variation is shared between geographic groups and thus arguing that there is little genetic basis to race. He also discussed the challenges of inferring heritability in human genetic studies, an issue that has continued to plague the many genome-wide association studies performed in human populations.

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