The Apportionment of Human Diversity
"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]
Background
[edit]By the 1960s, anthropologists such as Frank B. Livingstone had concluded that "there are no races, there are only clines" – smooth gradients of genetic variation in a species across its geographic range. Lewontin's mentor Theodosius Dobzhansky challenged this, arguing that there are human discrete populations that can be distinguished by differences in the frequency of genetic traits, which he called races.[6] At that time the debate was largely semantic, stemming from their different ideas about what race is and how it would be manifested in humans genetics.[6][7] The evidence that was available to Livingstone and Dobzhansky was mostly limited to qualitative observations of phenotypes thought to express genetic variation (e.g. skin colour).[6] This changed over the course of the 1960s, as new techniques began to produce direct evidence for genetic variation in humans at a molecular level.[8] By 1972, when Dobzhansky invited Lewontin to contribute to his edited volume of Evolutionary Biology, Lewontin felt that there was sufficient data to look at the problem anew, from a "firm quantitative basis":[8]
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.
— Richard Lewontin, in an interview in 2003.[8]
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]
Findings
[edit]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]
Legacy
[edit]Many subsequent studies confirmed Lewontin's main finding.[10][11][12]
The paper was not frequently cited in the years following its publication.[2][13]
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]
References
[edit]- ^ Lewontin, R. C. (1972). "The Apportionment of Human Diversity". Evolutionary Biology. Vol. 6. Springer US. pp. 381–398. doi:10.1007/978-1-4684-9063-3_14. ISBN 978-1-4684-9065-7. S2CID 21095796.
- ^ a b Ruvulo, Maryellen; Seielstad, Mark (2001). "'The Apportionment of Human Diversity' 25 Years Later". In Singh, Rama S.; Krimbas, Costas B.; Paul, Diane B.; Beatty, John (eds.). Thinking about Evolution: Historical, Philosophical, and Political Perspectives. Cambridge University Press. pp. 141–151. ISBN 978-0-521-62070-3.
- ^ Sapp, Jan (6 February 2017). "Race Finished". American Scientist.
- ^ Long, Jeffrey C.; Li, Jie; Healy, Meghan E. (May 2009). "Human DNA sequences: more variation and less race". American Journal of Physical Anthropology. 139 (1): 23–34. doi:10.1002/ajpa.21011. hdl:2027.42/62133. ISSN 1096-8644. PMID 19226648.
- ^ Graves, Joseph L. (7 August 2021). "Richard Lewontin: Race Science for the People • SftP Magazine". Science for the People Magazine.
- ^ a b c Kaplan, Jonathan Michael; Winther, Rasmus Grønfeldt (December 2014). "Realism, Antirealism, and Conventionalism about Race". Philosophy of Science. 81 (5): 1039–1052. doi:10.1086/678314. ISSN 0031-8248. S2CID 55148854.
- ^ Kaplan, Jonathan Michael; Winther, Rasmus Grønfeldt (2013). "Prisoners of Abstraction? The Theory and Measure of Genetic Variation, and the Very Concept of 'Race'". Biological Theory. 7 (1): 401–412. doi:10.1007/s13752-012-0048-0. S2CID 52825769.
- ^ a b c d e f Novembre, John (2022-06-06). "The background and legacy of Lewontin's apportionment of human genetic diversity". Philosophical Transactions of the Royal Society B: Biological Sciences. 377 (1852): 20200406. doi:10.1098/rstb.2020.0406. PMC 9014184. PMID 35430890.
- ^ Ramachandran, S.; Tang, H.; Gutenkunst, R. N.; Bustamante, C. D. (2010). "Chapter 20: Genetics and Genomics of Human Population Structure" (PDF). In Speicher, M. R.; et al. (eds.). Vogel and Motulsky's Human Genetics: Problems and Approaches. Heidelberg: Springer. p. 596. doi:10.1007/978-3-540-37654-5. ISBN 978-3-540-37653-8. Archived from the original (PDF) on 3 December 2013. Retrieved 29 October 2013.
- ^ Hunley, Keith L.; Cabana, Graciela S.; Long, Jeffrey C. (2016). "The apportionment of human diversity revisited". American Journal of Physical Anthropology. 160 (4): 561–569. doi:10.1002/ajpa.22899. ISSN 1096-8644. PMID 26619959.
- ^ Feldman, Marcus (11 December 2014). "Echoes of the Past: Hereditarianism and A Troublesome Inheritance". PLOS Genetics. 10 (12): e1004817. doi:10.1371/journal.pgen.1004817. ISSN 1553-7404. PMC 4263368. PMID 25502763.
- ^ Brown, Ryan A.; Armelagos, George J. (2001). "Apportionment of racial diversity: A review". Evolutionary Anthropology: Issues, News, and Reviews. 10 (1): 34–40. doi:10.1002/1520-6505(2001)10:1<34::AID-EVAN1011>3.0.CO;2-P. ISSN 1520-6505. S2CID 22845356.
- ^ a b c d Carlson, Jedidiah; Harris, Kelley (2022-06-06). "The apportionment of citations: a scientometric analysis of Lewontin 1972". Philosophical Transactions of the Royal Society B: Biological Sciences. 377 (1852): 20200409. doi:10.1098/rstb.2020.0409. PMC 9019867. PMID 35430880.
- ^ "Philosophical Transactions of the Royal Society B: Biological Sciences: Vol 377, No 1852". royalsocietypublishing.org. 2022-06-06.
- ^ Lorusso, Ludovica; Winther, Rasmus Grønfeldt, eds. (2022). "Part I: Lewontin (1972), 50 Years Later". Remapping Race in a Global Context. History and Philosophy of Biology. New York: Routledge. doi:10.4324/9781315208893. ISBN 9781138631434. OCLC 1260692842. S2CID 239465657.