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'''''Human genetic diversity: Lewontin's fallacy''''' is a 2003 paper by [[A.W.F. Edwards]] that criticizes [[Richard Lewontin]]'s 1972 argument<ref>Made in ''The apportionment of human diversity'' (1972) and again in the 1974 book ''The Genetic Basis of Evolutionary Change''.{{Page needed|date=September 2010}}</ref> that [[Race (classification of human beings)|race]] is an invalid [[taxonomy|taxonomic]] construct.<ref name="Edwards2003">{{cite journal |author=Edwards AW |title=Human genetic diversity: Lewontin's fallacy |journal=BioEssays |volume=25 |issue=8 |pages=798–801 |year=2003 |month=August |pmid=12879450 |doi=10.1002/bies.10315}}</ref> Although academic texts generally avoid referring to Edwards' counterargument in the polemicist terms from Edwards' original title, Edwards' critique nevertheless appears in a number of subsequent academic books and [[popular science]] books that discuss Lewontin's argument.<ref>The Ancestor's Tale: A Pilgrimage to the Dawn of Evolution by Richard Dawkins and Yan Wong http://books.google.com/books?id=rR9XPnaqvCMC&pg=PA406</ref><ref>Sohini Ramachandran, Hua Tang, Ryan N. Gutenkunst, and Carlos D. Bustamante, ''Genetics and Genomics of Human Population Structure'', chapter 20 in M.R. Speicher et al. (eds.), ''Vogel and Motulsky’s Human Genetics: Problems and Approaches'', 4th ed., Springer, 2010, ISBN 3540376534, p. 596</ref>

==Lewontin's argument==
In the 1972 study "The apportionment of human diversity" [[Richard Lewontin]] performed a [[fixation index]] (''F''<sub>ST</sub>) statistical analysis using 17 markers including blood group proteins. His results were that the majority of genetic differences between humans, 85.4%, were found within a population, 8.3% of genetic differences were found between populations within a race, and only 6.3% was found to differentiate the various races which in the study were Caucasian, African, Mongoloid, South Asian Aborigines, Amerinds, Oceanians, and Australian Aborigines. (Later studies have generally agreed although sometimes with somewhat different values such as 75% for variation within a population.<ref name=Risch2002>{{cite journal |doi=10.1186/gb-2002-3-7-comment2007 |year=2002 |last1=Risch |first1=Neil |last2=Burchard |first2=Esteban |last3=Ziv |first3=Elad |last4=Tang |first4=Hua |journal=Genome Biology |volume=3 |pages=comment2007.1 |pmid=12184798 |pmc=139378 |issue=7 |title=Categorization of humans in biomedical research: genes, race and disease.}}</ref>) Lewontin argued "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."

This argument is widely cited as evidence that racial categories are biologically meaningless, and that behavioral differences between groups cannot have any genetic underpinnings. One example being the "Statement on 'Race'" published by the [[American Anthropological Association]] in 1998 which rejected the existence of races as unambiguous, clearly demarcated, biologically distinct groups.<ref name = "AAA">American Anthropological Association (May 17, 1998). [http://www.aaanet.org/stmts/racepp.htm ''Statement on 'race<nowiki>'</nowiki>''].</ref>

==Edwards' critique==

Edwards argued that while Lewontin's statements on variability are correct when examining the frequency of different [[allele]]s (variants of a particular gene) at individual [[Locus (genetics)|locus]] (the location of a particular gene) between individuals, it is nonetheless possible to classify individuals into different racial groups with an accuracy that approaches 100% when one takes into account the frequency of the alleles at several loci at the same time. This happens because differences in the frequency of alleles at different loci are correlated across populations — the alleles that are more frequent in a population at two or more loci are correlated when we consider the two populations simultaneously. Or in other words, the frequency of the alleles tends to cluster differently for different populations.

In Edwards' words, "most of the information that distinguishes populations is hidden in the correlation structure of the data." These relationships can be extracted using commonly-used [[ordination (statistics)|ordination]] and [[cluster analysis]] techniques. Edwards argued that, even if the probability of misclassifying an individual based on the frequency of alleles at a single locus is as high as 30% (as Lewontin reported in 1972), the misclassification probability becomes close to zero if enough loci are studied.

Edwards' paper stated that the underlying logic was discussed in the early years of the 20th century. Edwards wrote that he and [[Luigi Luca Cavalli-Sforza]] had presented a contrasting analysis to Lewontin's, using very similar data, already at the 1963 International Congress of Genetics. Lewontin participated but did not refer to this in his later paper. Edwards argued that Lewontin used his analysis to attack classification which he deplored for social reasons, such as [[Arthur Jensen]]'s research on [[race and intelligence]]. He wrote:
<blockquote>There is nothing wrong with Lewontin’s statistical analysis of variation, only with the belief that it is relevant to classification. It is not true that "racial classification is . . . of virtually no genetic or taxonomic significance". It is not true, as ''Nature'' claimed, that "two random individuals from any one group are almost as different as any two random individuals from the entire world" and it is not true, as the ''New Scientist'' claimed, that "two individuals are different because they are individuals, not because they belong to different races" and that "you can’t predict someone’s race by their genes".</blockquote>

He also argued:

<blockquote> Very recent studies (14,15) have treated individuals in the same way that Cavalli-Sforza and Edwards treated populations in 1963, namely by subjecting their genetic information to a cluster analysis thus revealing genetic affinities that have unsurprising geographic, linguistic and cultural parallels. As the authors of the most extensive of these (15) comment, "it was only in the accumulation of small allele-frequency differences across many loci that population structure was identified."</blockquote>

[[Neven Sesardic]] has argued that, unbeknownst to Edwards, Jeffry B. Mitton already made the same argument about Lewontin's claim in two articles published in ''[[The American Naturalist]]'' in the late 1970s.<ref>{{Cite journal|doi=10.1007/s10539-009-9193-7 |title=Race: A Social Destruction of a Biological Concept |year=2010 |pages=143 |last1=Sesardic |volume=25 |first1=Neven |journal=Biology & Philosophy|issue=2}} Mitton's articles are the following:
*{{Cite journal|first=Jeffry B. |last=Mitton |month=April |year=1977 |title=Genetic Differentiation of Races of Man as Judged by Single-Locus and Multilocus Analyses |journal=The American Naturalist |volume=111 |issue=978 |pages=203–212 |doi=10.1086/283155}}
*{{Cite journal|first=Jeffry B. |last=Mitton |year=1978 |title=Measurement of Differentiation: Reply to Lewontin, Powell, and Taylor |journal=The American Naturalist |volume=112 |issue=988 |pages=1142–1144 |doi=10.1086/283359}}</ref>

==See also==
* [[Race and genetics]]
* [[Human genetic clustering]]
* [[Population groups in biomedicine]]

==References==
{{Reflist}}

[[Category:Race]]
[[Category:Taxonomy]]
[[Category:Genetics]]
[[Category:Population genetics]]
[[Category:Scientific controversies]]
[[Category:Human genetics| ]]
[[Category:Humans|Genetics]]

Lewontin's Fallacy - Revision history

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