I am always happy to answer reader emails set to me via the contact form at the About page of this blog. This email comes from “Nigel”. Nigel writes that:
Speaking about denialism, what about politically correct race-deniers? These people are so wrapped up on some ideology of Boasian Cultural Marxism that they regularly try to subvert the truth.
In just this short message, consisting of nothing more than two sentences, Nigel has managed to set off my baloney detector several times. This is because phrases such as “politically correct” and “cultural Marxism” are buzzwords frequently used by extremist right-wing…thinkers, who are often anti-immigration. “Politically correct” designates their belief that they are being suppressed by the establishment and “cultural Marxism” signifies the related idea that the establishment was been taken over by leftists who ignore the truth that race realists think is plain as day. Thus, Nigel has carried out two very common denialist tactics that I described in the article Common Denialist Tactics Defined and Destroyed, namely playing the martyr card and conspiratorial thinking:
Tactic: Playing the Martyr Card.
Description: Instead of replying with solid evidence or arguments, denialists often complain that they are being persecuted by the establishment because, in their own view, they are questioning the dogmatic status quo. Comparisons with Galileo or Einstein are extremely common.
Countermeasure: Explain that criticism is not the same as persecution, that science thrive on overturning old ideas and replacing them with ideas that better fit the evidence.
Tactic: Conspiratorial Thinking.
Description: In order to explain away embarrassing facts or problems, a conspiracy theory is proposed, which not only lacks evidence but is absurd on many levels.
Countermeasure: Explain that it is a bad idea to attribute things to malice that could equally well be explained by human ignorance or stupidity, that something would have leaked by now or that results would have been too unpredictable and the cost of failure too large for the risk of carrying it out to be worth it.
The question of race depends on, as do so many other questions, on definitions. When we use the term “race”, what are we talking about? In a previous entry, I discussed some of the problems with race realism. Specifically, I noted the problem that traditional racial categories are not biologically sound, but rather form groups. Pigliucci and Kaplan (2003) explains that:
Biological research on race has often been seen as motivated by or lending credence to underlying racist attitudes; in part for this reason, recently philosophers and biologists have gone through great pains to essentially deny the existence of biological human races. We argue that human races, in the biological sense of local populations adapted to particular environments, do in fact exist; such races are best understood through the common ecological concept of ecotypes. However, human ecotypic races do not in general correspond with ‘folk’ racial categories, largely because many similar ecotypes have multiple independent origins. Consequently, while human natural races exist, they have little or nothing in common with ‘folk’ races.
In other words, Pigliucci and Kaplan, rejects traditional racial categories because they are biologically invalid, but draw the trivially true conclusion that local populations of humans can be adapted to their particular environment. This, however, does not justify racial realism, which is much stronger position. They continue:
And of course, as has already been noted, insofar as folk races are supposed to pick out populations that systematically differ from each other over a wide range of genetic and phenotypic measures, biology provides no support for the existence of such populations (and indeed, provides evidence that no such populations exist).
Another instructive bit of evidence against traditional racial categories is the distribution of human genetic variation. Rosenberg et. al. (2002) studied almost 400 short tandem repeats from over 1000 individuals from around 50 populations. He showed that “within-population differences among individuals account for 93 to 95% of genetic variation; differences among major groups constitute only 3 to 5%”. Again, different local populations of humans may be adapted to the environments which in they live, but this shows that the vast majority of human genetic variation lies within populations, not between them.
Nick Matzke (2012) explains that human genetic variation is characterized by mostly continuous geographic structure, rather than discrete races. In doing so, he quotes Templeton (1998):
The genetic data are consistently and strongly informative about human races. Humans show only modest levels of differentiation among populations when compared to other large-bodied mammals, and this level of differentiation is well below the usual threshold used to identify subspecies (races) in nonhuman species. Hence, human races do not exist under the traditional concept of a subspecies as being a geographically circumscribed population showing sharp genetic differentiation. A more modem definition of race is that of a distinct evolutionary lineage within a species. The genetic evidence strongly rejects the existence of distinct evolutionary lineages within humans. The widespread representation of human “races” as branches on an intraspecific population tree is genetically indefensible and biologically misleading, even when the ancestral node is presented as being at 100,000 years ago.
Attempts to salvage the idea of human “races” as evolutionary lineages by invoking greater racial purity in the past followed by admixture events are unsuccessful and falsified by multilocus comparisons of geographical concordance and by haplotype analyses. Instead, all of the genetic evidence shows that there never was a split or separation of the “races’” or between Africans and Eurasians. Recent human evolution has been characterized by both population range expansions (with perhaps some local replacements but no global replacement within the last 100,000 years) and recurrent genetic interchange. The 100,000 years ago “divergence time” between Eurasians and Africans that is commonly found in the recent literature is really only an “effective divergence time” in sensu Nei and Roychoudhury (1974, 1982). Since no split occurred between Africans and Eurasians, it is meaningless to assign a date to an “event” that never happened. Instead, the effective divergence time measures the amount of restricted gene flow among the populations (Slatkin 1991).
Because of the extensive evidence for genetic interchange through population movements and recurrent gene flow going back at least hundreds of thousands of years ago, there is only one evolutionary lineage of humanity and there are no subspecies or races under either the traditional or phylogenetic definitions. Human evolution and population structure have been and are characterized by many locally differentiated populations coexisting at any given time, but with sufficient genetic contact to make all of humanity a single lineage sharing a common, long-term evolutionary fate.
I think I will end here, but there are a lot more to say about how race realists abuse principle component analysis and statistics in general in order to prop up their ideological crusade.
So in conclusion, the existence of “race” depends on what we are talking about. Can local populations be adapted to their environment? Yes. Do genetic variation that have medical implications exist in these populations? Yes. Are traditional racial categories based on scientific evidence? No.
I’m sorry Niles, you are on the side of the denialists this time.
References and further reading
Kaplan, J. and M. Pigliucci. (2004). On the concept of biological race and its applicability to humans. Philosophy of Science 70: 1161-1172
Matzke, N. (2012). Continuous geographic structure is real, “discrete races” aren’t. The Panda’s Thumb. Retrieved: 2012-03-04.
Templeton, A. R. (1998). Human Races: A Genetic and Evolutionary Perspective. American Anthropologist 100(3), 632-650.
Rosenberg, N. A. et al. (2002). Genetic structure of human populations. Science 298, 2381–2385.