Amerika

The biological basis for race

Let’s hop into this question with both feet:

Are racial-ethnic (when most people say race, they mean ethnicity, and vice-versa) differences innate, meaning biologically and genetically inherent?

I would rather not get into comparing IQs and other abilities here, but simply answering the question: are races biologically different?

Obviously, the answer will be somewhat complex. Races are from the same species and can interbreed, although some data suggest that leads to health problems. However, an individual can be identified as belonging to racial groups by osteopathology, genetic analysis, and even analysis of skin and hair — so obviously race is not “just skin color.”

Here’s some input from a mainstream source:

Apparently, participants to the meeting were trying to come up with new language that was based on “non-fraught” terminology, such as “geographic ancestry,” even though researchers acknowledged that they cannot control how the media and the public will interpret what they do anyway. For instance, Carlos Bustamante of Cornell complained that a paper he published was understood by the media to imply that blacks are fitter (presumably, in evolutionary terms) than whites. What Bustamante had actually said was that African-Americans have fewer deleterious genes in their genomes than European-Americans. Not exactly (or even approximately) the same thing!

Apparently, an interesting exchange occurred between Celeste Condit (a professor of speech communication) and Bruce Lahn, who in 2005 had co-authored a paper on natural selection in two genes regulating brain development, genes that are more frequent in Eurasians than in Africans. Condit complained that this sort of study may easily be read as having a “political message” embedded in it, suggesting for instance that Eurasians’ intelligence evolved faster than Africans’, an implication that Lahn firmly denied.

I often discuss the issue of race with my good friend Guido Barbujani, of the University of Ferrara (who occasionally comments on this blog). He is a population geneticist, and doesn’t believe the concept of human race has any biological foundation. I disagree, although with my other friend Jonathan Kaplan (a philosopher, and also occasional commentator on Rationally Speaking) we published a paper in which we made it clear that we don’t think “folk races” exist. (See: Kaplan, J. and M. Pigliucci (2004), On the concept of biological race and its applicability to humans. Philosophy of Science 70: 1161-1172.) That is, we think that what most people call “races” are actually independently evolved sub-populations, but that human races exist in the same sense as ecotypes exist among other animals and plants.

An ecotype is a locally adapted population (say, characterized by an “alpine” phenotype for a plant, or a “high light intensity” phenotype for a human), which is not genetically much different from other populations of the same species, except for genes specifically influencing whatever traits are adaptive in that environment (say, short and branched stalks in alpine plants, to protect against strong wind; or dark skin in humans living near the Equator, to protect from high light intensity).

Be that as it may, the question of what a race is, and whether it is a useful biological construct, is an empirical one, though with interesting implications for philosophy of science. It is not, however, something that should be dictated out of political correctness, as in the above mentioned rather silly (and intellectually offensive) statement by Condit. As another participant to the NHGRI meeting, philosopher Allen Buchanan (Duke) put it: “A visible, concerted effort to change vocabulary for moral reasons is likely to trigger a backlash.”

SciBlog

The United Nations thinks we should not even discuss this issue:

There is no proof that the groups of mankind differ in their intelligence or temperament. The scientific evidence indicates that the range of mental capacities in all ethnic groups is the same…. Genetic differences are not of importance in determining the social and cultural differences between different groups of Homo sapiens.

UN

Let’s take a look at another view, from traditional conservatives:

I should first explain my definition of “race.” In biological tradition the word race is simply synonymous with the terms “subspecies” or “variety.” The basic unit of classification in modern taxonomy is the species. A species is usually said to consist of a set of individuals capable of interbreeding and producing fertile offspring. If the offspring are not healthy and fertile, then the parent types are considered separate species. Mules are usually sterile so horses and donkeys are thought to be separate species.

However, in biology things are often fuzzy around the edges, and so it is with species. Sometimes what are considered to be separate species in nature can and will freely interbreed when brought together by man. Sometimes their hybrid offspring are partially or fully fertile. As one example of the fuzziness of species, consider Canis familiaris, the common dog, and Canis lupus, the Eurasian wolf. They are considered to be separate species because their habitats and life-styles are different. Within the dog species itself there are many varieties that are quite different in physiology and behavior. The tiny Mexican Chihuahua, would have a hard time mating with an Irish Wolfhound, but they are considered to be of the same species.

When wolves encounter dogs, they usually eat them. But sometimes they mate with them. When they mate it is almost always the male wolf with the female dog. The reverse is rare — male dogs are almost never able to mate with female wolves. The hybrid puppies are usually fully fertile, so by this definition Canis lupus and Canis familiaris are not different species. The point is that species and races are concepts of classification that often blur around the edges. This is because of the very nature of biological reality.

These days humans are thought to constitute one species — Homo sapiens. Humans are in many respects typical of geographically widespread mammalian species in that we are polymorphic (meaning we have “many forms”). This is what appears to us as individual differences. The bell-curve distribution of so many traits — height, weight, strength, intelligence, and the like — illustrates polymorphic traits. We are also typical among widespread mammals in being a polytypic species. Polytypic means “many types;” it is simply a fact of biological reality that not all different groups of humans are the same. Naturally occurring polytypic groups within a species are called varieties, subspecies, or races.

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This pattern is common among humans and among mammals generally, like the wolves and dogs mentioned earlier: When populations mix, it is usually males of the dominant group that take up with women from the subordinate group. Women are attracted to socially dominant males.

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While hybrid vigor is a biological reality, so are hybrid incompatibilities. Some crosses, particularly between genetically distant races, can lead to mixes that don’t work very well. Until quite recently there was much scientific concern over hybrid incompatibilities between blacks and whites, and remember from recent evidence the Africans are genetically most different from all others. Before about 1950 the scientific literature openly discussed the problem of what Madison Grant called “disharmonious combinations”. After the 1950s, concern over miscegenation almost completely disappeared from mainstream scientific literature. The only thing that had changed was the politics, not the data.

I would like to suggest that modern data, those gold nuggets laying about, contain much that is suggestive of hybrid incompatibilities between blacks and whites. For example, according to the so-called “one drop” rule, hybrids are almost always classified as blacks, so almost all blacks have some white genes. And one of the best reported phenomena in present-day America is that the African-American population suffers a very wide range of health problems. Blacks tend to die sooner and younger from almost every cause but osteoporosis. There are reports that even after all known causes are accounted for there is still “unexplained” poor health among blacks.

This difference is often ascribed to the stresses of “racism,” but this is not a very convincing explanation. Recently, Surgeon General David Satcher appeared on television to point out that in America, black babies are 2½ times more likely than whites to die in the first year of life. It is not clear how infants suffer from the stresses of “racism.” It may simply be that just as blacks mature more rapidly than whites, they succumb to disease more easily and die at younger ages. On the other hand, if there are no inherent racial differences in longevity and resistance to disease, the poor health could be caused by one of the greatest taboos of all: biological, genetic hybrid incompatibility.

AR

Inevitably, this issue gets tangled up with g, or general intelligence:

Murray argued that general intelligence, so-called “g,” a general factor that governs performance on all cognitive tasks, is highly heritable. He noted that g has a biological background in the brain. He cited differences in glucose metabolism, reaction times, and the volumes of specific grey matter in prefrontal cortices.
Reason

This becomes important because we get counter-arguments like this:

Intelligence is one of the personality traits most strongly influenced by genes. Although genes have a weaker influence in childhood, a full 80 percent of the variation among adults in intelligence is due to heredity.6 The IQs of identical twins have a correlation of 0.86, whereas those of fraternal twins have a much weaker correlation of 0.6. However, after they have grown to be adults, there is no correlation at all between the IQs of unrelated children who are reared in the same household.7

This research makes the environmentalist view of racial differences highly implausible. The social factors to which environmentalists attribute racial differences, such as poverty and inferior schooling, are part of blacks’ shared environment, as they affect the black population as a whole. However, shared environment has no effect on IQ and little effect on other personality attributes.

TIW

What I’d like to propose, instead, is that we look at races as groups of traits and do not narrow in on any single trait. We should analyze those traits as the products of the environments in which those races/ethnicities evolved.

More on this topic at We’re not all equal genetically, either which covers the differences in DNA between races, ethnicities and individuals.

More useful data here on the question of whether DNA indicates races exist:

Q: Isn’t there actually more genetic distance between populations within the traditional human races than between the major races themselves?

In 1972, Richard Lewontin studied global variation at seventeen protein polymorphisms,[69] and found that about 85% of genetic variation existed between individuals within a given population. The next largest portion, about 8%, was found between populations within continents, with the remaining 6% of variance attributable to differences between the major human races (Fig. 2). The ~85% within-population figure has been affirmed numerous times, while the relative size of the other components of variance probably depends on the specific populations chosen for analysis, and is often the reverse of Lewontin’s findings. In any event, many data sets have been assembled since 1972 for classical polymorphisms and all other genetic markers, and as a general rule, populations within continents are more closely related to one another than they are to the populations of other continents. This pattern can be seen in any matrix of global genetic distances, such as those assembled by Cavalli-Sforza et al. in The History and Geography of Human Genes.

Population genetic studies often report AMOVA statistics (Analysis of MOlecular VAriance), which show the hierarchical proportions of variance between aggregates of the individuals sampled. The following is a discussion of worldwide data on autosomal microsatellites and RFLPs, Alu insertions, mtDNA and Y chromosome STRPs:

“The hierarchical AMOVA analysis shows that, with the exception of Y STRPs, all systems show much less differentiation between populations within continents than between continents. This result is expected when there is greater gene flow between populations that are in close geographic proximity to one another. The autosomal values…are especially small, ranging from 1.3% for the RSPs to 1.8% for the Alu polymorphisms. This is in agreement with the small continental GST values shown in table 4…they are highly consistent both with one another and with previous analyses of worldwide variation in autosomal microsatellites and RFLPs, which also show considerably greater differentiation between continents than between populations within continents… The fact that there is little differentiation between populations within continents has important implications in the forensic setting, in that it supports the current practice of grouping reference populations into broad ethnic categories when autosomal STRP data are used…” [73]

The Race FAQ

Interesting.

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