Racism - Lets keep it civil. Also, Gravy is white.

Genetics and Race
Wade's primary argument is that the distances between human populations resulted in genetic bottlenecks that prevented gene flow and resulted in the independent evolution of various lineages of human population clusters centered on continental islands. (Wade 1, 76-77) While having already addressed the sort of mythological foundations of this narrative, I feel it is important to now tackle the substance of it as well. Was gene flow reduced in prehistoric human populations such that they were able to evolve independently from one another?
Alan R. Templeton, of Washington University in St. Louis, has quite a bit to say on this matter in his article "The Genetic and Evolutionary Significance of Human Races" published in Jefferson M. Fish's compilation of works on race titled "Race and Intelligence; Separating Science from Myth". First, however, it should be noted that a sort of shell game is played by people such as Nicholas Wade when they use the word race. The classic definition of race in the context of human variation tends to indicate distinct populations grouped based on a combination of geographic and phenotypic characteristics, such as skin and hair color, cranial morphologies, and other physical features. (Lieberman and Rice 3) The more modern definition of race seems to conform more with the biological concept of subspecies, which can be defined as "a biological classification that ranks immediately below a species and designates a population of a particular geographic region gene-tically distinguishable from other such populations of the same species and capable of interbreeding successfully with them where its range overlaps with theirs." (Merriam-Webster)
The shell game comes from different standards used to define sub-species in non-human species versus how subspecies is recognized in human populations. As Templeton notes "humans have tended to interpret their own intraspecific diversity in ways that are often inconsistent with how humans analyze and interpret genetic diversity in other species." (Templeton 31) He continues by pointing out that "Of particular importance for the concept of race is the relative amount of genetic diversity that exists among individuals within a population versus the amount. that exists among populations." (Templeton 33)
Templeton builds a case from this point that the "distinct evolutionary lineage within a species" definition is the "defacto definition of subspecies in conservation biology," and that "this definition requires. genetic differentiation due to barriers to genetic exchange that persist for sufficient periods of time to have detectable genetic consequences." (Templeton 35) Then he goes on to test whether human variation fits this definition in the same ways that other subspecies of other species would.
Templeton states that "a standard criterion for a subspecies or race in the non-human literature under the definition of subspecies.is to have Fst values of at least .25 to .30." (Templeton 36) An Fst value is described as "a summary of genetic differentiation among groups." (Jakobsson et al 1) Templeton expands upon this definition in order to help elucidate its strength in describing diversity. He states "Fst measures the relative amount of genetic diversity found within and among populations, with 0 indicating all genetic diversity is individual variation with no differences.among populations, and 1 indicating all individuals are genetically identical within a local population but that genetic diversity exists as fixed differences among populations." (Templeton 36)
So, with this understanding of Fst values and their purpose in helping to demonstrate genetic diversity in populations, Templeton takes a long and critical look at the claim that human genetic diversity meets the standards applied to subspecies in nonhuman populations. His results are relatively clear, and straightforward. The average Fst for human populations, averaged across 16 populations spread out across Africa, Europe, Asia, the Americas, and the Australian and Pacific regions, is .156. (Templeton 36) As Templeton explains, this is "too small to have taxonomic significance under the traditional subspecies definition with the threshold values used in the recent non-human literature." (Templeton 36)
Templeton tackles some issues with this approach, such as differences between specific groups that exceed this value. (Templeton 36-38) The largest difference is between sub-Saharan African and Melanesian populations, at .265. The caveat, Templeton explains, is that "[these groups] would not be considered separate races by [this criteria] because geographically intermediate populations exist [between them] that fall well below this threshold." (Templeton 38) So Templeton demonstrates first that genetic variation between human populations is both consistent with the sorts of clinal variation models often cited by social scientists as a justification for disregarding racial classifications, and that the diversity amongst human populations is well below common standards other subspecies in non-human populations are held to.
But were the genetic bottlenecks significant barriers to gene flow between these populations? Templeton addresses this issue as well, utilizing a formula that relates the Fst value to local population size (N) multiplied by migration rate between isolated populations (m). (Templeton 38) He demonstrates that, with an Nm ? 1.0, "massive amounts of movements of large numbers of individuals are not needed to explain the modest level of genetic differentiation observed in human races." (Templeton 38-39) He also points out that "for the human Fst value of .156, Nm = 1.35." (Templeton 38) What this indicates is that modern genetic differences between these populations could be achieved with minimal exchange of members between these populations. (Templeton 39) So, genetic bottlenecking was not sufficient to prevent this gene flow, and human populations have been evolving as a mostly complete whole throughout our history, despite geographic distances and isolation.
This appears to be a strong rebuttal to Wade's primary assertion justifying his conclusion for racial classification. But one researcher's work probably shouldn't be relied upon too heavily to rebut Wade's claims. Are there other findings consistent with Templeton's research, and how do they relate to Wade's claims?
Returning to the May 2009 issue of the American Journal of Physical Anthropology, "Race Reconciled", we find a very interesting article. The article, authored by Keith L. Hunley, Meghan E. Healy (both associated with the University of New Mexico in Albuquerque) and Jeffrey C. Long (University of Michigan at Ann Arbor), is titled "The Global Pattern of Gene Identity Variation Reveals a History of Long-Range Migrations, Bottlenecks, and Local Mate Exchange: Implications For Biological Race". In it, the team of Hunley et al "used computer simulations to identify the global geographic pattern of neutral genetic variation predicted by several of the views of human variation." (Hunley et al 36) Four models were chosen; independent evolution of regions, isolation by distance, serial fissions, and a nested regions model.
These computer models were compared to actual data on human genetic diversity patterning to discern which, if any, matched the observations of human genetic diversity found in "neutral genetic data collected from a large sample of globally distributed human populations." (Hunley et al 36) The real world data used for comparison utilized 783 autosomal microsatellites from over 1000 individuals drawn from 53 populations in seven geographic regions (Africa, the Middle East, Europe, South Central Asia, Oceania, East Asia, and the Americas). (Hunley et al 36) The unit used for this study is gene identity, which Hunley et al define as "the probability that two randomly drawn copies of a locus are identical by state. The two copies. may be sampled from within the same local populations, or. from different local populations." (Hunley et al 36)
It is important to understand the differences between each view of human diversity being tested, so a short summary of each will follow:
1) Independent Region Model:
a) Assumes independent evolution of geographically distinct populations
b) Gene identities highest within local populations, medial between local populations sharing geographic region, and lowest between local populations in separate geographic regions
(Hunley et al 36)
2) Isolation by Distance
a) Not consistent with any taxonomic concept of race
b) Results from sexual selection of mates from nearby local populations, rather than in group selection within a local population
c) Results from monotonic decay in gene identity
d) Gene identity high and uniform in local populations, monotonic decay correlated with geographic distance
(Hunley et al 36-37)
3) Serial Fission
a) Single ancestral population grows and divides
b) Parental population persists, daughter population grows and divides
c) Gene identity lowest in original population, and increases with each new division
d) Consistent with taxonomic units above and at population level
(Hunley et al 37)
4) Nested Regions
a) Large bottlenecks during initial colonization of geographic regions
b) Serial fission with larger bottlenecks
c) Ppredicts multiple uniform gene identity strata based on time of division
d) Eeach strata should be uniform in gene identity throughout each geographic region
e) Potentially consistent with taxonomic units above and at population level
(Hunley et al 37)

Hunley et al report that no single simulation matched the observed actual data, but of the four, the nested regions model was closest. (Hunley et al 44-45) So they modified the nested regions model to account for 5% migration between groups that were continuous geographically. (Hunley et al 43) The results from this fifth simulation were a significant improvement in terms of fit. (Hunley et al 43)
What this indicates is that serial fissions with some bottlenecking occurred, with migration leading to gene exchange between populations. (Hunley et al 45) For all intents and purposes, this conclusion justifies that genetic bottlenecking was not sufficient to reduce gene flow and allow for independent regional evolution of human lineages based around continents.
Some other observations Hunley et al make regarding the relevance of this inquiry to the race issue are that "the problem of finding a threshold level of gene identity for declaring taxonomic significance. remain unsolved. the between population pattern is nested in sub-Saharan Africa, and because sub-Saharan African populations straddle the root of the species-wide population tree, there can be no sub-Saharan race under. [this] criterion." (Hunley et al 45) Thus, this nested variation excludes classic definitions of race and is "at odds with the patterns of diversity that evolutionary independence of regions would produce." (Hunley et al 45)
Hunley et al conclude that "traditional anthropological classifications placed human populations that reside on different continents at the same level of classification (i.e. race), a classification that takes into account evolutionary relationships and the nested cascade of diversity would require that sub-Saharan Africans are not a race, and that nested sub-races would be necessary to account for non-sub-Saharan Africans." (Hunley et al 45) This needlessly complex over-splitting of human geographic populations would be unwarranted and offers no benefits over clinal variation models in terms of elucidating human variation patterns.
The final article reviewed for this work is authored by David Serre and Svante P??bo, both of the Max Planck Institute for Evolutionary Anthro-pology in Leipzig, Germany. Titled "Evidence for Gradients of Human Genetic Diversity Within and Among Continents", the purpose of this study was to determine if "worldwide genetic diversity is best described as discrete units. or by continuous variation in allele frequencies." (Serre and P??bo 1679)
Serre and P??bo created two data sets to test this hypothesis. The first was based on populations, and "consists of 89 individuals sampled from 15 populations" while the second, based on geography, "consists of 90 individuals from 52 different populations, selected such that their geographic distribution. approximates the distribution of human populations as a whole and includes areas where Africa, Asia, and Europe meet." (Serre and P??bo 1680)
When they examined the two data sets with an inference of two populations, they found two very different views on human genetic diversity. In the population based data set, they found that 83% of the individuals fell into either one, or the other, of the two inferred populations. (Serre and P??bo 1680) The inferred populations, one African and the other non-African, had high values in regards to ancestry (85%-100%). (Serre and P??bo 1680)
The geography based data set dealing with individuals, on the other hand, demonstrated that "all individuals are estimated to be 40-50% admixed between the two inferred populations, and [with] no qualitative difference between Africans and non-Africans" (Serre and P??bo 1680) Serre and P??bo point out that the sort of continental groupings seen in studies such as Rosenberg et al are likely related to sampling methodology based on selecting from the most distal portions of each continent. (Serre and P??bo 1680)
Another interesting aspect of this article is that it directly rebuts Rosenberg et al, probably Wade's most important source of data for his own position. It should be noted here that, shortly after Wade's book was published in 2014, over 135 geneticists, anthropologists, and biologists signed a letter to the New York Times, republished on Stanford's own web cluster, decrying Wade's misuse of their findings to justify his conclusions. One of the main five signatories, the people who actually drafted the letter, was none other than Noah Rosenberg! This letter will be referred to in the remainder of this text as "Coop et al". Other signatories to Coop et al included Neil Risch, Richard Myers, and Jun Z. Li, all of whom are heavily cited by Wade when making his case. (Coop et al 1)
The salient portion of the letter is reprinted here:
"Wade juxtaposes an incomplete and inaccurate account of our research on human genetic differences with speculation that recent natural selection has led to worldwide differences in I.Q. test results, political institutions and economic development. We reject Wade's implication that our findings substantiate his guesswork. They do not.
We are in full agreement that there is no support from the field of population genetics for Wade's conjectures." (Coop et al 1)
Wade's response to this letter will be addressed in my discussion.
Returning to Serre and P??bo, as mentioned, they tackle Rosenberg et al by testing their results to see if the continental clustering found in that study is an artifact of sampling methodology. The full methodology involved is too long to relay here, but the thrust of Serre and P??bo's work here involves attempting to "find a stable assignment of. individuals to inferred populations in which allele frequencies are allowed to be independent of one another." (Serre and P??bo 1681) This is opposed to Rosenberg et al's methodology which correlated these allele frequencies to one another. (Serre and P??bo 1681)
The results of this test demonstrated that "when the whole data set is analyzed, the choice of the model does not change the results, but neither does it allow finding a stable representation of human genetic diversity." (Serre and P??bo 1681) Further, the results "show that population based sample schemes. produce views of human genetic diversity characterized by discrete units of diversity that tend to correspond to continents. This is especially true for samples in which few geographically disconnected populations from different continents are sampled." (Serre and P??bo 1682)
Serre and P??bo's conclusions demonstrate, once again, that continental clustering is the result of design frameworks that emphasize extremes of human populations. They state unequivocally that "using a homogenous sampling strategy and a model in which allele frequencies in different inferred populations are allowed to be independent, [they] find a stable and reproducible representation of human genetic diversity in which the extent of admixture between individuals. changes continuously. without any major discontinuities." (Serre and P??bo 1683)
Emphasis is placed on the fact that this does not indicate that no variation between populations exists, but rather that these variations are small (9.2% between continents) with the majority of the variation (87.6%) between individuals. (Serre and P??bo 1683) This confirms the classic findings from researchers, such as Lewontin, that clinal variation is a better representation than continental clustering for human genetic diversity. Serre and P??bo believe this finding rebuts Neil Risch's claim that racial classifications are valid (Serre and P??bo 1683), and the authors state that they "see no reason to assume that races represent any units of relevance for understanding human genetic history." (Serre and P??bo 1683)