Racial polyphyletism

Polyphyletic theories of human races are discredited models of human evolution which argue that different races belong to separate lineages and evolved parallel to one another for hundreds of thousands to millions of years. The most recent common ancestor between the races is pushed back far in time, and the races are considered to have sprung from multiple ancestral sources, e.g. different species (Gates, 1948), or a single polytypic species but of considerable time-depth as continental subspecies (Coon, 1962).
M. H. Wolpoff points out that the Multiregional hypothesis of human evolution should not be confused with racial polyphyletism, and blames Stephen Jay Gould for this error:
==Background==
Before Darwin (B.D.), while there were theories of transmutation of species within biology, most biologists accepted a creationist worldview. The original polygenism vs. monogenism debate therefore focused on whether all human races descend ab initio (from the beginning) from Adam and Eve, or whether some descend from other ancestors such as Pre-Adamites. After the publication of The Origin of Species in 1859, biologists incorporated common descent into their study of animals, including humans. However, the polygenism vs. monogenism issue did not disappear but shifted to a debate as to whether human races share recent or archaic common ancestry. Polyphyletism as a form of evolutionary polygenism emerged to argue that distinct human races are millions of years old and evolved in parallel (as separate lineages) from the Miocene, Pliocene or Early Pleistocene:
==1860s-1940s==
Karl Vogt in 1864 first proposed while the different races of man shared an early primate ancestor millions of years ago, they had evolved separately from different apes on the continents.Vogt, 1864: 466. This view was taken up by F. G. Crookshank who argued in The Mongol in our Midst (1924) that the Mongoloid race evolved from the orangutan, the Negroid from the , and the Caucasoid from the chimpanzee.
In 1931, the anthropologist Earnest Hooton argued for a Miocene origin of the races from the descendants of dyropithecines:
Thomas Griffith Taylor (1937) considered the Negrito to have evolved separately from the other races who descended from the Neanderthal:
A late convert to the evolutionary polygenism of human races was Arthur Keith in 1936:
In his A New Theory of Human Evolution (1948) Keith argued human races were a single species, but that they had arisen over two million years ago and evolved parallel:
Most evolutionary polygenists like Keith by the 1940s had abandoned or denounced the idea human races were separate species, instead opting to classify them as subspecies, but still with long separate phylogenies. A notable exception was the botanist and geneticist R. R. Gates (1944, 1948) who cited instances of cross-species fertility among plants to argue racial hybridization does not discredit the Australoid, Bushmenoid, Negroid, Mongoloid and Caucasoid races being different species. According to Gates, Homo sapiens is better comparable to a genus taxonomic rank, and the five human races (in his classification) as species.Gates, 1948: 367. Gates (1948) considered "there have been two more or less independent streams in human evolution":
*Australoid: Pithecanthropus > Javanthropus soloensis > Wadjak > Australoid
*Capoid: Africanus njarensis > Homo rhodesiensis > Florisbad > BushmenoidGates, 1948: 141f.
While treating these two races (or rather species) as parallel lineages, Gates would derive the Caucasoid, Negroid and Mongoloid stocks from a mixture of fossil sources, allowing for some limited interbreeding between them. In contrast, Hooton's (1946) polyphyletism did not allow for any gene flow between his "major races" at all, only between subraces: "he allowed for reticulation or interbreeding in the formation of what he considered secondary and tertiary racial groups. He believed the essential, primary races emerged through polygenism".Wolpoff & Caspari, 2013.
==1950s-1980s==
Polyphyletic theories of racial origins were criticized by the geneticist Theodosius Dobzhansky from the 1950s. He pointed out that if races had evolved parallel (and isolated to one another) for millions of years, with virtually no genetic exchanges between them, they would no longer be intraspecific races, but species, that could no longer interbreed with each other.Wolpoff & Caspari, 1997: 162f.
In 1957, the polygenist Robert Gayre citing Gates, argued that Dobhansky's argument is unfounded since there are instances of interfertile species, i.e. different species in the wild that reproduce with one another. He therefore wrote: "if sterility is no test, as such, of speciation, then neither is its converse, interbreed-ability, a test of belonging to the same species" and "since sterility fails as the criteria of species, we have to rely on the traditional basis of morphological differences in the discrimination of species, including man".Gayre, 1957. Gayre regarded Caucasoids, Mongoloids and "Melanoids" (Negroids, Australoids) to be different species, having evolved parallel (with almost no contact for millions of years) on the different continents, and dated their divergence as old as the human-chimpanzee split.
The primatologist Osman Hill in his book Man's Ancestry (1954) wrote:
===Carleton Coon===
Carleton S. Coon published The Origin of Races (1962) which defended a polyphyletic view of race, but was less extreme than his predecessors in time-depth. Coon claimed to have traced the origin of five human races to the early Middle Pleistocene, or 750,000 years ago. He also allowed for peripheral or minor gene flow between the races, but not multidirectional. For Coon, it was Caucasoids and Mongoloids who occasionally migrated and mated with Congoids, Capoids and Australoids throughout the Middle and Late Pleistocene, almost never vice-versa:
Coon introduced the concept of "line and grade": each race he considered an ancestor-descendant group that passed through a sapiens state threshold from a more 'brutal' erectus, synonymous with an evolutionary grade.Trigger, 1965. According to Coon, the races are subspecies, and belong to a single polytypic species. However Coon proposed each subspecies or geographical race crossed the sapiens-erectus threshold at different times, five times in total, and could also be classified as phyletic "lines", i.e. independent lineages, minimizing gene flow between them. Dobzhansky criticized Coon's theory in a paper entitled: "Possibility that Homo sapiens evolved independently 5 times is vanishingly small".Dobzhansky, 1963. Coon responded that he "did not state that the subspecies evolved in complete isolation, but that they failed to speciate [separately by branching] because of peripheral gene flow". Coon's model is still polyphyletic, involving parallel evolution, since he proposed differential evolutionary rates for the races crossing the sapiens threshold, i.e. the Congoid line becoming sapien more than 200,000 years after the Caucasoid (this extreme view Dobzhansky pointed out could be taken advantage of by white separatist propagandists); so for Coon, the level of relative isolation between the human races and non-multidirectional gene flow accounted for distinct racial lineages.Delisle, 2007: 287. Caspari and Wolpoff (1996) note:
In 1981, Coon died. His book Racial Adaptations (1982), published posthumously, continued to defend a polyphyletic origin of five races.
In his final book Coon discussed saltationism, struggling to explain how the races crossed the erectus-sapiens threshold (at different times) despite evolving parallel:
Regarding Coon's polyphyletism, Grover Krantz in 1980 wrote:
Krantz considered there to have been continuity in non-adaptive skeletal traits in East Asia for up to one million years, and that Mongoloids were "largely unaltered" by migration. He though cautioned that: "I hope no one took this to imply total genetic separation between these lines". Like Coon, Krantz argued for minor non-multidirectional gene flow (some races he thought were more-or-less isolated) and that the races (although contrary to Coon, less than 5, possibly 3) crossed the erectus-sapiens threshold in their continents at different times. In his book Climatic Races and Descent Groups, Krantz wrote a "polyphyletic origin for sapiens is clearly indicated".Krantz, 1980b: 234. Krantz (1981) argued that cultural behavior and linguistic ability accounted for sapienization, without having to invoke much, if any, gene flow.Krantz, 1981.
===Decline in support===
Coon failed to produce an evolutionary mechanism that could explain how human races evolved parallel for hundreds of thousands of years, and yet independently reached the same sapienization grade, from an archaic (erectus) human, to anatomically modern human. Dobzhansky showed this was a problem for all racial polygenists: their ideas of parallelism require a "mystical inner drive that propels evolution".Race Relations: Montagu, Dobzhansky, Coon, and the Divergence of Race Concepts Polyphyletic evolutionary theories of human races also disappeared from the scientific literature after Coon (1982) because human races were shown to be an inaccurate way of studying biological variation: "many physical anthropologists therefore believe that the concept of cline is more useful for research purposes than the race concept".Barnouw, 1989: 40.
Modern genetic analyses support a clinal concept of variation between populations (e.g., see the work of Luigi Cavalli-Sforza).Cavalli-Sforza, 1994.
Geneticist Alan Templeton (1998) has shown "genetic evidence strongly rejects the existence of distinct evolutionary lineages within humans":
The Origin of Races (1962) and racial polygenism in general has also been criticized as having racist implications."The polygenic aspects of Coon’s theory were racist and widely recognized to be wrong (Dobzhansky 1963, 1968; Hulse 1963; Montagu 1963; Oschinsky 1963; Washburn 1963 [based on the presidential address at the AAA])." (Hawks & Wolpoff, 2003)
==Multiregionalism==
Wolpoff, et al. (1984) founded the Multiregional hypothesis of human evolution (which covers the Pleistocene). In their first paper, Wolpoff and his colleagues Alan Thorne and Xinzhi Wu reviewed, criticized and rejected the previous polyphyletic models of human races, including Coon's. Instead Wolpoff founded an evolutionary model that argues for a single human species that incorporates multidirectional gene flow between all Old World populations, but with more gene flow from the center of the species range. This model states that the human species emerged 2 million years ago in Africa and spread across the Old World, and that there has been regional continuity spanning the Pleistocene of four "morphological clades", defined not as lineages, but as sets of cranial traits that "uniquely characterise a geographic region". These regional traits were stabilized in peripheral or 'edge' regions on earth through a balance of genetic drift, gene flow and selection.
Multiregionalism has been misinterpreted as evolutionary polygenism, or in particular Coon's model of human origins which Wolpoff and his colleagues have distanced themselves from.Wolpoff, et al. 2000.Caspari & Wolpoff, 1996.
==Sources==
*Barnouw, V. (1989). Physical Anthropology and Archeology. Chicago: The Dorsey Press.
*Caspari, R., Wolpoff, M. H. (1996). "Weidenreich, Coon, and multiregional evolution". Human evolution. 11(3-4): 261–268.
*Cavalli-Sforza, L. (1994). The History and Geography of Human Genes. Princeton University Press. ISBN 0691087504.
*Coon, C. S. (1962). The Origin of Races. New York: Alfred A. Knopf.
*Coon, C. S. (1982). Racial Adaptations. Nelson-Hall.
*Delisle, R. G. (2007). Debating humankind's place in nature, 1860-2000: the nature of paleoanthropology. Prentice Hall.
*Delisle, R. G. (2012). Welcome to the Twilight Zone: a forgotten early phase of human evolutionary studies. Endeavour. 36(2): 55-64.
*Dobzhansky, T. (1963). "Possibility that Homo sapiens evolved independently 5 times is vanishingly small". Current Anthropology. 4(4): 360-367.
*Gates, R. R. (1944). "Phylogeny and classification of hominids and anthropoids". American Journal of Physical Anthropology. 2(3): 279-292.
*Gates, R. R. (1948). Human ancestry: from a genetical point of view. Harvard University Press.
*Gayre, R. (1957). "A Brief Discussion of Ethnology, Palaeontology and the Problem of the Polygenic Origin of Mankind". Jour. Pal. Soc. India. 2: 58-68. 
*Osman Hill, W. C. (1954). Man's Ancestry. William Heinemann.
*Hawks, J.D., Wolpoff, M. H. (2003). "Sixty Years of Modern Human Origins in the American Anthropological Association". American Anthropologist. 105(1):87-98.
*Hooton, E. (1931). Up from the Ape. New York: Macmillan Company.
*Hooton, E. (1946, rev. ed.). Up from the Ape. New York: Macmillan Company.
*Keith, A. (1948). A New Theory of Human Evolution. New York: Philosophical Library.
*Krantz, G. (1980a). "Sapienization and Speech". Current Anthropology. 21(6): 773-792.
*Krantz, G. (1980b). Climatic Races and Descent Groups. Cristopher Publishing House.
*Krantz, G. (1981). The Process of Human Evolution. Schenkman Books.
*Taylor, T. G. (1937). Environment, Race, and Migration. University of Toronto Press.
*Templeton, A. R. (1998). "Human races: a genetic and evolutionary perspective". American Anthropologist. 100(3): 632-650.
*Trigger, B. (1965). "Coon's Theory on The Origin of Races". Anthropologica. 7(2): 179-187.
*Vogt, C. (1864). Lectures on Man. London: Longman, Green, Longman and Roberts.
*Wolpoff, M., Wu, X., Thorne, A. G. (1984). "Modern Homo sapiens origins: a general theory of hominid evolution involving the fossil evidence from East Asia". In: The Origins of Modern Humans: a World Survey of the Fossil Evidence. Smith, F. H (ed.). New York: Liss.
*Wolpoff, M. H., Hawks, J., Caspari, R. (2000). "Multiregional, Not Multiple Origins". American Journal of Physical Anthropology. 112: 129–136.
*Wolpoff, M., Caspari, R. (1997). Race and Human Evolution: A Fatal Attraction. Simon and Schuster.
*Wolpoff, M., Caspari, R. (2013). "Paleoanthropology and Race". In: A Companion to Paleoanthropology. Begun, David R. (ed.). Wiley-Blackwell.
==References==
Category:Evolution
Category:Biology
Category:Racism