Blood Group Determinations of Prehistoric American Indians I
American Anthropologist 1937 Vol. 39:583-592.
Wyman, Leland C. and William C. Boyd
Wyman and Boyd address three problems present in American anthropology with regard to blood groups: the antiquity of the blood groups present in the New World, whether prehistoric or the result of historic migration from the Old World; the relations between the Basket Maker people and the later Pueblo people, and how these peoples relate to other peripheral groups; and the relation of ancient Peruvian peoples to ancient North American groups and to the groups presently living in South America.
Wyman and Boyd briefly describe their methods and materials of research, which focus on the chemically stable substances called agglutinogens A and B. Agglutinogens can be found in tissue as well as the blood. The samples tested were ground tissue, usually muscle, taken from 226 human burials that dated back to various periods of prehistory. Of the specimens, 133 were from Peru, 59 were from the southwestern United States, and 34 were from Alaska or the Aleutians.
In their results, Wyman and Boyd claim to have definitely shown the presence of the antigens A and B in prehistoric American Indians, and they present the specific findings for the sample material of each location. The authors question whether the mutation rates in humans could be high enough to account for this presence of these antigens. Wyman and Boyd propose, instead, that human populations, lacking one or more of the blood groups, have appeared intermittently through accidental isolation from an original population that possessed all three factors A, B, and O.
Wyman and Boyd assert that the presence of antigens A and B in prehistoric American Indian tissue suggests the antiquity of these genes in human evolution, and thus, does not support the theory that these genes were the result of recent mutations. The authors also offer tentative hypotheses suggesting relations between the Lovelock Cave group and the pre-Pueblo people, distinguishing the Basket Maker group from the Pueblo people, suggesting a more recent origin for the presence of agglutinogen A among the Navaho, confirming the antiquity of the agglutinogen B in South America, and relating the ancient South Americans to the Big Bend Cave people and other groups.
Blood Group Determinations of Prehistoric American Indians II
American Anthropologist 1937 Vol.39:583-592
Wyman, Leland C. and Boyd, William C
The issue addressed by this article in American Anthropologist is whether or not it was the European immigration into the Americas that introduced the A and B blood alleles. This determination would give strong evidence as to the timeframe that these alleles appeared in the human genome. If A and B alleles appear in Prehistoric American Indian Populations then the alleles appeared before or during the great migrations. The authors tested the remains of North American and of Peruvian Indians. The samples of each population were not large enough to determine a population majority of one blood type or another. The overall results for the North American Indians reflected that the A allele was present in the first and third of the four major migrations. The B allele was present in the Peruvian Indians as well as A to a much lesser degree. There were even two AB individuals in their sample.
The process used to determine the presence of A or B alleles was relatively straightforward. Blood type is determined by the presence or absence of two proteins (A and B). When neither type is present the blood type is O. When just A is present the blood type is A, when just B the blood type is B. When both are present the blood type is AB. When proteins are bonded with anti-proteins the result is a neutral compound. So in order to determine the blood type of the ancient samples Anti-A and Anti-B proteins were added. These would bond to the corresponding proteins in the sample if they existed in the sample. Later A and B proteins were added to the sample as well. Any Anti-proteins still remaining would then bond to these new proteins. Thus if there was any A or B proteins left unbonded, it meant that the corresponding Anti-protein had bonded with that protein type in the sample. So whichever proteins were unbonded at the end were of the same type as the sample. If neither were left the sample was O. If just A was left then the subject was A. If just B was left then the subject was B. If both proteins were left unbonded then the sample was AB.
The process is reliable for determining whether or not the A or B proteins existed in prehistoric Indians. Even though the sample was too small to accurately describe the distribution of the blood proteins in the Indian populations, it does show that the alleles existed before humans arrived in the Americas. Since both the A and the B protein are present in Peru's prehistoric societies the mutation existed before their migration. The A allele present in the North American migrations prove it existed at the time of the first migration, however, it is interesting to note that the second and fourth migrations seem to be predominantly O. This could raise the possibility that although the alleles existed, it may have been in minor numbers and only in certain populations.