Blood Groups and Ancestry: A Test Case From the New Guinea Highlands

The blood group genes constitute the major source of data for genetic anthropology. Mourant's (1954 and 1958) summaries indicate the overwhelming mass of data that have been collected over the years for these genetic systems, and the collection continues today at an accelerated rate. In many publications there is little attempt to explain the data so that the work appears to be data collection for its own sake; a situation which closely approaches that which has filled libraries with masses of anthropometric measurements. Of course, many studies on blood groups have contributed significantly to the elucidation of our theories on the nature of human genetic diversity. However, many attempts to explain the similarities in blood group frequencies which have been obtained are in the form of assertions of common ancestry or migrations. This is true both for farreaching studies which claim to find Berber strains in England or American Indians in the Pacific and for smaller microevolutionary studies which are restricted to a single geographic region. If the blood group genes are "relatively stable" and hence give some indication of distant common ancestry, then presumably within a small area and among closely related peoples they should also be correlated with common ancestry. The purpose of this paper is to attempt to test this assumption in one small area, the Eastern Highlands of New Guinea. The blood groups of this area have been examined by Kariks, Kooptzoff, Steed, Cotter, and Walsh (1960:225-236) and by Simmons, Graydon, Zigas, Baker, and Gajdusek (1961 :639-664). The paper by Watson, Zigas, Kooptzoff, and Walsh (1961:25-41) does not give the results by language groups, so it has not been used. For the same human populations, the linguistic relations have been examined by Wurm, and for many of the languages he has calculated the percentage of cognates they share with neighboring languages. These data on the percentage of shared cognates have been obtained mostly from Gajdusek, Zigas, and Baker (1961:599-627), but also from Watson et al (19,61) and from Wurm (1961:14-23). In some cases the percentage of cognates had to be estimated from dates of separation which were given, but these cannot be wrong by more than one percent. In addition, geographical distance between linguistic communities was estimated from the map given in Gajdusek and Zigas 1959:442-469). In Table I the absolute value of the difference in blood group gene frequencies for the ABO, MN, and Rh blood groups, the mean difference for all blood group genes, the mean difference using only two genes from each system, the mean of the maximum gene frequency difference for the 3 loci, the percentage of shared cognates, and the distance between the various language pairs are shown. Since the Keiagana blood group sample was quite small but much cognate data was available for this language, this sample has been combined with that of the Kanite, a mutually intelligible language. Although the ABO and Rh blood groups of these two languages were not significantly different, the MN blood groups of these two groups were significantly different at the . 01 level; so this could reduce the significance of the results. This and other problems will be discussed after the results have been given.