title: The genetic structure of a tribal population, the Yanomama Indians. XIV. Clines and their interpretation.
abstract: The Yanomama Indians are a South American tribe distributed over an irregular area approximately 200 X 300 miles. The gene frequencies observed at 12 loci in 47 villages within this area have been analyzed for the occurrence of clines. Apparently significant clines are observed for alleles of the Rh, MNSs, Kidd, Gm, Inv and serum albumin system. Available data concerning recent tribal expansion and admixture permit a tentative analysis of the causes of these clines. Although the action of selection cannot be rigorously excluded, it seems unlikely to be the major couse. Admixture with surrounding tribes plays a role which can be quantified because of the fortuitous cicumstance of two genetic markers for admixture. It is suggested that an important factor in the origin of these clines is the manner in which the tribe has recently expanded through successive village fissionings and a predominantly centrifugal pattern of village migration.
mesh_terms: D000483:Alleles; D001938:Brazil; D004375:Duffy Blood-Group System; D005260:Female; D005787:Gene Frequency; D005826:Genetics, Medical; D005828:Genetics, Population; D006242:Haptoglobins; D006801:Humans; D007199:Indians, South American; D007667:Kidd Blood-Group System; D007983:Lewis Blood Group Antigens; D008951:MNSs Blood-Group System; D008297:Male; D010733:Phosphoglucomutase; D011159:Population Surveillance; D012204:Rh-Hr Blood-Group System; D012709:Serum Albumin; D014687:Venezuela
chemical_list: D004375:Duffy Blood-Group System; D006242:Haptoglobins; D007667:Kidd Blood-Group System; D007983:Lewis Blood Group Antigens; D008951:MNSs Blood-Group System; D012204:Rh-Hr Blood-Group System; D012709:Serum Albumin; D010733:Phosphoglucomutase