BLOOD-GROUPS OF OLD-WORLD MONKEYS, EVOLUTIONARY AND TAXONOMIC IMPLICATIONS

For practical purposes two classes of blood groups of Old World monkeys can be distinguished: human-type and simian-type, depending on the kind of reagents used for testing. Of the human-type blood groups, only the A-B-O groups, defined by saliva inhibition and serum tests, are polymorphic in some, but not all, monkey species. The distributions of those groups show wide differences not only among monkey species but also among troops of one and the same species. The tests for other human-type antigens give with the monkey red cells either uniformly positive or uniformly negative results. Thus, the human-type blood groups seem to be of limited use as taxonomic tools in the systematics of the Old World monkeys. On the other hand, the simian-type blood groups, defined by isoor crossimmune monkey sera, display highly polymorphic patterns in most species of Old World monkeys, and the capability of the antisera to react with combining groups on the red cells of monkeys of closely related species seems to reflect the taxonomic closeness of two or more species. The fact that some of the simian-type specificities, notably those belonging to the rhesus Drh graded blood group system, are shared by many species of Old World monkeys, indicates that they were introduced into genotypes during early stages of evolution of the Cercopithecidae. © 1979.