This text provides summaries of the main systems of blood group antigens and MHC molecules. The human systems are used to explain the necessary background knowledge and the systems in nonhuman primates are then described and compared. The emphasis is on the molecular nature of the gene products, the evolutionary relationships among the various systems, and the presumed mechanism by which the systems have evolved. All articles are written in such a way that they can serve as an introduction to the field for nonexperts, and at the same time as a handbook for experts. Numerous tables, diagrams...

Zoologists have categorized primates into a single order, and no one doubts today that they share a common ancestry. Humans and Old and New World non- human primate species, from the lemurs of Madagascar to the African anthro- poid apes, represent diverging branches of an evolutionary common trunk. Along with species-specific characters, all primates have retained a number of ancestral traits, relics of their common origin. The comparative study of these species-specific and ancestral traits makes it possible to reconstruct the evolu- tionary pathways of humans and nonhuman primates. The...