Deciphering primate phylogeny from macromolecular specificities

A problem in deciphering primate phylogeny, morphological convergence between different evolutionary lines, can be overcome by species comparisons of proteins, macromolecules with specificities closely linked to the genetic code in DNA. Various chemical, electrophoretic, and immunological data on serum and tissue proteins in primates are reviewed with respect to their phylogenetic significance. Much of this data deals with protein specificities in the Hominoidea and depicts a particularly close genetic relationship between man and the African apes. Hominoidea, Cercopithecoidea, Ceboidea, and Lorisoidea are characterized by their proteins as monophyletic or natural taxa, even though the conventional subdivisions within several of these superfamilies are not in complete accord with the protein analyses. The protein evidence supports the conventional grouping of Cercopithecoidea with Hominoidea in the infraorder Catarrhini and the grouping of Catarrhini and Platyrrhini (Ceboidea) in the suborder Anthropoidea. Lemuroidea and Lorisoidea appear to be closer to one another than to either Tupaioidea or Anthropoidea and closer to the Anthropoidea than to the Tupaioidea. Comparisons of primate DNA's by Hoyer and coworkers are demonstrating genetic affinities among primates which agree with those deduced from the comparison of protein specificities. Species differences and similarities in the relative amounts of different protein macromolecules reflect the grade relationships of primates, but, unlike the comparisons of amino‐acid sequences or antigenic specificities, are not reliable indicators of phyletic affinities. Data on the ratios of M(uscle) to H(eart) type lactate dehydrogenase in a series of primate brains provides a biochemical example of the concept that there are “lower” (primitive) and “higher” (advanced) grades of evolutionary development among the extant primates.