Primate fibrinopeptides: Evolutionary significance

Simian sarcoma virus onc gene, v-sis, is derived from the gene (or genes) encoding a platelet-derived growth factor

The transforming protein of a primate sarcoma virus and a platelet-derived growth factor are derived from the same or closely related cellular genes. This conclusion is based on the demonstration of extensive sequence similarity between the transforming protein derived from the simian sarcoma virus onc gene, v-sis, and a human platelet-derived growth factor. The mechanism by which v-sis transforms cells could involve the constitutive expression of a protein with functions similar or identical to those of a factor active transiently during normal cell growth.

The functional morphology of the cercopithecoid wrist and inferior radioulnar joints, and their bearing on some problems in the evolution of the Hominoidea

The cercopithecoid wrist joint differs from the wrist joints of hominoids in several ways. The distal ulna, the distal radius, the pisiform, the triquetrum, the hamate, and the base of the fifth metacarpal are on the one hand remarkably alike among cercopithecoid genera, and on the other remarkably distinct from homologous bones in the Hominoidea. Functionally, the triquetrum and the pisiform, in conjuction with the ulnar styloid process, check the proximal carpal row during ulnar deviation, and are possibly important in stabilizing the wrist during dorsiflexion as well. The head of the ulna almost certainly betokens a range of radioulnar supination in cercopithecoids that is substantially less than is to be found in any of the hominoid genera. The articulation between the hamate bone and the base of the fifth metacarpal allows for considerable dorsiflexion in the Cercopithecoidea; this potential was not evidenct in any of the hominoids examined. Behaviorally, the cercopithecoid wrist can most profitably be viewed as an adaptation for a quadrupedal life style involving dorsiflexion of the wrist and palmigrade/digitigrade substrate contact. The hominoid wrist joint is not adapted for such a behavioral potential.