Origin of the human hand

A means of determining the phylogenetic implications of similarities between the hands of man and non-human primates is proposed. The only traits shared by man and non-human primates accepted as evidence of our ancestral hand structure and functions are those which are incompatible or out of keeping with current behavior of the human hand. They may be assumed to remain only as relics of adaptations to former habits of locomotion and feeding. The relics found through this analysis are all traits that are present in the apes (some of them only in African apes) and probably related to functions of the hand in suspension of the body, fist-walking, and knuckle-walking. The presence of these traits in man implies that human ancestors similarly used the hand to suspend the body in the trees and to support it on the back of the flexed fingers.