JAMA 100 Years Ago Section Editor: Jennifer Reiling, Assistant Editor.
The question of the simian ancestry of man has long been the subject of jest. From the zoologic point of view it has been a matter of more serious concern as far as the position of man in any scheme of classification is involved. With the advent of certain of the modern methods of study applied to blood and the problems of immunity, data of a new sort have been furnished to bear on the real relationship of man to some of his animal competitors. The precipitin reaction has made it possible to bring to light features of this sort and to substantiate family resemblances in various species. Transfusion experiments and the untoward results which attend them when they are conducted between unrelated animals are contributions in the same direction. By the methods here indicated it has already been shown that precipitins which are specifically developed for human serum are also applicable to the group of anthropoid apes which includes the chimpanzee, orang-outang and gorilla. They fail to react with the blood of the familiar cynomorphic monkeys. Similar are the findings in the way of relationship after blood transfusions, the two groups of the monkey tribe exhibiting different behavior in respect to the induction of hemolysis by the presence of human serum. The latter does not lake the corpuscles of the anthropoid apes, which endure the introduction of human blood into their circulation without notable distress. To this evidence of blood relationship have now been added fresh facts derived from the domain of metabolism. It is now familiarly recognized that whereas the end-product of the metabolism of purins in man is uric acid, which is excreted in the urine, in most of the higher animals, such as the dog, cat, rabbit, etc., allantoin represents the final stage in the degradation of the purin nucleus. Wiechowski of Prague has now demonstrated that the chimpanzee, an anthropoid ape, resembles man in respect to the presence of uric acid and the absence of allantoin in the urine.1 In the common macacus monkey2 and in the baboon the reverse appears to be the case, the individuals of this class falling in line with other familiar laboratory animals. The long-known contrast between man and the animals in respect to this feature of metabolism is thus made less striking by the discovery of these intermediate species exhibiting human characters in more than one way. The gap has been bridged by the studies on the anthropoid apes which have now furnished to science the reputable evidence for that relationship which the behavior of apes in vaudeville and elsewhere has strongly suggested.
MAN AND MONKEY. JAMA. 2013;309(14):1439. doi:10.1001/jama.2012.145361