82 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 
general, are utterly dependent upon such an environment for their 
sustenance. 
Geologic record.—Primates are found in the North American 
sediments from Lower to Upper Eocene time, when they became 
extinct. Thus, while their remains constitute a relatively large per- 
centage of the total fauna of the Eocene, primates are utterly unknown 
on this continent from that time until the coming of man. In Europe 
the record is similar except that the extinction occurred at a somewhat 
later date, the Oligocene. Furthermore, they reappear in Europe in 
the Lower Miocene, at the time of the proboscidean migration out of 
Africa, whence these primates may also have come. Their second 
European extinction was in the Upper Pliocene shortly before the first 
appearance of mankind. 
But in southern Asia, Africa, and South America the evolution of 
primates seems to have been continuous since the first great southward 
migration. The evidence, however, is not so much the historical 
documents as the presence of primates in those places at the present 
time, the fossil record is not entirely lacking although highly incom- 
plete. The South American monkeys may have had their origin in 
the ancient North American primates, or more doubtfully, the stock 
may have come by way of Africa. Scott inclines toward the latter 
view although he says the evidence is by no means conclusive. 
ORIGIN OF MAN 
Stock.—According to W. K. Gregory, the stock from which man 
arose was some big-brained anthropoid related most nearly to the 
chimpanzee-gorilla group, an assumption based upon anatomical 
evidences, in spite of wide differences in habitus and consequent 
adaptation. 
Place.—Evidences point to central Asia as the place of descent 
from the trees of the human precursor, the reasons for this belief being 
several. First, it was central for migrations elsewhere; Europe, on 
the other hand, where the most conclusive, in fact almost the exclusive 
evidence for fossil man is found, is too small an area for the divergent 
evolution of the several human species. Second, Asia is contiguous 
to the oldest known human remains, which, as we shall see, were found 
in Java. Third, it was the seat of the oldest civilizations, not only of 
the existing nations which, like the Chinese, trace their recorded 
history back to a hoary antiquity, but of nations which preceded them 
by thousands of years, and whose records have not yet come to light. 
