Page:Popular Science Monthly Volume 60.djvu/377

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369
THE DESCENT OF MAN.

abounded in game of all sorts; but the superficial food-ground was already preempted by other animals, which were not likely to allow man to encroach upon their subsistence without a struggle. Adaptation to the new surroundings must consequently have been effected at the expense of a conflict with the former lords of the forest. But the human prototype does not appear to have become fitted for such a contest either through heredity or environment. From his ape-like ancestors the pliocene precursor merely inherited a large cranial capacity and the ordinary anthropoid characters; while in adapting him to the terrestrial habitat, selection simply set him upright on his feet and accorded him the free use of his arms and hands. Leaving aside his inherited endowment for the moment, the structural modifications that occurred during the period of specific differentiation seem at first sight to have set man at a positive disadvantage over against the frugivorous apes, on the one hand, from whom he descended, and the land-dwelling carnivora, on the other, with whom he had henceforth to contend. The food of frugivorous creatures remains fixed in its place and only requires to be plucked. These animals have, therefore, no need of powerful prehensile organs in attack, while for defense they usually rely upon their locomotive organs in flight. The prey of carnivorous creatures has, on the contrary, to be caught and killed, and on this account these animals are supplied with vigorous attacking organs, which in times of necessity may readily be employed for defense. The apparent anomaly in man's case is that in becoming terrestrial, he lost his former facility for climbing and making his escape through the trees, without by way of compensation acquiring sufficient strength or agility to cope with the land-dwelling carnivora. Cut off from escape above and surrounded with animal enemies below, physically unfitted to lie in wait and spring, having neither claws nor talons wherewith to grasp and hold, and not being fleet enough either to take flight or to follow fast on foot, how then was it possible for man to gain his acknowledged ascendancy over the beasts?

As a group the anthropoidea are structurally adapted to two sets of physical exercises: swinging and climbing, and striking and throwing. In a more restricted sense, however, the two practices are incompatible, for skill in one direction can only be acquired at the expense of proficiency in the other. For the former exercises, moreover, instinct alone is sufficient; while for the latter a certain amount of ingenuity is required. Being arboreal, swinging and climbing are essential to the frugivorous apes, both for food-getting and for flight, and on this account their instincts are set and their organs especially adapted to this purpose. Those that come occasionally to the ground in search of other aliment are, however, also able after a fashion to strike and throw. Both the gorilla and the chimpanzee, for example, are in-