ation he also mentions but regards it in the light of a secondary factor.[1] Man, by the light of reason, and the strength of will, has essentially modified all of these factors, and at times has completely neutralized one or more of them. The natural course of the hereditary process must have experienced some radical transformation when man first appeared as an off-shoot of the Simian stock. Characterize it as an extreme variation, as a mutation, or as the development of a recessive into a dominant factor, or of a potential into an actual, or what you will, the fact remains that certain new and definite determinants must have appeared in the midst of the old. For the natural processes of heredity, whether we regard them as simply conserving the original germ-plasm, or as gradually accumulating the natural gains and accomplishments of a race experience, are not sufficient alone to account for the unique, unannounced, and unanticipated evolution of man. Moreover, so far as his ontogenetic development is concerned, the human being possesses so large a capacity of educability that the progress of a single generation brings to him acquisition and achievement incomparably superior to that which other orders of the animal kingdom can show through ages upon ages.
It is in reference to his environment that man's power and unique position are most conspicuously shown. He not only knows how to adapt himself to his environment, but he knows how to adapt his environment to himself. He does not wait for natural selection to promote him on the one hand, or on the other to degrade and destroy him. He is master of his fate; he compels his surroundings to serve his need and desire. Moreover, by virtue of his intellectual endowments man shows an increased tendency toward variation. In originality and in inventiveness he puts forward his progressive development in knowledge and efficiency by immense stretches. Professor Osborn shows in the same article to which I have referred above that when one of these factors varies, all the others vary with it. Consequently man, who is able to cause all of these factors to vary at will, brings into the natural course of evolution determining factors of profound significance and far-reaching influence. The terms which are used to describe the process of evolution before the appearance
- ↑ Science, N. S., Vol. XXVII, p. 148.
