722 THE AMERICAN JOURNAL OF SOCIOLOGY
especially the sociologist, are concerned with the genus Homo and with what has taken place since that genus acquired its full standing as such.
Biologists are now practically unanimous in maintaining that every distinct species has developed through descent with modifi- cation under conditions that combined to produce that particular form. Such conditions can only exist in a definite and more or less limited territorial area. Each species is thus usually confined to such an area. If it has a wider distribution, the form is correspond- ingly varied, indicating dispersion subsequent to the time at which it attained its specific character at some one point or limited area. That this was the case with man is as certain as it is with other species. The idea once quite prevalent, even among leading biologists, that the same species could originate at different times and places has disappeared along with the conception of special creation upon which it was based, and the theoteleogical views that formerly prevailed. It is negatived by the admission of a phylogenetic connection with ancestral forms, since, under the infinitely varied conditions by which every new form is produced, the chances are infinity to one against the production of two identical species at different points. So much for the doctrine of polygenism which some anthropologists and sociolo- gists have thought it necessary to revive and call in to explain certain phenomena presented by human races and human society. I shall endeavor to show that no such hypothesis is necessary.
Assuming, 'then, that man was developed upon some limited area presenting the conditions to the production of just such a being, we may gain a fairly clear conception of the nature of his early history. It must be remembered, however, that there does not now exist any race of men corresponding to the absolutely primitive type. The lowest races known to us are such as have for one reason or another remained for ages in an undeveloped state, but during all these ages they must of necessity have undergone profound modification. Many of them have fluctu- ated, having once belonged to far more developed types, and subsequently degenerated in adapting themselves to simpler or severer conditions of existence.
