As may be imagined, we know comparatively little about the most ancient inhabitants of this continent. However, when one considers the thousands of years which have elapsed and how little of their material culture could be preserved since they had neither pottery nor metals, it is rather remarkable that we know as much as we do. At least we know something of the tools and weapons which they used, the animals which they hunted, and the conditions under which they lived. Apparently the earliest Americans had a rather simple culture and did not practice agriculture nor have fixed habitations. Little is known of their physical appearance since only two skeletons have been found in this country which are accepted as being of relatively great antiquity by any considerable number of competent scientists.[69][70] What evidence we have suggests that the first men to enter the new world were sufficiently modern in morphological type to differ very little in appearance from many present day Indians. The question naturally arises: Where did the aboriginal inhabitants of America come from? Man did not evolve on this continent; therefore he must have come to this hemisphere from the Old World where he had existed for many thousands of years. All evidence points to migrations from Asia and the logical route is by way of Bering Strait where the two continents are separated by only fifty-six miles of water broken by three islands. Later migrants may also have arrived from Asia following a route through the Aleutian Islands. It must be emphasized that it is not believed that there was only one immigration. Actually there must have been many and they apparently continued into relatively recent times.