About one million years ago the immediate ancestors of mankind made their appearance by three successive and sudden mutations stemming from early stock of the lemur type of placental mammal. The dominant factors of these early lemurs were derived from the western or later American group of the evolving life plasm. But before establishing the direct line of human ancestry, this strain was reinforced by contributions from the central life implantation evolved in Africa. The eastern life group contributed little or nothing to the actual production of the human species.

The early lemurs concerned in the ancestry of the human species were not directly related to the pre-existent tribes of gibbons and apes then living in Eurasia and northern Africa, whose progeny have survived to the present time. Neither were they the offspring of the modern type of lemur, though springing from an ancestor common to both but long since extinct.

While these early lemurs evolved in the Western Hemisphere, the establishment of the direct mammalian ancestry of mankind took place in southwestern Asia, in the original area of the central life implantation but on the borders of the eastern regions. Several million years ago the North American type lemurs had migrated westward over the Bering land bridge and had slowly made their way southwestward along the Asiatic coast. These migrating tribes finally reached the salubrious region lying between the then expanded Mediterranean Sea and the elevating mountainous regions of the Indian peninsula. In these lands to the west of India they united with other and favorable strains, thus establishing the ancestry of the human race.

With the passing of time the seacoast of India southwest of the mountains gradually submerged, completely isolating the life of this region. There was no avenue of approach to, or escape from, this Mesopotamian or Persian peninsula except to the north, and that was repeatedly cut off by the southern invasions of the glaciers. And it was in this then almost paradisiacal area, and from the superior descendants of this lemur type of mammal, that there sprang two great groups, the simian tribes of modern times and the present-day human species.

A little more than one million years ago the Mesopotamian dawn mammals, the direct descendants of the North American lemur type of placental mammal,