^61:7.6 ¶ 250,000 years ago the 6^th and last glaciation began. And despite the fact that the northern highlands had begun to sink slightly, this was the period of greatest snow deposition on the northern ice fields.

^61:7.7 In this invasion the three great ice sheets coalesced into one vast ice mass, and all of the western mountains participated in this glacial activity. This was the largest of all ice invasions in North America; the ice moved south over 2,400 km from its pressure centres, and North America experienced its lowest temperatures.

^61:7.8 ¶ 200,000 years ago, during the advance of the last glacier, there occurred an episode which had much to do with the march of events on Urantia — the Lucifer rebellion.

^61:7.9 ¶ 150,000 years ago the 6^th and last glacier reached its farthest points of southern extension, the western ice sheet crossing just over the Canadian border; the central coming down into Kansas, Missouri, and Illinois; the eastern sheet advancing south and covering the greater portion of Pennsylvania and Ohio.

^61:7.10 This is the glacier that sent forth the many tongues, or ice lobes, which carved out the present-day lakes, great and small. During its retreat the North American system of Great Lakes was produced. And Urantian geologists have very accurately deduced the various stages of this development and have correctly surmised that these bodies of water did, at different times, empty first into the Mississippi valley, then eastward into the Hudson valley, and finally by a northern route into the St. Lawrence. It is 37,000 years since the connected Great Lakes system began to empty out over the present Niagara route.

^61:7.11 ¶ 100,000 years ago, during the retreat of the last glacier, the vast polar ice sheets began to form, and the centre of ice accumulation moved considerably northward. And as long as the polar regions continue to be covered with ice, it is hardly possible for another glacial age to occur, regardless of future land elevations or modification of ocean currents.

^61:7.12 This last glacier was 100,000 years advancing, and it required a like span of time to complete its northern retreat. The temperate regions have been free from the ice for a little over 50,000 years.

^61:7.13 The rigorous glacial period destroyed many species and radically changed numerous others. Many were sorely sifted by the to-and-fro migration which was made necessary by the advancing and retreating ice. Those animals which followed the glaciers back and forth over the land were the bear, bison, reindeer, musk ox, mammoth, and mastodon.

^61:7.14 The mammoth sought the open prairies, but the mastodon preferred the sheltered fringes of the forest regions. The mammoth, until a late date, ranged from Mexico to Canada; the Siberian variety became wool covered. The mastodon persisted in North America until exterminated by the red man much as the white man later killed off the bison.

^61:7.15 In North America, during the last glaciation, the horse, tapir, llama, and sabre-toothed tiger became extinct. In their places sloths, armadillos, and water hogs came up from South America.

^61:7.16 The enforced migration of life before the advancing ice led to an extraordinary commingling of plants and of animals, and with the retreat of the final ice invasion, many arctic species of both plants and animals were left stranded high upon certain mountain peaks, whither they had journeyed to escape destruction by the glacier. And so, today, these dislocated plants and animals may be found high up on the Alps of Europe and even on the Appalachian Mountains of North America.

^61:7.17 ¶ The ice age is the last completed geologic period, the so-called Pleistocene, over 2,000,000 years in length.

^61:7.18 ¶ 35,000 years ago marks the termination of the great ice age excepting in the polar regions of the planet. This date is also significant in that it approximates the arrival of a Material Son and Daughter and the beginning of the Adamic dispensation, roughly corresponding to the beginning of the Holocene[2] or postglacial period.

^61:7.19 ¶ This narrative, extending from the rise of mammalian life to the retreat of the ice and on down to historic times, covers a span of almost 50,000,000 years. This is the last — the current — geologic period and is known to your researchers as the Cenozoic or recent-times era.

^61:7.20 [Sponsored by a Resident Life Carrier.]

PAPER № 62

THE DAWN RACES OF EARLY MAN

^62:0.1 About 1,000,000 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.

1. THE EARLY LEMUR TYPES

^62:1.1 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.

^62:1.2 While these early lemurs evolved in the Western Hemisphere, the establishment of the direct mammalian ancestry of mankind took place in south-western 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 south-westward 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 favourable strains, thus establishing the ancestry of the human race.

^62:1.3 With the passing of time the seacoast of India south-west 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.

2. THE DAWN MAMMALS

^62:2.1 A little more than 1,000,000 years ago the Mesopotamian dawn mammals, the direct descendants of the North American lemur type of placental mammal, suddenly appeared. They were active little creatures, almost 91 cm tall; and while they did not habitually walk on their hind legs, they could easily stand erect. They were hairy and agile and chattered in monkeylike fashion, but unlike the simian tribes, they were flesh eaters. They had a primitive opposable thumb as well as a highly useful grasping big toe. From this point onward the prehuman species successively developed the opposable thumb while they progressively lost the grasping power of the great toe. The later ape tribes retained the grasping big toe but never developed the human type of thumb.