^58:3.3 These eventualities in the origin of the space rays are determined by many cosmic occurrences as well as by the orbits of circulating matter, which vary from modified circles to extreme ellipses. Physical conditions may also be greatly altered because the electron spin is sometimes in the opposite direction from that of the grosser matter behaviour, even in the same physical zone.

^58:3.4 The vast hydrogen clouds are veritable cosmic chemical laboratories, harbouring all phases of evolving energy and metamorphosing matter. Great energy actions also occur in the marginal gases of the great binary stars which so frequently overlap and hence extensively commingle. But none of these tremendous and far-flung energy activities of space exerts the least influence upon the phenomena of organized life — the germ plasm of living things and beings. These energy conditions of space are germane to the essential environment of life establishment, but they are not effective in the subsequent modification of the inheritance factors of the germ plasm as are some of the longer rays of radiant energy. The implanted life of the Life Carriers is fully resistant to all of this amazing flood of the short space rays of universe energy.

^58:3.5 ¶ All of these essential cosmic conditions had to evolve to a favourable status before the Life Carriers could actually begin the establishment of life on Urantia.

4. THE LIFE-DAWN ERA

^58:4.1 That we are called Life Carriers should not confuse you. We can and do carry life to the planets, but we brought no life to Urantia. Urantia life is unique, original with the planet. This sphere is a life-modification world; all life appearing hereon was formulated by us right here on the planet; and there is no other world in all Satania, even in all Nebadon, that has a life existence just like that of Urantia.

^58:4.2 ¶ 550,000,000 years ago the Life Carrier corps returned to Urantia. In co-operation with spiritual powers and superphysical forces we organized and initiated the original life patterns of this world and planted them in the hospitable waters of the realm. All planetary life (aside from extraplanetary personalities) down to the days of Caligastia, the Planetary Prince, had its origin in our three original, identical, and simultaneous marine-life implantations. These three life implantations have been designated as: the central or Eurasian-African, the eastern or Australasian, and the western, embracing Greenland and the Americas.

^58:4.3 ¶ 500,000,000 years ago primitive marine vegetable life was well established on Urantia. Greenland and the arctic land mass, together with North and South America, were beginning their long and slow westward drift. Africa moved slightly south, creating an east and west trough, the Mediterranean basin, between itself and the mother body. Antarctica, Australia, and the land indicated by the islands of the Pacific broke away on the south and east and have drifted far away since that day.

^58:4.4 We had planted the primitive form of marine life in the sheltered tropic bays of the central seas of the east-west cleavage of the breaking-up continental land mass. Our purpose in making three marine-life implantations was to ensure that each great land mass would carry this life with it, in its warm-water seas, as the land subsequently separated. We foresaw that in the later era of the emergence of land life large oceans of water would separate these drifting continental land masses.

5. THE CONTINENTAL DRIFT

^58:5.1 The continental land drift continued. The earth’s core had become as dense and rigid as steel, being subjected to a pressure of almost 3.9·10⁶ kg/cm², and owing to the enormous gravity pressure, it was and still is very hot in the deep interior. The temperature increases from the surface downward until at the centre it is slightly above the surface temperature of the sun.

^58:5.2 The outer 1,600 km of the earth’s mass consists principally of different kinds of rock. Underneath are the denser and heavier metallic elements. Throughout the early and preatmospheric ages the world was so nearly fluid in its molten and highly heated state that the heavier metals sank deep into the interior. Those found near the surface today represent the exudate of ancient volcanoes, later and extensive lava flows, and the more recent meteoric deposits.

^58:5.3 The outer crust was about 64 km thick. This outer shell was supported by, and rested directly upon, a molten sea of basalt of varying thickness, a mobile layer of molten lava held under high pressure but always tending to flow hither and yon in equalization of shifting planetary pressures, thereby tending to stabilize the earth’s crust.

^58:5.4 Even today the continents continue to float upon this noncrystallized cushiony sea of molten basalt. Were it not for this protective condition, the more severe earthquakes would literally shake the world to pieces. Earthquakes are caused by sliding and shifting of the solid outer crust and not by volcanoes.

^58:5.5 ¶ The lava layers of the earth’s crust, when cooled, form granite. The average density of Urantia is a little more than 5.5 times that of water; the density of granite is less than 3 times that of water. The earth’s core is 12 times as dense as water.

^58:5.6 The sea bottoms are more dense than the land masses, and this is what keeps the continents above water. When the sea bottoms are extruded above the sea level, they are found to consist largely of basalt, a form of lava considerably heavier than the granite of the land masses. Again, if the continents were not lighter than the ocean beds, gravity would draw the edges of the oceans up onto the land, but such phenomena are not observable.

^58:5.7 The weight of the oceans is also a factor in the increase of pressure on the sea beds. The lower but comparatively heavier ocean beds, plus the weight of the overlying water, approximate the weight of the higher but much lighter continents. But all continents tend to creep into the oceans. The continental pressure at ocean-bottom levels is about 1,400 kg/cm². That is, this would be the pressure of a continental mass standing 4,572 m above the ocean floor. The ocean-floor water pressure is only about 350 kg/cm². These differential pressures tend to cause the continents to slide toward the ocean beds.

^58:5.8 Depression of the ocean bottom during the prelife ages had upthrust a solitary continental land mass to such a height that its lateral pressure tended to cause the eastern, western, and southern fringes to slide downhill, over the underlying semiviscous lava beds, into the waters of the surrounding Pacific Ocean. This so fully compensated the continental pressure that a wide break did not occur on the eastern shore of this ancient Asiatic continent, but ever since has that eastern coast line hovered over the precipice of its adjoining oceanic depths, threatening to slide into a watery grave.

6. THE TRANSITION PERIOD

^58:6.1 450,000,000 years ago the transition from vegetable to animal life occurred. This metamorphosis took place in the shallow waters of the sheltered tropic bays and lagoons of the extensive shore lines of the separating continents. And this development, all of which was inherent in the original life patterns, came about gradually. There were many transitional stages between the early primitive vegetable forms of life and the later well-defined animal organisms. Even today the transition slime moulds persist, and they can hardly be classified either as plants or as animals.