TABLE SHOWING PROPORTIONS OF YEARS AND HOURS Geological Periods | Years | Hours ------------------------+-------------+--------- Archæan | 18,000,000 | 6 Laurentian | 18,000,000 | 6 Cambrian | 6,000,000 | 2 Silurian | 6,000,000 | 2 Devonian | 6,000,000 | 2 Carboniferous | 6,000,000 | 2 Triassic | 3,000,000 | 1 Jurassic | 3,000,000 | 1 Cretaceous | 3,000,000 | 1 Tertiary and Quaternary | 3,000,000 | 1 ------------------------+-------------+--------- The Quaternary Period | 72,000,000 = 24 is that in which we live| TERTIARY AND QUATERNARY PERIODS At a rough guess, three million years may be allowed for the Tertiary and Quaternary periods --------------------+-----------+------+------+------ Geological Periods | Years | Hrs. | Min. | Sec. --------------------+-----------+------+------+------ Tertiary | 2,600,000 | -- | 52 | -- Pleistocene | 300,000 | -- | 6 | -- Human | 100,000 | -- | 2 | -- +-----------+------+------+------ Total | 3,000,000 | 1 | -- | -- --------------------+-----------+------+------+------ Human History | 10,000 == == 12 HOW LIFE BECAME POSSIBLE ON THE EARTH BY DR. ALFRED RUSSEL WALLACE Early writers on the relation of man and animated nature to the material universe not only assumed that the latter existed for the former, but that both alike were the results of special acts of creation. Furthermore, they usually took it for granted that all things were created very much in the condition in which we now see them, and that any changes that have since taken place are but slight superficial modifications of a permanent and unchanging whole. Not only were the sun and moon and stars created as appanages of the earth, but the earth itself in all its details of sea and land, hills and valleys, mountains and precipices, swamps and deserts, was made and fashioned just as we now see it, and every feature of its surface was supposed to have some purpose in connection with man. [Sidenote: The Old Ideas of Creation] These purposes we could, in some cases, understand, while in others they seemed wholly unintelligible, and much ingenuity was bestowed by the natural theologian and others to explain more and more of the observed facts from this point of view. The same opinions prevailed in regard to the infinite variety of animals and plants, each individual species being supposed to have been an independent creation, and all to have some definite and preordained purpose in relation to mankind.