Page:The World's Most Famous Court Trial - 1925.djvu/260

256 evidence from geology is written in the ground beneath our feet. The geologist's belief in a vast lapse of time and stupendous changes rests upon evidence that is everywhere at hand. Leonard da Vicini, in the fifteenth century, grasped the significance of important geological facts, when he wrote concerning the saltness of the sea and the marine shells found as fossils in the high mountains. Since the publication of James Hotton's "Theory of the Earth," in 1795, it has been the cardinal principle of geological science that past changes of the earth's surface are explicable in terms of changes now in operation. For example, such a vast chasm as the Grand Canyon is explained not as produced by miraculous creation or by sudden catastrophe, but by running water acting upon the rocks throughout innumerable centuries. The process may be observed in miniature in the wash of the soil in Tennessee fields. The weathering of rock in to soil, erosion with its transportation of the products of weathering, deposition of the material in the oceans or in large bodies of fresh water, uplift of the ocean's floors and its hardening into rock may all be seen in slow but certain progress in various parts of the world at the present day, and their occurrence in the past is recorded in the rocks. The subtitle of Charles Lyell's famous book, the "Principles of Geology," published in 1830, runs as follows: "An attempt to explain the former changes of the earth's surface by reference to causes now in operation." Lyell established the idea of evoluionevolution [sic] as the only reasonable interpretation of geological facts and his elaboration of Hutton's doctrines still constitute the very foundation of geologic science. Today, geology without an evolution of the earth's surface, from a molten mass to its present form, and extending over millions of years, would be on a par with a science of geography postulaingpostulating [sic] a flat earth. The conclusions of modern astronomy and geology, therefore, point to an evoluionaryevolutionary [sic] process—involving many millions of years and still in progress—to an earth hoary with age and still growing old.

Astronomy and geology, despite their practical importance, are remote from human concern, insofar as their evolutionary doctrines are concerned. To borrow from the phraseology of a distinguished anti-evolutionist, the age of the rocks is of no particular consequence insofar as the Rock of Ages is concerned. Cosmic evolution and geologic evolution are readily accepted by the laity on the authority of science, because they do not seriously interfere with doctrines that are deemed vital. But the evolution of plant and animal life, and hence human evolution, is inseparable from that of inorganic matter as described by astronomy and geology, because of the fossils in the rocks.

Organic evolution resembles the cosmic and geologic evolution above described, since it concludes that the living bodies, which are the objects of its investigation, have not always existed as they are today, but have undergone a process of change. As with the evidence of geologic change, the evidence for an evolution of animals and plants rests upon facts that are immediatlyimmediately [sic] before us, for example, the structure and development of animals, their distribution over the earth, the fossils in the rocks. Our time will permit of only enumeration and brief characterization of the recognized lines of evidence for organic evolution, which are as follows:

First—Evidence from structure is devived from:

Comparative anatomy.

Comparative embryology.

Classification.

Second—Evidence from distribution, past and present, is derived from:

Palaeontology.

Zoogeography.

Third—Evidence from physiology is derived from:

Fundamental resemblances in vital processes.