Page:General History of Europe 1921.djvu/791

Progress of Modern Science and Invention 591 The work of more recent geologists has tended to substantiate Ly ell's views by adding much new evidence for his conclusions. 1075. Darwin and the Theory of Evolution. Even in the eighteenth century it began to be suspected by distinguished in- vestigators that plants and animals had slowly developed through the ages. Charles Darwin was the first, however, to advance such careful arguments for this view that it was accepted by large numbers of people. In his famous book The Origin of Species by Means of Natural Selection, published in 1859, he maintained that the various species of animals and plants all the different kinds of trees and shrubs, fishes, snakes, birds, and mammals were not descendants from original separate and individual species created in a certain form which they had always kept, but that these species as they exist in the world today were the result of many changes and modifications which have taken place during the mil- lions of years in which plants and animals have lived upon the earth. The theory that higher and more complicated kinds of animals and plants are derived from earlier lower and simpler ancestors is called evolution. Evolution, although far more disturbing to the older ideas of the world than the discovery of Copernicus that the earth revolves around the sun, made its way far more rapidly into general acceptance, and today a large majority of zoologists, botanists, geologists, and biologists, and indeed a great part of those who have received a scientific training, accept the general theory of evolution. 1 The opponents of the theory have slowly decreased in numbers. At first the clergy, both Protestant and Catholic, could find no words too harsh to apply to the patient and careful Darwin, who seemed to them to contradict the express word of God and to rob man of all his dignity. But as time went on many religious leaders became reconciled to the new view. For on further thought it seemed to them to furnish a more exalted notion of God's pur- poses and methods than that formerly held. 1 Many investigators feel, however, that Darwin's explanation of evolution is, as he himself freely admitted, only a partial one and quite inadequate to account for the exist- ing forms of animals and plants.