Thursday, November 19, 2009

Evolution

The theory of evolution in its simplest form is that the universe as it now exist is the result of an immense series of changes. This theory was first advanced to account for the different forms of life on the earth. Geology shows us that the Earth and its living forms have existed for millions of years. Continents and mountains are known to have been formed by natural causes, and throughout their rocky layers, formed one after the other, are found the fossils of animals and plants that lived and died ages ago. The lowest forms of life appeared first. The mollusks and like animals were followed by the fishes, higher in the scale, which gave place to reptiles, and these to amphibious (land and water) animals. Then came mammals, and lastly man. It is to be noted that the lower animals were general in character, while the higher have been more special; that is, there has been a development from uniformity to unlikeness. Also, many of the extinct animals were halfway between the different groups. For example, the early fishes bore unmistakable traits of reptiles, and the early reptiles had some of the characteristics of birds which had not yet appeared. It must be borne in mind that one period did not come to a sudden stop when another began. Fishes began to be in the age of mollusks, and reptiles in the age of fishes. The various kinds of animals passed into each other by slight and slow changes. The arm of a man, the paw of a dog, the wing of a bird and the fin of a fish, have the same necessary parts, modified and changed, according to the uses to which they were put, and the animal's surroundings. There are many cases of useless organs which are called rudimentary organs and which show the growth of one kind of animal into another. In the growth before birth these rudimentary organs develop up to a certain point and usually are kept through life. Some snakes have rudimentary hind legs hidden under the skin, and rudimentary teeth have been found in some birds. The study of rocks shows further that every species has come into being at the place where a preexisting species flourished and before the former species had died out. These facts seem to point to the working a great natural law of descent by which the present life of the earth has been got from preexisting life. The great majority of naturalists believe in some form of evolution as a great fact of nature. But to find out how these immense changes have been brought about is a harder problem. It was the wok of Darwin to account for these changes by what he calls "natural selection." Darwinism is not the same as evolution, but only a small part of it. Evolution seeks to account not only for animal and plant life, but for the whole universe. The nebular hypothesis explained the beginning and motion of the sun and planets by slow condensation from a nebulous mist scattered throughout space. Geology shows that the earth was first a globe of fire, then had its oceans and dry land, and in course of time received its rivers and mountains. Animal sand plants, as we have seen, developed into greater unlikeness and perfection. The mind grows with body and so human thought is the outcome of progressive change. Society is made up of individuals that change , and so civilization is an evolution. In all these cases change has brought about by a great general law to which the whole universe conforms - from the uniform to the unlike, and from the indefinite to the definite. Spencer has shown that these world changes have been brought about by three agencies, force, matter and motion - force as the cause of change, matter as that which is changed, and motion as the result of change. See Herbert Spencer, System of Philosophy; Darwin, Origin of Species and Descent of Man; Huxley, Man's Place in Nature and Critiques and Addresses.

Charles Robert Darwin, the naturalist, was born at Shrewsbury, England, Feb 12, 1809. He studied at Edinburgh University and at Christ's College, Cambridge. Both Darwin's father and grandfather were naturalists, and he early became interested in the same line of study. At the close of 1831, he sailed as naturalist on the steamer Beagle. On his voyage which lasted five years, he gained a knowledge of the animals, plants and rocks of many countries, which equipped for his future studies. His Journal, giving his observations while on the Beagle, was published in 1839. In the same year, Darwin married and settled down on his country estate to his life work - the problem of the origin of species. This work he carried on in spite of distressing sickness. After five years' of work, "he allowed himself to speculate on the subject, and drew up some short notes. He was a cautious student, and his discoveries were kept to himself for years. It was not till 1859, that his famous book, The Origin of Species, came out. The book is an attempt to prove that species of animal or plant life are evolved from other species, and that the cause of this evolution is natural selection, or the survival of the fittest in the struggle for existence. The doctrine of evolution has been argued before, but Darwin was the first to find a sufficient cause, and so to change what had been a mere guess into a theory that could be proved or disproved. The book was received with great interest throughout the world, was violently attacked and defended, but at length was accepted in the main by all scientists. Darwin published a number of other books further carrying his ideas. His kindliness of character, honesty of purpose, devotion to truth and attachment to his friends made him liked wherever known. He died April 19, 1882. See his Life and Letters, by his son Francis Darwin.

Herbert Spencer an English philosopher, was born at Derby England, April 27, 1820. His father was a teacher, and the son received from him a taste for natural science, keeping collections of insects and making drawings of them as a boy. His first work was that of a civil engineer, in which was engaged for about eight years, publishing during the time several articles in the Civil Engineers' and Architects' Journal. From 1848 to 1853 he was an editor of the Economists. His first important publication was Social Statics in 1850. His great plan was the working out of a system of philosophy which is based on the doctrine of evolution, that is, the theory that the world is a result of a long series of changes, produced by force acting on matter, and resulting in motion. In applying evolution to the study of man in society, Spencer employed assistants to collect and arrange all sorts of facts, in regard to customs, worship, government, etc., of savage tribes, ancient and modern races. His philosophical writings are very numerous, Principles of Psychology, First Principles, Principles of Biology, Data of Ethics and several volumes of essays being among the best known. His brilliant power of drawing conclusions from a vast array of facts, his great knowledge of science, and his wealth of illustration make him popular as well as give him a high position among philosophers. His most popular works are a small book on Education and The Study of Sociology, intended for the ordinary reader.

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