Page:Popular Science Monthly Volume 68.djvu/444

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IN a preceding article[1] the author has attempted to show that man, as a result of the development of medical science and education, is approaching his limit in evolution, both physically and mentally. The burden of the argument here was to show that, as a result of the incorporation into his environment of his cumulating knowledge, man's social and economical conditions are continually changing, but that with his increased intelligence he has greater power of adapting himself to the new conditions of life which are inevitably the result. And as soon as man acquired those intellectual and moral qualities which distinguish him from the lower animals, he began to invent weapons, tools and various stratagems to procure food and to defend himself, and was but little liable to bodily modification through nattural selection. When he migrated into colder climates he used clothes, built shelter, made fires. He also aided his fellows and anticipated his future. Selection seized upon intelligence and man was enabled to keep an unchanged body in harmony with a changing environment. Progress implies a continued increase of control over nature, through the gradual acquisition of knowledge of her laws. One of the great fields of acquisition of human intelligence is along the line of human diseases, and the means of combating them. Medical science advanced until at present, through surgery and inoculation, she succeeds to a considerable degree in keeping the race adjusted to its ever changing environment without sacrificing many of her individuals, and, consequently, without bringing about any marked change in the type of the human body. Education, too, succeeds in maintaining the intellectually unfit by adapting them to the environment so that they are enabled to make a living and to bring up a family, thus precluding a rise in the average of intelligence in the race. Man is enabled to advance independently of heredity, and natural selection is cheated out of her work. Man can select everything in his world except his own body and mind. He is born with a body and mind which were developed by natural selection and are naturally adapted to the environment that existed when selection ceased. So adaptation to the environ-

  1. 'Limits of Evolution in the Human Race,' University of Colorado Studies, Vol. II., No. IV., June, 1905.