| Themes > Science > Physics > About Physics, Generalities > A Brief History and Philosophy of Physics > Darwin's Theory of Evolution |
A brief mention must be made here to the theory of biological evolution, because of its philosophical relevance to the physical idea of an evolving universe. A basic tenet of the theory of evolution is that the world as we know it today has evolved from an earlier form of the world under the pressures of natural forces which were in existence at the time, such as erosion and sedimentation, and not by divine intervention in this process. This idea of "uniformitarianism" was first put forward by James Hutton of Edinburgh in 1785, as an explanation for the formation of the geological structures of the earth. He found part of his justification for this theory in the motion of the planets, which required only the forces of nature to keep them moving in their orbits forever. In analogy to the timeless motion of the planets, Hutton assumed that the formation of the earth had occurred over extremely long periods of time. Hutton's ideas were unpopular in his time because they were perceived to be in conflict with the teaching of the Bible. They were received little better by scientists when revived by Charles Lyell in The Principles of Geology published in 1830-33, but were accepted much more readily by the populace. Mason suggests that one of the reasons for this change in reception was that the idea of the progress of humanity, championed by such writers as Francis Bacon and the economist Adam Smith who published An Enquiry into the Nature and Causes of the Wealth of Nations in 1776, was now generally accepted by society. Charles Darwin acknowledges that it was the concept of uniformitarianism that led him to his theory of evolution, the idea that biological species might evolve in the same way that the earth's geology did, under the natural forces continually in existence. The part that needed to be added was the answer to what determined the direction of this evolution. Offspring are born with characteristics which are slightly different from those of the parents. Darwin claimed that when these new characteristics better prepared the organism to live to reproductive age, then it would be able to pass these characteristics on to its children: thus, nature selected those offspring for survival much as a cattle owner selected for breeding those animals born with desirable characteristics. His theory did not require a reason for the variation readily observed in offspring, although he speculated that it might be due to changes in food or climate. However, he believed that these changes were exceedingly slight, and could result in a new species (a class of life that is only fertile within that class) over very long periods of time. Knowing that his theory was in contradiction with a literal interpretation of the Bible, Darwin spent twenty years amassing data before the publication of On The Origin of the Species in 1859. Although this book raised a furore when first published, the logic of its arguments and its philosophical consistency with other scientific theories gradually won the day. Indeed, evolution turned out to be a useful, though fallacious, argument for justifying both colonialism and racism. Herbert Spencer coined the phrase "survival of the fittest" to replace Darwin's "natural selection", and applied it to the evolution of society. With the idea of human progress fully ensconced in society's thinking, it was a short step to assume that the race or nationality in power deserved to be there, because it was the one most fit to rule. "Survival of the fittest" soon became "might is right", a belief which is still at work in the world today. |
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