It is probably true to say that no scientific publication during the nineteenth century started a bigger storm of general protest and argument than a book produced in 1859. It was called The Origin of Species by Means of Natural Selection by a biologist called Charles Darwin. The book put forward the scientist’s ideas on the evolution of plants and animals from simple forms by a process of a slow, gradual change. It was a rather revolutionary idea, for before that time the vast majority of scientific workers accepted the belief that all living things were created in their present form. Even today there are a great many people who feel that Charles Darwin’s theory is not completely acceptable.
Charles Robert Darwin was born in Shrewsbury in 1809. After attending Shrewsbury School and training for medicine at Edinburgh University, he went to Cambridge to take a degree with the idea of finally being ordained as a priest. In fact, however, on leaving Cambridge in 1831 he took up a quite different career. Charles Darwin had long been interested in natural history and his big chance came when Captain FitzRoy of H.M.S. Beagle offered to take him on his official surveying voyage around the world. The tour lasted for about five years (1831-6), during which time Charles Darwin found a great deal to interest himself.
On the Galapagos Islands, off the west coast of South America, for example, he saw birds which showed marked differences in structure from those on the mainland. This gave him the idea that perhaps the differences between the conditions there and the mainland were at least partly responsible for the ways in which the birds differed. Could it be, he asked, that only those animals and plants best suited to their surroundings could survive in the fierce struggle for existence? He found plenty of evidence that this may have been so. Over the millions of years which the Earth has taken to develop, quite startling differences in plants and animals could result. Ancient, primitive creatures such as the dinosaur died out because conditions were no longer right for them. Other animals – the giraffe, for instance – can survive in conditions where the only food to be found is high above ground, because their long necks enable them to reach it. Smaller species would have much greater difficulty in finding food in such places, if they could not climb trees, and would tend to die out. Reasoning in such ways, Charles Darwin came to the conclusion that plants and animals have reached their present state by what he called Natural Selection, the weeding out by Nature which leaves only those animals best fitted for their conditions. Because conditions vary from place to place and have varied over the course of time, a vast range of animal and plant types has appeared and tried to live. Sometimes they have become extinct; sometimes they have survived to reproduce their kind.
It is a complicated theory, not easily described, and difficult if not impossible to prove conclusively without seeing all the links in the chain of developing plants and animals throughout history. Nor was it absolutely new, for other scientists before Charles Darwin had sought to explain the variety and the similarities between creatures by various means. Charles Darwin’s real achievement lay in looking at the problem in a systematic and scholarly way, putting his case before the public in a way which could be understood. (A fuller explanation of evolution will appear in later articles.)
Charles Darwin died in 1882. His tomb is in Westminster Abbey in London.