Darwin, Charles Robert (1809-1882), was a British naturalist who became famous for his theories on evolution. Darwin proposed that, through millions of years, all species of plants and animals had evolved (developed gradually) from a common ancestor.
Darwin’s theories included several related ideas. These ideas included the belief that evolution had occurred and that most evolutionary change was gradual, requiring thousands or millions of years. Darwin also proposed that the primary mechanism for evolution was a process called natural selection. He said that the millions of species on Earth arose from a single original life form through a branching process called speciation. By speciation, one species can give rise to two or more species. Darwin set forth his theories in his book On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life (1859).
Darwin’s theories shocked most people of his day. They believed that each species had been created by a separate divine act. His book, which is usually called simply The Origin of Species, presented facts that refuted this belief. It caused a revolution in biological science and greatly affected religious thought.
Darwin’s life.
Darwin was born in Shrewsbury, England, on Feb. 12, 1809. He was the grandson of the noted physician and naturalist Erasmus Darwin. Erasmus Darwin had proposed a theory of evolution in the 1790’s. As a boy, Charles often heard his grandfather’s theories discussed.
Darwin studied medicine at the University of Edinburgh and theology at Cambridge University. He received a bachelor’s degree from Cambridge in 1831. From 1831 to 1836, Darwin served as a naturalist with a British scientific expedition aboard the H.M.S. Beagle. The expedition visited places throughout the world. Darwin studied plants and animals everywhere the ship went.
In South America, Darwin found fossils of extinct animals that closely resembled modern species. On the Galapagos Islands in the Pacific Ocean, he noticed many variations among plants and animals of the same general type as those in South America. He collected the fossils and other specimens for future study.
Darwin returned to England in 1836 and settled in London. He spent the rest of his life studying specimens, doing experiments, corresponding with other scientists, and writing about his findings. Darwin’s early books included The Structure and Distribution of Coral Reefs (1842) and a journal of his research aboard the Beagle.
In 1839, Darwin married his cousin Emma Wedgwood. The family moved to Downe, near Croydon, in 1842. Darwin lived there until his death on April 19, 1882. He was buried in Westminster Abbey in London.
Darwin’s theories.
The study of the specimens from the voyage of the Beagle convinced Darwin that modern species had evolved from a common ancestor. He documented the evidence and first presented his theories on evolution to a meeting of scientists in 1858.
In most cases, according to Darwin, no two members of any species are exactly alike. Each organism (living thing) has an individual combination of traits. Many of these traits are inherited. Darwin noted that gardeners and farmers commonly developed special kinds of plants and animals by selecting and breeding organisms that had desired traits. He believed a similar selective process took place in nature. Darwin called this process natural selection. Others have called it the survival of the fittest.
Darwin showed that living things commonly produce many more offspring than are necessary to replace themselves. Earth cannot possibly support all these organisms. As a result, living things must compete for such necessities as food. Their lives also are threatened by animals that prey on them, by unfavorable weather, and by other environmental conditions.
Darwin suggested that some members of a species have traits that aid them in this struggle for life. Other members have less favorable traits and therefore are less likely to survive or reproduce. On the average, the members with favorable traits live longer and produce more offspring than do the others. They also pass on the favorable traits to their young. The unfavorable traits are eventually eliminated. When this process occurs in two isolated populations of one species, members of one species may become so different that they will be regarded as separate species.
Darwin wrote several books that further discussed his theories of evolution. These included The Descent of Man and Selection in Relation to Sex (1871) and The Expression of the Emotions in Man and Animals (1872).
The influence of Darwin’s ideas.
Darwin’s theories of evolution through natural selection set off a bitter controversy among biologists, religious leaders, and the general public. Many people thought Darwin had implied that human beings were descended from monkeys. They angrily criticized his revolutionary ideas. But such noted British scientists as Thomas Henry Huxley and Alfred Russel Wallace supported Darwin’s work. Virtually all scientists eventually accepted his theories. These theories, and the facts that supported them, gave biologists new insight into the origin of living things and the relationship among various species.
Darwin’s theories stimulated studies in biology, particularly in paleontology and comparative anatomy. During the first half of the 1900’s, discoveries regarding heredity and developmental biology were used as evidence for theories of evolution that regarded natural selection as unimportant. But after World War II ended in 1945, Darwin’s theories again became the dominant influence in evolutionary biology. Scientists used his theories in a form often called Neo-Darwinism. Neo-Darwinism gave a fuller explanation for the genetic origin of variation within species and for how species are formed. Most biologists consider Darwin’s ideas to be an essential foundation of modern biology.
Darwin’s work has had a tremendous impact on religious thought. Many people strongly oppose the idea of evolution—and the teaching of it—because it conflicts with their religious beliefs. For example, they claim that the theory of evolution disagrees with the Biblical account of the Creation. Some people argue against the theory of natural selection because they believe it diminishes the role of divine guidance in the universe.
Darwin avoided discussing the theological and sociological aspects of his work. Other writers, however, used his ideas in their own theories about society. The German philosopher Karl Marx compared the struggle for survival among organisms to the struggle for power among social classes. Certain other writers referred to natural selection to justify the concept of the development of superior races of human beings. Scholars called social Darwinists used Darwin’s ideas to promote the belief that people in a society—and societies themselves—must compete for survival. Many people reject these interpretations of Darwin’s theories.
