Charles Darwin was born in Shrewsbury, Shropshire. He was the son of Robert Waring Darwin and his wife Susannah, and the grandson of the scientist Erasmus Darwin. His mother died when he was eight years old, and he was brought up by his sister. He was taught the classics at Shrewsbury, then sent to Edinburgh to study medicine, which he hated. Like many modern students Darwin only excelled in subjects that intrigued him.
Although his father was a physician, Darwin was uninterested in medicine and he was unable to stand the sight of surgery. He did eventually obtain a degree in theology from Cambridge University, although theology was of minor interest to him also. What Darwin really liked to do was tramp over the hills, observing plants and animals, collecting new specimens, scrutinizing their structures, and categorizing his findings, guided by his cousin William Darwin Fox, an entomologist.
Darwin’s scientific inclinations were encouraged by his botany professor, John Stevens Henslow, who was instrumental, despite heavy paternal opposition, in securing a place for Darwin as a naturalist on the surveying expedition of HMS Beagle to Patagonia. Under Captain Robert Fitzroy, Darwin visited Tenerife, the Cape Verde Island, Brazil, Montevideo, Buenos Aires, Chile, the Galapagos Islands, Tahiti, New Zealand, and Tasmania. In the Cape Verde Island Darwin devised his theory of coral reefs.
Another significant stop on the trip was in the Galapagos Islands, it was here that Darwin found huge populations of tortoises and he found that different islands were home to significantly different types of tortoises. Darwin then found that on islands without tortoises, prickly pear cactus plants grew with their pads and fruits spread out over the ground. On islands that had hundreds of tortoises, the prickly pears grew substantially thick, tall trunks, bearing the pads and fruits high above the reach of the tough mouthed tortoises.
During this five-year expedition he obtained intimate knowledge of the fauna, flora, and geology of many lands, which equipped him for his later investigations. In 1836, Darwin returned to England after the 5 years with the expedition, and by 1846 he had became one of the foremost naturalists of his time, and he also published several works on the geological and zoological discoveries of his voyage. He developed a friendship with Sir Charles Lyell, became secretary of the Geological Society, a position which Darwin held for four years.
In 1839 Darwin married his cousin Emma Wedgwood. But constantly bothering Darwin was the problem of the origin of the species. Darwin sought to prove his ideal of evolution with simple examples. The various breeds of dogs provided a striking example of what Darwin sought to prove. Dogs descended from wolves, and even today the two will readily crossbreed. With rare exceptions, however, few modern dogs actually resemble wolves. Some breeds, such as the Chihuahua and the Great Dane, are so different from one another that they would be considered separate species in the wild.
If humans could cross breed such radically different dogs in only a few hundred years, Darwin reasoned that nature could produce the same spectrum of living organisms given the hundreds of millions of years that she had been allowed. From 1842 Darwin lived at Down House, a country gentleman among his gardens, conservatories, pigeons, and fowls. The practical knowledge he gained there, especially in variation and interbreeding proved invaluable. At Down House Darwin addressed himself to the great work of his life, the problem of the origin of species.
After five years of collecting the evidence, Darwin began to speculate on the subject. In 1842 he drew up his observations in some short notes, expanded in 1844 into a sketch of conclusions for his own use. These conclusions were the principle of natural selection, the germ of the Darwinian Theory, but with typical caution he delayed publication of his hypothesis. However, in 1858 Alfred Wallace sent Darwin a letter of his book, Malay Archipelago, which, to Darwin’s surprise, contained the main ideas of his own theory of natural selection.