Charles Robert Darwin is one of the most influential naturalists of all time. His primary area of expertise is the development of species over time. Darwin established that all species have common ancestors and developed over time due to natural selection and the survival of the fittest.
Charles Darwin was born in England in 1809. Already at the age of eight, when he joined school, young Darwin was interested in natural history and collecting. He studied at the University of Edinburgh Medical School where he joined the Plinian Society, a student group for natural history, and learned to classify plants. As he neglected his medical studies, his father sent him to the University of Cambridge to become an Anglican parson. At Cambridge he started beetle collecting and became friends with other naturalists who were of the opinion that scientific work is religious natural theology. After graduation Darwin was eager to contribute actively to science and journeyed to Tenerife with some of his fellow students. After that he was invited to join the HMS Beagle on a two-year expedition to chart the coasts of South America.
The expedition took five years instead of two. Most of that time Darwin spent on land, making natural history collections and studying geology. Despite being heavily seasick, Darwin noted down all his theories and observations and sent them to Cambridge regularly. Although he specialised in geology, beetle collecting and marine invertebrates, Darwin started collecting other specimen eagerly. One of his most notable finds on that voyage were fossil bones of huge extinct mammals. On the Galápagos Islands Darwin found variations of mockingbirds and tortoise shells, indicating which island they lived on.
When the ship reached England, Darwin was already known by scientists. He labelled birds to certain islands and noted that there was a variation in offspring depending on an adaptation to a changing wold. In 1844 he anonymously published his essay on transmutation Vestiges of the Natural History of Creation, and in 1849 he published On the Origin of Species in which he explained his theory of natural selection. Both books were best-sellers and aroused interest as well as controversy internationally.