Charles Robert Darwin (1809-1882) was a British naturalist who developed a theory of evolution based on natural selection. “He proposed that species can change over time, that new species come from pre-existing species, and that all species share a common ancestor.” Throughout all his research on the evolution of the species, he came to the conclusion that only the strongest members of a species survive and so do the best characteristics they have. Also, the weakest ones do not survive and so do the features that do not help them survive either. Darwin suggests hereditary traits that help organisms reproduce become more common in the population over time. That is how, little by little, species adapt to the environment and change.
In the 1850s, Darwin wrote a book called On the Origin of Species, where he suggested that all living things have a common ancestor.
Charles Darwin, before being so interested in evolution, loved to hunt, and it was during the voyage of the Beagle, a survey expedition that took place from 1831 to 1836, that he started observing different species. He noticed a specific pattern in the distribution of organisms from the Galápagos Islands regarding also the nearby mainland of Ecuador. It was after this expedition when he started piecing things together, that later led to his theory of evolution and natural selection.