Charles Darwin attempted to answer the question of how evolution happened. Many theorists prior to Darwin hypothesized that evolution took place, but Darwin was the first to develop a theory of natural selection to explain the mechanism by which evolution occurred.
A theory of evolution was first proposed by the French scientist Jean Lamarck. He correctly inferred from fossil evidence that species evolved over time, but he had no evidence to explain how evolution worked.
Charles Darwin voyaged around South America to collect specimens and observe differences between species. On returning to England in 1836, Darwin analyzed the evidence and came to the conclusion that species adapt to new environments over time.
Those species that were capable of surviving passed on the genes to the next generation. Darwin argued it was this process of natural selection that leads to the formation of new species from a common ancestor.