British naturalist whose On the Origin of Species (1859) established evolution by natural selection — the unifying theory of modern biology.
Closely associated with
Thomas Henry Huxley (his 'bulldog' public defender) and Alfred Russel Wallace (independent co-discoverer of natural selection).
For an intellectual contrast, see
William Paley, Anglican theologian and Natural Theology author (1743-1805) — Origin of Species is structurally a 400-page reply to Paley — Darwin admired Paley's watchmaker-argument as an undergraduate at Cambridge and then spent 20 years building the empirical machinery to displace him. The cleanest 'design argument vs natural selection' founding rebuttal in science.
The standard scholarly entry points to Charles Darwin's work:
Janet Browne (Harvard, history of science) — Charles Darwin: Voyaging (1995) and The Power of Place (2002);
Adrian Desmond (UCL, biographer) — Darwin: The Life of a Tormented Evolutionist (1991, with James Moore).
These are the works graduate seminars cite when teaching Charles Darwin.