Credit: AFP
It was a shift in self-perception that was as humbling as it was, for many, troubling. Evangelical Christians and other religious groups that take a literal view of scriptures contest it even today.
"Just as Copernicus cast the Earth out from the centre of the universe, the Darwinian universe displaced humans as the epicentre of the natural world," says the U.S. publication Scientific American.
With characteristic modesty, Darwin acknowledged he was not the first to propose a theory of evolutionary change. In the late 1700s, French naturalist Georges Cuvier showed that some organisms got wiped out by environmental change. Later, zoologist Jean-Baptiste Lamarck proposed that some organisms adapted in response to their environments.
But they saw evolution as a linear process, in which simple organisms became more complex, and humans were at the pinnacle, the peak of perfection. Darwin, though, rejected this in favour of branching evolution, a "tree of life" in which species diverge from a common ancestor.
It remains the conceptual backbone of biology today and is the inspiration for a whole range of newer sciences, from genomics and evolutionary psychology to self-teaching robots.
The tragic downside to Darwin's legacy is that "survival of the fittest" was also misinterpreted or twisted, used by eugenicists of the late 19th and early 20th century as an argument to eradicate a social or ethnic underclass.
Such acts would have been monstrous to Darwin, a deeply civilised man who reviled slavery and was unfailingly generous to the poor and needy.
"I would easily count him among the five greatest thinkers in human history," says German historian Wilfried Rogasch. "There are lots of people who are trying desperately to find bits and pieces where his theory was wrong, but they haven't succeeded. It seems to be not a theory but a fundamental law of nature."
Read more about Darwin in our Special Report: Darwin at 200
