Debate continues to swirl around the theory of evolution Charles Darwin proposed 150 years ago in his groundbreaking book, "On the Origin of Species," despite its universal acceptance among scientists.
Before Darwin's discovery, the world was generally thought to have remained more or less the same since its creation. This belief, based on Biblical interpretations, was contested through fossil studies showing that species change over time.
Darwin's legendary round-the-world 1831-1836 voyage aboard the HMS Beagle generated his most significant observations and discoveries, inspiring his work on natural selection.
Although Darwin first used the term "natural selection" in a paper in 1842, it wasn't until 1859 that he published his controversial theory that all living beings share a common ancestry -- a discovery that remains vital to modern biology.