Yeah, well, he didn't have any of the evidence we have now - he had plenty of ideas that were simply wrong, but we can't deny the genius behind his work.<quoted text>
"I can see no difficulty in a race of bears being rendered, by natural selection, more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale,"
--Charles Darwin. Originally in The Origin of the Species, removed due to ridicule.
We know more about cetaceans now, which species they're most genetically related to, and where the fossils take us back. Darwin wasn't correct, but not so far off.