Some have tried to claim Darwin was racist because of his use of racial terms also used by just about everyone else at the time. He has been entirely misquoted for the term "superior races" when he was referring to plants and animals in "Origins." Voyage of the Beagle has incidents in Brazil where Darwin was describing local people accurately as a naturalist would that read as racist today. His opinion of slavery, where he personally saw it in action, leaves no doubt that he was against it and had empathy for the slaves.
"I may mention one very trifling anecdote, which at the time struck me more forcibly than any story of cruelty. I was crossing a ferry with a negro, who was uncommonly stupid. In endeavouring to make him understand, I talked loud, and made signs, in doing which I passed my hand near his face. He, I suppose, thought I was in a passion, and was going to strike him; for instantly, with a frightened look and half-shut eyes, he dropped his hands. I shall never forget my feelings of surprise, disgust, and shame, at seeing a great powerful man afraid even to ward off a blow, directed, as he thought, at his face. This man had been trained to a degradation lower than the slavery of the most helpless animal." -- Charles Darwin, Voyage of the Beagle (1839), Chapter II.."
I'd like to see Voyage of the Beagle as a movie with a big budget and CGI for the natural disasters!