The result of this belief is that some animals are lower on the evolutionary chain then other animals. Go a little further and apply this to humans, and you will reach the conclusion that some humans are lower on the evolutionary scale then others. This means that there are separated 'races' of people, and that some people groups are closer to animals then others.
Darwin understood this when he wrote Origin of Species. In fact as I read through the book I find that one of the major goals of the book is to show that some men are more highly evolved then others. The subtitle of the book is very telling: The Preservation of Favored Races in the Struggle for Life. Darwin's later book, The Descent of Man, is even worse then Origin of Species in its claim that some men (namely white men) were more highly evolved then others. On the last page of The Descent of Man, Darwin wrote this:
The main conclusion arrived at in this work, namely, that man is descended from some lowly organized form, will, I regret to think, be highly distasteful to many. But there can hardly be a doubt that we are descended from barbarians. The astonishment which I felt on first seeing a party of Fuegians on a wild and broken shore will never be forgotten by me, for the reflection at once rushed into my mind--such were our ancestors. These men were absolutely naked and bedaubed with paint, their long hair was tangled, their mouths frothed with excitement, and their expression was wild, startled, and distrustful. They possessed hardly any arts, and like wild animals lived on what they could catch; they had no government, and were merciless to every one not of their own small tribe. He who has seen a savage in his native land will not feel much shame, if forced to acknowledge that the blood of some more humble creature flows in his veins. For my own part I would as soon be descended from that heroic little monkey, who braved his dreaded enemy in order to save the life of his keeper, or from that old baboon, who descending from the mountains, carried away in triumph his young comrade from a crowd of astonished dogs--as from a savage who delights to torture his enemies, offers up bloody sacrifices, practices infanticide without remorse, treats his wives like slaves, knows no decency, and is haunted by the grossest superstitions.
In other words what Darwin is trying to say is that he rather descend from a “that heroic little monkey... or from that old baboon” then from another human being which he calls a savage. In short he is saying some men are equal to or lower then apes! Thus, we can see that racism is at the very root of the evolutionary worldview.