Man's origin analysis

The following passage is taking from "The descent of man". Darwin here expounds his theory of evolution as a result of accidental mutations in the species, and wards off possible objections. In the text the author pointed out three steps of man's descent. The first one is that persons descent from some lowly organized form. The second one is that our ancestors were the Furigians.( people with colored faces, an wild, startled and distrustful expression) .
The last one is that people descent from a little monkey.
In the last paragraph Darwin pulls out his scientific vision, indeed he told: only with the truth( so with the scientific method) the people can discover his/her descendent.
He concluded with a critical to the human being as he exalted powers etc but he are "still bears in his bodily frame the indelible stamp of his lowly origin."