Catastrophism viewed the planet as having been molded by forces far more powerful than any observable at the present day.
Denis Diderot mooted the possibility of a creature evolving through habitual functioning into another form of life altogether.
Alfred Wallace was arguing his position from simple logic rather than on the authority of revelation from any of the Abrahamic faiths.
The notion that the building blocks of life were easily gotten may have seemed intuitive to journalists and others acquainted with Mary Shelley’s novel.
It is certainly startling to see the N-word cropping up in Darwin’s letters, but this is not the only place.