This is in beginning of Martin Chuzzlewit. Dickens seems to be satirizing some of the scientific writing of his time by dragging in names of obscure scientists whose views nobody can be expected to know. From the Internet:

In fact, Darwin?s principles were an application of social science concepts to biology. Early thinkers such as Monboddo, Millar, Turgot, Condorcet, Ferguson inspired the discussion of biological evolution by St.-Hilaire, Erasmus Darwin and Lamarck

My copy of Martin Chuzzlewit has a note on Lord Monboddo (1714-1799). He wrote a 6 volume work "Of the Origin and Progress of Language" in which he put forward the idea that Man and Orangutan are the same species, only human mental powers had developed more, part of which was the development of language.

There seems to be quite a bit about him on the Internet, including his correspondence with Sir William Jones, who first put forward the idea of Indo-European being behind Sanskrit, Latin, Greek, Germanic, Celtic, etc.

http://www.aaanet.org/gad/history/020cannon.pdf

Since Martin Chuzzlewit was published some 15 or 16 years before Origin of Species, Monboddo was more naturally associated with the idea of humanity and other primates being related.

Edit. I've also just found this bio. of Monboddo: http://www.electricscotland.com/history/other/burnet_james.htm. It's a shame they don't say where they got it from. I assume this is not Electric Scotland's normal style of writing.

Bingley