Breaking: Darwin was not the first to study evolution! I'm surprised the Conservapedia article about him doesn't sling this mud. And you know how he covered it up? By putting it in the introduction to his book.
There's a lot of Darwin in the Daily Reading Guide, and in the Harvard Classics as well, and I can only think that they were excited to have some cutting-edge, yet equation-free, science in the mix. Also, the liberal, pro-knowledge types enjoyed pretty much total control over the media in 1908, as there were not even radio preachers yet to make them cower and cringe and say "Yes, but..."
As to this selection, Darwin's becoming modesty permeates it, as he gives an exhaustive catalog of others who've had similar ideas. Part of it's CYA, I imagine -- so that he's not out there alone -- but the general tone is one of "I'm just another worker out here in the fields." There's not much else to say about it except to list some of the excellent 19th-century sounding titles of works Darwin refers to:
‘An Account of a White Female, part of whose skin resembles that of a Negro’
"Professor Grant's well-known paper... on the Spongilla"
‘Naval Timber and Arboriculture’
‘New Flora of North America’
‘Vestiges of Creation’
‘Nature of Limbs’ (my favorite, I think)
‘Essays on the Unity of Worlds’
I think at least one of these will wind up being a future album title for The Decemberists.