Another example of Darwin's being well ahead of the game:
Right across Britain, animals are on the march, moving northwards and going to higher ground as the climate warms, experts have told a major conference…
Chris Thomas from the University of York said the changes fitted neatly with the predictions of climate models. "Species are moving north, they're climbing mountains, they're retreating at their southern boundaries," the professor added.
Compare the above with the situation at the end of a former glacial period, as envisaged by Charles Darwin in chapter 11 of Origin of Species:
As the warmth returned, the arctic forms would retreat northward, closely followed up in their retreat by the productions of the more temperate regions. And as the snow melted from the bases of the mountains, the arctic forms would seize on the cleared and thawed ground, always ascending higher and higher, as the warmth increased, whilst their brethren were pursuing their northern journey. Hence, when the warmth had fully returned, the same arctic species, which had lately lived in a body together on the lowlands of the Old and New Worlds, would be left isolated on distant mountain-summits (having been exterminated on all lesser heights) and in the arctic regions of both hemispheres.
True, unlike in Darwin's scenario, we aren't emerging from an ice age, but the principle is the same: our climate is getting warmer and species are on the move. Exactly as Darwin predicted.