Marleen Cobben gives more details on her fascinating model:
The results from our model suggest that the spatial process of range shifting under climate change can have a big impact on the genetic composition of new populations. This is because the individuals arriving first in a new climatically suitable natural area, have a competitive advantage (in numbers) over individuals arriving later. So even if these latter individuals are better adapted to the local conditions, adaptation of the population takes a while because there’s initially so little to select for. No news thus far I’d say. The problem is, that this ‘while’ is fairly long compared to the predicted rate of temperature increase.
And there’s a lot more, all of it interesting. Have a look.