Snell-Rood is one of many researchers who have updated the conventional narrative of urban animals, in which city life favors a few tough, adaptable jack-of-all-trades — hello, crows! — and those species fortunate enough to have found a built environment similar to their native niches, such as the formerly cliff-dwelling rock doves we now call pigeons and find perched on building ledges everywhere.
The long view, though, is rather more multidimensional. Cities are just one more setting for evolution, a new set of selection pressures. Those adaptable early immigrants, and other species that once avoided cities but are slowly moving in, are changing fast.
As Snell-Rood and colleagues describe in an August 21 Proceedings of the Royal Society B article, museum specimens gathered across the 20th century show that Minnesota’s urbanized small mammals — shrews and voles, bats and squirrels, mice and gophers — experienced a jump in brain size compared to rural mammals.
via Wired
Image: regina dunmire/Flickr
