Species Evolve Faster in Cooler Climes

Contrary to popular belief, the 'hot spots' of evolution are actually quite cool: a study suggests that new species emerge more frequently in temperate regions than in the tropics.

Scientists had assumed that new species develop faster in the tropics, since they are home to greater species diversity than at higher latitudes. But the researchers behind the new analysis say the explanation for this is that fewer species have gone extinct near the equator.

Jason Weir and Dolph Schluter at the University of British Columbia in Vancouver, Canada, compared how animal species across the Americas have evolved. They looked at pairs of 'sister species', which share an immediate common ancestor and so are the most closely related species.