Climate change and mountain building led to mammal diversity patterns

ScienceDaily (2010-05-08) -- Travel from the tropics to the poles, and you'll notice that the diversity of mammals declines with distance from the equator. Move from lowland to mountains, and you'll see diversity increase as the landscape becomes more varied. Ecologists have proposed various explanations for these well-known "biodiversity gradients," invoking ecological, evolutionary and historical processes. New findings suggest that the elevational patterns of diversity we see today have appeared, disappeared and reappeared over Earth's history and that these patterns arise from interactions between climate change and mountain building.