Bergmann's rule is one of the most studied and controversial “ecogeographical” patterns, and refers to the increasing body size of organisms towards higher latitudes.
Although it has been studied since the mid 19th Century, it is not until now that new statistical techniques have made it possible to disentangle the underlying influences of evolutionary history and ecology. In a new study in the journal Ecography, an inter¬national team of researchers have analyzed Bergmann's rule in European carnivore mammals. Their approch allows them to, for the first time, partition body mass variation into historical and ecological components. Doing this, they show that patterns can be better explained by recent and independent evolution of each species as a response to environmental conditions, and not only as a consequence of deep-time evolutionary events. Their finding provides a unified framework to interpret Bergmann's rule across different taxonomic levels (within and between species) and solves controversies about its interpretation that have existed since the rule was first investigated in 1847.
Ecography