Global biogeographical regions reveal a signal of past human impacts

Ecologists have long documented that the world's biota is spatially organised in regions with boundaries shaped by processes acting on geological and evolutionary timescales. Although growing evidence suggests that historical human impact has been key in how biodiversity is currently assembled, its role as a driver of the geographical organisation of biodiversity remains unclear. Using non-volant terrestrial mammals, we set up a bioregionalization procedure focused on two data sets, one describing the current ranges of terrestrial mammals, and another describing their potential natural ranges in the absence of historic anthropogenic land use. We then quantified the relative importance of anthropogenic land use (5000 and 2000 years ago, and present time) to predict the current and natural biogeographical regions across the Earth. In general, past and present human land use were important predictors of current bioregions but did not largely contribute to predicting natural bioregions. Pas...