Biotic homogenization: a few winners replacing many losers in the next mass extinction

Human activities are not random in their negative and positive impacts on b iotas. Emerging evidence shows that most species are declining as a result of human activities ('losers') and are being replaced by a much smaller num ber of expanding species that thrive in human-altered environments ('winner s'). The result will be a more homogenized biosphere with lower diversity a t regional and global scales. Recent data also indicate that the many loser s and few winners tend to be non-randomly distributed among higher taxa and ecological groups, enhancing homogenization.