A quick glance at noteworthy articles in this month's issue

DISPERSAL INTO NEWLY EMERGING ENVIRONMENTS CAN INCREASE SPECIES DIVERSIFICATION RATE Accelerated rates of net diversifi cation (speciation minus extinction) have oft en been associated with the appearance of a novel morphological character, or key innovation, that allows a group of organisms to use a niche in a new way. Recently, an alternative mechanism, dispersifi cation (dispersal and diversifi cation), has been proposed; movement into a new geographic area triggers an increase in the net diversifi cation rate without any apparent morphological changes. Uribe-Convers and Tank (p. 1854) test this hypothesis using chloroplast and nuclear ribosomal sequence data of 49 species in the Rhinantheae clade of Orobanchaceae, including 15 Andean species of the genus Bartsia . Th ey fi nd that the net diversifi cation rate for this South American clade is up to four times higher than the background rate of the tree, and that biogeographical dispersal of this group to the New World corresponded temporally with emergence of an alpine Andean environment, the páramo. Th ese fi ndings provide phylogenetic and biogeographic support for a rapid radiation via dispersifi cation.