Eocene habitat shift from saline to freshwater promoted Tethyan amphipod diversification.

ABSTRACT: Current theory predicts that a shift to a new habitat would increase the rate of diversification, while as lineages evolve into multiple species, intensified competition would decrease the rate of diversification. We used Holarctic amphipods of the genus Gammarus to test this hypothesis. We sequenced four genes (5,088 bp) for 289 samples representing 115 Gammarus species. A phylogenetic analysis showed that Gammarus originated from the Tethyan region with a saline ancestry in the Paleocene, and later colonized the freshwater habitat in the Middle Eocene. Ancestral range reconstruction and diversification mode analysis combined with paleogeological and paleoclimatic evidence suggested that the habitat shift from saline to freshwater led to an increased diversification rate. The saline linea

SUBMITTER: Hou Z 

PROVIDER: S-EPMC3167504 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature