Uplift of the Tibetan plateau: Evidence from divergence times of glyptosternoid catfishes

The Tibetan plateau is the largest and highest plateau on Earth, covering more than 5 million square km at an average elevation of over 5 km. Its geomorphology and climate show substantial interregional variation, leading to remarkable faunal and floral diversity and high levels of endemism. Much of the elevation of the plateau derives from the collision of India and Eurasia around 50-45 million years (Ma) ago. The Cenozoic uplift processes of the Tibetan plateau and its environmental effects are of considerable scientific interest, but the mechanism, amplitude, and timing of the uplift are still controversial (Li and Fang, 1999; Tapponnier et al., 2001). Studies of molecular phylogeny and biogeography of organisms endemic to the plateau offer an alternative approach for investigating the historical processes of the geological events and the concomitant ecological changes. Paleobiogeographic analyses of freshwater fishes can provide a link between the geological and biotic evolution of the Tibetan plateau, because their dispersal depends on the formation of direct connections between drainages (Bermingham and Martin, 1998; Lundberg, 1993); the history of these interconnections reflects the underlying geology. Glyptosternoid catfishes present an ideal group for investigating the history of the plateau because of their limited distribution among the drainages of southern Tibet and east Himalaya, a distribution pattern that is likely to have been influenced significantly by the tectonic movements during the strong uplift of the Tibetan plateau. We estimate the phylogeny and divergence times of extant glyptosternoid catfishes from nucleotide sequences of one nuclear and two mitochondrial genes to produce a comprehensive in situ view of glyptosternoid evolution within the Tibetan plateau. Several different relaxed molecular clock methods, including penalized likelihood and Bayesian analysis, are used to estimate divergence dates. These date estimates are then placed in the context of geological and climatological events, with a view to identifying possible correlations between biotic and abiotic phenomena. Our findings are consistent with a significant uplift of the Tibetan plateau in the Late Miocene extending to the Pliocene. © 2005 Elsevier Inc. All rights reserved.