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Did southern Western Ghats of peninsular India serve as refugia for its endemic biota during the Cretaceous volcanism?

Joshi, Jahnavi and Karanth, Praveen (2013) Did southern Western Ghats of peninsular India serve as refugia for its endemic biota during the Cretaceous volcanism? In: ECOLOGY AND EVOLUTION, 3 (10). pp. 3275-3282.

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Official URL: http://dx.doi.org/10.1002/ece3.603

Abstract

The Western Ghats (WG) of south India, a global biodiversity hotspot, has experienced complex geological history being part of Gondwana landmass and encountered extensive volcanic activity at the end of Cretaceous epoch. It also has a climatically and topographically heterogeneous landscape. Thus, the WG offer a unique setting to explore the influence of ecological and geological processes on the current diversity and distribution of its biota. To this end, three explicit biogeographical scenarios were hypothesized to evaluate the distribution and diversification of wet evergreen species of the WG - (1) southern WG was a refuge for the wet evergreen species during the Cretaceous volcanism, (2) phylogenetic breaks in the species phylogeny would correspond to geographic breaks (i.e., the Palghat gap) in the WG, and (3) species from each of the biogeographic subdivisions within the WG would form distinct clades. These hypotheses were tested on the centipede genus Digitipes from the WG which is known to be an ancient, endemic, and monophyletic group. The Digitipes molecular phylogeny was subjected to divergence date estimation using Bayesian approach, and ancestral areas were reconstructed using parsimony approach for each node in the phylogeny. Ancestral-area reconstruction suggested 13 independent dispersal events to explain the current distribution of the Digitipes species in the WG. Among these 13 dispersals, two dispersal events were at higher level in the Digitipes phylogeny and were from the southern WG to the central and northern WG independently in the Early Paleocene, after the Cretaceous Volcanism. The remaining 11 dispersal events explained the species' range expansions of which nine dispersals were from the southern WG to other biogeographic subdivisions in the Eocene-Miocene in the post-volcanic periods where species-level diversifications occurred. Taken together, these results suggest that southern WG might have served as a refuge for Digitipes species during Cretaceous volcanism.

Item Type: Journal Article
Additional Information: copyright for this article belongs to WILEY
Keywords: Centipedes; historical biogeography; invertebrates; species richness; time tree; tropics
Department/Centre: Division of Biological Sciences > Centre for Ecological Sciences
Depositing User: Id for Latest eprints
Date Deposited: 06 Nov 2013 06:10
Last Modified: 06 Nov 2013 06:10
URI: http://eprints.iisc.ac.in/id/eprint/47688

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