Phylogeny of endemic skinks of the genus Lygosoma (Squamata: Scincidae) from India suggests an in situ radiation.

Abstract

The Indian subcontinent is an interesting biogeographical entity as it is isolated from the rest of the Asian landmass by very high mountain ranges of the Himalayas in the north and is surrounded by ocean in the south. Furthermore, much of this land mass was part of a Gondwanan fragment that merged with Asia around 42–55 mya (Briggs 2003). Thus, the Indian subcontinent has witnessed prolonged period of isolation (Datta-Roy and Karanth 2009) and appears to be largely cut-off from much of Asia. In this regard, the subcontinent could be considered as an island separated from the mainland (Asia). One interesting feature of an isolated island is the presence of endemic radiations, i.e., unique clades of taxa whose members are endemic to the island. As a consequence, the island’s biota tends to be unique and distinct from that of the mainland. Similarly, the Indian subcontinent harbours many endemic species and its biota is quite distinct from rest of Asia.