Molecular differentiation and morphological variation in microteiid lizards of the tribe Iphisiini (Squamata, Gymnophthalmidae)

Abstract

Phylogeography is a study field that has achieved great prestige, and which tools have been applied to deal with many questions in biogeography, systematics, ecology and evolution. An interest group for phylogeographic studies is the tribe Iphisiini, a lineage of microteiid lizards composed of six species distributed throughout the main morphoclimatic domains of Brazil. The species of the tribe are highly conservated in external morphology, in contrast to the tribe Gymnophthalmini, a lineage of related species which have notable cases of morphological adaptation to fossorial habits. However, it was demonstrated that there are cryptic diversity in Iphisa elegans, an Amazonian species of Iphisiini with wide distribution. It sister species, Colobosaura modesta, occurs widely in the Cerrado, associated to forest formations that are irregularly distributed in the landscape. It is supposed that this species may also represent a case of cryptic diversity. Another interesting issue relatated to Iphisiini is the occurrence of two species with relictual distribution in humid forest formations of northeastern Brazil, considered as "Pleistocene refugia". Similarly, species of the genus Acratosaura occur "constrained" in mild environments or of altitude, presumably in response to historical changes in climatic conditions for the occurrence of the species. Thus, the species of the tribe Iphisiini represent interesting models to explore questions related to time of diversification, its relation to morphological and molecular diversity, and the roles of isolation caused by past climatic events for the patterns of diversification.