Phylogeography and species limits in the Gymnodactylus darwinii complex (Gekkonidae, Squamata): genetic structure coincides with river systems in the Brazilian Atlantic Forest

Author(s)

Pellegrino, Katia C. M. ^[1] ; Rodrigues, Miguel T. ; Waite, Aaron N. ; Morando, Mariana ; Yassuda, Yatiyo Y. ; Sites Junior, Jack W.

Affiliation

^[1] Universidade de São Paulo (USP). Instituto de Biociências. - Brasil

• Document type: Journal article
• Source: Biological Journal of the Linnean Society; v. 85, n. 1, p. 13-26, 2005.
• Field of knowledge: Biological Sciences - Genetics

Abstract

Phylogenetic analyses based on mtDNA cytochrome bwere performed in 42 lizards of the Gymnodactylus darwinii complex from three regions within Brazil's Atlantic Forest. Mainland regions and continental shelf islands in the south-eastern range and mainland areas from the north-east were sampled. The criteria of maximum parsimony (MP), maximum likelihood (ML) and Bayesian methods were explored, with the robustness for nodes assessed by bootstrapping (MP and ML) and posterior probabilities (Bayesian searches). By all methods, three distinctive phylogroups were recovered: a south-eastern clade (SE) and two clades from northern regions (NE₁ and NE₂). The pattern of genetic structure of the major clades coincided with the presence of river systems in the Atlantic Forest, and based on corrected genetic distances between those clades, divergence times were tentatively estimated using mtDNA rates calibrated for squamate reptiles. The putative role of Atlantic Forest rivers in generating differentiation is discussed. We present a hypothesis of species limits for G. darwinii, based on concordant lines of evidence including cytogenetic and mtDNA analyses. Two chromosome races (cytotype A, 2n = 38; and cytotype B, 2n = 40) had distributions concordant with clades SE and NE₁ + NE₂, respectively. These races are interpreted to be full species on the basis of a number of empirical criteria. (AU)