Filogenia e evolução de Teiidae (Squamata: Reptilia) com ênfase em Cnemidophorus

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

This study aims to improve the knowledge of phylogeny, biogeography and diversity of Teiidae. The first chapter provides an analysis of phylogenetic relationships among teiid genera based on molecular and morphological data. The total combined analysis corroborated the monophyly of Tupinambinae, Teiinae, and cnemidophorines. We present an evolutionary scenario for Teiidae, based on molecular dating of evolutionary events using Bayesian methods, ancestral areas analysis, the fossil record, the geographic distribution of genera, and environmental and geologic changes during the Tertiary. According to this scenario, (1) all current teiid genera, except Aspidoscelis, originated in isolation in South America, (2) most teiid genera originated during the Eocene, a period characterized by savanna expansion in South America, and (3) Cnemidophorus originated in South America, after which some populations dispersed to Central America during the Late Miocene. The second chapter presents a reconstruction of phylogenetic relationships among species of Kentropyx, based on morphology and mitochondrial DNA data, and evaluated biogeographic scenarios based on ancestral areas analyses and molecular dating by Bayesian methods. Our results showed that Kentropyx comprises three monophyletic groups, with K. striata occupying a basal position in opposition to previous suggestions of relationships. Additionally, Bayesian analysis of divergence time sugested that Kentropyx may have originated during the Tertiary (Eocene/Oligocene) and the Pleistocene Refuge Hypothesis may not explain the species diversification. Based on ancestral reconstruction and molecular dating, we argued that a savanna ancestor is more likely and that historical events during the Tertiary of South America promoted the differentiation of the genus. The third chapter deals with the description of a new species of Cnemidophorus found in Jalapão in the northeast Cerrado biome. Finally, the fourth chapter deals with an analysis of the phylogenetic relationships of Cnemidophorus based on a combination of mitochondrial and nuclear DNA sequences and morphological data, including others cnemidophorines as internal group. The divergence time among species was estimated by Bayesian methods. The results of this chapter indicate that (1) cnemidophorines includes eight monophyletic groups, (2) Aspidoscelis and Kentropyx are monophyletic, (3) Cnemidophorus and Ameiva are paraphyletic, (4) the origin of the group occurred mainly during Oligocene and diversification within the group occurred mainly during the Miocene, (5) C. parecis is more closely related to Ameiva from the continent than to other species of Cnemidophorus and (6) diversification of the lemniscatus complex occurred during the Miocene and, therefore, was not strongly influenced by Quaternary climatic fluctuations as previously proposed.

ASSUNTO(S)

cnemidophorus ciencias biologicas datação molecular teiidae filogenia

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