2009年8月29日 星期六

櫛尾蜥的共祖可能起源自安地斯山東側

文獻來源: Torres-Carvajal O, de Queiroz K. 2009. Phylogeny of hoplocercine lizards (Squamata: Iguania) with estimates of relative divergence times. Molecular Phylogenetics and Evolution 50(1): 31-43.

Abstract
Hoplocercine lizards form a clade of 11 currently recognized species traditionally placed in three genera (Enyalioides, Hoplocercus, and Morunasaurus) that occur in the lowlands on both sides of the Andes between Panama and the Brazilian Cerrado. We analyze 11 mitochondrial and two nuclear loci using probabilistic methods and different partitioning strategies to (1) infer the phylogenetic relationships among species of Hoplocercinae, (2) examine amounts of inter- and intraspecific sequence divergence, (3) address monophyly of four species, (4) test previous phylogenetic hypotheses, and (5) estimate divergence times. Our preferred hypothesis places H. spinosus as the sister taxon to all other species of hoplocercines, with M. annularis nested within Enyalioides. Species with multiple samples are monophyletic except for Enyalioides oshaughnessyi, which is paraphyletic relative to an undescribed species of Enyalioides. All previously published phylogenetic hypotheses for hoplocercines are rejected. Monophyly of Enyalioides cannot be rejected and, consequently, the position of Morunasaurus remains unclear. The most recent common ancestor of Hoplocercinae probably occurred east of the Andes; western taxa included in our analyses originated from at least two separate colonizations whether pre- or post-dating vicariance resulting from uplift of the Andes.

圖片連結: The Reptiles Database (photo credit: Pedro H. Bernardo)