Phylogenetic Relationships Within the Australian Sphenomorphus Group (Squamata: Scincidae) and the Study of Limb Reduction

里德9707428 楔头蜥属（Sphenomorphus）的蜥蜴类至少有210种，是澳大利亚爬行动物（两栖动物和爬行动物）的主要组成部分。 这些蜥蜴的特点是四肢的退化有很大的差异：在14个描述的属中，有8个物种表现出肢体退化，从失去一个趾骨（手指或脚趾中的一个骨质元素）到完全没有肢体。 圣地亚哥大学的Tod里德将利用由染色体编码的12 S和16 S核糖体（r）RNA基因的DNA序列来评估70多个楔鼻蝶属物种和盟友之间的系谱关系。 他还将研究一套形态特征，主要来自骨骼结构和鳞片。 这些数据将用于生成物种的系谱，部分用于生成自然分类。 将从系谱背景中评估这些物种的肢体减少模式，以确定肢体减少的次数和轨迹，并确定与这些形态学变化相关的生活史特征。 还将评估前肢和后肢之间肢体复位的相对比率。 该项目的结果将提高对蜥蜴生殖的理解，为蜥蜴生殖和生物学中还原特征的实用性提供经验信息，并为其他生物和生态属性的调查提供必要的框架。

9707428 Reeder The scincid lizards of the Sphenomorphus group include at least 210 recognized species and represent a dominant component of the Australian herpetological (amphibian and reptile) fauna. These lizards are characterized by extensive variation in reduction of limbs: eight of the fourteen described genera contain species that exhibit limb reduction, ranging from loss of a single phalange (a bony element in a finger or toe) to complete limblessness. Tod Reeder of the University of San Diego will employ DNA sequences from the mitochondrially-encoded 12S and 16S ribosomal (r)RNA genes to assess genealogical relationships among over 70 Sphenomorphus species and allies. He also will examine a suite of morphological characters, derived primarily from osteological structures and scales. These data will be used to generate a genealogy of the species, in part to generate a natural classification. The patterns of limb reduction in these species will be assessed from within the context of the genealogy in order to determine the number of times and trajectories of limb reduction and to determine the life-history traits associated with these morphological changes. Relative rates of limb reduction between fore- and hind-limbs also will be assessed. Results from this project will improve understanding of lizard phylogeny, provide empirical information on the utility of reductive characters in lizard phylogeny and biology, and contribute a necessary framework for the investigation of other biological and ecological attributes.