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

[9707428] Reeder Sphenomorphus类群的科学蜥蜴包括至少210种已知的物种，代表了澳大利亚爬行动物（两栖动物和爬行动物）动物群的主要组成部分。这些蜥蜴的特点是四肢的减少有很大的差异：在描述的14个属中，有8个包含有肢体减少的物种，从失去单个趾骨（手指或脚趾的骨骼成分）到完全没有四肢。圣地亚哥大学的托德·里德将利用线粒体编码的12S和16S核糖体RNA基因的DNA序列来评估70多种蝶兽及其盟友之间的谱系关系。他还将研究一套形态学特征，主要来自骨结构和鳞片。这些数据将用于生成物种的系谱，部分用于生成自然分类。为了确定肢体减少的次数和轨迹，以及确定与这些形态变化相关的生活史特征，我们将从系谱的角度对这些物种的肢体减少模式进行评估。还将评估前肢和后肢之间肢体减少的相对比率。本项目的研究结果将提高对蜥蜴系统发育的认识，为蜥蜴系统发育和生物学中还原性的应用提供经验信息，并为其他生物学和生态学属性的研究提供必要的框架。

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.