Phylogenetic Analysis of Murid Skull Shape Ontogeny

动物的许多特征，如头骨形状， 在它的一生中。 然而，头骨形状的比较研究， 包括那些试图推断进化关系的人， 小组，以及那些研究头骨形态进化变化的小组， 通常只调查成年人。 该研究将分析 头骨形态的发育变化，以确定这些 转换提供有关进化的信息， 选择的啮齿动物之间的关系，并剖析进化 头骨发育的变化。 方法的最新进展 量化形状变化已经产生了有前途的技术， 将应用于本分析。 薄板法 我建议使用的样条函数方法具有独特的优势 因为它提供了一种识别一系列独立形状方法 上具有特定位置和空间范围的字符 头骨 在这个项目的第一阶段，我将比较三个 鼠属、鼠属和鼠属。 关系 这几个属之间没有争议。 我会比较：1） 每个物种头骨形状随年龄的变化; 2） 各物种各年龄段的平均头骨形状;以及3） 头骨形状的种内变异及其 转变 本阶段的研究将探讨几个 方法学问题，如编码方法， 形状特征的变换。 的第二阶段 研究将使用这些方法来分析 Sigmodon物种，并描述进化的修改， 头骨生长

Many features of an animal, such as its skull shape, change throughout its life. Yet, comparative studies of skull shape, including those that seek to infer evolutionary relationships among groups, and those that examine evolutionary changes in skull form, commonly survey only adults. The proposed research will analyze developmental changes in skull form to determine whether these transformations provide information about evolutionary relationships among selected rodents, and to dissect evolutionary changes in skull development. Recent advances in methods for quantifying shape change have yielded promising techniques that will be applied in this analysis. The method of thin-plate splines, the method that I propose to use, has a unique advantage in that it gives a way to identify a series of independent shape characters that have specific location and spatial extent on the skull. In the first stage of this project, I will compare three genera of murid rodent Mus, Sigmodon and Peromyscus. Relationships among these genera are not controversial. I will compare: 1) transformations in skull shape from age to age in each species; 2) average skull shape at each age across species; and 3) intraspecific variability of skull shapes and their transformations. This phase of the research will explore several methodological issues, such as methods for coding developmental transformations of shape characters. The second stage of the research will use these methods to analyze relationships among Sigmodon species, and to describe evolutionary modifications of skull growth.