Dissertation Research: Extensions of Landmark-Based Morphometric Methods to Articulated Structures: An Example Using Plethodon

基于Rohlf 9800636地标的几何形态计量学是一种通过分析同源地标的笛卡尔坐标来研究生物体形状的方法。它们可以应用于二维和三维坐标，并允许描述组内和组间的可变性，并以一种允许更有意义的生物学解释的方式可视化变化。这项拟议的研究有两个主要目标。第一个是开发和统计评估方法来分析铰接式结构的地标数据。将开发三种新方法，并将通过计算机模拟研究对基于每种方法的测试进行统计评估，以量化其I类错误率和相对功率。这些模拟将使用具有各种协方差结构的各种人工数据集来执行，以尝试确定一种方法对于预期数据类型是更好的，或者哪种方法最适合于特定类型的数据。第二个目标是将这些技术应用于一个数据集，该数据集包含来自同域和异地的两种多齿蜥蜴的头骨和下颌骨的地标，以了解这些物种的营养生态和形态变异之间的关系。

ROHLF 9800636 Landmark-based geometric morphometrics is an approach to the study of shape of organisms in which one analyzes the Cartesian coordinates of homologous landmarks. They can be applied to two- and three-dimensional coordinates, and allow both a description of within- and between-group variability, and a visualization of the variation in a manner that allows a more meaningful biological interpretation. The proposed research has two main goals. The first is to develop and statistically evaluate methods to analyze landmark data from articulated structures. Three new methods will be developed, and tests based on each will be statistically evaluated through computer simulation studies designed to quantify their type I error rates and relative powers. These simulations will be performed using a variety of artificial data sets with various covariance structures in an attempt to determine whether one method is superior for expected data types, or which method is best suited for particular types of data. The second goal is to apply these techniques to a data set containing landmarks from skulls and mandibles of two species of plethodontid salamanders from sympatric and allopatric localities, to gain understanding of the relationship between trophic ecology and morphological variation in these species.