International Research Fellowship Program: Ontogenetic and Evolutionary Shape Variation and Modularity in the Mammalian Skull

国际研究奖学金计划使美国科学家和工程师能够在国外进行三到二十四个月的研究。 该计划的奖项为联合研究提供了机会，并利用国外独特或互补的设施，专业知识和实验条件。该奖项将支持Anjali Goswami博士与Marcelo Sanchez-Villagra博士在英国伦敦的古生物学自然博物馆进行为期22个月的研究。发育通常被认为是形态变异的主要影响，为进化提供了原材料。 这一假设的明确测试需要量化的发育形状，以衡量其对成人的变化的影响，但是，到目前为止，量化的发展形态已受阻的困难，从切片组织学标本的测量。 本研究采用新的成像和数字化软件，从切片材料构建三维模型。 通过这些模型，Goswami博士对哺乳动物头骨的个体发育形状进行了形态测量分析，以测试发育对成年形态影响的基本假设。 Goswami博士先前的工作表明，成年哺乳动物的头骨分为几个独立的组件或模块，它们可以彼此独立地变化。 这些研究表明，在成人头骨中观察到的模块是由发育中的骨骼之间的相互作用产生和影响的。 测量颅骨发育过程中的形状变化和变化可以直接测试发育对成人颅骨形状的影响。 然后将此个体发生数据纳入计算机模拟，以模拟进化变化，以确定如何在头骨模块的发展差异可能会创建所观察到的哺乳动物species.This研究的差异提供了第一个比较形态测量数据集跨越一个复杂的系统，哺乳动物头骨的发展。 这项研究中开发的新方法和分析大大扩展了胚胎学和形态学研究的范围。 这个独特的数据集也将有助于许多其他研究，包括发育遗传学，缝合形成，进化速率和遗传学，以及为发育障碍的医学研究提供广泛的比较数据。

0502186GoswamiThe International Research Fellowship Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-two-month research fellowship by Dr. Anjali Goswami to work with Dr. Marcelo Sanchez-Villagra at the Natural Museum of Paleontology in London, UK.Development is often presented as a major influence on morphological variation, which provides the raw material for evolution. Explicit tests of this hypothesis require quantification of developmental shape to measure its influence on adult variation, but, thus far, quantification of developing morphology has been hindered by difficulties in obtaining measurements from sectioned histological specimens. This study adapts new imaging and digitizing software to construct 3-D models from sectioned material. With these models, Dr. Goswami conducts morphometric analysis of ontogenetic shape in the mammalian skull to test fundamental hypotheses on the influence of development on adult morphology. Previous work by Dr. Goswami has shown that the adult mammalian skull is divided into several independent components, or modules, that can vary independently of each other. Those studies suggested that the observed modules in the adult skull are created and influenced by interactions among developing bones. Measuring the changes in shape and variation during skull development allows for direct testing of the influence of development on adult skull shape. This ontogenetic data is then incorporated into computer simulations to model evolutionary change to determine how developmental differences in skull modules may create the observed differences across mammalian species.This study provides the first comparative morphometric dataset spanning the development of a complex system, the mammalian skull. The new methodologies and analyses developed in this study greatly expand the current scope of embryological and morphometric research. This unique dataset will also be useful for many other studies, spanning developmental genetics, suture formation, evolutionary rates, and phylogenetics, as well as providing extensive comparative data for medical research of developmental disorders.