NSF Postdoctoral Fellowship in Biology FY 2012

本研究的目的是利用工程原理发现复杂生物结构功能中的基本力学模式，并利用这些发现来检验进化多样化。确定功能的研究对于理解物种如何多样化至关重要。然而，这样的研究在毫米大小的生物上是困难的，这些生物往往构成了地球的大部分？S的多样性，因为尺寸限制使得解剖和体内操作几乎不可能。然而，基于同步加速器的微断层扫描提供了一种方法来收集关于内部微小生物结构的详细信息，即使是最小的生物。这项技术在毫米大小的陷阱颚蜘蛛家族中至关重要。在这个家族中，极其快速的、基于惯性的颌合机制已经独立进化了3-4次。同步加速器扫描将允许可视化内部肌肉组织和结构涉及颚功能，而且，这项技术将允许构建3D计算机模型，作为运动学模拟的输入。这些模拟的结果，加上预先存在的系统发育，将允许测试：(1)形式变化与功能变化直接相关的假设；(2)物种多样化模式与形态和功能变化速率成正比的假设。培训包括学习从基于同步加速器的断层扫描中重建3D计算机模型的技术，执行运动学模拟，以及运行统计分析，以确定进化多样化率和功能和形态变化在谱系之间的变化。在博士后研究期间，更广泛的影响包括培训和指导本科生，在本科课程中进行客座讲座，并将成果（如3D数字重建）发布到网上。社区外展的其他机会包括在公共场所展示研究成果和创建在线课程计划，以促进进化论的教学。

Function and rates of diversification in complex miniature structures: the trap-jaw mechanisms in spiders The goal of this research is to use principles of engineering to discover basic mechanical patterns in the function of a complex biological structure, and then to use these findings to examine evolutionary diversification. Studies that determine function are essential for understanding how species diversify. However, such studies are difficult on the millimeter-sized organisms that tend to make up the majority of earth?s diversity, as size limitations make dissections and in vivo manipulations virtually impossible. However, synchrotron-based micro-tomography scanning presents a means for gathering detailed information about internal minute biological structures in even the smallest organisms. This technique is crucial in the case of the millimeter-sized trap-jaw spider family. Within this family extremely rapid, inertia-based, jaw closing mechanisms have evolved 3-4 times independently. Synchrotron scans will allow for visualizing internal musculature and structures implicated in jaw function, but also, this technique will allow for constructing 3D computer models to be used as inputs for kinematic simulations. Results from these simulations, coupled with a pre-existing phylogeny, will allow for testing (1) the hypothesis that changes in form directly relate to changes in function; and (2) the hypothesis that patterns of species diversification are proportional to rates of morphological and functional change.Training includes learning techniques for reconstructing 3D computer models from synchrotron-based tomography scans, performing kinematic simulations, and running statistical analyses that determine shifts among lineages in rates of evolutionary diversification and functional and morphological change. Broader impacts during the course of the postdoctoral fellowship include training and mentoring undergraduates, giving guest lectures in undergraduate courses, and making results, such as 3D digital reconstructions, available online. Other opportunities for community outreach include presenting research at public venues and creating online lesson plans that facilitate the teaching of evolution.