REU: Intraspecific Variation and Evolutionary Innovation

目前的研究被提议继续进行两年，项目旨在揭示变异性、遗传和差异适应度如何影响动物物种内形态变异的进化。多态的老虎火蜥蜴，将是一个解决三个问题的模型。1)。随着进化时间的推移，发育时间的变化是否会影响物种内部形态变异的起源？2)描述物种持续变异的遗传模型是否会简单地扩展？3)自然选择，特别是通过物种内的竞争和水生生境的可预测性，是维持种群内和种群之间形态变异的一种力量？这些问题涉及到一个物种内的连续形态变异如何维持或转化为种群内或种群间的不连续形态变异的一般问题。这些问题将通过实验室和现场实验和观察来研究。这些包括对动物成长过程中大小和形状变化的形态计量分析，以及对形态上的地理变化的描述。育种实验将量化遗传和环境对种群间形态差异的贡献。最后，设计了几个实验，以提供一种将解剖学、饮食和健康的差异联系起来的方法。总而言之，所提出的研究项目有助于我们加深对与物种内变异和新进化形式的起源相关的生态和进化过程的理解。

A two-year continuation of current research is proposed with projects designed to uncover how variability, inheritance, and differential fitness affect the evolution of morphological variation within species of animals. The polymorphic tiger salamander, Ambystoma tigrinum, will be a model to address three questions. 1). Have changes in timing of development over evolutionary time affected the origin of morphological variation within species? 2) Will simple extensions of genetic models describing continuous variation in species? 3) Is natural selection, especially through competition within species and predictability of the aquatic habitat, a force maintaining morphological variation within and between populations? These questions relate to the general issue of how continuous morphological variation within a species is maintained or converted into discontinuous morphological variation within or between populations. Questions will be studied using laboratory and field experiments and observations. These include morphometric analyses of changes in size and shape as animals grow, complemented by descriptions of geographic variation in morphology. Breeding experiments will quantify genetic and environmental contributions to morphological variation among populations. Finally, several experiments are designed to provide a means for relating variation in anatomy, diet, and fitness. Collectively, the research projects proposed contribute to our developing understanding of the ecological and evolutionary processes relating variation within species and the origin of novel evolutionary forms.