DISSERTATION RESEARCH: Evolution of Reproductive Strategies

当研究繁殖策略的进化，或有助于繁殖的性状集合时，有必要研究相关性状如何对相同的选择机制做出反应。此外，母性特征也会对选择作出反应。这项研究的目的是在考虑母体影响的情况下，测量模式蜥蜴(Plethodon Cinereus)生殖特征的适应性。Plethodon cinereus在两栖动物中表现出最具衍生性的生殖策略，其特征是卵子小、卵大、单独的陆地筑巢地点以及对卵的母性照料。这些特征是两栖动物成为第一批陆生脊椎动物的必要适应。这项研究旨在通过实地研究和实验来确定繁殖性状和适合度(产生的后代数量)之间的相关性。卵子大小、蛋大小、产卵日期和适合度将在自然种群中记录下来，在自然种群中，母体效应无法测量。实验还将控制两个重要的母性特征，即乳房大小和筑巢地点。通过比较这些分析得出的生殖性状和适合度之间的相互关系，可以评估作用于这些性状的选择的强度和方向，并可以确定母体性状调节选择的方式。正是对生殖特征之间的生理和生态相关性的了解，才能预测生物体将如何应对环境的变化，这些变化可能是由全球警告、栖息地退化或人类的不信任造成的。

When studying the evolution of reproductive strategies, or the collection of traits that contribute to reproduction, it is necessary to study how correlated traits respond to the same selective regime. In addition, maternal traits respond to selection. This study is designed to measure the adaptive nature of reproductive traits in a model oranism, the redbacked salamander Plethodon cinereus, with consideration of maternal effects. Plethodon cinereus exhibits the most derived reproductive strategy among amphibians, characterized by small clutch sizes, large egg sizes, solitary terrestrial nest sites, and maternal care of eggs. These traits were necessary adaptations for amphibians to become the first terrestrial vertebrates. This study is designed to determine correlations between reproductive traits and fitness (number of offspring produced) through the use of field studies and experimentation. Clutch sizes, egg sizes, egg-laying dates, and fitness will be recorded in an natural population, where maternal effects cannot be measured. Experiments will also be controlling for two important maternal traits, bosy size and nest site. By comparing the interrelationships among reproductive traits and fitness from these analyses, the strength and direction of selection acting on these can be assessed, and the way in which maternal traits mediate selection can be determined. It is this understanding of the physiological and ecological correlates among reproductive traits that will allow predictions of how organisms will respond to changes in their environment, which may be caused by global warning, habitat degradation, or human distrubance.