Dissertation Research: The Consequence of Early Selection on Life History Evolution

在生命周期的不同阶段进行选择，最终可能会限制或加快进化的步伐，这取决于不同生命阶段的特征是如何联系在一起的。这里提出的研究将考察在生活期内和跨生活期选择的强度和方向，特别是在一年生入侵植物Agrostema githago[石竹科]的生活史早期选择的延迟效应。这将在一项大规模的田间试验中得到解决，在该试验中，通过使用连续移植来操纵生命周期早期的选择性制度。实验设计在促进早期生命阶段不同选择方案的比较方面是独一无二的，同时保持晚期生命环境在治疗过程中保持不变。因此，这项研究代表了一种新的方法来评估生命历史是如何通过发生在物种生命周期中的选择性事件来塑造和制约的。它将探索自然种群的生活史进化，并将解释选择的时间变化。这项实验的结果将回答长期以来在生活史、进化和生物人口学领域的问题。通过解决哪个生命阶段对入侵物种的成功最关键，这项工作的结果也将与保护工作相关。这项研究的更广泛影响包括两名目前正在从事与这项研究相关的项目的本科生女性的本科生研究部分。

Selection operating at different points in the life cycle may ultimately limit or accelerate the pace of evolution, depending on how traits are linked across life stages. The research proposed here will examine the strength and direction of selection within and across life stages, focusing particularly on the delayed effects of selection early in the life cycle of an annual invasive plant, Agrostemma githago [Caryophyllaceae]. This will be addressed in a large-scale field experiment, in which the selective regime early in the life cycle is manipulated through the use of serial transplants. The experimental design is unique in facilitating a comparison of different selective regimes across the early life stages, while keeping late life environments constant across treatments. This research thus represents a novel way to assess how life histories are shaped and constrained through selective events taking place across the life cycle of a species. It will explore life history evolution in a natural population, and will account for temporal variation in selection. The results from this experiment will respond to longstanding questions in the fields of life history evolution and biodemography. By addressing which life stage is most critical to the success of an invading species, the results from this work will also be relevant to conservation efforts. The broader impacts of this research include an undergraduate research component for two undergraduate women currently working on projects related to this research.