COLLABORATIVE RESEARCH: LTREB RENEWAL: EVOLUTIONARY DEMOGRAPHY - THE CONTRIBUTION OF ADAPTATION AND ENVIRONMENT TO POPULATION DYNAMICS, RANGE SIZE, AND NICHE WIDTH

生态学和进化生物学的一个基本目标是解释物种的地理分布。但物种是动态的实体，它们的地理分布会对不断变化的环境做出反应。如果它们适宜栖息地的环境发生变化，一个物种的种群可以通过自然选择来适应现有的栖息地，或者它们需要转移到新的地点。由于环境变化的步伐加快，理解物种分布的机制尤其及时。适应对种群动态、地方持久性和物种所居住的地理范围的贡献很少被量化。虽然比较生态学研究和物种分布模型通常假设物种地理范围内的遗传一致性，但遗传研究一再证明了当地的适应性。该项目通过继续进行长期实地人口统计研究和使用物种分布模型，明确审查适应对种群增长的贡献和物种地理范围的范围。该项目还将延伸到一所农村中学，让学生参与研究活动，并将通过一个名为市场科学的创新推广项目将公民与研究科学家联系起来，在市场科学中，研究人员在农贸市场与公众接触。研究小组将把重点放在加州本土植物物种Clarkia Xantiana上，该物种12年来一直是密集的实地研究的重点。这项研究将提供有关物种范围如何演变以及可能影响物种对气候变化反应的因素的新的、异常详细的信息。该项目的具体目标是研究：(1)种群动态是否从物种范围的中心到边缘变化，以及是什么环境因素驱动这种变化；(2)局部适应的空间尺度及其与种群之间人口相似性的关系；(3)种群动态和适应在形成环境容忍度(生态位宽度)和地理范围大小方面的相互作用。只有长期的研究才能提供关于什么控制种群持久性、进化适应及其对物种范围的影响的可靠预测。在35个自然种群中收集了生命率(如存活、繁殖)、种群增长以及非生物和生物(草食)因素的长期人口数据集，这些种群横跨物种范围的主要部分。对实地人口的所有监测将再继续十年。过去的工作通过在人口统计上不同的人群之间进行大规模的相互移植实验来检验局部适应。这项实验将在项目的第二个五年阶段重复。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

A fundamental objective of ecology and evolutionary biology is to explain the geographic distributions of species. But species are dynamic entities, and their geographic distributions respond to changing environments. If the environment of their suitable habitat changes, populations of a species can sustain themselves in their current habitat by adaption through natural selection, or they need to shift to new locations. Understanding the mechanisms that account for species distributions is especially timely because of the accelerating pace of environmental change. The contribution of adaptation to population dynamics, local persistence, and to the geographic range inhabited by a species, has rarely been quantified. Although comparative ecological studies and species distribution models typically assume genetic uniformity across a species geographic range, genetic studies have repeatedly demonstrated local adaptation. This project explicitly examines the contribution of adaptation to population growth and the extent of a species geographic range, through the continuation of a long-term field population demographic study and the use of a species distribution model. The project will also involve outreach to a rural middle school, engaging students in research activities, and it will connect citizens to research scientists through an innovative outreach program, Market Science, where researchers engage the public at farmer's markets. The research team will focus on a well-studied California native plant species, Clarkia xantiana, which has been the focus of intensive field research for over 12 years. This research will provide new, exceptionally detailed information about how species' ranges evolve and the factors that are likely to influence species responses to climate variation. The specific objectives of this project are to examine: (1) whether population dynamics vary from the center to margins of the species' range and what environmental factors drive this variation; (2) the spatial scale of local adaptation and how it relates to demographic similarity among populations; and (3) the interplay of population dynamics and adaptation in shaping environmental tolerances (niche width) and geographic range size. Only long-term studies can provide robust predictions about what controls population persistence, evolutionary adaptation, and their consequences for species ranges. Long-term demographic datasets of vital rates (e.g. survival, reproduction), population growth, and abiotic and biotic (herbivory) factors, have been collected in 35 natural populations spanning the major portion of the species' range. All monitoring of field populations will be continued an additional ten years. Past work has examined local adaptation using a large reciprocal transplant experiment among demographically-divergent populations. This experiment will be repeated in the project's second five-year phase.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.