DISSERTATION RESEARCH: Evolutionary dynamics of female polymorphism: an invasive damselfly model

在许多动物物种中，雌性的颜色变化很大。是什么维持了这种多样性，它又如何影响我们对进化的一般理解？虽然理论表明，性选择和自然选择都可能使女性的肤色多样化，但这些机制在女性进化中的作用尚未在单一研究系统中得到联合测试。一种豆娘的入侵种群，Ischnura ramburii提供了独特的机会来弥补这一差距。自夏威夷殖民以来，兰伯里氏瓢虫雌性颜色变异的频率发生了巨大变化。今天，？andromorph？雌性在视觉上与雄性相似，与入侵的种群密度和降雨量都有关系。研究人员将利用在入侵点内构建的实验性中生态系统，研究雌雄之间的相互作用和颜色形态表现（存活率和繁殖力）如何受到形态频率、种群密度和非生物环境（降雨）的影响。研究结果将用于确定社会和自然环境如何推动女性颜色进化，并确定促进女性多样性的条件。除了确定自然界中维持雌性变异的因素外，这项研究还将揭示入侵种群是如何进化的，并提出减轻入侵的新策略。拟议的工作将为几名本科生提供独特的研究机会，研究结果将通过媒体和研究者在2008年共同创办的一系列非常成功的外展会谈与公众分享。

Female coloration is highly variable within many animal species. What maintains this diversity, and how can it inform our general understanding of evolution? While theory suggests that both sexual and natural selection might diversify female color, the role(s) of these mechanisms in female evolution have not been jointly tested within a single study system. Invasive populations of a damselfly, Ischnura ramburii provide unique opportunities to close this gap. Frequencies of I. ramburii female color morphs have changed dramatically since the colonization of Hawaii. Today, the frequencies of ?andromorph? females, which visually resemble males, are correlated with both invasive population densities and rainfall. Using experimental mesocosms constructed within invaded sites, the investigators will examine how male-female interactions and color morph performance (survival and fecundity) are influenced by morph frequency, by population density, and by the abiotic environment (rainfall). Outcomes will be used to determine how social and physical environments drive female color evolution, and to identify conditions that promote female diversity. In addition to identifying factors that maintain female variation in nature, the study will shed new light on how invasive populations evolve, suggesting novel strategies for mitigating invasions. Proposed work will provide unique research opportunities for several undergraduates, and findings will be shared with the public via the media, and through a series of highly successful outreach talks that the investigators co-founded in 2008.