Collaborative Research: BEE: Niche evolution and the assembly of replicate island lizard faunas

为什么有些物种在群落中占主导地位，而另一些则很罕见？是什么决定了这样的生态成功是生物学中的一个基本问题。物种专业化的差异经常被用来解释成功。物种可以专注于少数资源（例如，一种食物），或者采用多面手策略，并尝试使用多种。然而，一个单一的物种可能专注于一种食物类型，但就其栖息地而言，它是一个多面手。由于这种复杂性，目前还不清楚何时专家策略是有益的。该项目旨在通过研究西印度群岛岛屿上的蜥蜴群落来了解有利于专家的条件。西印度群岛的群落中有1至8个物种，每个岛屿上的物种都不同。首先，研究人员将通过量化蜥蜴的丰度来衡量物种的成功程度。其次，他们将测量蜥蜴的饮食，它们耐受的温度和它们使用的栖息地的专业化。第三，研究人员将研究物种之间的进化关系，以评估专家进化的速度。最后，他们将测量食物资源、温度和栖息地的常见程度。该研究计划将支持本科生和研究生的培训，并促进高中的科学教育。此外，它将探索新的方式来交流科学与艺术家合作，创造艺术的基础上的研究。专业化在决定生态和进化成功方面的作用一直存在争议。在生态社区中，权衡是否会使通才“万事通”沦为脚注？或者，专家们是否只限于稀有或不太理想的资源，以至于通才在数量上占主导地位？同样，专家是如何进化的也不清楚。生态位的扩张和收缩在宏观进化过程中是不稳定的吗？还是动物群的进化阶段很重要，在适应性辐射期间，早期的物种形成事件更有可能产生通才，而专家只在后期，物种饱和的社区中形成？为了回答这些问题，本研究探讨了大安的列斯群岛的阿诺利斯蜥蜴适应辐射。研究人员使用标记重捕获来量化牙买加，波多黎各和伊斯帕尼奥拉岛上两个地理上不同的动物群的当地社区的结构。每个岛屿的动物群在进化上都是独立的，但却不断进化出许多生态性质相似的物种。研究人员将通过测量每个物种沿着热量，植被结构和饮食轴的生态位位置（例如最常用的资源）和宽度（例如使用的资源跨度）来量化生态相似性。这样做使研究人员能够检验生态位宽度与生态群落中的优势相对应的假设。通过将生态位信息与系统发育关系相结合，研究人员将解决生态位宽度在宏观进化时间内的不稳定性。最后，研究人员将量化每个社区和岛屿中可用的热量，结构和饮食生态位空间的可用性，以评估通才是否在具有充足未使用生态位空间的年轻和多样性较低的社区中更成功。该项目将提供新的见解到专业化的进化的生态基础，测试长期持有的假设，并提供这些假设在进化复制faunas.This奖项反映了NSF的法定使命的一般性的见解，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Why do some species dominate communities while others are rare? What determines such ecological success is a fundamental question in biology. Differences in species’ specialization are often used to explain success. Species can either specialize on a few resources (e.g., one type of food), or employ a generalist strategy, and try to use many. However, a single species might specialize on one food type, but be a generalist in terms of the habitats that it’s found in. Because of this complexity it’s still unclear when a specialist strategy is beneficial. This project seeks to understand the conditions that favor specialists by examining lizard communities on islands in the West Indies. Sites in the West Indies communities contain one to eight species, with different species on each island. First the researchers will gauge how successful species are by quantifying lizard abundances. Second, they will measure lizard specialization with regards to their diets, the temperatures they tolerate, and the habitats they use. Third, the researchers will look to the evolutionary relationships between species, to assess how fast specialists evolve. Finally, they will measure how common food resources, temperatures, and habitats are. The research program will support undergraduate and graduate student training and promote science education in high schools. Further, it will explore new ways to communicate science by working with an artist to create art based on the research. The role of specialization in determining ecological and evolutionary success has been long debated. Do trade-offs render generalists ‘jacks-of-all-trade but masters-of-none’—relegated to footnotes in ecological communities? Or, are specialists restricted to rare or less desirable resources, such that generalists are numerically dominant? Likewise, it is unclear how specialists evolve. Is niche expansion and contraction labile over macroevolutionary time? Or does the stage of a fauna’s evolution matter, such that during adaptive radiations early speciation events are more likely to produce generalists, with specialists only forming in late-stage, species-saturated communities? To answer these questions this research examines the Anolis lizard adaptive radiation in the Greater Antilles. The researchers use mark-recapture to quantify the structure of local communities on Jamaica, Puerto Rico, and two geographically distinct faunas on Hispaniola. Each islands’ fauna is evolutionarily independent, but has nevertheless repeatedly evolved many species with qualitatively similar ecologies. The researchers will quantify ecological similarities by measuring the niche positions (e.g. most frequently used resource) and breadths (e.g. span of resources used) of each species along thermal, vegetation structural, and dietary axes. Doing so allows the researchers to test the hypothesis that niche breadth corresponds to dominance in ecological communities. By combining niche information with phylogenetic relationships, the researchers will then address how labile niche breadths are over macroevolutionary time. Lastly, the researchers will quantify available thermal, structural, and dietary niche space availability in each community and island to assess whether generalists are more successful in younger and less diverse communities with ample unused niche space. This project will provide novel insights into the ecological underpinnings of the evolution of specialization, testing long held hypotheses and offering insights into the generality of these hypotheses across evolutionarily replicated faunas.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.