The Role of Ecological Interactions in Diversification: Rates of Habitat Shifts and Within-Habitat Diversification in the Enallagma Damselflies of Two Communities

小行星9419318 我们管理世界生物多样性的能力取决于我们对在不同生态环境中产生和维持生物多样性的过程的理解。 本研究探讨了进化过程在影响一组水生昆虫，Enallagma豆娘（蜻蜓目：Coenagrionidae）在不同生境的生物多样性格局的重要性。 一些Enallagma物种只在无鱼的水体中发现。 此外，有鱼生境中的物种比无鱼生境中的物种多3-4倍。 物理环境方面，主要猎物，主要的捕食者物种与各种Enallagma物种共存，将被确定和用于评估这些水生群落如何在美国东南部的变化。 此外，将使用现代分子DNA技术开发大部分北美Enallagma的系统发育。 为测试多样化率差异而开发的统计技术将被应用于评估两种湖泊类型之间物种数量的差异是否可以通过该群体的物种形成和灭绝来解释。 沿着解决多样化进入多种生境的基本问题，这项研究对保护生物多样性具有重要意义。 大多数保护物种的努力都是针对导致灭绝的过程，因为灭绝的直接和不可挽回的影响。 然而，从长远来看，需要了解保护做法如何影响分类群的持续进化和多样化，以保护功能正常的生态系统和物种对长期环境变化作出进化反应的能力。 通过研究生态条件如何影响多样化，这项研究将提供初步数据，以评估生态环境的属性可能会影响分类群的持续进化。

9419318 McPeek Our ability to steward the world's biological diversity depends on our understanding of the processes that generate and maintain biodiversity in different ecological settings. This research explores the importance of evolutionary processes in affecting biodiversity patterns in different habitats for a group of aquatic insects, the Enallagma damselflies (Odonata: Coenagrionidae). Some Enallagma species are found only in fishless water bodies. Furthermore, 3-4 times more species exist in habitats with fish than in fishless habitats. Aspects of the physical environment, the major prey, and major predator species that coexist with various Enallagma species will be identified and used to evaluate how these aquatic communities vary across the southeastern USA. Also, a phylogeny for most of the North American Enallagma will be developed using modern molecular DNA techniques. Statistical techniques developed to test for differences in diversification rates will be applied to evaluate whether the differences in the number of species between the two lake types can be explained by speciation and extinction in the group. Along with addressing basic questions about diversification into multiple habitats, this study has important implications for the conservation of biological diversity. Most effort for conserving species is directed at the processes leading to extinction, because of extinction's immediate and irreparable impacts. However, in the longer term an understanding of how conservation practices influence the continued evolution and diversification of taxa is needed to preserve functioning ecosystems and the abilities of species to respond evolutionarily to long-term environmental changes. By studying how ecological conditions influence diversification, this research will provide initial data to evaluate how properties of ecological settings may influence the continued evolution of taxa.