DISSERTATION RESEARCH: Adaptive radiation and hybridization: testing the hybrid swarm origin hypothesis for adaptive radiations in a phylogenetic framework

论文研究：自适应辐射和杂交：在系统发育框架中测试自适应辐射的混合群起源假说

• 批准号: 1502049
• 负责人: David Tank
• 金额: $ 1.87万
• 依托单位: Regents of the University of Idaho
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1502049&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Adaptive; radiation; hybridization

Adaptive radiation and ecological opportunity are known to play major roles in the formation of new biodiversity. In this model, a few ancestral species diversify rapidly to fill ecological space with a variety of new morphological and ecological strategies. Recently, hybridization among closely related species has been hypothesized to play an important role during the early stages of an adaptive radiation, but studies investigating this process in plants are currently lacking. This project will evaluate the role of hybridization in facilitating an adaptive radiation using the Andean plant genus Lachemilla (Rosaceae) as a model. Lachemilla comprises approximately 50 described species and is restricted to high elevation habitats throughout the Andes. Phylogenetic analyses of chloroplast and single-copy nuclear DNA gene sequences from multiple Lachemilla species will first be used to reconstruct evolutionary relationships. Using this evolutionary framework, researchers will then use a variety of statistical approaches to investigate the role played by hybridization in driving diversification within the lineage. This research will provide extensive training in systematics and evolutionary biology to a graduate student, and enhance international scientific collaboration with researchers in Ecuador. This project will provide training for one undergraduate student in laboratory techniques and data analysis, and also provide valuable mentoring experience for the co-PI. This project will use phylogenetic methods to investigate and test the hybrid swarm origin and syngameon hypotheses for the generation of functional diversity during an adaptive radiation using the plant genus Lachemilla (Rosaceae). A robust and comprehensive phylogeny from hundreds of Lachemilla accessions using high-throughput sequencing approaches of whole chloroplast and multiple single-copy nuclear regions will be generated using Bayesian approaches. This phylogenetic framework will then be used to first test for evidence of hybridization, and then investigate whether morphological, functional, and phylogenetic diversification in the clade coincides with hybridization events. By integrating modern comparative phylogenetic measures of trait evolution with sophisticated analyses of lineage diversification rates, this research will investigate the explicit role of hybridization in the early stages of an adaptive radiation.

众所周知，适应性辐射和生态机会在新生物多样性的形成中发挥着重要作用。 在这个模型中，一些祖先物种迅速多样化，以各种新的形态和生态策略填充生态空间。最近，人们假设密切相关的物种之间的杂交在适应性辐射的早期阶段发挥重要作用，但目前缺乏对植物中这一过程的研究。该项目将使用安第斯植物属 Lachemilla（蔷薇科）作为模型，评估杂交在促进适应性辐射中的作用。 Lachemilla 包含大约 50 个已描述的物种，仅限于整个安第斯山脉的高海拔栖息地。对多个 Lachemilla 物种的叶绿体和单拷贝核 DNA 基因序列的系统发育分析将首先用于重建进化关系。 利用这个进化框架，研究人员将使用各种统计方法来研究杂交在推动谱系多样化方面所发挥的作用。 这项研究将为研究生提供系统学和进化生物学方面的广泛培训，并加强与厄瓜多尔研究人员的国际科学合作。该项目将为一名本科生提供实验室技术和数据分析方面的培训，并为联合首席研究员提供宝贵的指导经验。该项目将使用系统发育方法来研究和测试杂交群体起源和联配子假设，以使用 Lachemilla（蔷薇科）植物在适应性辐射过程中产生功能多样性。将使用贝叶斯方法，使用整个叶绿体和多个单拷贝核区域的高通量测序方法，从数百个 Lachemilla 种质中生成稳健且全面的系统发育。 然后，该系统发育框架将首先用于测试杂交的证据，然后研究进化枝中的形态、功能和系统发育多样化是否与杂交事件相一致。通过将性状进化的现代比较系统发育测量与谱系多样化率的复杂分析相结合，本研究将研究杂交在适应性辐射早期阶段的明确作用。