DISSERTATION RESEARCH: Mechanisms of reproductive isolation along the speciation continuum: from micro- to macro-evolutionary scales

论文研究：沿着物种形成连续体的生殖隔离机制：从微观到宏观进化尺度

• 批准号: 1601186
• 负责人: Sharon Strauss
• 金额: $ 1.92万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1601186&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Mechanisms; reproductive; isolation

This project will examine the forces maintaining diversity in populations, species, and more distantly related lineages to build a more comprehensive picture of the speciation process in California Jewelflowers. Understanding how new species originate from existing ones is a major goal in biology. After new species are formed, both ecological and genetic forces may act to preserve species boundaries, prevent hybridization, and maintain biodiversity. It is unclear if these forces act similarly at population, species, and higher taxonomic levels. A comprehensive understanding of how biodiversity is generated and maintained in a single group of plants will inform basic models of the maintenance of Earth's biodiversity. It will also guide important conservation and management decisions for small, isolated, or fragmented populations. This research will provide training of a graduate student and several undergraduate research assistants. It will also provide citizens with a richer context for understanding plant biodiversity through public outreach efforts on California's plant biodiversity. Previous research at the middle and late stages of speciation in the plant clade Streptanthus suggests that both genetic incompatibilities and divergent ecology contribute to the maintenance of species-level diversity. Experimental hybridizations show that genetic incompatibility increases with species divergence times. Some recently diverged species pairs can, however, still produce viable hybrid offspring in the greenhouse. Field research shows that ecological differences in such species, including microhabitat affinity, pollinator preferences and constancy, and phenology may play a role in maintaining potential interbreeders as distinct species in nature. It is unclear whether the same ecological and evolutionary forces act at different stages of the speciation continuum, or if distinct genetic and ecological forces are characteristic of each stage of speciation. This research delves deeper into the early stages of speciation in Streptanthus, by focusing on population divergence and early reproductive isolation at the population level. Experimental hybridizations and Restriction site Associated DNA sequencing will be used to examine patterns of genetic relatedness among multiple geographically and environmentally divergent populations of S. breweri. The same techniques will also be used to analyze the influence of genetic, geographic, and environmental distance, on reproductive isolation at the population level. This research complements previous work in Streptanthus, providing new data on population-level processes, which will illuminate patterns of reproductive isolation observed at the species level, and provide a comprehensive view of the speciation process within a single study system.

该项目将研究维持人口，物种和更遥远的谱系多样性的力量，以建立加利福尼亚珠宝商的物种过程的更全面的画面。了解新物种如何来自现有物种是生物学的主要目标。形成新物种后，生态和遗传力都可以起到维护物种边界，防止杂交和维持生物多样性的作用。 目前尚不清楚这些力量是否在人口，物种和较高的分类水平上起作用。对在一组植物中如何产生和维持生物多样性的全面了解将为维持地球生物多样性的基本模型提供信息。它还将指导小型，孤立或分散的人群的重要保护和管理决策。 这项研究将为研究生和几位本科研究助理提供培训。它还将通过公共宣传对加利福尼亚植物生物多样性的公共宣传工作来为公民提供更丰富的背景，以了解植物生物多样性。 在植物进化链链球菌中间和晚期阶段的先前研究表明，遗传不相容性和不同的生态学都有助于维持物种水平的多样性。 实验杂交表明，遗传不相容性随着物种差异时间而增加。但是，一些最近分歧的物种对仍可以在温室中产生可行的混合后代。 现场研究表明，此类物种的生态差异，包括微栖息地亲和力，传粉媒介的偏好和恒定性，而物候学可能在将潜在的杂交中的潜在杂交中发挥作用。 目前尚不清楚相同的生态和进化力是否在形成连续性的不同阶段起作用，还是不同的遗传和生态力是每个物种阶段的特征。 这项研究更深入地研究了链霉菌的早期阶段，通过关注种群差异和人口水平的早期生殖隔离。 实验性杂交和相关的DNA测序将用于检查多个地理和环境不同的Breweri种群中的遗传相关性模式。同样的技术也将用于分析遗传，地理和环境距离对种群水平生殖隔离的影响。 这项研究补充了链球动物的先前工作，提供了有关人群级过程的新数据，这些数据将阐明在物种水平上观察到的生殖隔离模式，并在单个研究系统中对物种形成过程进行全面的看法。