Collaborative Research: BEE: Bridging the ecology and evolution of East African Acacias across time and space: genomics, ecosystem, and diversification.

物种的物理属性和行为是由进化形成的。这些特征决定了个体如何与其环境（生态）相互作用，进而影响进化进程。因此，生态和进化是密不可分的。连接进化和生态学领域是具有挑战性的，因为所涉及的过程可以在相似或非常不同的时间尺度上运行。非洲大草原上的金合欢树已经进化到在许多其他树种无法忍受的恶劣条件下生存和繁殖。金合欢可以忍受火灾，干旱，长颈鹿和大象的食草，以及来自其他植物的竞争。但是金合欢过去如何适应这些条件将影响它们对当前非洲大陆不断变化的环境的反应。本研究的目的是全面了解非洲金合欢的进化历史和生态分布，并探讨物种特征和分布如何随时间变化而响应热带稀树草原气候的变化。最终，这些知识将有助于预测金合欢栖息地将如何受到持续气候变化的影响。该项目不仅具有广泛的社会效益，而且将培养进化生物学、生态学、植物生理学和分子基因组学方面的本科生、研究生和博士后。此外，该项目将扩大以塞伦盖蒂国家公园为特色的生态学和进化论本科教学模块的内容和范围，并将与非洲的大学合作开设新的生物信息学培训课程。该项目将把多样性的系统发育方法与性状响应和基因表达的直接生态现场测量联系起来。活动包括：(1)构建新的详细的非洲金合欢进化支系物种和性状的系统发育历史和生态分布模型；(2)利用系统基因组分析研究与热带稀树草原综合征相关的选择、渗透和基因家族扩展；(3)在坦桑尼亚阿鲁沙的一个普通花园实验中测量金合欢性状对热带稀树草原综合征成分（干旱、火灾、草食、草竞争）的反应。(4)通过分析在坦桑尼亚和对照温室试验中收集的金合欢转录组图谱，从分子方面分析表型响应。总的来说，这些相互联系的证据线将提供关于热带草原群落过去的进化、中新世发生的非洲热带草原的迅速崛起以及它对当前生态变化的可能反应的关键信息。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The physical attributes and behaviors of species are shaped by evolution. These traits determine how individuals interact with their environment (ecology) which then influences the course of evolution. Thus, ecology and evolution are inextricably intertwined. Bridging the fields of evolution and ecology is challenging because the processes involved can operate on similar, or very different, time scales. African savanna acacia trees have evolved to survive and reproduce under harsh conditions not tolerated by many other tree species. Acacias can tolerate fires, droughts, herbivory by giraffes and elephants, and competition from other plants. But how acacias have adapted to these conditions in the past will influence their response to the current changing environment on the African continent. The goal of this study is to develop a comprehensive understanding of the evolutionary history and ecological distribution of African acacias and to explore how species traits and distributions changed over time in response to change in the savanna climate. Ultimately, this knowledge will inform predictions about how acacia habitats will be affected by ongoing climate change. This project not only has broader societal benefit but also it will train undergraduate and graduate students and postdoctoral fellows in evolutionary biology, ecology, plant physiology, and molecular genomics. In addition, the project will expand the content and reach of a successful undergraduate teaching module of ecology and evolution featuring Serengeti National Park and will begin a new bioinformatics training course in partnership with universities in Africa.This project will bridge phylogenetic approaches to diversification with direct ecological field measurement of trait responses and gene expression. The activities include: (1) constructing new, detailed models of the phylogenetic history and ecological distribution of species and traits in the African Acacia Clade, (2) using phylogenomic analyses to study selection, introgression, and gene family expansion in relation to the Savanna Syndrome, (3) measuring acacia trait responses to Savanna Syndrome components (drought, fire, herbivory, grass competition) in a common garden experiment in Arusha, Tanzania, and (4) analyzing the molecular aspects of the phenotypic response through analysis of acacia transcriptomic profiles collected both on site in Tanzania and in controlled greenhouse experiments. Collectively, these linked lines of evidence will provide crucial information about the past evolution of the savanna community, the rapid rise of savannas across Africa that occurred in the Miocene, and its likely response to present ecological change.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.