Collaborative Research: A millennial-scale chronicle of organism-environment interactions resulting in microevolutionary physiological and genomic shifts in Daphnia

当代生物学面临的一个中心挑战是了解生物体如何适应不断变化的环境。这项研究的重点是，是否可以基于生态系统水平的信息来预测动物种群生理上的微进化变化。对这些问题的回答应该促进建立更好的全球环境变化预测模型，并为有效的管理提供信息。利用一种独特的模式生物--水蚤--一种生活在湖泊中的小型甲壳类动物，它产生的休眠卵可以在沉积物中休眠几个世纪，首席调查员能够直接观察到自然种群中人为变化的进化后果。在这个项目中，PIs将阐明所观察到的进化变化与关键环境参数变化(如磷负荷历史(即影响水质的营养物质丰富)相一致的确切机制)。具体地说，他们将使用尖端的古湖沼学工具来研究湖底沉积物，以精确地重建反映欧洲前和欧洲后定居的昔日环境，并利用这些信息来测试古代和现存的水蚤基因类型的表现，以评估人类活动的影响。此外，他们将把实验进化和高通量基因组学方法结合起来，以确定支撑这种进化转变的基因。还将评估这些基因在预测不同湖泊的营养物质丰富(即富营养化)反应方面的表现。PIs将继续从不同级别(高中、本科生和研究生)代表性不足的群体中招收学生。该项目将培养一名博士后研究员、三名研究生研究生、一名博物馆实习生、三名本科生研究助理和一名高中实习生。拟议实验产生的基因组信息将尽快通过www.wFleabase.org向科学界提供，而在该项目期间产生的水蚤克隆库将在赠款期限结束后共享。此外，这项研究的结果与水质和环境变化问题有关(特别是来自古湖水分析)，私人投资机构将继续与明尼苏达州自然资源部分享数据，以便与湖泊管理者和普通公众进行接触。与明尼苏达州科学博物馆合作，该项目将成为NSF赞助的获奖在线展览www.Science encebuzz.org的一部分，该在线展览将最新的科学新闻(通过RSS技术)与传统的博物馆互动体验相结合，每年可能接触到50万至80万人。PIs将提供有关全球环境变化，特别是与湖泊有关的变化，以及水生生物适应不断变化的条件的能力的内容。最后，这项工作有助于并受益于联邦资助的资源，如水蚤基因组学联盟和国家湖泊核心基金。

A central challenge facing contemporary biology is to understand how organisms adapt to changing environments. This research focuses on whether predictions of microevolutionary shifts in the physiology of animal populations can be based on ecosystem-level information. Answers to such questions should foster better forecasting models of global environmental change and inform effective management. Using a unique model organism, Daphnia, a small crustacean that lives in lakes and produces resting eggs that can lay dormant in sediments for centuries, the Principal Investigators (PIs) have been able to directly observe the evolutionary consequences of man-made change in a natural population. In this project, the PIs will elucidate the precise mechanisms that underlie observed evolutionary shifts coinciding with changes in key environmental parameters such as phosphorus (P) loading history (i.e., nutrient enrichment that affects water quality). Specifically, they will use cutting-edge paleolimnological tools to examine lake-bottom sediments to precisely reconstruct erstwhile environments reflective of pre- and post-European settlement, and use that information to test the performance of ancient and extant Daphnia genotypes to assess anthropogenic impacts. Furthermore, they will couple experimental evolution, and high throughput genomics methods to identify the genes that underlie such evolutionary shifts. The performance of these genes in predicting responses to nutrient enrichment (i.e., eutrophication) in a different lake will also be assessed. The PIs will continue to recruit students from underrepresented groups at various levels (high-school, undergraduate, and graduate). This project will train a postdoctoral fellow, three graduate research students, a museum intern, three undergraduate research assistants, and a high school intern. The genomic information generated from the proposed experiments will be made available to the scientific community via www.wFleabase.org as soon as possible, while the Daphnia clone bank generated during this project will be shared after the duration of the grant. Moreover, results from this study are relevant to issues of water quality and environmental change (particularly from paleolimnological assays), and the PIs will continue to share data with the Minnesota Department of Natural Resources for outreach to lake managers and the general public. In partnership with the Science Museum of Minnesota, the project will be part of the NSF-sponsored award-winning www.sciencebuzz.org online exhibits that blend up-to-the-minute science news (via RSS technology) with traditional museum interactive experiences, reaching potentially 500,000-800,000 individuals per year. The PIs will provide content on global environmental change, particularly related to lakes, and the ability of aquatic organisms to adapt to changing conditions. Finally, this work contributes to and benefits from federally-funded resources such as the Daphnia Genomics Consortium and the National Lacustrine Core Facility.