BEE: Testing eco-evolutionary effects of genetic drift and gene flow in stressful environments

BEE：测试压力环境中遗传漂变和基因流的生态进化效应

• 批准号: 2016569
• 负责人: Sarah Fitzpatrick
• 金额: $ 85.83万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2016569&HistoricalAwards=false
• 关键词: BEE; Testing; eco; evolutionary; effects

Habitat loss is splitting the world’s plants and animals into smaller and more isolated fragments. At the same time, many organisms also have to withstand rapid and stressful changes to their environment. Combined, these factors can increase extinction risk. One possible escape from extinction is through adaptation. Yet, small populations with low genetic diversity may be unable to adapt in time to keep pace with environmental change. An approach sometimes used to increase genetic diversity is to move individuals from one site to another. In theory, this method could prevent extinction by increasing the potential and speed of adaptation. But, it is unknown how this occurs, or how often it works. This project will determine whether small populations that received new genes can adapt faster to a stressful environment and avoid extinction compared to those that have not. This project will focus on studying eastern mosquitofish in outdoor tanks. These fish tanks will have different amounts and types of genetic diversity, and some will be heated to make their environment stressful. The researchers will measure changes in genes and in the number of fish in each tank over several years. At the end of the experiment they will determine whether fish from heated tanks can resist heat better than fish from unheated tanks. Genes involved in adaptation to heat will be identified, and the researchers will assess whether tanks that received new fish were less likely to go extinct. This project will reveal the genetic factors that contribute to adaptation versus extinction. Importantly, outcomes from this work will inform management decisions and improve biodiversity conservation. Broader Impacts include K-12 outreach through teacher training and summer camp activities for students. A postdoctoral researcher and several graduate and undergraduate students will be trained as part of this project. Rapid adaptation has the potential to rescue populations facing novel, stressful environments. Yet, this will only happen if populations can survive under stressful conditions and also have sufficient genetic variation to respond to selection. Most of the evolutionary rescue literature focuses on the roles of local standing variation or de novo mutation, largely ignoring the beneficial or constraining roles of gene flow and genetic drift. Recent evidence suggests that gene flow may be an important source of variation that can result in increased population growth, especially when recipient populations are small and inbred. However, direct evidence that gene flow can prevent extinction is lacking from natural populations, and long-term benefits of gene flow such as increased adaptive potential have almost never been shown. The proposed research will investigate how differences in recent evolutionary history (i.e., genetic drift and gene flow) affect adaptive response and persistence in the face of novel stress. The project will generate experimental populations of eastern mosquitofish with different recent evolutionary histories. The researchers will use acute stress experiments to test the effects of evolutionary history on initial and evolved thermal tolerance. A multigenerational mesocosm experiment will be used to test how evolutionary history affects individual fitness, population dynamics, and extinction probability in populations exposed to chronic novel stress (near-lethal heat) compared to a benign environment. Finally, the researchers will generate whole genome sequence data from wild populations and from a time series collected from the mesocosm populations to identify genomic mechanisms underlying adaptation and demography. This project will provide a unique mechanistic view of the eco-evolutionary roles of genetic drift and gene flow and may fundamentally change generally accepted expectations about the role of gene flow in contemporary populations.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.

栖息地丧失将世界的动植物分为较小，更孤立的碎片。同时，许多生物也必须承受对环境的快速和压力的变化。这些因素结合在一起可以增加扩展风险。从扩展中进行的一种可能的逃脱是通过适应。然而，遗传多样性低的人群可能无法及时适应环境变化。有时用来增加遗传多样性的方法是将个体从一个站点转移到另一个站点。从理论上讲，这种方法可以通过增加适应的潜力和速度来防止扩展。但是，未知是如何发生的，或运行的频率。该项目将确定收到新基因的小种群是否可以更快地适应压力大的环境，并避免与没有的那些相比。该项目将着重于研究室外坦克中的东部蚊子。这些鱼缸将具有不同数量和类型的遗传多样性，有些将加热以使其环境压力很大。研究人员将在几年内测量基因的变化和每个水箱中的鱼类数量。在实验结束时，他们将确定来自加热罐中的鱼是否比未加热的水箱中的鱼更好地抵抗热量。将确定参与适应热量的基因，研究人员将评估收到新鱼类的储罐是否不太可能灭绝。该项目将揭示有助于适应与扩展的遗传因素。重要的是，这项工作的结果将为管理决策提供依据，并改善生物多样性保护。更广泛的影响包括通过教师培训和学生夏令营活动的K-12外展活动。该项目的一部分将对博士后研究员以及几名研究生和本科生进行培训。快速适应有可能挽救面临新型压力环境的人群。但是，只有在种群在压力条件下生存并具有足够的遗传变异以应对选择时，这才会发生。大多数进化救援文献都集中在局部常规变异或从头突变的作用上，在很大程度上忽略了基因流和遗传漂移的有益或约束作用。最近的证据表明，基因流量可能是可能导致人口增长增加的重要变异来源，尤其是当受体种群较小且近交时。但是，直接证据表明基因流可以预防自然种群缺乏扩展，并且几乎从未显示出基因流的长期益处，例如增加的自适应潜力。拟议的研究将调查最近进化史（即遗传漂移和基因流）的差异如何影响新应激的适应性反应和持久性。该项目将产生东部蚊子的实验人群，并具有不同的最近进化史。研究人员将使用急性应力实验来测试进化史对初始和进化的热耐受性的影响。与良性环境相比，多代介体实验将用于测试进化史如何影响暴露于慢性新颖应激（接近致命的热量）的人群中的个人适应性，人群动态和扩展概率。最后，研究人员将从野生种群中产生整个基因组序列数据，以及从中cosm人群收集的时间序列，以识别适应性和删除术的基因组机制。该项目将为遗传漂移和基因流的生态进化作用提供独特的机械观点，并可能从根本上改变人们对基因流在当代人群中的作用的普遍公认的期望。该奖项反映了NSF的法定任务，并通过使用该基金会的知识分子和更广泛的影响来评估NSF的法定任务，并通过评估诚实地表示支持。

项目成果

Reproductive benefits associated with dispersal in headwater populations of Trinidadian guppies ( Poecilia reticulata )

与特立尼达孔雀鱼（Poecilia reticulata）源头种群扩散相关的生殖益处

• DOI: 10.1111/ele.13929
• 发表时间: 2021
• 期刊: Ecology Letters
• 影响因子: 8.8
• 作者: Borges, Isabela L.;Dangerfield, Jillian C.;Angeloni, Lisa M.;Funk, W. Chris;Fitzpatrick, Sarah W.;Grether, ed., Greg
• 通讯作者: Grether, ed., Greg

Understanding Local Adaptation to Prepare Populations for Climate Change

了解当地的适应措施，让人们做好应对气候变化的准备

• DOI: 10.1093/biosci/biac101
• 发表时间: 2022
• 期刊: BioScience
• 影响因子: 10.1
• 作者: Meek, Mariah H;Beever, Erik A;Barbosa, Soraia;Fitzpatrick, Sarah W;Fletcher, Nicholas K;Mittan-Moreau, Cinnamon S;Reid, Brendan N;Campbell-Staton, Shane C;Green, Nancy F;Hellmann, Jessica J
• 通讯作者: Hellmann, Jessica J

Road salt is more toxic to wood frog embryos from polluted ponds

• DOI: 10.1016/j.envpol.2021.118757
• 发表时间: 2022-03-01
• 期刊: ENVIRONMENTAL POLLUTION
• 影响因子: 8.9
• 作者: Forgione, Mia E.;Brady, Steven P.
• 通讯作者: Brady, Steven P.

The crucial role of genome-wide genetic variation in conservation

• DOI: 10.1073/pnas.2104642118
• 发表时间: 2021-11-30
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Kardos, Marty;Armstrong, Ellie E.;Funk, W. Chris
• 通讯作者: Funk, W. Chris