CAREER: Empirically evaluating the genomic consequences of assisted migration in heterogeneous environments

应对人为气候变化既是一个社会学问题，也是一个科学问题。目前的研究表明，许多物种现在落后于不断变化的气候条件，相对于过去的条件，它们的表现很差。确定哪些物种受到影响，物种减少的速度有多快，以及评估应对下降的潜在解决方案是关键目标。一种可能的解决办法是协助移徙，即有意将地理上相距遥远的人口中更好地适应不断变化的条件的个人引入重点人口。辅助移民是有争议的，因为当将新的变异引入种群时，往往会产生未知的后果，而且它在很大程度上没有通过对照实验进行测试。这一奖项实验性地解决了在一种分布广泛的植物中辅助迁移的后果，该植物在其分布的一小部分受到威胁。来自已经适应当代条件的种群的种子和幼苗将被引入重点种群的子集。对这些实验种群和附近对照种群的特征、基因组和种群成功进行比较，将提供迄今为止收集到的关于辅助迁徙的效率和潜在效用的最佳经验数据。该奖项还通过向中学教育教师提供在课堂上解决这一问题所需的技能、教案和信息，满足了全美公众更好地了解气候变化的需要。该奖项资助创建了一个动态的类似游戏的气候变化推广模块，一个由研究生领导的走进中学课堂的科学推广小组，以及一个为有抱负的STEM教师开设的研讨会课程，以指导教师如何解决有争议的问题。这里授予的辅助迁移实验评估了三个主要问题：导入后整个基因组发生了多少导入，以及这种导入持续了多长时间？内倾是否改变了性状分布或使超越型表型出现？在正常年份或极端年份，引种是否能改善当地人的健康状况？该项目通过利用模式生物Mimulus guttatus的基因组资源来解决这些问题。初步数据表明，与海拔匹配的加州种群比本地俄勒冈梯级种群具有更高的适合度，俄勒冈梯级种群在极端气候年份面临灭绝的危险。该项目将加州人口引入了过去三年一直被跟踪的12个人口子集。通过使用低复盖率的全基因组测序来跟踪引进种群在引进后三年内特有的遗传变异，将调查引进种群导入的数量和时间。一项为期多年的普通花园实验将用每年在实验期间收集的种子来评估辅助迁徙后表型和适应能力的变化。虽然这项实验为保护区提供了重要的价值，但它也将为进化力量如何在自然种群中相互作用以消除和维持快速生态时间尺度上的多态提供新的见解。这一奖项主要用于培训五名本科生研究人员和一名研究生，主要通过多样性倡议招募，以及通过针对多个年龄段的既定外展活动进行公开传播。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Responding to anthropogenic climate change is both a sociological and a scientific issue. Current studies suggest that many species are now lagging behind changing climatic conditions and are doing poorly relative to past conditions. Determining which species are impacted, how fast species are declining, and evaluating potential solutions to counter declines are key goals. One potential solution is assisted migration, where individuals from a geographically-distant population that are better adapted to the changing conditions are intentionally introduced into a focal population. Assisted migration is controversial because there are often unknown consequences when introducing new variation into a population, and because it has largely been untested via controlled experiments. This award experimentally addresses the consequences of assisted migration in a widespread plant that is threatened in a small portion of its distribution. Seeds and seedlings from populations already adapted to contemporary conditions will be introduced into a subset of focal populations. Comparisons of traits, genomes, and population success between these experimental populations and nearby control populations will provide the best empirical data collected to date on the efficiency and potential utility of assisted migration. This award also addresses the need for greater public understanding of climate change across the U.S. by providing secondary education teachers with the skills, lesson plans, and information necessary to address this issue in the classroom. This award funds the creation of a dynamic game-like climate change outreach module, a graduate student-led science outreach team to go into secondary education classrooms, and a seminar course for aspiring STEM teachers to instruct teachers how to address contentious issues. The assisted migration experiment awarded here evaluates three main questions: how much introgression occurs across the genome following the introduction and how long does it persist? Does introgression shift trait distributions or enable transgressive phenotypes to emerge? Do introductions improve fitness of the native populations in normal or extreme years? This project addresses these questions by leveraging the genomic resources of a model organism, Mimulus guttatus. Preliminary data indicate that elevation-matched California populations have higher fitness than native Oregon Cascades populations, and that Oregon Cascades populations are in danger of extirpation in extreme climatic years. This project introduces California populations into a subset of twelve populations that have been followed for the last three years. The amount and timing of introgression following introduction will be surveyed by using low coverage whole genome sequencing to track genetic variants specific to the introduced populations over three years post-introduction. A multi-year common garden experiment with seeds collected each year during the experiment will be used to evaluate how phenotypes and fitness changes following assisted migration. While this experiment provides important value to the conservation community, it also will provide novel insights into how evolutionary forces interact within a natural population to remove and maintain polymorphism on rapid ecological timescales. This award funds training for five undergraduate researchers and a graduate student recruited primarily through diversity initiatives as well as public dissemination via established outreach events targeting multiple age groups.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.