NSFGEO-NERC: Evolutionary Response of Southern Ocean Diatoms to Environmental Change

这项研究将考察硅藻（南大洋中一种重要的浮游生物）如何适应环境变化。硅藻将从南大洋的不同区域取样，包括德雷克海峡、南大洋的太平洋部分和罗斯海，并检查以确定这些地区硅藻的遗传变异范围。对一系列硅藻的实验将在家庭实验室进行，目的是测量几代硅藻的生理能力随着环境（温度和pH值）的方向性变化而发生的变化。野外种群遗传多样性的信息与潜在适应率和基因组变化率的信息相结合，将有助于深入了解极地海洋硅藻种群对未来表层海洋可能发生的或在过去气候条件下可能发生的环境变化作出反应的方式。这些信息可以更好地模拟海洋中的生物地球化学循环，并提高我们解释过去海洋状况记录的能力。该项目将支持一名博士生和一名博士后研究员以及几名本科生。这些科学家将学习实验进化的基础知识，这是生物学和海洋学领域正在寻求的一套技能。该项目还包括与梅特卡夫海洋与环境报告研究所的合作，该研究所将设计和促进在美国科学作家协会（NASW）年会上举行的一次会议，重点讨论与进化和气候变化有关的当前研究。生理和遗传变异是理解浮游植物进化过程的关键参数，但对南大洋硅藻来说，它们基本上是未知的。这两个因素在多大程度上决定了野外种群的可塑性和适应性，以及它们之间的相互作用将影响冷适应硅藻如何以及是否能够应对不断变化的环境。该项目包括利用分子方法识别硅藻遗传多样性的实地工作和实验室实验，以评估当代硅藻种群的生理变异范围，以及实验室进化实验，以评估遗传多样性和生理变异的结合如何影响硅藻在不断变化的环境下的进化潜力。这项研究将揭示生理变异、遗传多样性和进化潜力之间的一般关系，这些关系可能适用于不同的微生物分类群和地理区域，从而大大改善预测海洋生态系统变化的努力。该研究的结果可以整合到开发模型中，这些模型将进化纳入预测未来气候变化情景下的生态系统变化。

The research will examine how diatoms (an important group of plankton in the Southern Ocean) adapt to environmental change. Diatoms will be sampled from different regions of the Southern Ocean, including the Drake Passage, the Pacific Sector of the Southern Ocean and the Ross Sea and examined to determine the range of genetic variation among diatoms in these regions. Experiments on a range of diatoms will be conducted in home laboratories and will be aimed at measuring shifts in physiological capacities over many generations in response to directional changes in the environment (temperature and pH). The information on the genetic diversity of field populations combined with information on potential rates of adaptability and genome changes will provide insight into ways in which polar marine diatoms populations may respond to environmental changes that may occur in surface oceans in the future or may have occurred during past climate conditions. Such information allows better modeling of biogeochemical cycles in the ocean as well as improves our abilities to interpret records of past ocean conditions. The project will support a doctoral student and a postdoctoral researcher as well as several undergraduate students. These scientists will learn the fundamentals of experimental evolution, a skill set that is being sought in the fields of biology and oceanography. The project also includes a collaboration with the Metcalf Institute for Marine and Environmental Reporting that will design and facilitate a session focused on current research related to evolution and climate change to be held at the annual conference of the National Association of Science Writers (NASW). Both physiological and genetic variation are key parameters for understanding evolutionary processes in phytoplankton but they are essentially unknown for Southern Ocean diatoms. The extent to which these two factors determine plasticity and adaptability in field populations and the interaction between them will influence how and whether cold-adapted diatoms can respond to changing environments. This project includes a combination of field work to identify genetic diversity within diatoms using molecular approaches and experiments in the lab to assess the range of physiological variation in contemporary populations of diatoms and evolution experiments in the lab to assess how the combination of genetic diversity and physiological variation influence the evolutionary potential of diatoms under a changing environment. This research will uncover general relationships between physiological variation, genetic diversity, and evolutionary potential that may apply across microbial taxa and geographical regions, substantially improving efforts to predict shifts in marine ecosystems. Results from this study can be integrated into developing models that incorporate evolution to predict ecosystem changes under future climate change scenarios.