The evolutionary consequences of environmental uncertainty

自然环境是不断变化的，这是众所周知的，有时会导致极端变化的进化适应性。现存物种是迄今为止所有环境中幸存者的少数代表。这个NSERC支持的研究计划的最终目标是帮助了解生物体如何在不断变化的情况下进化。它涉及基本问题，但具有广泛的适用性。例如，引起传染病的微生物的进化是一个适应不断变化的宿主环境的故事。生物体对变化的反应主要有三种方式：1）通过适应性地“跟踪”变化的环境，2）通过一生中的“可塑性”调整，3）通过进化“对冲”特征来降低完全失败的风险。关于这三种反应形式的相对重要性，它们如何相互作用以影响成功，或者它们演变的时间尺度，我们知之甚少。这项由NSERC发现资助支持的研究采用了在实验室和现场进行的理论，观察和实验方法，以促进对生物体对不断变化的环境的反应的理解。 第一项研究使用计算和实验来询问所谓的赌注对冲的进化是如何可能的。根据定义，下注对冲特征在长时间内是有利的，但在“正常”时期是有害的。一名博士生的目标是发现在正常情况下不会“不进化”有害的下注对冲特征的遗传基础;另一名博士生将建立一个计算模型，以询问这种约束在较长时间内的进化。 第二组项目使用草本植物，半边莲膨胀，问的问题，负责表达的特点，潜在的健身机制。例如，L.从异交进化而来？这个问题将通过比较这个物种与密切相关的异交物种，并通过公民科学（iNaturalist）的交配系统的地理差异的摄影证据L。穿越了整个北美东部 第三组项目的重点是微小的漂浮水生植物，螺旋藻，独特的生产哈代种子般的“洋葱”，下沉到沉积物，使生存，尽管不可预测的冬季开始。在春季从沉积物中重新激活的时间是由一个多样化的风险传播策略的影响，这种策略在种群之间的遗传差异。这种植物提供了一个机会，问基本问题的重要性，多样化的生存，也对“生态进化动力学”：遗传差异的影响多样化的结果物种之间的竞争相互作用。这项研究将有助于生物体对环境变化的反应的基础知识，包括灭绝抗性。

Natural environments are continually changing, which is known to cause sometimes extreme variation in evolutionary fitness. Existing species are the few representatives of survivors of all environments to the present time. The ultimate goal of this NSERC-supported research program is to contribute to an understanding of how organisms evolve in the face of continual change. It addresses fundamental questions, but has broad applicability. For example, evolution of infectious disease-causing microbes is a story of adaptation to changing host environments. There are three main ways in which organisms respond to change: 1) by adaptively "tracking" changing environments, 2) through "plastic" adjustments within a lifetime, and 3) by evolving "bet-hedging" traits that reduce risk of complete failure. Little is known about the relative importance of these three forms of response, how they interact to influence success, or the time scales over which they evolve. The research supported by this NSERC Discovery Grant takes theoretical, observational and experimental approaches conducted both in the lab and the field to advance understanding of organismal response to changing environments.    The first study uses computation and experiments to ask how the evolution of so-called bet hedging is even possible. By definition, bet-hedging traits are advantageous over long time periods, but are detrimental during "normal" times. One PhD student aims to discover the genetic basis of not "un-evolving" the detrimental bet-hedging trait during normal times; another will build a computational model to ask about the evolution of such constraints over longer time periods.    A second set of projects uses the herbaceous plant, Lobelia inflata, to ask questions about the mechanisms responsible for expression of traits underlying fitness. For example, how did the self-fertilizing mating system in L. inflata evolve from outcrossing? This question will be addressed by comparing this species with closely related outcrossing species, and through citizen science (iNaturalist) photographic evidence of geographical differences in mating systems of L. inflata across eastern N.A.    The third set of projects focuses on the tiny floating aquatic plant, Spirodela polyrhiza, unique in producing hardy seed-like "turions" that sink to the sediment, allowing survival despite the unpredictable onset of winter. The timing of reactivation from the sediment in the spring is influenced by a diversified risk-spreading strategy, and this strategy differs genetically among populations. This plant offers the opportunity to ask fundamental questions about the importance of diversification for survival, and also about "eco-evolutionary dynamics": the effect of genetic differences in diversification on the outcome of competitive interactions among species. This research will contribute to fundamental knowledge of organismal response to environmental variance, including extinction resistance.