Evolutionary response to environmental uncertainty

自然环境在不断变化;变化可以是任何规模，并在所有时间尺度上发生。 超过99%居住在这个星球上的物种现在已经灭绝，剩下的物种是进化谱系的代表，它们在所有变化中幸存下来。 适应变化的研究具有广泛的适用性;例如，引起传染病的微生物的进化是一个快速适应新（宿主）环境的故事。 尽管它很重要，但关于生物体如何进化以科普变化，还有很多东西需要了解。 我们知道，适应有三种主要形式：1）随着环境的变化而进化的“跟踪”，2）在生物体的一生中进行可塑性调整以适应环境的能力的进化，以及3）安全或“对冲”特征的进化，以避免在困难时期的风险（类似于购买保险）。 关于这三种形式的适应的相对重要性，或者它们如何通过未来的变化相互作用以影响生存，人们知之甚少。这项由NSERC发现补助金支持的研究将通过使用新的实验室和现场方法，促进对生物体对环境变化的反应的理解。在实验进化研究中，我们将真菌粗糙脉孢菌置于可变环境中直接观察进化。 我们的目标是发现过去环境变化的模式对于使其能够生存到未来的特征进化有多么重要。 然后，我们将使用DNA测序技术来识别参与这种适应变化的基因。 利用世界上最小的开花植物浮萍，我们将问是什么机制允许生存通过艰难的时期。 我们研究的水生物种通过产生沉到池塘底部的“turions”来度过冬天。 为了更好地了解适应不可预测的季节长度，我们将研究先天和环境差异在确定的物候期的turion生产的相对重要性。 在另一组研究中，我们将使用“DNA指纹”技术直接研究可变环境对田间草本植物基因型命运的影响。 最后，我们使用树木年轮中包含的信息来告诉我们特定环境的变化，然后询问在相同环境中草本植物的适应是否与预测的一样，以及这些适应的性质是什么。 因此，我们使用了一系列广泛的实验系统，使我们能够解决所有统一的中心问题，即生物体如何进化以应对环境变化。 这项基础研究提供的知识对加拿大具有重要的潜在应用，从应对气候变化到医学。

Natural environments are constantly changing; changes can be of any magnitude and occur over all time scales. Over 99% of species that have inhabited this planet are now extinct, and the remaining species are representatives of evolving lineages that have survived all change. Study of adaptation to change has broad applicability; for example, evolution of infectious disease-causing microbes is a story of rapid adaptation to new (host) environments. Despite its importance, much remains to be learned about how organisms evolve to cope with change. We do know that adaptation takes three main forms: 1) evolutionary "tracking" of the environment as it changes, 2) the evolution of the ability to make plastic adjustments to suit the circumstances within an organism's lifetime, and 3) the evolution of safe or "bet-hedging" characteristics to avert risk during hard times (analogous to purchasing insurance). Little is known about the relative importance of these three forms of adaptation, or how they interact to influence survival through future change. The research supported by this NSERC Discovery Grant will lead to progress in the understanding of organismal response to environmental variation by using novel experimental laboratory and field approaches.*** In an experimental evolution study, we will subject the fungus Neurospora crassa to variable environments to observe evolution directly. We aim to discover how important the past pattern of changing environments is to the evolution of traits that allow it to survive into the future. We will then use DNA sequencing techniques to identify the genes that are involved in this adaptation to change. Using duckweed, the smallest flowering plants in the world, we will ask what mechanisms allow survival through harsh times. The aquatic species we study survives winter by producing "turions" that sink to the bottom of ponds. To better understand adaptation to unpredictable season length, we will study the relative importance of innate and environmental differences in determining the phenology of turion production. In another set of studies, we will use "DNA fingerprinting" techniques to directly study the effect of variable environments on the fate of genotypes of herbaceous plants in the field. Finally, we use information contained in tree rings to inform us about how variable particular environments have been, and then ask whether adaptations in herbaceous plants in the same environments are as would be predicted, and what the nature of these adaptations are. Thus, we use a wide array of experimental systems that enable us to address problems all unified by the central question of how organisms evolve in response to environmental variation. This fundamental research provides knowledge that has potential applications important to Canada ranging from response to climate change to medicine.**