The role of contemporary evolution in shaping life history, demography and the fate of functional genetic variation in natural populations

当代进化在塑造自然种群的生命史、人口统计学和功能遗传变异的命运方面的作用

• 批准号: RGPIN-2015-03683
• 负责人: Milot, Emmanuel
• 金额: $ 1.89万
• 依托单位: Université du Québec à Trois-Rivières
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=681710
• 关键词: role; contemporary; evolution; shaping; life

Evolutionary biology has undergone a small revolution with the recent demonstration that evolution by natural selection can be detected over just a few years or decades in the wild. For example, there is evidence that selection due to global warming can modify the timing of reproductive timing in animals at the genetic level. This raises major questions about the importance and consequences of rapid evolution in contemporary natural populations, e.g. how evolution contributes to their short-term adaptation and alters ecological processes such as population dynamics. My research programme will address these questions by following genetic variation "in real time", namely generation-by-generation, using genealogical and molecular data. I will use the French-Canadian population from Québec as a model to study life-history traits (e.g., fertility, lifespan) evolution. Exceptional data spanning four centuries, and unequalled by long-term animal data sets, is available for this population. Previously, I documented a microevolutionary change (i.e. a genetic response to natural selection) in the age at first reproduction of women in a regional population from Québec over 140 years. With my Discovery Grant, I will assess the heterogeneity of such evolutionary responses across populations facing similar or different environmental conditions. I will then quantify how temporal changes in life history moulded the demography of populations. Rapid life history evolution can also have cascading effects on functionally important genetic variants. Hence, I will develop a new class of models that will allow the measurement, across generations, of natural selection on variants affecting organismal condition and lifespan, to link dynamically changes in life history to those in the frequency of genetic variants. By following molecular variation across generations, I will also test the "mother's curse", an important hypothesis that could partly explain the faster senescence and shorter lifespan of males in many species. This programme will thus follow a logical sequence by investigating the feedback loop "life-history trait evolution->demography->variant frequencies-> life-history trait evolution". It should provide major insights into how contemporary evolution shapes the dynamics of population and their adaptation. This issue is most relevant within the context of global environmental changes that modern living organisms are currently facing.

进化生物学已经经历了一场小小的革命，最近的证据表明，自然选择的进化可以在几年或几十年内在野外被发现。例如，有证据表明，全球变暖导致的选择可以在遗传水平上改变动物的生殖时间。这就提出了关于现代自然种群快速进化的重要性和后果的重大问题，例如进化如何有助于它们的短期适应和改变生态过程，如种群动态。我的研究计划将通过“真实的时间”，即逐代跟踪遗传变异，利用系谱和分子数据来解决这些问题。我将使用魁北克的法裔加拿大人作为研究生活史特征的模型（例如，生育力、寿命）进化。对于这一种群，可获得跨越四个世纪的特殊数据，这些数据是长期动物数据集所无法比拟的。在此之前，我记录了一个微进化的变化（即自然选择的遗传反应）在魁北克地区人口的妇女在第一次繁殖的年龄超过140年。有了我的发现补助金，我将评估面临相似或不同环境条件的人群中这种进化反应的异质性。然后，我将量化生活史的时间变化如何塑造人口的人口统计学。快速的生活史进化也可能对功能重要的遗传变异产生级联效应。因此，我将开发一类新的模型，它将允许跨代测量影响生物体状况和寿命的变异的自然选择，将生命史的动态变化与遗传变异频率的变化联系起来。通过跟踪几代人之间的分子变异，我还将测试“母亲的诅咒”，这是一个重要的假设，可以部分解释许多物种中雄性的衰老速度更快和寿命更短。因此，这一方案将遵循一个逻辑顺序，调查反馈回路“生活史特征演变->人口统计学->变异频率->生活史特征演变”。它应该为当代进化如何塑造人口动态及其适应提供重要见解。这一问题在现代生物体目前面临的全球环境变化的背景下最为相关。