Evolutionary Epigenetics - Epigenetic Variation in Natural Populations and its Relevance to Ecology and Evolution

自世纪达尔文进化论和孟德尔遗传原理合并以来，遗传变异一直是进化研究的核心。全基因组范围内的遗传变异分离在自然种群的审查提供了基本的见解适应和物种形成的进化过程。然而，将DNA蓝图的表观遗传修饰纳入扩展的进化合成的呼吁一再提出。事实上，表观遗传变异构成了表型变异的重要修饰因子，并可能促进可塑性反应，使种群能够探索新的生态位空间。然而，表观遗传修饰的进化相关性将取决于环境诱导和跨代稳定性之间的关系，而与潜在的遗传变异无关。这两个方面的综合数据基本上是缺乏的。本研究计划提出，以填补这一知识空白，使用广泛的地理抽样制度，超过2,400个人的血统知情的自然种群的两种鸟类作为模型：大山雀，山雀，蓝山雀，蓝山雀。具体来说，我们将使用这种设置来表征在各种整合尺度上形成5 mC DNA甲基化多样性的内在和外在力量。首先，我们将量化这些表观遗传标记在家庭（育雏）内的遗传模式，利用额外的一对年轻人的额外力量。其次，我们将确定不同环境中群体水平的表观遗传变异程度。第三，通过增加欧洲乌鸦，乌鸦（Corvus（corone）spp。我们将评估4400万年进化过程中遗传和表观遗传差异的程度。2这一综合性的研究计划在范围上是无与伦比的，并有望为形成表观遗传变异的力量提供基本的见解。通过量化母系和父系遗传成分和环境影响的贡献，它提供了一个有价值的基线，讨论表观遗传修饰在进化中的潜在作用。

Since the merger of Darwinian evolution and Mendelian hereditary principles at the onset of the 20th century, genetic variation has been at the core of evolutionary research. Genome-wide scrutiny of genetic variation segregating in natural populations has provided fundamental insights into the evolutionary processes underlying adaptation and speciation. Yet, calls for incorporating epigenetic modifications of the DNA blueprint into an extended evolutionary synthesis have repeatedly been made. And indeed, epigenetic variation constitutes an important modifier of phenotypic variation and may promote plastic responses allowing populations to explore novel niche space. Evolutionary relevance of epigenetic modification, however, will depend on the relationship between environmental inducibility and trans-generational stability independent of the underlying genetic variation. Comprehensive data on both of these aspects are essentially absent.This research program proposes to fill this knowledge gap using a broad geographic sampling regime of over 2,400 individuals from pedigree-informed natural populations of two avian species as a model: the great tit, Parus major, and the blue tit, Cyanistes caeruleus. Specifically, we will use this setup to characterize the intrinsic and external forces shaping diversity in 5mC DNA methylation across various scales of integration. First, we will quantify the inheritance patterns of these epigenetic marks within families (broods) leveraging additional power from extra pair young. Second, we will determine the extent of population-level epigenetic variability across diverse environments. Third, by adding populations of the European crow, Corvus (corone) spp. we will assess the degree of genetic and epigenetic divergence across 44 million years of evolution.This comprehensive research program is unparalleled in scope and is expected to provide fundamental insights into the forces shaping epigenetic variation. By quantifying the contribution of maternal and paternal genetic hereditary components and environmental effects it provides a valuable baseline to discuss the potential role of epigenetic modifications in evolution.