Demographic history and genomic diversity and divergence in blue tit populations across heterogeneous environments

Understanding the genomic processes underlying local adaptation is a central aim of modern evolutionary biology. This task requires identifying footprints of local selection but also estimating spatio-temporal variation in population demography and variation in recombination rate and diversity along the genome. Here, we investigated these parameters in blue tit populations inhabiting deciduous versus evergreen forests and insular versus mainland areas, in the context of a previously described strong phenotypic differentiation. Neighboring population pairs of deciduous and evergreen habitats were weakly genetically differentiated (FST = 0.004 on average), nevertheless with a statistically significant effect of habitat type on the overall genetic structure. This low differentiation was consistent with the strong and long-lasting gene flow between populations, inferred by demographic modeling. In turn, insular and mainland populations were moderately differentiated (FST = 0.08 on average),...解析局部适应背后的基因组学过程，是现代进化生物学的核心研究目标之一。该研究不仅需要识别局部选择的遗传印迹，还需估算种群动态的时空变异，以及基因组范围内重组率与遗传多样性的变异情况。本研究以蓝山雀（blue tit）种群为研究对象，在已有研究报道其存在显著表型分化的背景下，探究了栖息于落叶林与常绿林、岛屿与大陆生境的种群的上述参数。相邻落叶林与常绿林生境的种群对遗传分化程度较弱，平均遗传分化系数（Fixation Index, FST）为0.004，但生境类型对整体遗传结构仍存在统计学上的显著影响。这种低水平的遗传分化与通过种群动态模型推断得到的种群间强烈且持久的基因流相符。反之，岛屿与大陆种群的遗传分化程度中等，平均遗传分化系数（Fixation Index, FST）为0.08，...