A central goal in evolutionary biology is to understand how different evolutionary processes cause trait change in wild populations. However, quantifying evolutionary change in the wild requires linking trait change to shifts in allele frequencies at causal loci. Nevertheless, datasets that allow for such tests are extremely rare and existing theoretical approaches poorly account for the evolutionary dynamics that likely occur in ecological settings. Using a decade-long integrative phenome-to-genome time-series dataset on wild threespine stickleback ( Gasterosteus aculeatus ), we identified how different modes of selection (directional, episodic, and balancing) drive microevolutionary change in correlated traits over time. Most strikingly, we show that feeding traits changed by as much 25% across 10 generations which was driven by changes in the genetic architecture (i.e., in both genomic breeding values and allele frequencies at genetic loci for feeding traits). Importantly, allele frequencies at genetic loci related to feeding traits changed at a rate greater than expected under drift, suggesting that the observed change was a result of directional selection. Allele frequency dynamics of loci related to swimming traits appeared to be under fluctuating selection evident in periodic population crashes in this system. Our results show that microevolutionary change in a wild population is characterized by different modes of selection acting simultaneously on different traits, which likely has important consequences for the evolution of correlated traits. Our study provides one of the most thorough descriptions to date of how microevolutionary processes result in trait change in a natural population.

中文翻译：

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野生粘背鱼的微观进化变化：使用综合时间序列数据推断对选择的反应


进化生物学的一个中心目标是了解不同的进化过程如何导致野生种群的性状变化。然而，量化野生进化变化需要将性状变化与因果位点等位基因频率的变化联系起来。然而，允许进行此类测试的数据集极为罕见，现有的理论方法无法很好地解释生态环境中可能发生的进化动力学。使用野生三脊背鱼 （ Gasterosteus aculeatus ） 长达十年的表型组到基因组时间序列数据集，我们确定了不同的选择模式（定向、情景和平衡）如何随着时间的推移驱动相关性状的微进化变化。最引人注目的是，我们表明，在 10 代中，摄食性状发生了 25% 的变化，这是由遗传结构的变化驱动的（即，摄食性状的遗传位点的基因组育种值和等位基因频率）。重要的是，在漂移下，与摄食性状相关的遗传位点的等位基因频率的变化速度大于预期，这表明观察到的变化是定向选择的结果。与游泳性状相关的基因座的等位基因频率动态似乎处于波动选择之下，这在该系统的周期性种群崩溃中很明显。我们的结果表明，野生种群的微进化变化的特点是不同的选择模式同时作用于不同的性状，这可能对相关性状的进化产生重要影响。我们的研究提供了迄今为止对微进化过程如何导致自然种群性状变化的最详尽描述之一。