Comparing genetic diversity, genetic differentiation, and performance between native and nonnative populations has advanced our knowledge of contemporary evolution and its ecological consequences. However, such between‐range comparisons can be complicated by high among‐population variation within native and nonnative ranges. For example, native vs. nonnative comparisons between small and non‐representative subsets of populations for species with very large distributions have the potential to mislead because they may not sufficiently account for within‐range adaptation to climatic conditions, and demographic history that may lead to non‐adaptive evolution. We used the cosmopolitan weed Conyza canadensis to study the interplay of adaptive and demographic processes across, to our knowledge, the broadest climatic gradient yet investigated in this context. To examine the distribution of genetic diversity, we genotyped 26 native and 26 nonnative populations at 12 microsatellite loci. Furthermore, we recorded performance traits for 12 native and 13 nonnative populations in the field and in the common garden. To analyze how performance was related to range and/or climate, we fit pedigree mixed‐effects models. These models weighed the population random effect for co‐ancestry to account for the influence of demographic history on phenotypic among‐population differentiation. Genetic diversity was very low, selfing rates were very high, and both were comparable between native and nonnative ranges. Nonnative populations out‐performed native populations in the field. However, our most salient result was that both neutral genetic differentiation and common garden performance were far more correlated with the climatic conditions from which populations originated than native vs. nonnative range affiliation. Including co‐ancestry of our populations in our models greatly increased explained variance and our ability to detect significant main effects for among‐population variation in performance. High propagule pressure and high selfing rates, in concert with the ability to adapt rapidly to climatic gradients, may have facilitated the global success of this weed. Neither native nor nonnative populations were homogeneous groups but responded comparably to similar environments in each range. We suggest that studies of contemporary evolution should consider widely distributed and genotyped populations to disentangle native vs. nonnative range effects from varying adaptive processes within ranges and from potentially confounding effects of demographic history.

中文翻译：

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对于国际化杂草的遗传学和常见花园表现，气候胜过原生和非原生范围效应

比较本地居民和非本地居民之间的遗传多样性，遗传分化和表现，提高了我们对当代进化及其生态后果的认识。但是，这种范围之间的比较可能会由于本地和非本地范围内较高的人群间差异而变得复杂。例如，对于分布非常大的物种，种群的小种群和非代表性种群之间的本地与非本地比较可能会产生误导，因为它们可能不足以说明在一定范围内对气候条件的适应性，以及可能导致人口统计学变化的人口历史非适应性进化。我们使用了世界性杂草加拿大康乃滋就我们所知，研究适应气候变化和人口统计过程之间的相互作用，这是迄今为止在此背景下调查的最广泛的气候梯度。为了检查遗传多样性的分布，我们对12个微卫星基因座处的26个本地种群和26个非本地种群进行了基因分型。此外，我们记录了田间和公共花园中12个本地种群和13个非本地种群的性能特征。为了分析性能与范围和/或气候之间的关系，我们拟合了谱系混合效应模型。这些模型权衡了共同祖先的人口随机效应，以说明人口历史对人口之间表型分化的影响。遗传多样性非常低，自交率非常高，在本地和非本地范围内都相当。在该领域中，非本地人口的表现优于本地人口。然而，我们最显着的结果是，中性遗传分化和常见的园林表现都与种群起源的气候条件相比，与本地和非本地范围的隶属关系更为相关。在我们的模型中包括我们的人口共同祖先，极大地增加了解释方差，并且我们能够发现绩效中种群间差异的重大主要影响。高繁殖力和高自交率，以及快速适应气候梯度的能力，可能促进了该杂草的全球成功。本地和非本地人口都不是同质群体，但在每个范围内对相似环境的反应都相当。