A lack of optimal gene combinations, as well as low levels of genetic diversity, is often associated with the formation of species range margins. Conservation efforts rely on predictive modelling using abiotic variables and assessments of genetic diversity to determine target species and populations for controlled breeding, germplasm conservation and assisted migration. Biotic factors such as interspecific competition and hybridization, however, are largely ignored, despite their prevalence across diverse taxa and their role as key evolutionary forces. Hybridization between species with well‐developed barriers to reproductive isolation often results in the production of offspring with lower fitness. Generation of novel allelic combinations through hybridization, however, can also generate positive fitness consequences. Despite this possibility, hybridization‐mediated introgression is often considered a threat to biodiversity as it can blur species boundaries. The contribution of hybridization towards increasing genetic diversity of populations at range margins has only recently gathered attention in conservation studies. We assessed the extent to which hybridization contributes towards range dynamics by tracking spatio‐temporal changes in the central location of a hybrid zone between two recently diverged species of pines: Pinus strobiformis and P. flexilis. By comparing geographic cline centre estimates for global admixture coefficient with morphological traits associated with reproductive output, we demonstrate a northward shift in the hybrid zone. Using a combination of spatially explicit, individual‐based simulations and linkage disequilibrium variance partitioning, we note a significant contribution of adaptive introgression towards this northward movement, despite the potential for differences in regional population size to aid hybrid zone movement. Overall, our study demonstrates that hybridization between recently diverged species can increase genetic diversity and generate novel allelic combinations. These novel combinations may allow range margin populations to track favourable climatic conditions or facilitate adaptive evolution to ongoing and future climate change.

中文翻译：

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在物种形成的人口统计历史和基因流下追踪移动混合区的足迹。

缺乏最佳基因组合以及遗传多样性水平较低通常与物种分布范围边缘的形成有关。保护工作依靠使用非生物变量和遗传多样性评估的预测模型来确定控制育种、种质保护和辅助迁徙的目标物种和种群。然而，种间竞争和杂交等生物因素在很大程度上被忽视，尽管它们在不同的类群中普遍存在，并且它们作为关键的进化力量发挥着作用。具有良好生殖隔离障碍的物种之间的杂交通常会导致产生适应性较低的后代。然而，通过杂交产生新的等位基因组合也可以产生积极的适应性结果。尽管存在这种可能性，但杂交介导的基因渗入通常被认为对生物多样性构成威胁，因为它会模糊物种界限。杂交对增加分布范围边缘种群遗传多样性的贡献最近才引起保护研究的关注。我们通过跟踪两种最近分化的松树（松树和松树）之间的杂交区域中心位置的时空变化，评估了杂交对范围动态的贡献程度。通过比较地理 Cline 中心对全球混合系数的估计与与生殖输出相关的形态特征，我们证明了混合区的北移。通过结合空间明确的、基于个体的模拟和连锁不平衡方差划分，我们注意到适应性渗入对这种向北移动的显着贡献，尽管区域人口规模的差异可能有助于混合区移动。总的来说，我们的研究表明，最近分化的物种之间的杂交可以增加遗传多样性并产生新的等位基因组合。这些新颖的组合可能允许范围边缘种群跟踪有利的气候条件或促进对当前和未来气候变化的适应性进化。