Data from: Modelling competition and dispersal in a statistical phylogeographic framework

Competition between organisms influences the processes governing the colonization of new habitats. As a consequence, species or populations arriving first at a suitable location may prevent secondary colonization. While adaptation to environmental variables (e.g., temperature, altitude, etc.) is essential, the presence or absence of certain species at a particular location often depends on whether or not competing species co-occur. For example, competition is thought to play an important role in structuring mammalian communities assembly. It can also explain spatial patterns of low genetic diversity following rapid colonization events or the “progression rule” displayed by phylogenies of species found on archipelagos. Despite the potential of competition to maintain populations in isolation, past quantitative analyses have largely ignored it because of the difficulty in designing adequate methods for assessing its impact. We present here a new model that integrates competition and dispersal into a Bayesian phylogeographic framework. Extensive simulations and analysis of real data show that our approach clearly outperforms the traditional Mantel test for detecting correlation between genetic and geographic distances. But most importantly, we demonstrate that competition can be detected with high sensitivity and specificity from the phylogenetic analysis of genetic variation in space.

生物间的竞争会影响调控新栖息地定殖过程的相关机制。因此，率先抵达适宜生境的物种或种群，往往会阻碍后续的定殖事件。尽管对环境变量（如温度、海拔等）的适应性至关重要，但特定区域内某些物种的存在与否，通常取决于是否有竞争物种与之共存。例如，学界普遍认为竞争在塑造哺乳动物群落的组装过程中发挥着关键作用。此外，竞争还可以解释快速定殖事件后出现的低遗传多样性空间格局，以及群岛物种系统发育所呈现的“前进法则”。尽管竞争具备维持孤立种群的潜力，但过往的定量分析大多未将其纳入考量，原因在于难以设计出有效评估其影响的方法。本文提出了一种将竞争与扩散整合至贝叶斯系统地理学框架（Bayesian phylogeographic framework）的全新模型。大量模拟实验与真实数据分析结果表明，在检测遗传距离与地理距离的相关性方面，我们的方法显著优于传统的曼特尔检验（Mantel test）。而最为关键的是，本研究证明，通过对空间遗传变异开展系统发育分析，可以高灵敏度、高特异性地检测到竞争作用的存在。