Phylogenomic approaches reveal how climate shapes patterns of genetic diversity in an African rain forest tree species

The world’s second largest expanse of tropical rain forest is in Central Africa and it harbours enormous species diversity. Population genetic studies have consistently revealed significant structure across central African rain forest plants, in particular a North-South genetic discontinuity around the equatorial line, in a continuous expanse of rain forest but where a climatic inversion is documented. Here, we took a phylogeographic approach by sequencing 351 nuclear markers in 112 individuals across the distribution of the African rain forest tree species Annickia affinis (Annonaceae). We showed for the first time that the North-South divide is the result of a single, major colonisation event across the climatic inversion from an ancestral population located in Gabon. We suggested that differences in ecological niche of populations located on either side of this inversion may have contributed to this phylogenetic discontinuity. We found evidence for inland dispersal, predominantly in ...世界第二大热带雨林分布于中非地区，这里孕育着极为丰富的物种多样性。种群遗传学研究始终揭示，中非热带雨林植物类群存在显著的遗传结构，尤其在这片连续分布的热带雨林中，赤道沿线存在一处南北向的遗传间断，而该区域曾被记录存在气候反转现象。本研究采用系统地理学研究方法，对非洲热带雨林树种Annickia affinis（番荔枝科Annonaceae）整个分布范围内的112个个体进行了351个核标记的测序。本研究首次证实，该南北向遗传间断源自一次跨越气候反转区的大规模拓殖事件，拓殖种群来自加蓬地区的祖先种群。我们推测，气候反转区两侧种群的生态位差异，可能是促成该系统发育间断形成的原因之一。本研究发现了内陆扩散的相关证据，且该扩散主要发生在……