Understanding the evolutionary dynamics of genetic diversity is fundamental for species conservation in the face of climate change, particularly in hyper-diverse biomes. Species in a region may respond similarly to climate change, leading to comparable evolutionary dynamics, or individualistically, resulting in dissimilar patterns. The second-largest expanse of continuous tropical rain forest (TRF) in the world is found in Central Africa. Here, present-day patterns of genetic structure are thought to be dictated by repeated expansion and contraction of TRFs into and out of refugia during Pleistocene climatic fluctuations. This refugia model implies a common response to past climate change. However, given the unrivalled diversity of TRFs, species could respond differently because of distinct environmental requirements or ecological characteristics. To test this, we generated genome-wide sequence data for >700 individuals of seven codistributed plants from Lower Guinea in Central Africa. We inferred species’ evolutionary and demographic histories within a comparative phylogeographic framework. Levels of genetic structure varied among species and emerged primarily during the Pleistocene, but divergence events were rarely concordant. Demographic trends ranged from repeated contraction and expansion to continuous growth. Furthermore, patterns in genetic variation were linked to disparate environmental factors, including climate, soil, and habitat stability. Using a strict refugia model to explain past TRF dynamics is too simplistic. Instead, individualistic evolutionary responses to Pleistocene climatic fluctuations have shaped patterns in genetic diversity. Predicting the future dynamics of TRFs under climate change will be challenging, and more emphasis is needed on species ecology to better conserve TRFs worldwide.

了解遗传多样性的进化动态是面对气候变化时物种保护的基础，尤其是在高度多样化的生物群落中。一个地区的物种可能对气候变化做出相似的反应，从而导致类似的进化动态，或者个体化，导致不同的模式。世界上第二大连续热带雨林（TRF）位于中非。在这里，目前的遗传结构模式被认为是由更新世气候波动期间 TRF 进出避难所的反复扩张和收缩决定的。这种避难所模型意味着对过去气候变化的共同反应。然而，鉴于 TRF 无与伦比的多样性，由于不同的环境要求或生态特征，物种可能会做出不同的反应。为了测试这一点，我们为来自中非下几内亚的七种共分布植物的 700 多个个体生成了全基因组序列数据。我们在比较系统地理学框架内推断了物种的进化和人口历史。遗传结构水平因物种而异，主要出现在更新世，但分歧事件很少一致。人口趋势从反复收缩和扩张到持续增长。此外，遗传变异模式与不同的环境因素有关，包括气候、土壤和栖息地稳定性。使用严格的避难所模型来解释过去的 TRF 动力学过于简单。相反，对更新世气候波动的个人主义进化反应塑造了遗传多样性的模式。