Data from: When Darwin’s special difficulty promotes diversification in insects

Eusociality, Darwin’s special difficulty, has been widely investigated but remains a topic of great debate in organismal biology. Eusocial species challenge existing theories, and the impact of highly integrated societies on diversification dynamics is controversial with opposing assertions and hypotheses in the literature. Here, using phylogenetic approaches in termites – the first group that has evolved eusociality – we assessed the fundamental prediction that eusocial lineages have higher diversification rates than non-eusocial clades. We found multiple lines of evidence that eusociality provided higher diversification as compared to non-eusociality. This is particularly exacerbated for eusocial species with ‘true’ workers as compared to species with ‘false’ workers. Because most species with ‘true’ workers have an entirely prokaryotic microbiota, the latter feature is also related to higher diversification rates, but it should be investigated further, notably in relation to angiosperm diversification. Overall, this study suggests that societies with ‘true’ workers are not only more successful at ecological timescales but also over millions of years, which further implies that both organism- and species-level traits act on species selection.真社会性（Eusociality）作为达尔文提出的特殊难题，虽已得到广泛研究，但在有机体生物学（organismal biology）领域仍是极具争议的核心议题。真社会性物种对现有演化理论构成挑战，而高度整合的社会群体对物种分化动态的影响仍存在广泛争议，学界存在诸多对立的论断与假说。本研究以最早演化出真社会性的类群——白蚁为研究对象，采用系统发育研究方法（phylogenetic approaches），验证了“真社会性支系的物种分化速率高于非真社会性支系”这一核心预测。研究结果得到多维度证据支持：相较于非真社会性类群，真社会性物种具有更高的物种分化速率；其中，拥有“真”职虫的真社会性类群，其分化优势相较于拥有“假”职虫的类群更为显著。由于多数拥有“真”职虫的类群携带有完整的原核微生物组（prokaryotic microbiota），这一特征也与更高的物种分化速率相关，但该关联仍需进一步研究，尤其是在被子植物（angiosperm）物种分化的相关语境下。总体而言，本研究表明，拥有“真”职虫的社会类群不仅在生态时间尺度上更具演化优势，在百万年级的长期演化尺度中亦如此；这进一步暗示，有机体层面与物种层面的性状均会对物种选择（species selection）产生作用。