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）作为达尔文曾提出的特殊难题，尽管已被广泛研究，但在有机体生物学领域仍是极具争议的议题。真社会性类群对现有理论构成挑战，而高度整合的社会结构对物种多样化动态的影响尚存争议，相关文献中存在相互对立的主张与假说。本研究以首个演化出真社会性的类群——白蚁为研究对象，采用系统发育分析方法（phylogenetic approaches），验证了“真社会性支系的物种多样化速率高于非真社会性支系”这一核心预测。研究结果得到多条证据支持：相较于非真社会性类群，真社会性类群的物种多样化速率更高；其中以具有“真职虫（true workers）”的真社会性类群尤为显著，其优势相比具有“假职虫（false workers）”的类群更为突出。由于多数具有“真职虫”的类群拥有完全的原核微生物组（prokaryotic microbiota），这一特征也与更高的物种多样化速率相关，但该关联仍需进一步探究，尤其是在被子植物（angiosperm）多样化的相关研究中。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历程中亦如此；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产生作用。