Soil Biodiversity Group, Department of Life Sciences, The Natural History Museum, London SW7 5BD, UK.
Centre for Biodiversity and Environmental Research, Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK.
Proc Biol Sci. 2024 Jun;291(2024):20232791. doi: 10.1098/rspb.2023.2791. Epub 2024 Jun 5.
Sociality underpins major evolutionary transitions and significantly influences the structure and function of complex ecosystems. Social insects, seen as the pinnacle of sociality, have traits like obligate sterility that are considered 'master traits', used as single phenotypic measures of this complexity. However, evidence is mounting that completely aligning both phenotypic and evolutionary social complexity, and having obligate sterility central to both, is erroneous. We hypothesize that obligate and functional sterility are insufficient in explaining the diversity of phenotypic social complexity in social insects. To test this, we explore the relative importance of these sterility traits in an understudied but diverse taxon: the termites. We compile the largest termite social complexity dataset to date, using specimen and literature data. We find that although functional and obligate sterility explain a significant proportion of variance, neither trait is an adequate singular proxy for the phenotypic social complexity of termites. Further, we show both traits have only a weak association with the other social complexity traits within termites. These findings have ramifications for our general comprehension of the frameworks of phenotypic and evolutionary social complexity, and their relationship with sterility.
社会性是主要进化转变的基础，并显著影响复杂生态系统的结构和功能。社会性昆虫被视为社会性的巅峰，具有强制性不育等特征，这些特征被视为“主要特征”，被用作衡量这种复杂性的单一表型指标。然而，越来越多的证据表明，完全将表型和进化的社会复杂性以及强制性不育作为两者的核心对齐是错误的。我们假设强制性和功能性不育不足以解释社会性昆虫表型社会复杂性的多样性。为了验证这一点，我们在一个研究较少但多样化的分类群——白蚁中探索这些不育特征的相对重要性。我们使用标本和文献数据编制了迄今为止最大的白蚁社会复杂性数据集。我们发现，虽然功能性和强制性不育解释了很大一部分方差，但这两个特征都不是白蚁表型社会复杂性的充分单一代表。此外，我们还表明，这两个特征与白蚁内部其他社会复杂性特征的相关性都很弱。这些发现对我们对表型和进化社会复杂性的框架及其与不育的关系的一般理解具有重要意义。
