Data from: Defensive traits exhibit an evolutionary trade-off and drive diversification in ants

Evolutionary biologists have long predicted that evolutionary trade-offs among traits should constrain morphological divergence and species diversification. However, this prediction has yet to be tested in a broad evolutionary context in many diverse clades, including ants. Here, we reconstruct an expanded ant phylogeny representing 82% of ant genera, compile a new family-wide trait database, and conduct various trait-based analyses to show that defensive traits in ants do exhibit an evolutionary trade-off. In particular, the use of a functional sting negatively correlates with a suite of other defensive traits including spines, large eye size, and large colony size. Furthermore, we find that several of the defensive traits that trade off with a sting are also positively correlated with each other and drive increased diversification, further suggesting that these traits form a defensive suite. Our results support the hypothesis that trade-offs in defensive traits significantly constrain trait evolution and influence species diversification in ants.

进化生物学家长期以来便已预测，性状间的进化权衡（evolutionary trade-off）会制约形态分化与物种多样化进程。然而，这一假说尚未在包括蚂蚁在内的多个多样演化支系（clade）的宽泛演化框架中得到检验。本研究重建了覆盖82%现生蚂蚁属级类群的扩展版蚂蚁系统发育树（phylogeny），构建了蚁科全类群的科级性状数据库，并通过多类基于性状的分析，证实蚂蚁的防御性状确实存在进化权衡。具体而言，具功能的螫刺（sting）的使用与一系列其他防御性状呈负相关，包括体棘、大眼体型以及大群势种群。此外，本研究发现，与螫刺存在进化权衡的多种防御性状之间也呈正相关，且能够推动物种多样化程度提升，进一步表明这些性状共同构成一套防御性状组合（defensive suite）。本研究结果支持如下假说：防御性状间的进化权衡会显著制约性状演化，并对蚂蚁的物种多样化进程产生影响。