Theoretical Research in Evolutionary Life Sciences, Groningen Institute for Evolutionary Life Sciences, University of Groningen, P.O. Box 11103, 9700 CC Groningen, The Netherlands.
Nat Commun. 2017 Jun 23;8:15920. doi: 10.1038/ncomms15920.
Explaining the origin of eusociality, with strict division of labour between workers and reproductives, remains one of evolutionary biology's greatest challenges. Specific combinations of genetic, behavioural and demographic traits in Hymenoptera are thought to explain their relatively high frequency of eusociality, but quantitative models integrating such preadaptations are lacking. Here we use mathematical models to show that the joint evolution of helping behaviour and maternal sex ratio adjustment can synergistically trigger both a behavioural change from solitary to eusocial breeding, and a demographic change from a life cycle with two reproductive broods to a life cycle in which an unmated cohort of female workers precedes a final generation of dispersing reproductives. Specific suits of preadaptations are particularly favourable to the evolution of eusociality: lifetime monogamy, bivoltinism with male generation overlap, hibernation of mated females and haplodiploidy with maternal sex ratio adjustment. The joint effects of these preadaptations may explain the abundance of eusociality in the Hymenoptera and its virtual absence in other haplodiploid lineages.
解释真社会性的起源，即工蜂和生殖蜂之间严格的劳动分工，仍然是进化生物学最大的挑战之一。膜翅目昆虫中特定的遗传、行为和人口特征组合被认为可以解释它们相对较高的真社会性频率，但缺乏整合这些预适应的定量模型。在这里，我们使用数学模型表明，帮助行为和母性性别比例调整的共同进化可以协同触发从独居到真社会性繁殖的行为变化，以及从具有两个生殖后代的生命周期到其中一个未交配的雌性工蜂群体先于最后一代分散生殖的生命周期的人口变化。特定的预适应套件特别有利于真社会性的进化：终生一夫一妻制、雌雄世代重叠的两化性、交配后雌性休眠以及具有母性性别比例调整的单倍二倍体。这些预适应的共同作用可能解释了膜翅目昆虫中真社会性的丰富性，以及在其他单倍二倍体谱系中真社会性的几乎缺失。
