Diversification of pre-mating behaviours through temporal reordering of components.

Many biological processes, including mating behaviour, are structured as ordered sequences in which each step enables the next. Diversity of such processes usually arises through the addition or loss of components rather than through changes in their order, since reordering can disrupt functional integration. Here, we show that reordering of the steps associated with termite nuptial pairing can generate behavioural diversity. In most termites, dispersed adults shed their wings before initiating tandem pairing, as wings interfere with communication between females and males. However, we found that, in the Australian termite Microcerotermes nervosus, tandem running occurs prior to wing shedding (dealation), and the act of tandem running itself facilitates dealation. Video tracking revealed that wing removal improves movement coordination, and comparative analysis of sympatric species showed that M. nervosus exhibits much higher tandem stability than others. These results suggest that enhanced movement coordination of this species may have potentiated step reordering. Our findings demonstrate that even functionally conserved sequences can be reorganized and that overcoming such constraints can open novel pathways for behavioural diversification.