Abstract/Summary

Self-organisation, prevalent in many species, is pivotal in enhancing an individual’s survival rate. Eusocial insects are a prime example of collective behaviour and self-organisation, while bacteria colonies also exhibit self-organised patterns stemming from mutual interactions, yielding increased complexity. Now, there needs to be more explanation of how the reciprocal interactions between individuals translate to the global structure. We introduce the concept of the internal state to address this. The internal state can represent certain physiological traits in a given context. We use the internal state to represent the ovary development of workers in Diacamma cf. Indicum. We explore how the reproductive division of labour is maintained via the patrol behaviour of the queen, whose movements are determined by her internal state. We used an agent-based simulation to model the internal state of the queen and workers and to include the spatial interactions between them. We extended the agent-based simulation to explain the development of altruistic behaviour in Diacamma workers. The findings showed that the coupling of the internal states of the queen and workers could explain the patrol behaviour of the queen and the observed colony size dependant behaviour in actual Diacamma colonies. The findings further showed that altruistic behaviour in workers gives a more significant inclusive fitness benefit than being selfish. It also offers an explanation for workers’ re-4 tention of functional ovaries in modern Diacamma colonies. Previous work has explored the self-organisation in bacteria colonies and the effect of the growth environment on morphology. We developed a morphological diagram to examine the landscape of observed morphologies in line with specific environmental conditions. We then used the fractal dimension to quantitatively measure the differences in morphology and use previous work to explore possible explanations. Using the concept of internal state coupling, we develop a framework for understanding the causal pathway from individual behaviour to collective behaviour.