October 20, 2014
Insects like honeybees and ants live in groups that constantly communicate with each other. In fact, communication networks in some insect groups have been successfully compared to artificial technological information transfer networks. Drawing parallels between such highly coordinated processes in living organisms and their artificial counterparts, a team of scientists from IISc, IISER-Kolkatta and BITS-Pilani, seek a better understanding of network communication, to improve the existing information processing networks.
The survival of living organisms depend on the well-coordinated processes at different levels – the cellular and genetic levels, for example. Group living animals take coordination to a different level — schools of fish and flocks of birds rely on competent communication by every individual to all other members, at every point in time. Efficient transfer of information happens through communication systems, which hold good even when there are time or energy constraints.
Among non-human living beings, social insects like bees have some of the most complex societies. Scientists study them to understand communication between the members of a colony, which ensures division of labour between thousands of individuals. Different species of social insects have different modes of communication: bees in large colonies communicate using chemical cues or pheromones, while wasps in smaller colonies use direct physical interactions.
Anjan Nandi and colleagues have studied a tropical wasp Ropalidia marginata to understand the flow of information within a colony. They found that the flow of information between individuals is by pairwise physical interactions, like dominance behaviour, which plays a major role in the regulation of activities of the workers in a colony. For example, foragers that find food receive more dominance over the non foragers, and the extent of dominance varies depending on the circumstances (higher during starvation while lesser during excess food). Apart from dominance, wasps also use paired behaviours like grooming, soliciting and food sharing for flow of information.
There are also global structures that emerge from the two way interactions: the average path length for communication and the average density of interactions could be determined from individual interactions. In other words, the building blocks of a network formation is identified by studying the local structural elements.
The analysis revealed that networks constructed from dominance behaviour in Ropalidia marginata is structurally similar to different biological and technological regulatory networks. Further, the networks are sufficiently robust and capable of efficient information transfer. Even though one would expect a wasp colony to be less complex because it has fewer individuals, a comparison demonstrates that there is a common design principle involved in different biological systems who have evolved to perform similar tasks
The paper was published in the journal Royal Society journal Interface during second week of October 2014.