From skin to brain:modelling a whole-body coordination scenario of nervous system origin

Abstract

Nervous systems are ubiquitous in the animal kingdom, yet the evolutionary origin of this essential feature, the basis of human cognition, is unclear. Since the emergence of nervous systems happened at least 430 but likely as much as 600 million years ago, there is little hard evidence to illustrate this evolutionary process. To understand the evolutionary origin of nervous systems, theoretical frameworks putting what evidence there is into context are crucial.One such framework, the interal coordination view, posits that nervous systems arose in order to allow early animals to coordinate their multicellular bodies as a whole. In this research, we explored potential intermediate evolutionary steps on the road to a true nervous system. To that end, we used computational models of very simple simulated animals. In these simulations, we investigated mechanisms short of nervous systems, using (simulated) biological building blocks which would likely have been present in animals at the time nervous systems evolved.These models demonstrate that even very rudimentary mechanisms have the potential of providing useful coordination to early animals, thereby supporting the internal coordination view of nervous system origin: nervous systems likely evolved to allow whole-body coordination