The transition from Cells to Nervous Systems
For around 4 billion years after the origin of life on Earth, until the Neoproterozoic Era, there were no neurons, no nervous systems and no cognition. In other words, there were no animals. Then, during the transition to the Phanerozoic Era (which began 541 million years ago), animals appeared and rapidly diversified, evolving nervous systems, body tissues, locomotion and complex behaviour.
In the process they radically transformed the world around them, altering global ecology, geochemistry, and the physical environment.
This project is exploring interactions between ‘mind and body’, to test whether the evolution of nervous systems was promoted by positive feedback between the ability to ‘think’ and the ability to move. To do this we are replicating the evolution of multicellularity and the nervous system using computer simulations of artificial life.
At this point in early animal evolution, the unit of the individual underwent a fundamental shift from the single cell (comparable to living unicellular choanoflagellates) to the larger organism (with sponges as the most ancient, surviving representatives). Differentiated body tissues evolved progressively, among sponges, cnidarians, ctenophores and bilaterian animals. Alongside this, increasingly complex nervous systems developed to facilitate communication and coordination throughout the body.
Our computer simulations of artificial life are testing whether an analogous transition, from a single foraging cell to an integrated cell array, leads to the self-organisation of nervous system properties such as specialised communication networks and coordinated motor output.
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