In Stuttgart, at the University, for a Symbrion project meeting. Its been a really tough meeting - which is hardly surprising given that we're one year in and - next month - have the big end-of-first-year review meeting in Prague. So a major part of the meeting has been a dress rehearsal for the review.
However, spending a day and a half with a group of very smart people is always a pleasure, and there were some really interesting issues to debate. One concerns the fundamental question of how much of the Symbrion system should be designed and how much evolved (using evolutionary computing techniques). One could take a purist view and aim to evolve every aspect. My own view is more pragmatic. I think that achieving the aims of the Symbrion project is going to be so difficult that we should resort to artificial evolution only for the parts of the system that we can't design, because we don't know how.
Also, I think there's a 'biological plausibility' argument for taking the pragmatic view. The Symbrion system will be both a swarm of individual robots, behaving like a swarm, and - following self-assembly - a multi-cellular organism, behaving as a single organism. Swarm and organism have, I think, radically different control paradigms; the former fully decentralised and dependent on mechanisms of emergence and self-organisation, the latter centralised and coordinated (by a central nervous system). Of course ant genes must both contain the instructions to build multi-cellular animals (the ants with CNSs and coordinated control, e.g. for walking), and their behaviours which give rise to the colony's collective swarm intelligence. However, Symbrion goes beyond anything seen in nature. We want the Symbrion robots to sometimes behave like complicated ant-like creatures, and sometimes behave like complicated cells in a complex body (that can perform useful coordinated functions). I think if such a thing were possible to be evolved it would have been (except for the fascinating but much-simpler-than-Symbrion case of the social amoeba Dictyostelium discoideum sometimes self-assembling into multicellular structures).
This is why I think engineering a single evolutionary process that can evolve both swarm intelligent control and centralised coordinated control is asking too much.