From: ctf20 To: alergic_list@cogs.susx.ac.uk Sent: Monday, November 10, 2003 1:30 PM Subject: TIM HUTTON ON THE ORIGIN OF LIFE. Re: Alergic Wed 12th Nov 2003 16:30 in Pev 1A6. Dear All You are invited to hear Tim Hutton speak about theoretical approaches to the origins of life and open-ended evolution this Wednesday 12th Oct at ALERGIC, in Pev 1A6, at 4.30pm. Should be very exciting. Yours Chrisantha Fernando Lattice Artificial Chemistries: an Artificial Life Collidatron Lattice Artificial Chemistries are a simple physics platform on which different concrete artificial chemistries can be built. LACs are an extension of lattice gases, where atoms move on a lattice of sites with simple collision rules. The key concept in LACs is that the atoms can enter into reactions with other atoms that they encounter, again through simple local rules. LACs are a promising medium for Artificial Life experiments, since they are computationally efficient (compared to continuous simulations) and programmable with different behaviours. Recent work with LACs has followed two (complementary) paths: Naoaki Ono et al have shown how to make lipid membranes in 2D and 3D. Simple enclosures like micelles and vesicles are thought to have been important for early life (at least in the Lipid World hypothesis), as they act as test-tubes, allowing the local chemical concentrations to be controlled. A degree of evolution is even possible in these systems, through compositional inheritance. My work has followed the RNA World hypothesis, that information-carrying polymers were the earliest units of evolution. Self-replicating molecules can be implemented in LACs through a set of simple rules for temple-directed duplication and separation. I'll explain how this works, show some nice demos and discuss prospects for achieving the evolutionary growth of complexity in LAC-based systems. Naoaki et al's papers can be found at: http://www.his.atr.co.jp/~nono/ http://parallel.hpc.unsw.edu.au/~duraid/mlac3d/paper.pdf My papers can be found at: http://www.eastman.ucl.ac.uk/~thutton/Evolution/Squirm3/ Related reading: Lattice Molecular Automaton http://www.wspc.com.sg/profiles/anncat/anncat/jnlarticle/ijmpcv11n4/S0129183100000705.pdf