UNIVERSITY OF HERTFORDSHIRE COMPUTER SCIENCE RESEARCH COLLOQUIUM presents "Sex and the Self-Reproducing Automaton" Prof. Chrystopher Nehaniv (Computer Science, University of Hertfordshire, UK) 16 March 2011 (Wednesday) Meeting Room LD454 Hatfield, College Lane Campus 1 -2 pm Everyone is Welcome to Attend Refreshments will be available Abstract: In the late 1940s, before the discovery of the structure of DNA, one of the fathers of computer science, John von Neumann, asked, How is that a mechanistic system can produce something as or more complex than itself? Is this possible to explain to reproduction of living things without resorting to mystical factors, or can principles and logical mechanisms be identified? He thus initiated the study of self-reproducing systems. His models require only simple changes in response to local state information and some clever ideas which it turns out nature had also discovered. This area of self-reproduction is of great interest to advances not only in biology and medicine but also of crucial importance for nanotechnology (merely in order that nano- constructions can grow to reach human-scale), AI robotics (modular reconfigurable swarm robotics) and space sciences (astrobiology, off-world self-replicating factories, space colonization, etc), as well as self-repairing, reconfigurable, self-healing adaptive systems and hardware in remote and hazardous environments, etc. Using discrete dynamical systems, von Neumann was able explicitly show how it is indeed possible to algoritmically realize self-reproducing in several ways, solving the first problem, at least in principle. Since the mid-1990s it has become possible to implement some of his solutions in computational media, but only in recent years due to computational power increases have his models been able to actually complete a full reproduction cycle. Equally importantly, John von Neumann asked, How is complexity increase over several generations of self-reproductions possible? His answer was that the self-reproduction needs to support inheriable mutation so that Darwinian evolution becomes possible. His models indicate a direction in which this might occur, but he was unable to complete this work in his lifetime. Inheritable mutation provides variation which the fodder for evolution. Another source of variability in biology is sex, defined by biologists as the tranfer of heritable genetic information from one individual to another. Inheritable genetic changes and genetic change due to inheritable information coming from other individuals. None of von Neumann's models involved sex. In the past few years the use of inheritable variation and sex in self- reproducing automata has been pioneered in recent work at the University of Hertfordshire by Artificial Intelligence MSc students. This talk will present some of their results: the first realization of sex in self- reproducing automata was achieved in the SexyLoop models by Nicolas Oros, and successive inhertible mutation in the von Neumann self-reproducer was first exhibited by Ayoola R. Yinusa. We also survey related work issues on self-replicating and -reproducing automata, including asynchronous ones. Towards the evolvability of self-reproducting automata in physical and computational media, an understanding of sex and inheritable variation are fundamental but the level of complexity achieved to date is still much lower than that of any living organism. Next stages of the work will add self-maintaining capabilities to sexual and asexual reproducers in the achieve of more robust like-life reproduction. References: Nicolas Oros and C. L. Nehaniv, "Sexyloop: Self-Reproduction, Evolution and Sex in Cellular Automata", Proc. First IEEE Symposium on Artificial Life (Honolulu, Hawaii, USA), 2007. Nicolas Oros and C. L. Nehaniv, "Dude Where's My Sex Gene? --- Persistence of Sex over Evolutionary Time in Cellular Automata", Proc. Second IEEE Symposium on Artificial Life (Nashville, Tennessee, USA), 2009. Ayoola R. Yinusa and C. L. Nehaniv, "The Study of Inheritable Mutations in von Neumann Self-Reproducing Automata using the GOLLY Simulator", Proc. Third IEEE Symposium on Artificial Life (Paris, France), 2011 (in press). --------------------------------------------------- Hertfordshire Computer Science Research Colloquium http://homepages.stca.herts.ac.uk/~nehaniv/colloq