Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!tut.cis.ohio-state.edu!dendrite.cis.ohio-state.edu!pollack From: pollack@dendrite.cis.ohio-state.edu (Jordan B Pollack) Newsgroups: comp.theory.cell-automata Subject: Re: CA extensions Message-ID: Date: 8 Feb 91 20:06:51 GMT References: <9102071416.AA14396@t13.lanl.gov.> Sender: news@tut.cis.ohio-state.edu Reply-To: pollack@cis.ohio-state.edu Distribution: inet Organization: Ohio State Computer Science Lines: 42 In-reply-to: cgl@t13.lanl.GOV's message of 7 Feb 91 14:16:03 GMT > Indeed, many of the papers submitted for the proceedings of the most >recent workshop on Artificial Life note this phenomenon. Thus, is >appears that punctuated equilibrium behavior may well be ``generic'' >for evolutionary processes. The principles underlying punctuated equilibria may also be generic for other kinds of search and problem-solving. Certain kinds of connectionist learning curves jump through discrete levels of improvement. In my connectionist model of language induction to appear in NIPS 3, a sequential parity learner undergoes a phase transition which corresponds to the initial discovery of the xor "trick", which is rapidly exploited (in some sort of arms race) by back propagation. Human learning of mathematical concepts, gestalt recognition of distorted objects, and insight problem-solving (the AHA phenomena) also seem to be punctuated by phase transitions, where there no progress until right before the problem is solved. The idea of a pre-adaptive change leading to a massive reorganization of population elements seems to analogically apply. >These punctuation events are often accompanied by population crashes and >``species'' crashes. This is important, because it suggests that extinction>events on many different scales can occur due to the natural dynamics of >the evolutionary process alone, without having to evoke catastrophes like >asteroid impacts. Ive thought about that too, the idea that the asteroids and ET's and continental breaks and are just truly random noise added to the species bifurcation diagram. I even dallied with the idea of collecting the best dating evidence on the time frame of species introduction to see if it follows a classic period-double. The initial result looked promising: the first 5/6 of the time, there were single cellular creatures, then a long period of 2-cell creatures, then the first explosion of multicellular types. We are in a period of rapid species collapse due to humans (merging) with every other creature's niche. I'm sure there is a nobel prize in here somewhere :) -- Jordan Pollack Assistant Professor CIS Dept/OSU Laboratory for AI Research 2036 Neil Ave Email: pollack@cis.ohio-state.edu Columbus, OH 43210 Fax/Phone: (614) 292-4890