Path: utzoo!attcan!telly!lethe!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!ub!clarkson!grape.ecs.clarkson.edu!maguire From: maguire@sun.soe.clarkson.edu (Bill Maguire) Newsgroups: comp.ai Subject: Re: evolution is not a scale Message-ID: Date: 21 Dec 90 19:39:47 GMT References: <70996@bu.edu.bu.edu> <1870014@hpwrce.HP.COM> Sender: @grape.ecs.clarkson.edu Organization: Clarkson University, Potsdam NY Lines: 48 In-Reply-To: kingsley@hpwrce.HP.COM's message of 20 Dec 90 17:52:16 GMT >/ hpwrce:comp.ai / colby@bu-bio.bu.edu (Chris Colby) / >7:43 pm Dec 18, 1990 / >>The idea that evolution is a linear scale with humans at the pinnacle >>is simply not true. >> >>From a single common ancestor life multiplied and species diverged into many >>branches. In article <1870014@hpwrce.HP.COM> kingsley@hpwrce.HP.COM (Kingsley Morse) > writes: >I'm interested in evolution, and applying it to AI. I've been assuming that >evolution is goal directed, in a sense. I'm interested in feedback on my >assumption. >Do you think it's possible that Darwin's theory of natural selection uses >"fitness" as a goal? In other words, Darwin proposed that "survival of the >fittest" causes succeeding generations to be ever better adapted to >the environment. Could successively fitter generations be considered a > "scale", in that any given branch of evolution has "fitter" genes at it's >leaves than at the root? As one of the earlier posters suggested, read Gould's books. Fitness for an environment depends on that environment. Over the years a species' environment is in a constant state of change because of a number of factors. Among them continental drift (i.e. a continent moving closer or farther from a pole), the cycle of ice ages, earthquakes, volcanic activity, etc. Species adapt (evolve) to fit the changing environment. When the environment changes the ones that are most able to survie in that environment fare better and pass their genes along. Whether this happens fast or slow is discussed in several of the chapters in Gould's books. He is interesting to read. Thus evolution might be "goal directed" but the goal is constantly changing. You can't say that a species at a leaf is more fitter than a species at an earlier node, because the context has changed. We do not live in the environment that existed millions of years ago. The species now might be more fitter for the current environment, but who knows how well it would fare if it time travelled back to it's ancestors environment. Bill Maguire maguire@sun.soe.clarkson.edu She had so many chins she looked like a piece of lisp code :-)))))))