Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!aramis.rutgers.edu!athos.rutgers.edu!nanotech From: truesdel@prandtl.nas.nasa.gov (David Truesdell) Newsgroups: sci.nanotech Subject: Re: A fallacy: That which evolved can be rationally designed. Message-ID: Date: 1 Jul 89 02:25:35 GMT Sender: nanotech@athos.rutgers.edu Organization: Crays 'R Us, NASA Ames Research Center Lines: 69 Approved: nanotech@aramis.rutgers.edu dmo@turkey.philips.com (Dan Offutt) writes: [Mostly nonsense] >> ... The brain is not magic. If it can evolve, it can be >>purposely designed. There can be no credible refutation of this logic. >The proposition "if X can evolve via biological evolution, then X can >be purposely designed" is generally false. The human brain or immune >system might be copied or imitated, but neither human beings nor >"fast" AI could possibly design such systems. I fail to see a significant distinction between duplication/emulation, and "design". To duplicate, you need to know what's there, to emulate, you need to know how what's there works. >First, purposeful design presupposes a design problem definition. We >know very little about the design constraints for biological systems. >The human brain has been shaped by gravity, the ratio of oxygen to >nitrogen in the atmosphere, [etc., etc.] > ... > For example, the structure of >the human brain today may reflect, in some subtle way, the predatory >capabilities of saber-tooth tigers, which are now extinct. >Saber-tooth tigers are just one influence out of trillions. All of which is would be nice to know, BUT, are they really necessary for the design of a (possibly NON-biological) human equivalent "brain". One principle of "design" is to know what you DON'T need. How to deal with an extinct creature holds little value. Mr. Offutt obviously assumes that the human brain is the *ultimate* design and that a "proper" design specification would produce an *exact* replica. I'm afraid I don't share this opinion. The *current* design of the brain is simply a *local* optima. There's no rational reason to assume that the job could not be done better, with a little thought :-). Just remember, the same "trillions" of influences, also built lice. >The second reason the proposition is false is that all human designers >and all "fast" AI systems put together will never collectively possess >the parallel "computational resources" that biological evolution has >had to work with. Moreover, biological evolution has been searching >for more-viable forms of life for billions of years. The statements reflect a basic ignorance of what biological evolution is, and how it operates. A "billion-year-long design processes" requiring "trillions of billions of processor years" is only necessary if the "design process" is completely random, guided only by the viablity of each revision as determined by a changing environment. Mr. Offutt, are you a programmer? Do you develop your programs by blindly making changes, and testing the results? Would you care to estimate how long it would take to make a word-processor from the source of (lets say) a compiler using this method? >Dan Offutt >dmo@philabs.philips.com Just remember, the inforation required to build a human brain, it's "design" if you will, is tiny compared to the information capacity of the brain itself. There's no reason to assume that a brain couldn't improve on it's on design. -dave truesdell (truesdel@prandtl.nas.nasa.gov) "Character consists of what you do on the third and fourth tries." -dave truesdell (truesdel@prandtl.nas.nasa.gov) "Character consists of what you do on the third and fourth tries."