Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!bcm!dimacs.rutgers.edu!aramis.rutgers.edu!athos.rutgers.edu!nanotech From: john@granada.mit.edu (John Olson) Newsgroups: sci.nanotech Subject: Re: Is this stuff for real? Keywords: reality nanotech questions Message-ID: Date: 16 Mar 91 03:38:01 GMT Sender: nanotech@athos.rutgers.edu Organization: MIT Lines: 21 Approved: nanotech@aramis.rutgers.edu In article 992, Chris Phoenix writes: >that the DNA doesn't: it has a computer. The computer can manipulate >the memory far more easily and reliably than the cell can manipulate >the DNA. I am not convinced of this. My understanding is that DNA replication is very reliable. Keep in mind the vast information content of DNA, and the rarity of mutations. The August 1988 Scientific American had an article by Radman and Wagner, "The High Fidelity of DNA Duplication," on this topic. They say that DNA is duplicated with an error rate of about 1 error per ten billion (10^10) base pairs. A comparable number for the exabyte tape backup system here would be 1 error per trillion (10^12) bits. That's only a factor of 100, and each base carries two bits worth of data (four states for a base, vs. two states for a bit). How do these error rates compare to, say, the rates for reading RAM or ROM? Someone out there can probably tell us. John Olson.