On 24 March 2014 19:41, meekerdb <[email protected]> wrote: > On 3/23/2014 11:30 PM, LizR wrote: > > On 24 March 2014 17:41, meekerdb <[email protected]> wrote: > >> On 3/23/2014 8:57 PM, LizR wrote: >> >> *Is* DNA a universal programming language? >> >> >> I'm not sure what a "universal programming language" means. Just 1s and >> 0s are enough language. I think you probably mean to ask is whether a cell >> is a universal computer with DNA as the program. I don't know if there's >> been a formal proof but it almost certainly is. Making a universal >> computer is pretty easy. Wolfram's rule 110 produces a universal computer >> in one dimension with only two colors and nearest neighbor rules. >> >> I'm quoting the paper at http://www.cs.auckland.ac.nz/~*chaitin*/ > *darwin*.pdf > > (See section 9) > > Presumably DNA is a universal programming language, but how sophisticated > can mutations be in actual biological organisms? > > > That seems like a strange question. Mutations are "errors" by definition > and are random. So what does it mean to ask how sophisticated they can > be? Obviously they can accumulate as errors in DNA copying without doing > anything and then be "activated" by one more error. >
They are random, but I assume they are (very occasionally) improvements, and maybe that's what they're thinking of. > > In this connection, note that evo-devo views DNA as software for > constructing the embryo, and that the change from single-celled to > multicellular organisms is roughly like taking a main program and making it > into a subroutine, which is a fairly high-level > > mutation. Could this be the reason that it took so long|on the order of 109 > years|for this to happen > > > Sure, although 1e9yr seems pretty quick to me. The eukaryote cell is > already tremendously complicated, just becoming multicellular doesn't seem > like such a big step to me. > > I agree (insofar as my opinion on this is of any value) - it always seemed to me, or at least since I read Bill Bryson's description of a cell in his big book on science, that single cells are very, very complex machines, while multicellular organisms are almost "riding on top of" this complexity - getting a sort of free lunch as it were. I believe the figures are something like 4Gyr to evolve the sort of cells in our bodies and maybe 500Myrs to go from single cells to our multicellular current state. So I'd say cells are roughly 8 x as complex as organisms if you ignore the complexity of their cells. (Well, very roughly, but you probably see what I mean...) -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
