On Tuesday, August 13, 2013 3:17:48 PM UTC-4, Brent wrote: > > On 8/13/2013 12:00 PM, Chris de Morsella wrote: > > John >> Epigenetic changes do not change the sequence of bases in DNA, and > more important I see no evidence that the body has learned any lessons. I > see no evidence that epigenetic changes are more likely to happen in the > direction of greater adaptability rather than the reverse. All I see is the > environment causing random changes in hereditary factors that, like all > changes, are more likely to be harmful than helpful. > > Sure, but then neither do random mutations to an organisms DNA, imply that > the body has learned anything either. The introduction of some random > change is either harmful, beneficial or of little or no consequence to the > individual, whether this phenotypical change is the result of inhibiting or > promoting the expression of some underlying DNA or how that DNA get's > transcribed, or is the result of an actual change in the individuals > sequence of DNA. > What you say about epigenetic changes: "environment causing random changes > in hereditary factors" applies as much to the classical hereditary > mechanism of DNA changes. > > Evolution only happens after multiple generations of selective pressure > have either, presumably weeded out harmful maladaptations and promoted > beneficial ones. There is nothing qualitatively different in random DNA > mutation or random methylation and so forth. They are both instances of > mutations in an organisms hereditary mechanisms. Why make one a first class > citizen and the other an interloper? > > Naturally I am not arguing that epigenetic re-wiring is as permanent > or important as classic genetic based heredity; it certainly seems more > reversible for example. > > > But isn't that the problem with epigenetic 'evolution'. Evolution > requires faithful reproduction sufficient at least to create a local > breeding population. My understanding of epigenetics is that it is > hit-or-miss after only a couple of generations. >
"The methyl groups could become married permanently to the DNA, getting replicated right along with it through a hundred generations." http://discovermagazine.com/2013/may/13-grandmas-experiences-leave-epigenetic-mark-on-your-genes#.Ugq_7KwyglT > Brent > -- 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/groups/opt_out.
