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."
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 post to this group, send email to email@example.com.
Visit this group at http://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/groups/opt_out.