[lbo-talk] the epigenenome

[ravi]

On May 13, 2009, at 9:36 PM, Chuck Grimes wrote:
>
> Gould mounted a serious challenge with his punctuated equilibrium  
> hypothesis that lead to considering that species may not be the only  
> domain level undergoing natural selection, that higher orders may be  
> involved. Epigenetic phenomenon mount an even greater challenge from  
> within species, particularly the internal differentiation process.
>

Chuck,

we (Doyle and I) have been discussing this on PEN-L for a day or two.  
But w.r.t the above, IMHO you are wrong: Natural selection (as per  
standard theory and the MS) occurs at the level of the individual.  
Arguments for higher levels of selection, "group selection", have been  
around at least since Wynne-Edwards (late 50s?), and Gould/PE have  
little to do with that.


> The depth of its importance comes from the fact that natural  
> selection only works through phenotypes. If that's all there is,  
> then how do genetic sequences change, how does the genotype change?  
> Influence through epigenenome changes provides one answer.

Why do you need epigenetics to explain genotype changes? Drift, random  
mutation, etc -- the old bag of tricks -- have been around as  
explanations for a long time. One new problem may be how you explain  
the diversity in light of the comparatively small number of genes.  
Here epigenetics could play a part.

I do agree with you that this can be a very significant development in  
biology. I also share what I believe is your distaste for the gene's  
eye view of human biology (and often, destiny).

Here is a link I posted on PEN-L that you may find interesting:

http://www.amazon.com/gp/blog/post/PLNK3EC629BEDKT8X

	--ravi