Quote Originally Posted by Eviebae View Post
Everyone else may wanna skip this one...unless you don't...cuz I'm going to geek the &*$# out...



Yes, very true. I never meant to say they do--and frankly think I didn't. I said they cause change at the LEVEL of the chromosome by changing HOW the genes are expressed. Because of evolution; DNA is sort of messy string code and part of how genes are expressed are these para-chromosomal chemicals/proteins that can turn the expression of genes (and thus the traits they express) on and off. In Post Traumatic Stress Disorder, for example, the thinking is constant stress results in changes to chromosomal expression that result in some of the long term behaviors associated (besides and beyond having a predisposition) --like hypervigilance. It's like how in a house some lights are on and some are off; but they are all there being lights and if you don't want to use a light long term you can unscrew the lightbulb.
That's a great way to explain it!