At first I wasn't sure about what you were specifying. I thought "in what..a petri dish?" LOL. But I see what you're asking now. I haven't seen anything with people growing feathers. But I have seen pictures of people with horns. That is incredibly macabre.
The only spiritual association I've ever read about is the winged serpent. My husband knows more than I do on this.
Though, doing a short search I found something that might be of interest. Although it has nothing of bodily mutations, it has to do moreso with what the mind can overcome with yoga.
Yoga Changes the Molecular Structure of the Human Body Terrible Mutations May Turn Humans Into Plants or Animals Bizarre Baby (Tell you what, I just got high speed internet and was looking right up at the screen when this popped up..wow...first time I've jumped out of my seat in a long time LOL.)
Hope you find these of interest.
This post has been edited by Angalor: Jul 25 2006, 02:57 PM