JonB, I get the feeling I need to brush up on my Genetics notes! :wacko:
Well, the human genome project should be able to find some sort of genetic basis, I wouldn't be surprised if there were tons of seemingly unrelated factors involved though.
I mean, it isn't just the "meat" that has to have genes, but blood circulation, neural conections, hair growth, heck, ever noticed skin colouration changes?
Should be interesting what they find, but it wont be long after that people will be using gene theraphy for their genitals!