Originally Posted by bns

So I've been thinking about it. And I've convinced myself that it is theoretically possible for external environments to alter DNA. It should be, unless the genetic sequence is completely isolated, which it isn't. Clearly it doesn't happen very often, and that makes sense what with all the redundancy inherent in DNA. But I still think it's possible. The parts of just about any system are very interdependent, and that's particularly true of highly complex systems. So I would be shocked to learn that there isn't a way to affect the genetic sequence through external pressure.