Todd, <How does nutritional stress <cause mutations? What is nutritional stress anyway? Why should <this particular mutation be so predictable? And so on. I agree that mutations are the direct cause of the rise of new species, or evolution. I don't think mutations are caused by food sources. More like, mutations arise, and if they are more capable of thriving in an environment that contains mostlysuch and such a food source, they will be capable of beating out other competitors for that niche. Judith