"Dehammer, because there is no shortage of food and no predators, each line of fruit flies is preserved. So it seems to be ideal conditions for mutations to flourish and run their course."

Dear Blacknad. These are EXACTLY THE OPPOSITE conditions conducive to evolution. Evolution occurs best where food is scarce and predatation is fierce - resulting in a strong selective pressure. The Amazon is well-known for 2 factors 1) its incredible biodiversity and 2) the poorness of its soil overall.

From http://library.thinkquest.org/21395/textonlyb/deforestation.html

"The Amazon, though it is host to millions of lifeforms, is not full of fertile soil."