Suppose that after 22 months, guppies from the transplanted population were returned to the source pool. what would most likely happen to those guppies?

For the answer to the question above asking what would most likely happen to those guppies if, after 22 months, guppies from the transplanted population were returned to the source pool. 

the guppies would have probably lost all instincts because they weren't in their habitat. But they will learn it because it is in their instincts

Atp is is our little "pocket" of energy. of course, if you have too little, then it means you have too little energy, and you'll pass out. the way to not have enough, is to have no energy sources (glucose, fats, proteins). you can't have too many atp molecules. cycles like the krebs cycle produce it, but if you have too much of any substrate (or too little for that matter), the cycle stops and atp is no longer made (it stops until substrate levels are such that the process can go on). in any case, this is unlikely since atp is constantly hydrolyzed and remade, even while you're asleep. you won't have too much. if you have zero, you are dead or dying.