Originally Posted by Sunil
".... But we can explore the built in adaptations designed to help the organism survive changing conditions, like maybe a larger jaw if the only prey is large,..."

This is the simple thing that I was keying in on.

Could a smallie's physical geometry of jaw change slightly to allow it to eat more bluegill.

My buddy has a newly filled pond, and we've stocked it with (27) adult bluegill from my neighborhood pond. When it comes time for predators, I'd selfishly like him to put SMB in so I can 'reappropriate' some to my neighborhood pond, from time to time.

Exactly. Based on the observational evidence, there are many design hacks in the genome, if not DNA, to help fish & other organisms adapt. We don't know all of them, or what the trigger is in each case, but it would be amazing to research. Mutations are far more limited in what they can do. Besides, they tend to degrade the organism, not help. Very cool stuff!