I completely agree with these comments above Eric. The competitive environment in the pond prevents bad genetics from growing up to spread inferior genes. What makes it to reproductive age has great genetics, or I suppose might have been very lucky, but I do not believe in luck.
Perhaps there really is vigor resulting from the combination of Northerns and Florida. If so, even if F2 progeny is highly variable, the ones that survive to reproductive age are reasonably argued to be the ones with relatively greater vigor. So perhaps mother nature performs the selection of those progeny that are most like the parents (F1s)
Last edited by jpsdad; 01/14/21 12:54 PM.