there is much we don't know - info from prior threads

There is some scientific evidence that HBG can't backcross with BG and some to the contrary. In all the cases I have found even if HBG can back cross with BG the fecundity is very low ( several hundred vs 20 to 50 thousand for BG X BG).

I know I have posted this before but the studies are in conflict wrt the ability of HBG to backcross with either parental species. One says yes one says no. Both were well done studies and some very good scientists were involved and so far there is no answer for the different results. Some of us have even contacted fisheries geneticist PhDs at the highest level who have written on sunfish genetics and they have no answer as most have not studied HBG cross genetics.

Stop and think about that. If HBG can not backcross with parentals then they can not ever create or get genetically close producing GSF , even through repeated spawning attempts with GSF. If they can backcross then through repeated crossing of HBG with GSF for generations the population as a whole will have a higher content of GSF genes.

GSF can not come from crossing BG and HBG. There is even a question if HBG can backcross with either parent species. IMO best guess is they can backcross. GSF are a species and BG are a species and HBG are a cross between the two. Over time certain traits (good or bad) can become more predominate through outbreeding depression or hybrid vigor. Over very long periods of time a distinct population can change so that its outward traits (not necessarily genetics) are closer to GSF or BG.

Pros and cons of HBG? - Pond Boss Forum https://forums.pondboss.com/ubbthre...ords=backcross&Search=true#Post24189 - Finally, we found that reciprocal crosses often show asymmetrical hybrid viabilities.

We discuss several alternative explanations for this result including possible deleterious cytonuclear interactions

Last edited by ewest; 06/22/21 10:45 AM.