Why is it accurate to say that gene flow is largely random with respect to fitness?

I think that it is because of the thought of "who knows if the person you are in love with works out?" I mean, he'll probably tell you if he does, but there's no knowing who you're going to continue the gene flow with. For all you know, it could be a person who works out 24/7 (not literally) or someone who doesn't even go out to jog unless it involves Pokemon Go. See what I mean?

I hope this helps, please make me Brainliest, and have a fun night! :D

The person who utilize the progression principle will keep adding the difficulty of the exercise that he's doing, while the person who does not, will only stay stagnant.  the person that utilize progression principle, will get a stronger endurance because now his body is conditioned to do harsher routines.{the answer was already on verified)