@Skaggfacemutt “According to science, housecats would never have a better chance of survival than lions,”
I have no idea what this is supposed to mean. It sounds like you are saying that if you hold a cage match between a housecat and a lion, the lion should win. That has nothing to do with fitness in the evolutionary sense. Housecats and lions do not live in the same environments, they do not compete for the same resources, and they do not face the same dangers. They cannot be compared in this way. You say that you read the Wikipedia page that I posted, but you don’t seem to have understood the point. You call fitness a simple concept, but you don’t seem to have grasped it.
This is the same problem we encounter when people say “Evolution is just a theory.” You’re using a word that has a scientific meaning as if it means the same thing that it does in everyday common language. It doesn’t.
I can go to the gym and get very fit, or I can grow very tall or I can have perfect vision, or a useful prehensile tail, but if I never have a child, then evolutionarily speaking, my fitness is zero, zilch, nada. If you pass on more of your genes to the next generation than I do mine, then you’re fitter than me, even if you weigh 400 pounds and can barely walk.
@LostInParadise Sure, you can have indirect fitness through kin selection. But when people are struggling with the very simple difference between “being strong” (which is not fitness) and passing on genes (which is), that explanation is where I’m spending my energy.