Maybe we are talking about different meanings of 'fitness'. I'm just saying, we can increase different 'attributes' in animals, so we also can in humans. Huma

Maybe we are talking about different meanings of 'fitness'. I'm just saying, we can increase different 'attributes' in animals, so we also can in humans. Humans are not somehow a special case of animal where we can't improve any attributes. You are correct. Just like chickens, where we have breed them to have such huge breasts that they can't survive without assistance. We assist them to live just long enough to be slaughtered.. The chicken group with the over-sized breasts are less 'fit' as a species. But, the goal isn't fitness, it is large breast meat. That decreases overall fitness. Sure, but fitness to do what? You're saying overall fitness as in the group has variation, so adaptable to some future environment. I'm just saying, you can make them taller or bigger. Lets say you breed humans to be more resistant to hot temperatures, but that reduces the variability in the group by reducing the number of cold resistant. Then in future, surprise, the environment gets colder, so the group dies out, because they had lost the cold variations. So what. The goal wasn't how adaptable to some future environment, it was how can I increase attributes I value today in todays environment, like being bigger, faster, etc... Maybe in the future there is a food shortage and all the bigger people starve. That could happen. Of course. This is theoretical, breeding humans is hard. Because we'd also need a way to kill off the outliers. A lot of chickens get tossed in the trash in order to maximize the breast meat of the 'surviving' group. And, I think also, the Eugenics people probably also as you say, miss-understood 'fitness'. Because bigger, faster, etc.. isn't necessarily better. But the perception is that bigger, faster, etc.. would be a super human. Even if that super human might die from catching the flu or something.