... taken over their natural habitats, and then bred them into distorted shapes that would not survive in the wild. Chickens, for example, have been cross-bred

... taken over their natural habitats, and then bred them into distorted shapes that would not survive in the wild. Chickens, for example, have been cross-bred so that their breasts are freakishly huge compared to their ancestors ... some chickens have a harder time walking upright due to this. We couldn't send these animals back into the wild because their current genes didn't evolve / adapt in the wild in the first place.