Evolution does not always optimize survival of an organism  Male moose evolved giant antlers as a way of fighting other males for mates, giving those with the largest antlers an evolutionary advantage  But those antlers also make it harder to escape predators, since they can easily get tangled in trees
All male moose would be better off with antlers half the current size: they would all be less vulnerable to predators, and those with the largest antlers would maintain their relative advantage
challenging a general claim by presenting a counterexample