Humans aren't the only species to tend to their injured. Even some ants do that. The motivation is still debatable - is it done selflessly or because cooperation improves our own chances? Could that mean empathy is just an evolved impulse to help ourselves that was naturally selected? In some animals there may be an element of maintaining appearances that complicates things further. But there's no evidence to suggest that we aren't animals too or that the line we draw to separate less from 'more' isn't just drawn in some arbitrary place.