[Nightstar]

Remember the neanderthals? a race of more intelligent, physically stronger human-analogues? yea, we killed them.

Also, dolphins are smarter than humans(i know it!). Did you know they have sex for pleasure, and know how to, *cough* pull out? Oh yea, apply the idea of contraception to dolphins, and suddenly they seem much smarter, right? we make them do tricks, and we eat them in our tuna-safe dolphin, heh.