The question I want to have answered is why the Predators look so much like human beings. Yes, there are plenty of attributes like the mandibles and green blood that definitely set them apart from us, but I honestly don't think there are that many planets where the inhabitants have two arms, two legs, one head, hair, and (I think) ten fingers. They seem to do just fine surviving in our atmosphere; no problems at all with the air pressure, and as we learned from Predator 2, they like to eat beef too. All of this seems like too much to be a coincidence, even though it happens to plenty of sci-fi movies that try to brush it off.