Only humans?
My pet dog would have argued with that one. If she could talk, that is.
I'm guessing you mean:
* other primitive life forms = simple bacteria, sponges, etc... out there in the universe,
* non-primitive life forms = more highly evolved life forms (with bodies) out there in the universe,
* only earth beings = no other life out there in the universe
* divine being = a life form of some description that is (mostly) outside of the universe
In that case, I think it's unlikely that there is NOT primitive life out there. I think it's possible that some primitive life has evolved into more complex life. I don't think that we are the only planet with life, but of course, there's no evidence of any other life out there as yet. And I don't believe in a divine being of any kind.