I don't think "pre-human" ancestors have been established. Since man is the relative newcomer in the evolutionary cycle it would seem to me that the evolutionary trail would be the clearest and yet, there has been no clear evidence that man is the product of macro-evolution.
My friend, VadeRetro, can provide you with numerous links to a load of such evidence, and he probably will, as soon as he gets this ping. The progression of skulls from the early homonids to our own wonderful species will astonish you. And it's beyond dispute that we share a tremendous amount of our genetic material with other homonids, more so than with any other species on earth. But even if you don't find such evidence persuasive, it's still the only game in town. There's literally zero evidence for any other origin for man. (Mythology and conjecture aren't evidence, I'm sure you'll agree.)
I've found some other good links lately but these two will give you the overall picture.