The late Zecharia Sitchin, whose work includes 13 books on ancient astronauts, was featured in a short 1999 film, "Phenomenon--Lost Archives--Genesis Revisited". It's a nice starting point for those interested in alternative theories of human origins. The present writer finds the much criticized work, which threatens current creation dogma, a rather compelling reframing of human history. Sitchin established his theory from the gleanings of cylindrical seals from ancient Sumer.
The theory is based on the existence of a 12th planet Niburu set in a highly eliptical orbit whose return crosses near the asteroid belt--every 3,600 years. It was during one of these crossings Niburu collided with a planet, which displaced it into a new orbit, resulting in the present planet Earth and debris from the collision--the asteroid belt. Niburu inhabited by an advanced human race, who stood nine feet tall, came to Earth after detecting gold there. The gold was intended to repair breaches in Niburu's atmosphere in an attempt to save the planet. Those sent to Earth to secure the gold came to be known as the Annunaki. Mars became a way station. The oppressive labor of mining in the Abzu, near present day Victoria Falls in southern Africa, resulted in protest. They decided to create a primitive worker, the result of mixing their genes with the primitive Homo Erectus, called the Lullu, the one that is mixed.
Sitchin remained critical of present theories of evolution by his references to the "endless beginning" of early man. You can get to know the man by reading this New York Times article, from earlier this year, prior to Sitchin's passing in October. It's an interesting theory of human origins and worth a look.