Zecharia Sitchin has several books out about mankind's beginnings based on his study of the cuneiform tablets dug up from the ancient Sumerian haunts in the Middle East. Accordingly to his theory, the 'Those who came from the Stars,' the Annunaki, traveled from the Orion constellation to earth many thousands of years ago in order to mine gold here on earth.
Once they got here, they determined that the labor required to obtain the gold was just too much for their alien hands, and so they co-opted a local species of ape (our forebearers) to make it smart enough to do the slave labor involved in mining the gold, and once they trained the slaves, they could kick back and just count the ingots that their slaves dug up.
Or words to that effect, that's the Sitchin theory. Now, I can buy that these aliens may have appeared eons ago, and that they may have had a hand in altering the DNA in our ancestors to some extent, but what I don't buy is that they couldn't figure out how to extract gold from our planet without help.
This is a civilization that traveled through space hundreds of thousands of light years away, and once they got here, they climbed down the ladder from their space ships with a pick ax, a pan and a shovel and got frustrated at how hard gold mining was.
Gimme a break. These guys given their technology could have melted a mountain or two with their ray guns, contained the resultant lava in their tractor beams, isolated, refined and extracted the gold from the lava, all from the comfy confines of their environmentally controlled space ships. No need to get their hands dirty, or maybe their tentacles, whatever.
For them to monkey around with the DNA of some aboriginal primates, wait a few generations for these primates to wise up enough to take orders from the Annunaki masters, that really doesn't square with common sense.
A guy can only swallow so much malarkey.