I assume that this is one example of the stories you alluded to: [bbc.com]. This doesn't challenge the "out of Africa" theory as that refers to modern homo sapiens who weren't around at the time that these tools were produced. It does change the range of human (homo sapiens) ancestors and gives them a presence in China 400,000-500,000 years earlier than previously known.

Modern humans or humanoids? Cause many of our evolutionary cousins and ancestors used tools. Humanoids have been leaving Africa for a couple million years now. We also have observed other primates living today using tools, so it's not really a huge surprise.

Are you actually suggesting intelligent aliens visited Earth ages ago? Or was that sarcasm?

I was comfortable with the Africa story. I had this notion of the exit from Africa in a constant north-easterly direction until they all ended up in Sumer, blossomed into farmers and started thinking an awful lot about everything. Maybe lots of people went north or north-west and got to Spain and Italy long before the barricades were set up in Ceuta and Melilla.

According to Stephen Hawkins , we are made of stardust . According to a paper someone posted online , B- blood type was not original to this planet , and was introduced relatively recently . Therefore , I qualify as an alien . No wonder it's next to impossible to find a partner .