Yup. I believe the 'Bushmen' and Negritos were more wide-spread than presently recognized. I am presently re-reading (3rd time) J P Maloy and Victor Mair's book, The Tarim Mummies, fascinating book.
The Curse Of The Red-Headed Mummy
These folks may have made it all the way to Japan...some even believe they are the Ainu but, I don't. Their relatives, The Hakka, did make it to Japan.