DNA research does tend to spoil some theories on ethnic origins. If DNA mapping had been known in the 1930s it would have really spoiled Hitler’s day when he was told we all have a maternal great-great-…-grandmother who was an African. What it also spoils is the theory that the Negrito people of SE Asia are closely related to the African Pygmies as they look so very similar.
We do know the two small related Negrito populations in peninsula SE Asia, the Mani in Thailand and the Semang, (also called Sakai), in Malaysia, have been there a long time. They were there before the Malays and obviously the Tais. I think it’s a good guess that they are the descendants of the original settlers or at least a very early group migrating along the coastline of Asia. Malays call them the original people and who are we to argue. I would love to know how similar their DNA is to the Australian aborigines.
Below is a picture from Wikipedia of an Ati girl. The Ati are a Negrito group from the Philippines.
The Peoples of Thailand 