What happened to the 'aboriginal' peoples of pre-Austronesian Malay Archipelago?

Question

Humans first inhabited New Guinea, Australia, and Tasmania around 40k y.a., when the First Wave of H. s. sapiens migrating out of Africa eventually found their way to Sunda, then to Sahul. This theory is supported by both archaeogenetic (e.g., 1st branch of M haplogroups) and linguistic (e.g., distinctness of Papuan and Australian tongues) evidence. Fast fwd 35,000yrs. A group of Formosans venture out of present-day Taiwan to begin the great Austronesian Expansion, re-'colonizing' most of Malay Archipelago and beyond. While their legacy is great, they didn't fully displace the original Papuans and Australians.

So what happened to the peoples of Sumatra, Java, Borneo, etc. BEFORE the Austronesians veni-vidi-vicied? They would have descended from the First Wave, looked like Papuans, and spoken similar languages. Why were they displaced/assimilated into Austronesian cultures but their Papuan cousins spared? What made them so unlucky? And where are their archaeological remains?

Answer 1

Tricky question.

I've seen a 50k date for the Australian colonization somewhere, the Australoids seem to have reached America about 40k ago.

Some, like the Negritos were absorbed into the local expanding populations like the Malays.

The tiny 3ft high Palauns seem to have been wiped out.

There's some debate if the colonization of Australia was a single event as Mungo man's remains show non-Eve descended mtDNA, and some of the remains are very small and gracile. Also the Bradshaw paintings don't seem to be done by the Aborigines.

I suspect that Homo Erectus was in Australia first, they seem to have crossed fairly large bodies of water before to islands, so they seem to have had rudimentary boats or rafts. Some of the remains found have been borderline Erectus-like, and Aborigines do have a similar brow shape to them.

Answer 2

Matilda is probably right.  There are some surviving populations in vary remote regions.  In other areas, I suspect they were mostly wiped out and the remaining were absorbed.