(image via www.smallislandnotesan.blogspot.com)
Taiwan, being the host of Austronesian language-diversity could’ve been the origin, as linguists would argue. Austronesian languages also have a lot of similarities that when reconstructed would trace back to Taiwan. Peter Bellwood also has evidenced of carbon dating of materials used by the Austronesians — pottery, adzes, spindle whorl, etc. — and it shows that there is indeed an emerging pattern. The oldest ones are from Taiwan, next is in the Philippines and Indonesia, and the youngest ones are in Oceania. And also evidently, there are close similarities in the cultures of people from Madagascar in the west to Easter Island in the east. There are however problems with using genetic evidences since there had been mixes among the Southern Mongoloid Austronesian speaking people and the Australo-Melanesians, which had inhabited some islands such as Philippines but never really conquered vast areas or islands.
Now all that remains is the question, why? Why did the Austronesians migrated and conquered a vast area. Peter Bellwood also answers this question.
Bellwood says that there is demographic advantage in maritime traveling among Austronesians as they were near a chain of islands. Hence, they were able to enhance and develop their maritime skills. Their agricultural skills also gave them an advantage in conquering other islands, since they could practically live anywhere. Being able to cultivate means that they would have stable supply of food once they move to another island. Also, there is a prestige factor in colonizing a different land. He called it the “founder-focused ideology”. However, the main thing – according to Bellwood – that pushed the migration of the Austronesians could have been the rising population densities of agriculturalists from China (the pre-Austronesians were said to be from Southern China) pushing these Austronesians to get in their boats and move out. But of course, this “moving out” isn’t like the exodus from Egypt. There might’ve been separate sailings from groups followed by another and another. Later on, there might’ve been also backward routes.
Bellwood says that the dispersal of the Austronesians is one of the most amazing feats in the world as they covered half of the world. In fact, Austronesian languages have the most number of speakers. However, as was said, the Out-of-Taiwan theory is still not accepted by all scholars. Wilhelm Solheim proposes a different theory — which I’ll try to discuss later.
Bellwood, P.(2004) “The Origins and Dispersals of Agricultural Communities in Southeast Asia” in P. Bellwood, I. Glover (eds) Southeast Asia: From Prehistory to History, pp.21-40, Routledge
More stuff on the Out-Of-Taiwan theory:
Gut Bacteria, Language Analysis Solve Pacific Migration Mystery by Brandon Keim (Wired Science)
Science: DNA goes missing in Polynesian triangle by Michael Brooke
Bugs and tongues reveal human march across Pacific by Ewen Callaway (NewScientist)