A fellow who I believe is Chinese came to the site a while back with some very interesting ideas about the earliest speakers of the Tai-Kadai languages, of which Thai and Lao are the most famous. His statement is in blockquotes below.
He argues for a close relationship between Austronesian and Tai-Kadai, two huge language families in Southeast Asia and Oceania. Tai-Kadai researchers have long opposed this notion, including a professor who I worked with quite a bit while obtaining my Master’s Degree.
French linguist Laurent Sagart has recently proven to my satisfaction that Austronesian and Tai-Kadai are indeed related. I have looked over the evidence, and it looks very good. Sagart is clearly an expert on the language families of the region, including Sino-Tibetan, Tai-Kadai and Austronesian.
However, the field has not yet accepted Austro-Tai. Historical Linguistics has become so conservative in recent years that one wonders whether any new prominent language families will ever be proven to the satisfaction of the field. In this sense, ultra-conservative “scientism” has clearly taken over Diachronic Linguistics, and the only people making any headway these days are the trailblazers who are practicing what boils down to “fringe science” and are expectedly being trashed from here to Kingdom Come for not going along with the ultra-conservative mindset of the day.
The problem is that like cryptozoology, psi, ghosts, UFO’s and so many other fields, ultraconservative people practicing scientism and not science have set up the biggest roadblocks imaginable for dismantling any paradigms or in fact discovering anything new or breathtaking.
Modern science reminds me of the Catholic Church in the Middle Ages. It’s another faith-based fundamentalist philosophy. I guess we already know everything there is to know, and there’s nothing more to learn. In fact, incredibly, some scientistic practitioners are actually making statements along these lines.
Sagart’s new language would be called Austro-Tai, from which two branches, Tai-Kadai and Austronesian, descended. We know that the homeland of the Austronesians was in Taiwan and on the mainland adjacent to Taiwan possibly 5,000 YBP. From there, they mostly spread to the east – to Philippines, Malaysia, Indonesia, Polynesia, Melanesia and Micronesia, with some going back to Mainland Southeast Asia (most prominently the Malay, but also the Chams, etc.)
That Tai-Kadai and Austronesian were together as a macro-language on and west of Taiwan over 5,000 years ago makes intuitive sense on a lot of levels. They split up, with Tai-Kadai moving west and inland and Austronesian moving out to the islands to the west as the Lapita Culture.
Here it is below, with some edits and additions:
I have some words about the Zhuang to tell you. First of all, your article claims that the Proto-Tai came from Central Asia. That’s a questionable study. The most recent research on linguistics has revealed that the Proto-Tai-Kadai migrated back from Taiwan and they are closely related to the Austronesians.
The basic lexicon between the two branches of Hlai and Kadai in Tai-Kadai language family shows a striking similarity to Austronesian, i.e. Indonesian. However, examining the Tai branch, linguists see that original lexicon in the Tai branch were replaced by some other linguistic stock. That shows a linguistic contact between Proto-Tai and other groups in the ancient times and the genetic mix-up may also have taken place.
In conclusion, according to linguistic studies, the original Tai-Kadai Uhrmeit may have been the Austronesian-inhabited in Taiwan island. Then later, when moving back to the mainland of Southern China, they probably mixed with other ethnolinguistic groups.
It’s also worth mentioning that a trace of old Kam-Tai language from 2-3,000 YBP, an earlier form of Proto-Tai, has been discovered in southern part of the ancient Chu State (1030 BC–223 BC) by comparing the non-Sinitic words on unearthed inscriptions materials with reconstructed Old-Chinese.
This indicates that the geographic distribution of Proto-Tai speakers may have been quite different from our current understanding. And the identity of the group that they mixed with that replaced much of their original Austro-Tai lexicon is still not known. The location of Tai-Kadai speakers, especially the present-day Tai speakers in Yunnan in South China is quite a ways away from the location of most Austronesian speakers such as Malay and Indonesian speakers in Mainland and Island Southeast Asia.