Bayesian phylogenetic analysis of Japonic languages

Lee & Hasegawa (2011) use phylogenetic methods to trace the origins of Japonic languages and dialects.  Two hypotheses are considered:  First, the farming/language dispersal hypothesis posits that the main factor for the divergence of genetic and linguistic diversity was agricultural expansion.  Second, the diffusion/transformation hypothesis posits that cultural innovations such as farming can diffuse between societies, and so genetic and linguistic diversity should not be linked.  The estimate of the common linguistic ancestor was in accordance with the farming/language dispersal hypothesis, again suggesting that that linguistic diversity followed genetic diversity.

The study is notable in considering dialects as well as languages and using etymology dictionaries to reconstruct forms from Middle and Old Japanese.  The analysis is also done with their own reconstructions and another, unrelated set.  The technique is similar to that used by Russel Gray et al. (2009) to study Pacific settlement patterns.

Lee S, & Hasegawa T (2011). Bayesian phylogenetic analysis supports an agricultural origin of Japonic languages. Proceedings. Biological sciences / The Royal Society PMID: 21543358

Gray, R., Drummond, A., & Greenhill, S. (2009). Language Phylogenies Reveal Expansion Pulses and Pauses in Pacific Settlement Science, 323 (5913), 479-483 DOI: 10.1126/science.1166858

4 thoughts on “Bayesian phylogenetic analysis of Japonic languages”

  1. I was wondering when I would see this here (I’ve been pretty busy the past few days). This was a fascinating article to read about – I’m still going through it for details. Atkinson, I believe, said that it should be bushier at the bottom, but that as a whole it stands up pretty well.

    I wonder what effect the earlier Jomon substrata had on Japonics, and what effect levelling has had on the plausibility of the tree as a whole over the past hundred years of Tokyo influence.

  2. The standard estimate is that about 1% of the Japanese lexicon has Jomon roots, something that has a certain amount of credibility because Ainu, as a presumptive successor of the Jomon language is still around allowing linguists to compare Japanese words to it. About a third of the Japanese lexicon is considered “wago”, that is having a proto-Japonic root in the Yayoi era, with the balance of the Japanese lexicon being borrowed from Chinese (about half) and other languages (about a sixth) in the historic era in well attested ways.

    Comparisons of the oldest of the Old Japanese texts and later versions of it also show the loss of a significant number of phonemes. Perhaps this is a legacy because of Jomon adult language learners in the population who couldn’t discern the Yayoi language sounds, although it could also be Chinese influence (a bit like some of the shoehorned Latin influences on formal/pedantic English).

    The accuracy of the dates don’t necessary validate the Baysean method in other contexts, however, because this is a case where the punctuated evolution that some including Akinson’s later work, suggests takes place at language contact and differentiation. This was a gradualist linguistic drift era for Japanese with little effective outside competition to speed up the process.

  3. @Ohwilleke, the method used by Lee and Hasagawa accounts for variation in rates of cognate change using a covarion. This model allows changes in a cognate set to vary over time – so it should handle any punctuated effects quite happily. They also used a “relaxed” clock to estimate dates which should soak up a lot of variation in rates too.

    Simon

    ps: Bayesian not Baysean 🙂

  4. What is not accounted for are factors like the notion that language users intentionally bring about extraordinarily rapid language change at the time of language differentiation for the purpose of making their language unintelligable to speakers of the source language, and extraordinarily rapid language change that can occur during periods of intense contact with other languages and mass new language learning effects (basically creole like effects that don’t reach the point of becoming true creole languages).

    There is evidence that both of these phenomena are important in real life rates of language change as Akinson has estimated.

    The model of Lee and Hasagawa is perfectly adequate to date Japonic because neither of those factors are important other than at the very beginning of the language’s genesis in this particular case. But, my point is that their relative success with Japonic does not validate the method that they use in the case of languages that have had numerous differentiation or intense language contact events that Japanese has not experienced. Thus, one should not assume, for example, that is is safe to generalize from the results of the Japanese model to the Indo-European languages, which we would expect to evolve more quickly because they have had more of these events.

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