15.6.20.23:59: TONOGENETIC CLUES IN MIZO 'DECLENSION'?

I first heard of Mizo (as 'Lushai') back in the late 90s when I learned that Starostin had found a correlation between Mizo short vowels and Middle Chinese Grade III (going back to Old Chinese 'type B' syllables which he reconstructed with short vowels and which I reconstruct as nonemphatic). See Sagart's (1999: 42-43) summary of proposals concerning the origin of Grade III which is often reconstructed as a  medial *-j-.

I didn't look at Mizo again until tonight when I took a good look at its Wikipedia entry. Normally, I expect Asian tonal languages to be 'isolating' like Chinese, but Mizo nouns decline! Or is 'declination' an artifact of looking at Mizo through an Indo-Aryan lens and/or Mizo orthography? Would it be better to analyze the suffixed case forms as noun-postposition sequences as in DeLancey (2004)? In any case, the ergative and instrumental both end in -in but have different tones. Does that tonal alternation reflect one or more lost final consonants? Are the two -in from a single original suffix (or postposition) with or without a following glottal suffix that conditioned a different tone?

*-in > -in + tone

*-in-H > -in + a different tone

6.21.23:36: Segmental affixes may also be the source of tone changes in derived verbs (though some derivations may postdate tonogenesis and be by analogy with existing pairs of verbs).

6.21.23:57: How many tones does Mizo have? Wikipedia lists eight. But Khoi Lam Thang (2001: 40) listed five, and Lorrain (1940) in Namkung (1996: 234) listed only three! How can these different descriptions be reconciled? And where did these tones come from? Wikipedia makes it sound as if Mizo had Chinese-style tonogenesis:

Tone systems have developed independently in many of the daughter languages [daughters of which language?] largely through simplifications in the set of possible syllable-final and syllable-initial consonants. Typically, a distinction between voiceless and voiced initial consonants is replaced by a distinction between high and low tone, while falling and rising tones developed from syllable-final h and glottal stop, which themselves often reflect earlier consonants.

I hoped to see the details in this process in Khoi Lam Thang's (2001: 98) dissertation. Unfortunately, his reconstruction of Proto-Chin, the ancestor of Mizo and its sisters, lacked a tonal component.

This  analysis  shows  that  there  are  comparatively  clearer  tonal  correspondences between Tedim, Mizo and Hakha. However, tone in Mara, Khumi and Kaang are split within the Patterns [established by Gordon Luce for Chin languages such as Mizo], tremendously complicated and without predictable environments. Thus, while a reconstruction of proto Northern Chin may be proposed from this data, a reconstruction of Proto Chin tone is incomplete and cannot at present be proposed. Therefore this thesis will be limited to a segmental reconstruction for Proto Chin. A Chin tonal analysis is in progress by Dr. Fraser Bennett and Ajarn Noel Mann. Their initial findings seem much closer to Luce’s Tonal Patterns.

I wonder what their final findings were.