There is a nice overview of previous attempts at classifying Tungusic languages in Robeets’ review of Recent advances in Tungusic linguistics (Turcologica 89), available at ResearchGate. Most of the schemes (other than Vovin 1993) work with four subgroups: 1) Evenki-Even (with Negidal and Solon), 2) Udege-Oroch, 3) Nanaic (Nanai, Ulcha and Orok) and 4) Manchu; and disagree on their genetic relations, the most common question being whether Manchu is the first group to diverge or if it belongs with Nanaic, and whether Udege-Oroch belongs with Northern or Southern languages.
There are many details of Tungusic comparative phonology which may be discussed when attempting a categorization. However, if we’re researching genetic relatedness, only those correspondences which can plausibly represent earliest branch-defining innovations are of direct importance.
From the sound laws usually mentioned (lenition/debuccalization of *p-, contraction of *-VgV- sequences, …) the one I found most informative, is the correspondence of /i/ ~ /i/ ~ /u/ ~ /u/, reconstructed as original *ü. This is because the backing of a front rounded vowel seems less common cross-linguistical than other isoglosses offered. By emphasizing this law I commit to a North-South model which splits the family into two equal halves, so let’s see how this might work out chronologically.
The Southern group
The Southern group couldn’t have stayed together for too long as there aren’t that many clear common innovations after the backing, here are some I can think of:
The fortition of intervocalic nasals
Correspondance of Southern /-ŋg-/ to Northern /-ŋ-/ seems very clear cut as a Southern innovation, but it is also quite common and thus a possible parallel innovation.
However there are also plenty of cases of /-nd-/ corresponding to /-n-/ which is more meaningful and likely related to the velar analogue, but pretty problematic as both /n/ and /nd/ between vowels appear to be phonotactically permitted in all Tungusic languages. For what it’s worth, EDAL reconstructs words such as *ŋin(d)a-(kün) “dog” with an *-nd-. There are also some cases of variation between /-m-/ and /-mb-/, but they are too chaotic for me to make sense of.
Presumably someone wrote about all this already and collected the relevant data, but I haven’t read it, Tsintsius doesn’t go into much detail in her Comparative phonetics, and I also didn’t find it in my cursory readings of Doerfer’s Mongolo-Tungusica.
Contraction of *-VgV–
This one is sometimes mentioned as an argument for grouping the Udege-Oroch group together with the Southern, as it also found there, however this change is quite common, especially if assume that *g was medially a [ɣ] already in Proto-Tungusic as it is in Evenki and Even (but not in Negidal), so I wouldn’t be surprised if it happened in all three branches independently.
Palatalization of *-rK–
All languages except Even and Evenki have something going on with these clusters, so perhaps this concerns an earlier or a later period.
Nanai at least has a very clear change of *-rK– into –jK– (there are similar phenomena in some Northern languages, but they have a general iotation of *r) and Manchu has complete affrication. Ulcha and Orok show Č and T respectively, however they feature a more general change of *-RK– > –RČ-/-RT-, although resonants other than *r do not disappear in this position.
Then it could perhaps be possible to reconstruct *rK > *jK for Common South Tungusic, however the fact that Udege, Oroch and Negidal iotated *r probably indicates that this is an areal feature or that Proto-Tungusic *r was already somehow close to [j] by articulation and changed in several languages independently.
The Northern group
In the north:
- *ü became *i and *ui became*ī
- *p– became *h–
- *x– disappeared
- Intervocallically *p and *b became *w
- Possibly *ua became *ā
- Perhaps *-nd- became *n as discussed above
None of these changes are unique, but they are more numerous than common Southern Tungusic innovations, so this appears unproblematic. However, we glossed something important over merely by using the term “North Tungusic”, geographically Udege and Oroch are spoken to the south of Nanaic languages, this can be clearly seen on this Ethnologue map which sadly doesn’t display China, but if it did it would be clear that Nanai continues down Sungari (Songhua) river. There are some theories that the Udege could have come from the north, but historically, during the Jurchen empire, they were found even further to the south and later migrated north to their current position. (See Nikolaeva’s A Grammar of Udihe for more details)
Where then was “North Tungusic” spoken? We could probably do worse than look at major waterways (or a more detailed map in Russian) when considering expansions of ancient populations. Due to diversity found in the Amur region, I would prefer to place Proto-Tungusic here rather than near Baikal or in Manchuria as it has been suggested previously.
If we start from the Amur, it seems clear that the Evenki group could have followed Amur upstream to Siberia with Negidals looping back to Amur via Amgun river and Solons entering Manchuria by following the Argun. The Manchu group must have followed Songhua all the way to Yalu river on the Sino-Korean border where Jurchens are first mentioned, and deep into Manchuria by Nen river. Nanaic languages expanded down the Amur with the Oroks finally reaching Sakhalin. The situation with Udege-Oroch is less clear, and if don’t accept their hypothetical migration from the north, “Common North Tungusic” as such would be impossible.
How then did these isoglosses come to be? I believe the key lies in Nanai dialects of China and the Kur-Urmi region. Here is a recent presentation discussing these languages by Andreas Hölzl, even if they are traditionally considered dialects of Nanai, a lot (I previously had the impression that it was the most although it appears to be more complicated) of their vocabulary has features common to “North Tungusic”.
Hölzl considers these languages as mixed and he cites Kazama’s opinion (which he disagrees with) that one of these languages, Kilen is a “a “missing link” between Ewenic and Udegheic”. Under the Amuric hypothesis, it is exactly this view that appears most elucidating.Basically this is the plot as I’d have it:
The original Proto-Tungusic speakers spread across the Amur basin, most importantly splitting at the Songhua river delta. After this a subdialect develops on Songhua and down the Amur which will develop into “South Tungusic”, with the ancestors of Evenks and Evens to the north of it, and the Proto-Udeges to the south. But before long, a backflow from the north or the south or both enters the Songhua delta territory again along with the Kur-Urmi region, splitting the Proto-Manchu group from Proto-Nanaic and creating something like a Common “North Tungusic” area that linguistic innovations could be transmitted through. Not only between Evenki and Udege groups, but possibly also to Nanaic.
Meanwhile Manchu-Jurchen drifted away from the rest of Tungusic, but that is a story for another post.