The deviant typological profile of the Tocharian branch of Indo-European may be due to Uralic substrate influence

Tocharian agglutinative case inflexion as well as its single series of voiceless stops, the two most striking typological deviations from Proto-Indo-European, can be explained through influence from Uralic. A number of other typological features of Tocharian may likewise be interpreted as due to contact with a Uralic language. The supposed contacts are likely to be associated with the Afanas’evo Culture of South Siberia. This Indo-European culture probably represents an intermediate phase in the movement of speakers of early Tocharian from the Proto-Indo-European homeland in the Eastern European steppe to the Tarim Basin in Northwest China. At the same time, the Proto-Samoyedic homeland must have been in or close to the Afanas’evo area. A close match between the Pre-Proto-Tocharian and Pre-Proto-Samoyedic vowel systems is a strong indication that the Uralic contact language was an early form of Samoyedic.