Drastic demographic events triggered the Uralic spread

The widespread Uralic family offers several advantages for tracing prehistory: a firm absolute chronological anchor point in an ancient contact episode with well-dated Indo-Iranian; other points of intersection or diagnostic non-intersection with early Indo-European (the Late Proto-Indo-European-speaking Yamnaya culture of the western steppe, the Afanasievo culture of the upper Yenisei, and the Fatyanovo culture of the middle Volga); lexical and morphological reconstruction sufficient to establish critical absences of sharings and contacts. We add information on climate, linguistic geography, typology, and cognate frequency distributions to reconstruct the Uralic origin and spread. We argue that the Uralic homeland was east of the Urals and initially out of contact with Indo-European. The spread was rapid and without widespread shared substratal effects. We reconstruct its cause as the interconnected reactions of early Uralic and Indo-European populations to a catastrophic climate change episode and interregionalization opportunities which advantaged riverine hunter-fishers over herders.