Siberia's largest contribution to the study of religion is a single word, and what happened to that word is a lesson in how comparative categories are made.
Saman belongs to the Tungusic languages of eastern Siberia, and it named a specific kind of practitioner among specific peoples: someone called to the role, usually through illness or crisis, initiated by others already holding it, and working with drum, costume and helping spirits on behalf of a community. Russian travellers, officials and exiles reported on such practitioners from the seventeenth century onward, and the word entered European languages through those reports.
From there it expanded without limit. By the twentieth century shamanism was being used for practitioners in the Amazon, in Africa, in Korea, in Australia and in Neolithic Europe, on the strength of resemblances that the observers found striking. The category did real work, and it also flattened traditions that had their own names, their own training and their own theories of what was happening.
Meanwhile the practice in Siberia itself was suppressed. Soviet policy treated it as backwardness and as a rival authority; practitioners were persecuted, and drums and costumes were confiscated or destroyed. Much of the twentieth-century ethnographic record was made either just before that or in its shadow.
Practice has been reconstituted since, partly from the ethnographic literature, which makes the modern relationship between the record and the tradition unusually tangled.