I'll leave it to a Hungary expert to talk about Hungarian ethnogenesis, but just a few points:

• One often hears about race being a social construct, but this would be a great example of that. The idea that humans are divided into broad racial categories that can be scientifically defined by genetics and identified by physical appearances is largely an idea that developed during the Enlightenment and the 19th century.

These constructs rapidly break down when one deals with Inner Eurasia. Hungarians look "white", and Khanty look "Asian", but generally speaking those types of racial categories don't really have much of a deep meaning in Eurasia, definitely not in the way they do in contemporary North America. Identity has been shaped more by nationality, which tends to be broadly defined by language, religion, and culture. It's why Estonia (Estonians are speakers of a Finno-Ugric language) can hold a Kindred People's Day honoring their connections to people like the Khanty although an outside observer might look at their physical characteristics and say "they don't seem very kindred".

• Finno-Ugric languages are a family of languages spread across a wide geographic continuum. It does not just include Khanty and Hungarians, but also Finns, Estonians, Mari, Mansi, Komi, Mordvinians, Nenets, Sami, Karelians and Ingrians, and that's just the groups that still have extant identities (a large number of Finno-Ugric peoples were ultimately absorbed and assimilated into the Russian identity, for example). These peoples all look different, and many members of the same nationality look very different from each other as well! So I would caution against assuming any sort of essentialism.

• It's easy to talk about one group versus another group and lose track of the relative sizes. There are approximately 14 million ethnic Hungarians (more than all other Finno-Ugric speakers put together) and less than 30,000 Khanty, so relatively small changes will have a bigger impact on the latter than on the former.

• Language shift is a complicated process, and doesn't neatly line up with population genetics. For example, people in England speak a Germanic language closely related to languages like Frisian that are on the other side of the North Sea, while the genetic traits of the English population are much close to their Celtic neighbors such as the Welsh than they are to Germans or Dutch.