"In reading the genetics literature on South Asia, it is very clear that many of the studies actually start out with some assumptions that are clearly problematic, if not in some cases completely untenable. Perhaps the single most serious problem concerns the assumption, which many studies actually start with as a basic premise, that the Indo-Aryan invasions are a well-established (pre)historical reality. The studies confirm such invasions in large part because they actually assume them to begin with."
January 1, 1970
https://en.wikiquote.org/wiki/Genetics_and_archaeogenetics_of_South_Asia