“descended from Indigenous people, and not a remote branch of early Indo-Europeans”
Seeing how “Indo-European” is a linguistic/cultural category and not a genetic one, there’s no way that a genetic analysis can actually contradict this thesis.
It’s like saying “French people aren’t part of the Romance language group because genetically, they are Germanic”.
Exactly. Language is a meme, not a gene.
meme /mēm noun an element of a culture or system of behavior that may be considered to be passed from one individual to another by nongenetic means, especially imitation.
Except we know what groups made up that linguistic group.