Earlier quoted context omitted.
There is a saying I’ve seen: ‘genes don’t speak languages’. Languages can easily spread between population groupings, and conversely a single population can move from one language to another — and both processes happen with considerable regularity. (Consider what happened to Gaulish as Latin spread, or Hittite as Greek spread, or Ancient Egyptian as Arabic spread, or…)
> or Ancient Egyptian as Arabic spread By that period in history, you'd usually call it Coptic, not (the much older) Ancient Egyptian.
(And really, as it evolved so dramatically over 3000 years, ‘Ancient Egyptian’ can’t easily be called a single language to start with. I tend to think of Coptic as simply the latest stage of Ancient Egyptian.)