For anyone wondering about the field that studies this sort of phenomenon, welcome to the wonderful field of historical linguistics! Historical linguistics is

For anyone wondering about the field that studies this sort of phenomenon, welcome to the wonderful field of historical linguistics! Historical linguistics is a really cool intersection between anthropology and linguistics - in short the idea is we can look at languages around today and use certain well-founded assumptions about how languages change to understand the languages of the past; essentially the words we speak and sign today are the fossils of our linguistic history! Suggested reading is Historical Linguistics by Lyle Campbell, and Language Files for a more general Linguistics textbook.