He was professor emeritus of Slavic Languages and Literatures and Linguistics at the University of Michigan.

In 1988 he and Benjamin Stolz organized the First International Interdisciplinary Symposium on Language and Prehistory, at the University of Michigan, Ann Arbor.

Forty-six scholars participated as presenters and discussants, sixteen of which were from Russia and other eastern European countries (or recently emigrated therefrom).

This symposium led to renewed cooperation among historical linguists, archeologists, and physical anthropologists from East and West.

Some of his work on the relationship between linguistic associations and the hypothetical Proto-World language is controversial.