It’s noteworthy that so few identified both the named groupings and their (then-)current geographical distributions with such accuracy in an arena then so new to the gaze of social and cultural scientists.
Here I assume that most readers of these pages are scientifically-informed in a general sense but not experts in historical linguistics.
My own formal linguistic training (historical and otherwise) was largely limited to a few courses given by Stanley Newman (a master linguist of his time, to be sure) in the Department of Anthropology at the University of New Mexico in the 1950s, but from that brief contact I did develop lasting respect for and interest in the science of linguistic reconstruction.
An emerging body of evidence from studies of the last glacial/interglacial cycle suggests that the East and West Antarctic ice sheets have not advanced and retreated in concert.
The West Antarctic ice sheet advanced to the outer shelf in most regions during the Last Glacial Maximum (LGM).