Teeth, language and racial origins, page-35

As you say, language and the diversity of it is what makes us human.

The view of the OT is that we are above the animals as we have the power of thought.
Without language how can we have thought or more precisely, how can we express that thought?

It isn’t a bad assumption but if we consider the knowledge gained on crows/ravens over the last 20-30 years and their ability to pass on information to progeny about good people and bad people that the group has met previously our so called higher status could be on shaky ground.

The abilities of many creatures to communicate has been underestimated over the course of time but research keeps coming up with more languages for more of our fellow creatures.

Seagulls and Pelicans must have a sense of humour for instance