The Evolution of Universal Grammar

If language is more likely to have evolved as a system for the expression of thought, I suppose that implies that homo sapiens are the only creatures in the history of the planet to have thought thoughts. Incidentally, let me qualify the phrase expression of thought. It's a system forthe formulation of thought. As far as we know, it's unique in thehistory of life on Earth. We don't know if it might be unique in the universe.