Depends on how long from the exodus of HE from Africa, though. We have Dmanisi c 2 million years ago in Georgia so if HE walked out of Africa it had to have been prior to that. 2 million BC to 40,000 BC is a long time.
Of course, if HE arose in Asia and one group walked into Africa that sort of junks the whole thing.
It would not have been 40,000 years though. Assuming, pending further revision, that HSS arrived c 40,000 BC and HNS was extinct by 28,000 that is only 12k years of "peaceful coexistence" ( or combat ).
How rapidly might isolated groups of stone age hunter/gatherers have spread through Europe with its mountains and rivers?
I suspect that many HNS/HSS lived out their lives and never saw the other.
Of course, if HE arose in Asia and one group walked into Africa that sort of junks the whole thing.
It would not have been 40,000 years though. Assuming, pending further revision, that HSS arrived c 40,000 BC and HNS was extinct by 28,000 that is only 12k years of "peaceful coexistence" ( or combat ).
How rapidly might isolated groups of stone age hunter/gatherers have spread through Europe with its mountains and rivers?
I suspect that many HNS/HSS lived out their lives and never saw the other.