The Clovis theory, over time, acquired the force of dogma. “We all learned it as undergraduates,” Waters recalled. Any artifacts that scholars said came before Clovis, or competing theories that cast doubt on the Clovis-first idea, were ridiculed by the archaeological establishment, discredited as bad science or ignored.
The Solutreans, whose territory on the European continent was apparently rather compact, may have been forced by encroaching glaciers and extreme cold to cluster on the Atlantic coast. At some point, Stanford and Bradley say, the stresses of overpopulation may have forced some Solutreans to escape by sea. They headed north and west beneath the Atlantic ice sheet to nudge into North America at the Grand Banks of Newfoundland.
Posting mere quotes does not do the article justice. In the bigger picture - we don't know. There is enough evidence to suggest we are actually all in the dark, trying to figure it out. Agendas don't help either.
Cooling also happened when Amerindians killed all the megafauna. They killed species and especially very precious ones such as Mastodons. Same happened to Australia, these people were not as nice as showed in Hollywood movies such as "Dances with wolves"