These human ancestors lived during the Ice Age over 20,000 years ago ... The Nature of Things documentary Ice Bridge explores this controversial theory.

They have shown that many species, including humans, expanded their geographical ranges since the height of the last ice age, approximately 20,000 years ago. At this time, European ice sheets ...

However, a new Nature of Things documentary, Ice Bridge ... depicting them as intimidating beasts. But humans living in ice age North America had to deal with the real thing.