Answer:
The answer to the question: Why did geography have such a strong impact on the lives of hunter-gatherers in the Paleolithic Era, would be, because these groups depended entirely on the resources that were available at a geographic location and the environment. If things changed in any regards, hunter-gatherers had to relocate to a new place.
This is why hunter-gatherers led nomadic lifestyles. Their survival depended on what their geographical location could provide them with. Once things changed, they would have to move to seek new places where they could get the necessary resources to live.
Given that these groups did not have any means of adapting their locations so that they could produce the food and lodgings at will, and they rather depended on moving herds of animals, and plant life, in a region, when conditions in the gegraphic area where they were changed, and they could not extract anymore sustenance, they would move on.
