Climate swings shaped human evolution, researchers claim Ian Sample, science correspondent The Guardian Monday November 19 2007 The evolution of our earliest human ancestors was driven by wild swings in eastern Africa's ancient climate, scientists claim today. The rapidly changing climate reshaped the landscape, leaving once plentiful food and water resources in scarce supply and placing enormous pressure on early humans to adapt. The sustained upheaval drove some species to the brink of extinction, while other better-suited relatives emerged and flourished, the scientists believe. Researchers identified several extreme shifts in climate dating back millions of years to when humans were...