I heard an interview on NPR Science Friday March 25, 2011 about the Hunt for traces of America's first inhabitants. There is a new theory that American's first inhabitants traveled here by boat, long before the Asians crossed the Bering Straits on the land bridge. Now I have always been unable to understand the migration by Homo sapiens out of Africa to inhabit the entire world. I mean, why leave and travel miles and miles and then live in frozen climates? This theory, has me even more perplexed that these early humans would build a boat to travel onto the unknown oceans? Why leave the land you inhabit. Was the population that large? Did they feel like rats in a cage? There could not have been that many people in the world!