Fossil Feces Revise History

Fossilized feces found in an Oregon cave have scientists rethinking how and when humans first came to North America. At 14,300 years old, the ancient poop was deposited at least 1,000 years before humans were thought to roam the area, National Geographic reports. Discoveries like this "help us to reconstruct the American past," one of the scientists says.

The feces represent the oldest human DNA from the Americas, analysis showed. The evidence contradicts the theory that humans in the Clovis culture arrived in the Americas over a land-bridge connecting Alaska to Asia. "This is the first time we have been able to get dates that are undeniably human, and they are 1,000 years before Clovis," the scientist says. (More Oregon stories.)