Scientists have discovered fossilised human faeces, some 14.000 years old, in a cave known as the Paisley Cave, about 350 kilometers southeast of Eugene, Oregon. The DNA that was extracted provides biological verification that there were people in North America 14.000 years ago. The samples contain sinew and plant fibre threads, hide, basketry, cords, rope, wooden pegs and animal bones.

The matter of humans arriving in the Americas has always been debated, and most experts agree that the first people who migrated to American got the fromSiberia over a land bridge that once existed in what was known as the Bering Strait between Alaska and Russia. The best evidence of this is the Clovis culture, where archeologists have found many human remains.

Genetic and linguistic studies tend to date this migration about 15.000 years ago, which is also in accordance with the estimated time when the glaciers melted. Dr. Gilbert says that if they obtain more and better conserved DNA, they will be able to date the mitochondrial DNA, which is inherited directly from the mother.