The Caveats of Ancient DNA Dating

Dating techniques place it somewhere between 450,000 and 800,000 years old. Samples any older than that are probably too hopelessly degraded and contaminated to be meaningful. Paleoecologist Jamie Wood says painstaking measures have to be taken to ensure modern DNA doesn't get mixed up in the ancient sample. He recently obtained ancient DNA from rodent middens or debris piles buried in rock crevices in the Chilean desert as far back as 50,000 years ago.