The calcite-encrusted skeleton of an ancient human, still embedded in rock deep inside a cave in Italy, has yielded the oldest Neanderthal DNA ever found.

These molecules, which could be up to 170,000 years old, could one day help yield the most complete picture yet of Neanderthal life, researchers say.

Although modern humans are the only remaining human lineage, many others once lived on Earth. The closest extinct relatives of modern humans were the Neanderthals, who lived in Europe and Asia until they went extinct about 40,000 years ago. Recent findings revealed that Neanderthals interbred with ancestors of today's Europeans when modern humans began spreading out of Africa — 1.5 to 2.1 percent of the DNA of anyone living outside Africa today is Neanderthal in origin. [Image Gallery: Our Closest Human Ancestor] ...