Scientists have isolated blood from a 100,000-year-old Neanderthal human being, the most sensational discovery yet made in the fledgling science of genetic archaeology.
The announcement of the discovery generated a wave of excitement at last week's meeting of the American Association for the Advancement of Science and has been hailed as a critical breakthrough.
The finding means that for the first time, scientists may be able to use living materials to test controversial theories about the relations between Homo sapiens and Neanderthals.
In the past, researchers have had only fragments of fossil bone to argue over.
"We may soon be able to tell how closely related Neanderthals were to humans, decide whether we evolved from them, and confirm if they suffered from the same genetic ailments as us," said the discoverer, Dr. Thomas Loy, a research fellow at the Australian National University in Canberrra.
"We are going to learn a great deal about ourselves in the process," he told the AAAS meeting.
The blood found by Loy was left on a primitive tool uncovered at an archaeological dig at Bardabalka in northwest Iraq. The stone flake was small, triangular and little bigger than an arrowhead. Along one edge, it was covered with a reddish-brown substance.
Loy and other scientists have only recently discovered that blood and other organic material, hair, feathers and tissue adhere to stone tools and are often preserved for thousands of years. A battery of physical, biochemical and forensic techniques have since been developed to isolate these samples and to identify them.