Monday, July 20, 2009

Neanderthal wound from thrown spear points to Cro- Magnon homicide


For years the debate has raged over whether modern humans may have actually killed off Neanderthals. Finally, it looks like, at least in this one case, scientists may have come up with enough evidence to conclude that the remains of a Neanderthal known to the scholarly community as Shanidar 3, discovered in the Zagros mountains of northeastern Iraq in the late 1950s, was the victim of an attack by a spear-throwing Cro-Magnon rather than a hunting accident or intratribal dispute.

[Image - Model of Neanderthal at the Museum of Man, San Diego, California. Photo by Mary Harrsch]

The wound that ultimately killed a Neanderthal man between 50,000 and 75,000 years was most likely caused by a thrown spear, the kind modern humans used but Neanderthals did not, according to Duke University-led research.

Drawing from studies aimed at improving police and prison guard protection, the researchers concluded that the downward sweep of a knife could have the correct trajectory to produce Shanidar 3's rib injury. "Knife attacks generally involve a relatively higher kinetic energy," the report said. However, "whatever created that puncture was carrying fairly low kinetic energy at a low momentum," said Steven Churchill, an associate professor of evolutionary anthropology at Duke. "That's consistent with a spear-thrower delivered spear."

The investigators rigged up a special crossbow to fire stone-age projectiles, using calibration marks on the crossbow to tell them how much force they were delivering with each launch.

Those tests revealed the delivered energy needed to create similar wounds in the ribs of pig carcasses, which the researchers used as an approximation of a Neanderthal's body.

The researchers also used measurements from a 2003 study to estimate the impact of using a thrusted rather than thrown spear, the kind of jabbing that Neanderthals are thought to have employed. That produced higher kinetic energies and caused more massive rib damage than Shanidar 3 sustained.

Another clue was the angle of the wound. Whatever nicked his rib entered the Neanderthal's body at about 45 degrees downward angle. That's consistent with the "ballistic trajectory" of a thrown weapon, assuming that Shanidar 3 -- who was about 5 feet, 6 inches tall -- was standing, Churchill said. - More: ScienceBlog.com