May 2, 2012
Scientists Find 5,300-Year-Old Blood In Oetzi The Iceman
Image Credit: © South Tyrol Museum of Archaeology
Research of wounds on a 5,300-year-old body found frozen in the Italian Alps in 1991 has produced the oldest red blood cells ever identified, and suggests the well preserved “Iceman” did not immediately die from his injuries, nor did he live for a few days, scientists report in the Journal of the Royal Society Interface.
The bloody discovery is a first for the “Iceman,” called Oetzi, which has been extensively studied since being found by a pair of hikers along the Austrian-Italian border more than 20 years ago.
Dubbed the “victim of the world´s oldest murder puzzle,” due to his severely wounded and bruised corpse, scientists have studied Oetzi from head to toe, including his clothes, and even sequenced his DNA to determine age, his state of health and even his last meal (herb bread and red deer meat).
Scientists have determined that Oetzi died around the age of 45, was 5´2” tall and weighed 110 lbs. He suffered a violent death, with an arrow shot into his back, severing a major blood vessel between the rib cage and the left scapula. He also had a laceration on the hand.
Based on analysis using nano-scale technology to probe the mummy for signs of blood, the team of researchers, led by Albert Zink of the Ludwig Maximilian University in Munich, found that Oetzi in fact did not immediately die from his injuries, as leading theories suggest.
Blood cells degrade rather quickly, and earlier scans for blood within Oetzi´s body gave negative results.
“It was very surprising, because we didn´t really expect to find compete red blood cells," Zink, a biological anthropologist, told Stephanie Pappas of LiveScience. “We hoped to find maybe some remnants or shrunken red blood cells, but these are looking like a modern-day sample; the dimensions are the same.”
Zink and colleagues took tissue samples from the arrow wound and the earlier wound on his hand. Using a light microscope, they identified round objects that resembled red blood cells. To be positive, they needed more advanced technology.
Using an atomic force microscope, which works by “feeling” rather than “seeing” an object, the team studied the spots deeper. As the probe bumped up and down along the contours of the spots, a laser measured the movements. In the end, the team received a 3D “tracing” of the objects.
To the amazement of the team, the spots indeed turned out to be red blood cells. “They have the typical form, this kind of doughnut-like shape of red blood cells,” Zink told LiveScience. “The dimensions are the same in modern-day samples, so we were really quite sure these were red blood cells that had been preserved for 5,000 years.”
Modern forensic techniques are still not advanced enough to tell how long blood has been present at a crime scene, but scientists believe their nanotechnological approach could lead to a breakthrough in the field.
In the case of Oetzi, scientists were up in the air over whether Oetzi died immediately from his wounds, or whether he crawled to his mountainside grave after fleeing from attackers and dying from exhaustion or bleeding.
“Because fibrin is present in fresh wounds and then degrades, the theory that Oetzi died straight after he had been injured by the arrow, as had once been mooted, and not some days after, can no longer be upheld,” Zink said.
Through DNA sequencing, researchers also found that Oetzi had brown eyes, type “O” blood, and he was lactose intolerant. More surprisingly was the fact that he was more closely related to modern-day Corsicans or Sardinians than those living in the Alps near where his body was discovered.