Italian Researchers Claim to Have Found the Oldest Human Blood
One of the world’s best known and most ancient of murder mysteries took yet another twist when scientists studying “Oetzi”, the mummified body of a 5,300-year-old man found frozen in the Italian Alps by hikers back in 1991 found red blood cells around his wounds. The researcher’s work published in the scientific journal of the Royal Society Interface show that the corpse had remarkable preservation, with even traces of blood, which normally degrades very quickly, being found. The discovery represents the oldest red blood cells ever observed.
Earlier this year, scientists published details of the genome of this ancient person, part of an intensive study of the “Iceman of the Alps”.
To read more about the genome of “Oetzi”: Genome of “Oetzi” is Published
Although the body of this 45-year-old man, an inhabitant of Earth when stone tools were beginning to be replaced with ones forged from metal (copper), has provided scientists with a great deal of data, how he died remains a mystery. Analysis of pollen grains found in association with the corpse indicate that “Oetzi” died in the spring, even his last meal (the contents of his stomach having been analysed), is known. However, whether he was murdered or whether he was given a ceremonial burial remains a mystery.
The Iceman known as “Oetzi”
Picture Credit: BBC News
The discovery of an arrow head embedded in this man’s back sparked intense media interest. Could this be the world’s oldest “whodunnit”?
Scans in the late 1990s failed to reveal substantial traces of blood, as scientists from the Eurac Institute in Bolzano, Italy strived to find out as much about this person as they could. A detailed examination of a wound on the man’s hand showed evidence for haemoglobin, a protein found in blood. Haemoglobin carries oxygen, transporting it round the body and delivering it to muscles and tissue. However, a more advanced, sophisticated and sensitive technique referred to as atomic force microscopy has led to the discovery of red blood cells. It had been thought that delicate blood cells would not have survived for 5,000 years.
Professor Zink and his colleagues, who had published the genome back in February, collaborated with researchers at the Centre for Smart Interfaces at the University of Darmstadt in Germany to apply what is known the atomic force microscopy to thin slices of tissue taken from an area surrounding the arrow wound in “Oetzi’s” back.
This technique uses a minute metal tip with a needle-like point just a few atoms across, being dragged across the surface of a sample. As the tip interacts with the surface material, data is fed into a computer and a detailed three-dimensional image of the surface can be built up.
The team found that the samples contained structures with a “doughnut” shape, just as red blood cells have.
Evidence of the World’s Oldest Red Blood Cells
Picture Credit: Journal of Royal Society Interface
To ensure the structures were preserved cells and not contamination of some kind, the European research team confirmed the find using a laser-based technique called Raman spectroscopy, the subsequent results also indicated the presence of haemoglobin and the clot-associated protein fibrin.
The evidence of fibrin in association with a wound would prove helpful to a modern forensic scientist investigating a homicide today. Fibrin usually degrades very rapidly and it is normally associated with fresh wounds so it seems less likely that poor “Oetzi” died some days before he ended up buried on top of a mountain.
Professor Zink outlined what the presence of detected fibrin means:
“Because fibrin is present in fresh wounds and then degrades, the theory that “Oetzi” died some days after he had been injured by the arrow, as had once been mooted, can no longer be upheld”.
Based on this evidence, it suggests that “Oetzi” met a violent end in the Italian Alps being killed relatively near to where his body was found.
It is not just palaeoanthropologists that are benefiting from this scientific research. The methodologies employed to examine this New Stone Age potential murder victim are helping modern-day forensic specialists to establish the exact age of blood samples found in association with modern murder victims.