The Iceman's Last Meal

Less than 2 hours before he hiked his last steps in the Tyrolean Alps 5000 years ago, Ötzi the Iceman fueled up on a last meal of ibex meat. That was the conclusion of a talk here last week at the 7th World Congress on Mummy Studies, during which researchers—armed with Ötzi's newly sequenced genome and a detailed dental analysis—also concluded that the Iceman had brown eyes and probably wasn't much of a tooth brusher.


Source: © South Tyrol Museum of Archaeology

Caption: Uncovered. New DNA findings are fleshing out the picture of Ötzi's last minutes.


The Iceman, discovered in the Italian Alps in 1991 some 5200 years after his death, has been a gold mine of information about Neolithic life, as researchers have extensively studied his gear—copper ax, hide and leather clothing, and accessories—and his body. Previous research on the Iceman's meals focused on fecal material removed from his bowels. The contents showed that he dined on red deer meat and possibly cereal some 4 hours before his death.

But a team led by microbiologist Frank Maixner of the Institute for Mummies and the Iceman in Bolzano, Italy, recently reexamined computed tomography scans taken in 2005 and spotted, for the first time, the Iceman's stomach. As the researchers reported at the meeting, the organ had moved upward to an unusual position, and it looked full. When they took a sample of the stomach contents and sequenced the DNA of the animal fibers they found, they discovered that Ötzi, just 30 to 120 minutes before his death, had dined on the meat of an Alpine ibex, an animal that frequents high elevations and whose body parts were once thought to possess medicinal qualities.

The new findings are "cutting edge" says Niels Lynnerup, a specialist in forensic medicine at the University of Copenhagen. "We are now inching our way to the last minutes of the Iceman."

In a separate presentation, dentist Roger Seiler and anatomist Frank Rühli of the Centre for Evolutionary Medicine at the University of Zürich, examined the dental health of the Iceman, who probably died between the age of 35 and 40. Previously, researchers examining radiological images of his teeth discerned no trace of cavities or other dental problems. But the Swiss team created new three-dimensional images of the ancient traveler's dentition. These showed that the Iceman suffered a blunt force trauma to two teeth—possibly a blow to the mouth—at least several days before his death and was plagued by both periodontal disease and cavities. The cavities, Seiler said in his talk, confirm that the Iceman ate a diet abounding in carbohydrates, such as bread or cereal, and reveal that he possessed a "heavy bacterial dose on these teeth."

Also at the meeting, researchers led by geneticist Angela Graefen of the Institute for Mummies and the Iceman reported that they have succeeded in sequencing the Iceman's whole genome, despite the highly fragmented nuclear DNA. The genome has already revealed some surprises. One preliminary finding shows that the Iceman probably had brown eyes rather than the blue eyes found in many facial reconstructions done by artists. Graefen and her colleagues are also examining the DNA to see if Ötzi possessed genetic predispositions to diseases such as arthritis, which other researchers have diagnosed based on radiological and other evidence.

Lynnerup calls this new line of genetic research on the Iceman "a major milestone." Molecular anthropologist Christina Warinner of the University of Zürich agrees, but she thinks the best is yet to come. Last year, she notes, a research team sequenced another ancient human genome from a 4000-year-old human hair preserved in Greenland's permafrost. "The real jump forward [in understanding the antiquity of some inherited diseases] will happen when we have not just one or two ancient genomes, but hundreds, she says. "Technologically, this isn't very far off, but we're still at the beginning of this process."
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References:

Pringle, Heather. 2011. "The Iceman's Last Meal". Science. Posted: June 20, 2011. Available online: http://news.sciencemag.org/sciencenow/2011/06/the-icemans-last-meal.html