Mysteries of Prehistoric Ötzi the Iceman Mummy Are Finally Being Unraveled

Researchers have uncovered surprising new details about the world's oldest known ice mummy.

A genetic analysis of the iconic "Tyrolean Iceman"—also referred to by the nickname "Ötzi"—has challenged what we know about the more than 5,000-year-old mummy's ancestry as well as his appearance.

The study, published in the journal Cell Genomics, has shown that Ötzi likely had dark skin, dark eyes and a balding head.

Ötzi is the natural mummy of a man who lived between 3350 and 3105 B.C. and died in the Ötztal Alps, which are on the border of Austria and Italy. The mountain range is spread out across the state of Tyrol in western Austria and the province of South Tyrol in northern Italy.

The mummy, which had been frozen in ice for millennia, was found by two German tourists in 1991. The remains of Ötzi were subsequently excavated, and the mummy is now on display at a local museum in the region.

The presence of an arrowhead in the body and other wounds previously led researchers to conclude that he may have been killed. But many questions remain about his life and death.

The Tyrolean Iceman is one of the best-preserved ice mummies and the oldest known. As a result, researchers have conducted numerous studies on the remains to understand more about him.

"He is by far the oldest glacier mummy people have ever found. The exceptional preservation of a prehistoric [man who] lived long before the rise of civilizations is amazing by itself," Ke Wang, an author of the study, told Newsweek.

"Such naturally well-preserved human remains are rare and thus offer scientists a precise opportunity to study the life of the iceman, [his] appearance before death and also his genetic ancestry origins," said Wang, who is affiliated with China's Fudan University and Germany's Max Planck Institute for Evolutionary Anthropology.

Scientists sequenced Ötzi's genome in 2012, providing novel insights into his ancestry. But in the latest study, the authors used advanced techniques to analyze his genome and obtained a more accurate picture of the iceman's genetic origins and appearance.

The genetic makeup of most modern Europeans is primarily the result of a mixture of three different ancestral groups. The first of these groups consisted of Western hunter-gatherers who gradually spread out across the continent starting around 15,000 years ago.

These hunter-gatherers were largely replaced by early farmers who migrated from Anatolia—a large landmass in West Asia where modern Turkey is located—to Europe. These early farmers were later joined by steppe herders from Eastern Europe, starting around 4,900 years ago.

The initial analysis of the iceman's genome showed that he was closely related to modern-day Southern Europeans, particularly people living in isolated populations in Sardinia and Corsica. This analysis also revealed genetic traces of the Eastern European steppe herders.

But the latest analysis of Ötzi's genome has challenged these findings. Not only was the original analysis hampered by contamination with modern human DNA, but sequencing technologies have advanced significantly in the past decade or so.

In addition, scientists have fully decoded the genomes of many more prehistoric Europeans, making it possible to compare Ötzi's genetic code with that of his contemporaries. These factors enabled the authors of the Cell Genomics study to conduct a higher-quality analysis of Ötzi's genome, shedding new light on his ancestry.

The researchers found that the iceman had unusually high Anatolian early-farmer ancestry—higher than any other known contemporaneous population from Europe in the fourth millennium B.C.

In fact, they found that Ötzi has more than 92 percent Anatolian early-farmer ancestry while confirming the absence of steppe herder ancestry—contradicting the conclusions of the original genome analysis.

This finding indicates that Ötzi belonged to a somewhat isolated Alpine population that seemingly mixed very little with people living north and west of the mountains, which acted almost as a genetic barrier.

"We were very surprised to find no traces of Eastern European steppe herders in the most recent analysis of the Iceman genome; the proportion of hunter-gatherer genes in Ötzi's genome is also very low," said Johannes Krause, another author of the study who is also with the Max Planck institute, said in a statement.

"Genetically, his ancestors seem to have arrived directly from Anatolia without mixing with hunter-gatherer groups," he said.

Wang told Newsweek that the high Anatolian ancestry the scientists found indicates there were regional variations in terms of mixing between early-farmer and local hunter-gatherer groups in this period.

Besides yielding new information about Ötzi's ancestry, the latest study enabled researchers to produce a more accurate picture of what this Neolithic man looked like. The genome analysis revealed that he likely had darker skin than previously thought and a dark eye color.

"It's the darkest skin tone that has been recorded in contemporary European individuals," Albert Zink, a co-author of the study and head of the Eurac Research Institute for Mummy Studies in Bolzano, Italy, said in a statement.

"It was previously thought that the mummy's skin had darkened during its preservation in the ice, but presumably what we see now is actually largely Ötzi's original skin color," he said. "Knowing this, of course, is also important for the proper conservation of the mummy."

The researchers also found that the iceman had genes predisposing him to male pattern baldness, challenging previous depictions that showed him with hair on his head. "This is a relatively clear result and could also explain why almost no hair was found on the mummy," Zink said.

Overall, the results suggest that the iceman looked more like the mummy does today than previously thought.