New look at Iceman’s DNA Reveals New Ancestry, Other Surprises
A new look at the Iceman’s DNA reveals that his ancestors weren’t who scientists previously thought, the journal Cell Genomics reported.
In 2012, scientists compiled a complete picture of Ötzi’s genome; it suggested that the frozen mummy found melting out of a glacier in the Tyrolean Alps had ancestors from the Caspian steppe (SN: 2/28/12). But something didn’t add up.
The Iceman is about 5,300 years old. Other people with steppe ancestry didn’t appear in the genetic record of central Europe until about 4,900 years ago. Ötzi “is too old to have that type of ancestry,” says archaeogeneticist Johannes Krause of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. The mummy “was always an outlier.”
Krause and colleagues put together a new genetic instruction book for the Iceman. The old genome was heavily contaminated with modern people’s DNA. The new analysis reveals that “the steppe ancestry is completely gone.”
But the Iceman still has oddities. About 90 percent of Ötzi’s genetic heritage comes from Neolithic farmers, an unusually high amount compared with other Copper Age remains, Krause says.
The Iceman’s new genome also reveals he had male-pattern baldness and much darker skin than artistic representations suggest. Genes conferring light skin tones didn’t become prevalent until 4,000 to 3,000 years ago when early farmers started eating plant-based diets and didn’t get as much vitamin D from fish and meat as hunter-gathers did, Krause says.
As Ötzi and other ancient people’s DNA illustrate, the skin color genetic changes took thousands of years to become commonplace in Europe.
“People that lived in Europe between 40,000 years ago and 8,000 years ago were as dark as people in Africa, which makes a lot of sense because [Africa is] where humans came from,” he says. “We have always imagined that [Europeans] became light-skinned much faster. But now it seems that this happened actually quite late in human history.”
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