Danish geneticist is rewriting history with DNA
Unlocking mysteries of human development, his findings have enriched our understanding
COPENHAGEN — As a boy growing up in Denmark, Eske Willerslev could not wait to leave Gentofte, his suburban hometown. As soon as he was old enough, he would strike out for the Arctic wilderness.
His twin brother, Rane, shared his obsession. On vacations, they retreated to the woods to teach themselves survival skills. Their first journey would be to Siberia, the Willerslev twins decided. They would make contact with a mysterious group of people called the Yukaghir, who supposedly lived on nothing but elk and moose.
When the Willerslev twins reached 18, they made good on their promise. They were soon paddling a canoe up remote Siberian rivers.
“Nobody knew what you would see on the other side of a mountain,” said Dr. Eske Willerslev, who is now 44. “There were villages on the maps, and you wouldn’t even see a trace of them.”
Willerslev spent much of the next four years in Siberia, hunting moose, traveling across empty tundra and meeting the Yukaghirs and other people of the region.
The experience left him wondering about the history of ethnic groups, about how people spread across the planet. A quarter of a century later, Willerslev is still asking those questions, but now he’s getting some eye-opening answers.
As the director of the Center for GeoGenetics at the University of Copenhagen, Willerslev uses ancient DNA to reconstruct the past 50,000 years of human history. The findings have enriched our understanding of prehistory, shedding light on human development with evidence that can’t be found in pottery shards or studies of living cultures.
Willerslev led the first successful sequencing of an ancient human genome, that of a 4,000-year-old Greenlander. His research on a 24,000-year-old Siberian skeleton revealed an unexpected connection between Europeans and Native Americans.
Willerslev was one of the early pioneers of the study of ancient DNA, and today he remains at the forefront of an increasingly competitive field.
“His role is that of catalyst, choreographer, conductor and cajoler — and sometimes all at once,” said David Meltzer, an archaeologist at Southern Methodist University.
The scientific enterprise that Willerslev helped invent now sometimes crosses into culturally sensitive terrain.
Last June, he and his colleagues published the genome of an 8,500-year-old skeleton from Washington state known as Kennewick Man, or the Ancient One.
Native American tribes and scientists fought over control of the bones since their discovery in 1996. During his research, Willerslev met with representatives from the tribes. One tribe agreed to donate DNA for his study.
Kennewick Man, Willerslev and his colleagues concluded, was related to living Native Americans. That finding led to a momentous announcement last month: The Army Corps of Engineers said it would formally consider the request from the tribes to reclaim the skeleton and bury it.
“He just became the kind of scientist he should have become,” Rane Willerslev, now a cultural anthropologist at the University of Aarhus, said of his brother. “Anything else would have been wrong.”
THE FIRST ANCIENT HUMAN GENOME
It was on their third journey through Siberia, in 1993, that the Willerslev brothers finally found the Yukaghirs. An old man, covered in scars from hunting bears in his youth, led them to a Yukaghir village.
“It was completely different from what I imagined,” Eske Willerslev said.
The Yukaghir were not an exotic tribe living in utter isolation. In fact, virtually all of them could count Russians and people from other ethnic groups among their ancestors. The Willerslev twins could find only a single old man who still spoke the native language.
That encounter was fresh in his mind when, back in Denmark, Willerslev learned that some scientists were extracting DNA from fossil mummies, a technique that might help explain the history of people like the Yukaghir.
But there was no one in Denmark doing that research, so one of Willerslev’s professors suggested a Plan B. They could investigate ancient ice that climate researchers at the University of Copenhagen had brought back from Greenland.
Willerslev and a fellow graduate student, Anders Hansen, set up a room where they could search for DNA in the ice cores. And in ice as old as 4,000 years, Willerslev and
at least 50,000 years ago. Scientists have long wondered if the aboriginals on the continent today are descendants of those first settlers, or of later arrivals.
Willerslev saw a weakness in early genetic studies on aboriginal Australians: Many aboriginals alive today have some European ancestry. He decided to look for an aboriginal genome free of European DNA.
In 2010, he found a piece of hair collected in Australia in the 1920s at the University of Cambridge. He and his colleagues retrieved DNA from the hair and reconstructed the owner’s genome.
Their analysis revealed that the ancestors of aboriginal Australians split off from other non-Africans about 70,000 years ago. That finding supports the idea that the first settlers in Australia were the ancestors of today’s aboriginals.
Willerslev was eager to share the new finding. But one of Willerslev’s co-authors, Rasmus Nielsen of the University of California, Berkeley, declared that they had made a grave mistake by not getting the consent of living aboriginal Australians.
“It didn’t seem right to circumvent the wishes of the aboriginal community by using that sample,” Nielsen said. “I was about to remove myself from the study due to these concerns.”
At first, Willerslev didn’t understand the fuss. “My view was that human history belongs to all of us because we’re all connected, and no people have a right to stop our understanding of human history,” he said.
But Willerslev decided to travel to Australia to meet with aboriginal representatives. He was shaken to learn of the unethical history of scientific research on aboriginal Australians.
Victorian anatomists plundered burial grounds, for example, and carried off bones to put in museums. Years of such exploitation had left many aboriginal Australians suspicious of scientists.
Today, geneticists who want to study aboriginal DNA need to obtain consent not just from donors, but from community organizations. And in many cases, there are limits on how widely scientific results can be shared. “Paying attention now, I could see why they had this skepticism and resistance,” Willerslev said. “In retrospect, I should have definitely approached those people before undertaking the study. Just because it’s legally right doesn’t make it ethically right.”
In Australia, Willerslev met with the Goldfields Land and Sea Council, which represents aboriginal people in the region where the hair sample had been obtained. He described the results of his analysis and asked for consent to publish them.
The council gave him permission. In fact, when the study came out, they praised the results. “Aboriginal people feel exonerated in showing the broader community that they are by far the oldest continuous civilization in the world,” the council said in a statement.
THE NEW WORLD
His experiences in Australia have changed the way Willerslev and his colleagues investigate DNA from indigenous people. “I’ve evolved,” he said.
In 2011, he learned of a 12,700-year-old skeleton of a baby that had been found in 1968 on the Montana ranch of Melvyn and Helen Anzick. Willerslev got in touch with the family and received permission to search the bones of the so-called Anzick child for DNA.
Willerslev was aware that many Native Americans, like aboriginal Australians, have grown suspicious about being exploited by scientists. During the course of his research, he tried to make connections with the local tribes.
He contacted the Montana Burial Preservation Board, which protects Native American remains in the state. But the board told him he didn’t need their oversight because the bones were found on private land.
Willerslev and his colleagues succeeded in getting DNA out of the bones. Based on his research in Greenland, he had suspected that the child belonged to a vanished population with no close kinship to living Native Americans.
But the genome proved otherwise: The child was closely related to living Native Americans.
As the preliminary results emerged, Willerslev was introduced to Dr. Shane Doyle, a member of the Crow Tribe who was then a graduate student at Montana State University. Doyle took Willerslev to a series of meetings with tribal representatives.
Many of the people there were interested by the results. But many also told them that the Anzick child skeleton, like other remains found in Montana, deserved a proper burial.
“Their priority was to get the remains back of the ancestors and to reinter them,” said Francis Auld, who was then the program manager of the tribal historic preservation office for the Confederate Salish and Kootenai Tribes.
With tribal representatives in attendance, the Anzick family buried the remains in June 2014, four months after the genome paper was published.
“It was a complicated case, and it would have been complicated for anyone,” said Dennis O’Rourke, a geneticist at the University of Kansas who was not involved in the research.
He said it would have been best if Willerslev and his colleagues had been able to confer with the tribes before doing the research. “But I was pleased to see that it was ultimately done,” he said.
Willerslev was then invited to look for DNA in one of the most controversial skeletons ever found: Kennewick Man.
In 1996, Ripan Mahli, then a graduate student, had tried to find DNA in the newly discovered remains. The methods at the time were too crude for the job, and research on Kennewick Man soon came to a halt as local tribes went to court to claim the bones.
MEETING LOCAL TRIBES
After a decade of lawsuits, a team of scientists won the right to study Kennewick Man, and in 2013, Willerslev was invited to try again to retrieve DNA from the bones, using his latest methods.
As he assembled a team of experts, Willerslev asked Mahli, now at the University of Illinois, if he’d join.
At first Mahli was reluctant. He had spent years building better relationships between scientists and Native Americans. A study of Kennewick Man might weaken those links.
But Mahli decided to join the team when Willerslev began meeting with local tribes.
“My mind changed when I realized Eske was engaging with these communities,” he said.
“He has been great through all of this,” Jackie Cook, the repatriation specialist for the Confederated Tribes of the Colville Reservation, said of Willerslev.
The Kennewick Man genome, like the Anzick child’s, revealed an ancient continuity between living Native Americans and the earliest people in the New World.
After Willerslev and his colleagues published their results last year, John Novembre of the University of Chicago confirmed them at the request of the Army Corps of Engineers.
Willerslev has mixed feelings about the consequences of his research on Kennewick Man.
“I’m a scientist, and it means I regret that important material is getting reburied,” he said. “But when you find that these remains are genetically Native Americans, it’s not our call anymore.”
“My view was that human history belongs to all of us because we’re all connected, and no people have a right to stop our understanding of human history.” Dr.Eske Willerslev Director of the Center for GeoGenetics at the University of Copenhagen