Sunday, May 6, 2018

At His Ranch, John McCain Shares Memories and Regrets With Friends

Senator John McCain and former Vice President Joseph R. Biden Jr., in Philadelphia in October. Mr. McCain encouraged Mr. Biden to “not walk away” from politics during a recent visit.CreditMatt Rourke/Associated Press
PHOENIX — When former Vice President Joseph R. Biden Jr. traveled to Senator John McCain’s Arizona ranch last Sunday to spend a few hours with his ailing friend, the two reminisced about the “crazy senators” they had served with, the overseas trips they took together for decades and the friendship Mr. McCain forged with Mr. Biden’s two sons.
But the conversation on the sun-splashed deck off Mr. McCain’s bedroom was not all nostalgia.
“Here John knows he’s in a very, very, very precarious situation, and yet he’s still concerned about the state of the country,” Mr. Biden said in an interview. “We talked about how our international reputation is being damaged and we talked about the need for people to stand up and speak out.”
As he battles brain cancer and the debilitating side effects of his aggressive treatment, Mr. McCain himself is reckoning with his history and the future, as he and a stream of friends share memories and say what needs to be said.
No one is saying goodbye, not explicitly. The son and grandson of admirals, Mr. McCain “doesn’t like overt sentimentality,” as his friend the former chief of staff Grant Woods put it. But his visitors are telling him they love him, how much he has meant to them — and together they are taking care of unfinished business.
The Republican senator encouraged the former Democratic vice president to “not walk away” from politics, as Mr. Biden put it before refusing to discuss a possible 2020 presidential run. Mr. McCain is using a new book and documentary to reveal his regret about not selecting former Senator Joseph I. Lieberman as his running mate in 2008. His intimates have informed the White House that their current plan for his funeral is for Vice President Mike Pence to attend the service to be held in Washington’s National Cathedral but not President Trump, with whom Mr. McCain has had a rocky relationship.
And some of his associates, though not his family, have started to quietly put out word that they want a “McCain person” eventually appointed to fill his Senate seat, a roster that includes his wife, Cindy.
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Mr. McCain, 81, is still in the fight, struggling with the grim diagnosis he received last summer: He has been leading conference calls with his staff in a strained voice, grinding out three-hour physical therapy sessions and rewarding himself most days with a tall glass of Absolut Elyx on ice.
But his health has become a matter of immediate political interest. Mr. McCain’s future may determine whether Republicans retain their single-seat Senate majority: Should the senator die or resign before the end of May, there will most likely be a special election for the seat this fall. But under Arizona law, if he remains in office into June, there will probably not be an election for the seat until 2020, which Republicans would prefer given Democratic enthusiasm this year.
The matter of succession for the McCain seat — a topic of such intense discussion that Republicans officials here joke that Washington lawyers know Arizona election law better than any lawyer in the state — is officially verboten among party officials and the senator’s friends. They are determined to reward him with the same good ending that his friend Senator Edward M. Kennedy enjoyed before he succumbed to brain cancer in 2009.
Mr. McCain, who is not doing interviews, delights in sitting out on his deck where he once handled slabs of ribs on the grill, friends say. He and his wife listen to the hummingbirds and the burbling stream that runs through their 15-acre ranch, enjoy the verdant scenery in an otherwise arid region and divide their loyalties when the hawks start pestering Peanut, their Chihuahua mix. (Mrs. McCain sides with their dog, Mr. McCain the hawks.)
“He finds real solace there,” Mr. Biden said.
Mr. McCain, shown here in 2000, delights in sitting out on his deck where he once handled slabs of ribs on the grill, friends say.CreditDavid Hume Kennerly/Getty Images
A bout of diverticulitis temporarily landed him back in Phoenix’s Mayo Clinic last month. It caused him to miss seeing more than a hundred of his friends and colleagues, including the new secretary of state, Mike Pompeo, and Secretary of Defense Jim Mattis, who came to Arizona to attend the annual meeting of his foreign policy think tank, the McCain Institute.
Mr. Lieberman filled in for Mr. McCain at the forum and visited the senator afterward at the hospital, mixing talk of North Korea and Iran with well-worn jokes, like the one about the difference between a lawyer and a catfish. (One is a bottom-feeding scum-sucker; the other is a fish.)
“He was O.K., but he wanted to get out of the hospital,” recalled Mr. Lieberman, one of Mr. McCain’s closest friends. “Look, this is a man whose whole life has been active.”
Having spent over two years in solitary confinement while he was imprisoned in Vietnam, Mr. McCain has no use for being alone, whether it is in the intensive care unit or at his ranch. And his deck is where he receives a constant flow of friends — with visits that often end with Mr. McCain saying, “I love you” — and takes calls on the iPhone he just swapped for his tattered flip phone. (Mr. McCain finally made the switch to download the Major League Baseball app to better follow his Arizona Diamondbacks.)
Mr. Biden and his wife, Jill, were there last weekend; Senator Jeff Flake of Arizona, a Republican, and his wife, Cheryl, visited Friday; other colleagues are set to come this week and his seven children are there as often as they can. The phone calls have been even more frequent: Former President George W. Bush checked in last week, telling Mr. McCain the country is missing him.
In a visit on the deck earlier this year, Mr. Flake said he and Mr. McCain recalled how in the 1980s the legendary former Arizona congressman Morris Udall, a Democrat, had taken the newly elected Mr. McCain under his wing despite their differences in party.
“It was the two of us lamenting the loss of the politics of the past,” Mr. Flake said.
It was also at his Hidden Valley Ranch where the senator participated in a nearly two-hour HBO documentary and co-wrote what he acknowledges will be his last book, “The Restless Wave,” both of which are set to be released this month.
The film and the book, a copy of which The New York Times obtained independently of Mr. McCain, amount to the senator’s final say on his career and a concluding argument for a brand of pro-free trade and pro-immigration Republicanism that, along with his calls for preserving the American-led international order, have grown out of fashion under President Trump.
In the book, Mr. McCain scorns Mr. Trump’s seeming admiration for autocrats and disdain for refugees.
“He seems uninterested in the moral character of world leaders and their regimes,” he writes of the president. “The appearance of toughness or a reality show facsimile of toughness seems to matter more than any of our values. Flattery secures his friendship, criticism his enmity.”
Yet many in Mr. McCain’s own party believe that, by selecting Sarah Palin as his running mate in 2008, he bears at least a small measure of blame for unleashing the forces of grievance politics and nativism within the Republican Party.
While he continues to defend Ms. Palin’s performance, Mr. McCain uses the documentary and the book to unburden himself about not selecting Mr. Lieberman, a Democrat-turned-independent, as his running mate.
He recalls that his advisers warned him that picking a vice-presidential candidate who caucused with Democrats and supported abortion rights would divide Republicans and doom his chances.
“It was sound advice that I could reason for myself,” he writes. “But my gut told me to ignore it and I wish I had.”
Even more striking is how Mr. McCain expresses his sorrow in the documentary. He calls the decision not to pick Mr. Lieberman “another mistake that I made” in his political career, a self-indictment that includes his involvement in the Keating Five savings and loan scandal and his reluctance to speak out during his 2000 presidential bid about the Confederate battle flag flying above the South Carolina Capitol.
Mr. Lieberman said he didn’t know Mr. McCain felt that regret until he watched the film. “It touched me greatly,” he said.
Mr. McCain, in a new book and documentary, said he regretted not picking former Senator Joseph I. Lieberman, center, as his running mate in 2008. The two men, joined by Senator Lindsey Graham of South Carolina, visited the 2008 Republican convention hall together.CreditDamon Winter/The New York Times
Here in his adopted state, he has been immortalized as an icon. “John McCain is a giant in Arizona,” said Gov. Doug Ducey, a Republican, expressing sentiments that were echoed by the teachers protesting at the state Capitol last week.
Erik Gillman, a math instructor, said Mr. McCain had become the new Barry Goldwater, a figure as inextricably identified with the desert as cactus.
“It’s what people think about when they think about the state: the Grand Canyon and John McCain,” Mr. Gillman said.
But Mr. McCain’s conservative detractors have not forgiven his maverick tendencies simply because he is ill.
When Mr. Pence addressed a hard-right audience gathered in Tempe last week to promote the administration’s tax cuts, he said that “people all across America are praying for Senator John McCain” — and one woman yelled out, “to retire.”
Mr. McCain has long been both a flawed politician and a larger figure of history, by virtue of his refusal to be released early from Vietnamese captivity. Former Senator Robert J. Dole, for example, wore Mr. McCain’s P.O.W. bracelet while his future colleague was in the Hanoi Hilton prison camp.
Mr. Dole, now 94, said he planned to tell Mr. McCain in a coming phone call, “You’re a tough guy and you can overcome this.”
Mr. McCain's daughter, Meghan, shared a photo with her father at the ranch on social media in March.CreditMeghan McCain, via Associated Press
In Washington, Mr. McCain’s admirers believe the Senate and the Republican Party lack a needed counterbalance to Mr. Trump and worry that his absence only presages a larger decline in the country’s politics. With Mr. Kennedy gone and Mr. McCain ailing, Representative John Lewis of Georgia, the civil rights legend, is one of the few figures left in Washington who evoke a bigness at a moment in history that can seem all too small.
“The Senate is changing just like the country is changing,” said Senator Lindsey Graham, the South Carolina Republican, who is Mr. McCain’s closest friend in the chamber. “But Washington now reflects what’s going on in the country, rather than leading it.”
Another McCain protégée, Senator Amy Klobuchar of Minnesota, a Democrat, said she treasured how Mr. McCain treated her when they went on the congressional delegation trips he loves and foreign leaders would attempt to recognize the male lawmakers before her.
“They’d always look to Lindsey next,” Ms. Klobuchar said of the heads of state, referring to Mr. Graham, a frequent travel companion of Mr. McCain. “But he’d always say, ‘Senator Klobuchar is the Democratic lead and she’ll be going next.’”
Mr. McCain’s has been a lifetime of restlessness, beginning with the childhood relocations of his Navy family and evolving into unceasing demands of “what else?” aimed at his Senate staff. But the man whose political career took flight after he fended off charges of carpetbagging — by noting the longest he had lived in one place was as a prisoner of war — has found a measure of contentment on his ranch.
Mr. Biden said he was struck by how solicitous Mr. McCain was of him, inquiring about how he coped with the loss of his son Beau to brain cancer. Yet the former vice president said he was the one who hoped to impart a message.
“I wanted to let him know how much I love him and how much he matters to me and how much I admire his integrity and his courage,” Mr. Biden said.
Then he became more succinct. “I wanted to see my friend,” he said.
A version of this article appears in print on , on Page A1 of the New York edition with the headline: At Home, McCain Shares Memories and RegretsOrder Reprints | Today’s Paper | Subscribe

Tuesday, March 20, 2018

David Reich Unearths Human History Etched in Bone

BOSTON — David Reich wore a hooded, white suit, cream-colored clogs, and a blue surgical mask. Only his eyes were visible as he inspected the bone fragments on the counter.
Dr. Reich, a geneticist at Harvard Medical School, pointed out a strawberry-sized chunk: “This is from a 4,000-year-old site in Central Asia — from Uzbekistan, I think.”
He moved down the row. “This is a 2,500-year-old sample from a site in Britain. This is Bronze Age Russian, and these are Arabian samples. These people would have never met each other in time or space.”
Dr. Reich hopes that his team of scientists and technicians can find DNA in these bones. Odds are good that they will.
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David Reich in his office at Harvard. He and his colleagues have sequenced the genomes of more than 900 ancient individuals, shedding light on how humans spread across the globe. Credit Kayana Szymczak for The New York Times
In less than three years, Dr. Reich’s laboratory has published DNA from the genomes of 938 ancient humans — more than all other research teams working in this field combined. The work in his lab has reshaped our understanding of human prehistory.
“They often answer age-old questions and sometimes provide astonishing unanticipated insights,” said Svante Paabo, the director of the Max Planck Institute of Paleoanthropology in Leipzig, Germany.
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Dr. Reich, Dr. Paabo and other experts in ancient DNA are putting together a new history of humanity, one that runs in parallel with the narratives gleaned from fossils and written records. In Dr. Reich’s research, he and his colleagues have shed light on the peopling of the planet and the spread of agriculture, among other momentous events.
In a book to be published next week, “Who We Are and How We Got Here,” Dr. Reich, 43, explains how advances in DNA sequencing and analysis have helped this new field take off.
“It’s really like the invention of a new scientific instrument, like a microscope or a telescope,” he said. “When an instrument that powerful is invented, it opens up all these horizons, and everything is new and surprising.”
Dr. Reich oversees a team with many different skills, from genetics to mathematics. But the “clean lab” is where the raw material for all their work — ancient DNA — is recovered. The head-to-toe suits that the researchers don in an airlock each morning ensure that no stray flake of skin or bead of sweat contaminates the bones with modern DNA. Each night the entire lab is bathed in gene-destroying ultraviolet light.
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Interpreting Ancient DNA

A new book by David Reich, a geneticist at Harvard Medical School, details his laboratory’s findings on prehistoric human migrations and the complex mixing of different populations. This map shows some of those migrations, including the expansion of modern humans from Africa and the Near East, and several major mixing events.
A finger bone from a Siberian cave yielded the genome of a previously unknown lineage of humans called Denisovans, a diverse group who split from Neanderthals roughly 400,000 years ago.
As modern humans moved through Eurasia, they eventually displaced the Neanderthals, who were extinct by around 40,000 years ago.
Genetic evidence suggests there were at least four prehistoric migrations into North America, with the first at least 15,000 years ago and the last around 1,000 years ago.
Denisova Cave
Ancient North
range of
Ancestors of
East Asians and
East Asian
The first people in the remote Pacific arrived around 3,000 years ago, in a migration that began in Taiwan.
Dr. Reich helped prove that a wave of modern humans leaving Africa interbred with Neanderthals, likely in the Near East 54,000 to 49,000 years ago. Living humans outside Africa still carry traces of Neanderthal DNA.
A migration from West Africa beginning about 4,000 years ago spread agriculture to southern Africa. Bantu-speaking farmers displaced some hunter-gatherers and mixed with others, such as central African pygmies and the San in southern Africa.
Modern humans had arrived in Australia by at least 47,000 years ago.
Dr. Reich helped show that this group interbred with a branch of Denisovans, probably somewhere in Southeast Asia, 49,000 to 45,000 years ago.
The clean lab feels like it belongs in a computer chip factory. But Dr. Reich has not forgotten that these are human remains, not widgets on a conveyor belt.
“This is a bone from a person’s body who lived four thousand years ago, and we’re destroying it,” he said, gazing down at the Uzbek remains. “I think we need to do well by the individuals we’re studying.”
Doing well means understanding who these people were, and how they were linked to one another — and to us.
Standing next to Dr. Reich was a suited technician, Ann Marie Lawson. She picked up the Uzbek bone and lowered it into a box, which she covered with a clear plastic lid. She pushed her gloved hands through two rubber-lined holes on its sides.
She picked up the bone in her left hand; with her right hand, she switched on a sandblasting hose and pointed it at the bone. An outer layer of dirt flew upward, quickly sucked away by a fan in the box.
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Mr. Oppenheimer at work in Dr. Reich’s lab. DNA recovered from a small piece of bone can tell scientists about human migrations over thousands of years. Credit Kayana Szymczak for The New York Times
Ms. Lawson then inspected the freshly white bone. It came from the base of a skull, and deep inside was the inner ear. The bone that surrounds the inner ear turns out to be the best place in the body to search for ancient DNA.
Ms. Lawson began sandblasting again, chiseling away chunks of bone. Eventually, she was left holding a remnant only as big as a grain of rice.
“That’s the motherlode,” said Dr. Reich.

An Extraordinary Invitation

Dr. Reich grew up in Washington, the son of the novelist Tova Reich and Walter Reich, the first director of the Holocaust Memorial Museum and now a professor at George Washington University.
Dr. Reich began studying sociology as a Harvard undergraduate, but later he turned to physics and then to medicine. After graduating, he went to Oxford to prepare for medical school.
There he met Dr. David B. Goldstein, who at the time was comparing the DNA of living people for clues to what their distant ancestors were like.
“When I first met him, he was obviously smart, but he gave an impression of being a little bit shy and not having a very forceful personality,” said Dr. Goldstein.
“It turned out that’s the most misleading impression he could possibly give. He knows exactly what he wants to do.”
It was obvious that his student was captivated by the research. But Dr. Goldstein had come to view it as a scientific dead end.
“I said, ‘My God, don’t spend your career on human evolutionary genetics,” recalled Dr. Goldstein, who now studies disease genetics at Columbia University.
“He just listened very politely and wasn’t persuaded an iota,” he added with a laugh. “He wasn’t just proven right. He was proved dramatically right.”
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The cochlea, or inner ear, extracted by Mr. Oppenheimer. It may contain DNA that is tens of thousands of years old. Credit Kayana Szymczak for The New York Times
Abandoning medical school, Dr. Reich continued with genetics research and was hired by Harvard Medical School in 2003. By then, he had developed a close partnership with a mathematician named Nick Patterson, who had come late in life to genetics after twenty years working as a cryptographer in British intelligence and then joining a hedge fund.
Dr. Reich appointed Dr. Patterson deputy head of the newly formed genetics lab, and together they began developing new statistical techniques to plumb genetic data for hidden patterns.
The two researchers devised a way to determine whether a single population descended from two or more distinct groups. Collaborating with researchers at the Center for Cellular and Molecular Biology in Hyderabad, India, they put their method to its first big test.
Analyzing DNA from hundreds of villages, they discovered that just about every living Indian descends from two distinct groups. One, which the researchers called Ancestral North Indians, is related to Central Asians, Near Easterners and Europeans.
The second group, Ancestral South Indians, is a mysterious population that is not closely related to any living people outside of India. The two populations mixed together, Dr. Reich estimated, 2,000 to 4,000 years ago.
As Dr. Reich and his colleagues gained attention for their new methods, they got an extraordinary invitation: to study the DNA of Neanderthals.

A Mysterious Lineage

The invitation came from Dr. Paabo. In the 1990s, he had pioneered methods to extract ancient DNA from fossils dating back tens of thousands of years. While he studied many extinct species — such as cave bears, mastodons and ground sloths — Neanderthals were his deepest passion.
Fossils of these heavy-browed individuals date back over 200,000 years in Europe and the Near East. They made tools, weapons and even cave art. But they vanished about 40,000 years ago.
Dr. Paabo gradually filled in gaps to reconstruct the entire Neanderthal genome. In 2006, he invited Dr. Reich’s team to help figure out how modern humans and Neanderthals were related.
Dr. Reich threw himself into the project, and over the next few years, the scientists made a series of landmark discoveries.
The DNA of Neanderthals indicates that their ancestors split from our own about 600,000 years ago. But Dr. Reich’s tests revealed that living humans outside of Africa still carry traces of Neanderthal DNA.
How is that possible? Before Neanderthals became extinct in Europe, they encountered and interbred with the ancestors of modern humans as they departed Africa.
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Mr. Oppenheimer works with a machine handling bones samples. Credit Kayana Szymczak for The New York Times
As the scientists searched in more fossils for Neanderthal DNA, they got another surprise. In 2010, a nondescript pinkie bone recovered in a Siberian cave called Denisova yielded the entire genome of a previously unknown, and extinct, lineage of humans.
The Denisovans, as they came to be known, split off from Neanderthals about 400,000 years ago, genetic analysis revealed.
Denisovan DNA has turned up only in a few additional teeth discovered in that Siberian cave. The oldest such fossils date to over 100,000 years old; the pinkie bone belonged to a Denisovan who lived sometime between 48,000 and 60,000 years ago.
Dr. Reich and his colleagues discovered that Denisovans, like Neanderthals, left a genetic legacy in living people, mostly in Australia, New Guinea and Asia.
Their research also suggested that Denisovans divided early in their history into two lineages. “They were isolated from each other for many hundreds of thousands of years,” said Dr. Reich.
A study published on Thursday by Princeton geneticist Joshua Akey and his colleagues confirmed this finding and brought Denisovans into sharper focus.
Each branch, the new study suggests, interbred with the ancestors of living humans. One Denisovan group left behind DNA in modern-day Asians and Oceanians. The other branch left genetic traces only in living people in China and Japan.
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A cochlea, left, is measured in Dr. Reich’s lab. Right, a lab technician prepares to extract DNA. Credit Kayana Szymczak for The New York Times
Ancient DNA has summoned the genetic shadows of a long-vanished people, one that fossils alone could not reveal. Many scientists now suspect that ancient DNA will reveal other extinct kinds of humans in the future.
“The discovery of Denisovan DNA was a landmark in my thinking about ancient DNA,” said Dr. Reich. “It can reveal things about the past that are completely unexpected, that are not dreamed of in our philosophy.”

Setting the ‘Traps’

Dr. Reich’s voyage through prehistory left him wondering about what DNA could reveal about more recent events. Museums around the world were loaded with bones of people who lived within the last 20,000 years, after all.
Since those remains were younger, they’d be more likely to still have some DNA in them. To begin retrieving it, Dr. Reich retooled his laboratory, copying Dr. Paabo’s facility in Germany to the last detail.
“We even cloned the linoleum from Leipzig,” he said.
But in important ways, Dr. Reich broke from the standard scientific strategy for searching for ancient DNA.
Dr. Paabo and other experts typically examine many fossils to find a rare one packed with DNA. They then try to reconstruct the entire genome.
Dr. Reich’s lab instead designed DNA “traps” that snag hundreds of thousands of genetic fragments from the human genome. The result is far from a complete genome sequence, but enough to divine ancestries and even get some clues about the traits of ancient people.
In 2015, the first results emerged from Dr. Reich’s new research pipeline. He and his colleagues published DNA from 69 ancient Europeans who lived 3,000 to 8,000 years ago.

According to their results, farmers with Near East ancestry displaced hunter-gatherers already living in Europe. Then, about 4,500 years ago, another wave of people arrived, descended from the horse-riding nomads of what are now the Russian steppes.
Less than three years since that study, Dr. Reich’s team has published a torrent of similar findings. They have traced the spread of the first farmers in the Near East, for example, and have tracked the rise and fall of various populations in ancient Africa.
While some of these results describe migrations across continents, Dr. Reich’s team also focuses on smaller regions to reconstruct the genetic makeup of people over thousands of years.
Recently, for example, Dr. Reich and his colleagues published the DNA of people who lived on what are now the British Isles 3,500 to 10,000 years ago. It, too, tells a story.
When the Ice Age glaciers retreated from the islands, hunter-gatherers moved in from what is now Europe. About 6,000 years ago, farmers with Near Eastern ancestry reached Britain, and mostly replaced the hunter-gatherers.
About 4,500 years ago, archaeologist have found, there was a sudden shift in Britain to new styles of pottery and metalworking, known collectively as the Beaker culture. Many experts have argued that farmers borrowed the techniques from the European continent.
But the DNA says otherwise, Dr. Reich and his colleagues found. While the Beaker culture spread from society to society on the mainland, it was brought to Britain by immigrants descended from the nomads of what are now the Russian steppes.
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A tray in Dr. Reich’s lab holding ancient bones to be examined for DNA. Credit Kayana Szymczak for The New York Times
These people almost entirely replaced the earlier farmers. Today, British people trace 90 percent of their ancestry to this immigrant wave.
Were it not for the genetic findings, “nobody would have believed the scale of the turnover,” said Ian Armit, an archaeologist at the University of Bradford who collaborated with Dr. Reich on the research.
“Archaeologists will need to get to grips with this 90 percent replacement, and what this might really mean in human terms,” he added.

A Dramatic Voyage

The Beaker people needed only to cross the English Channel to get to the British Isles. A far more spectacular voyage took place about 3,300 years ago, when humans first sailed to remote islands in the Pacific.
Dr. Reich and his colleagues have shed light on that migration by analyzing ancient DNA from the skeletons of early Pacific voyagers.
“It’s changed the game,” said Matthew Spriggs, an archaeologist at Australian National University, who has collaborated with Dr. Reich.
Until recently, many archaeologists argued that the ancestors of Pacific Islanders were related to the indigenous people of Taiwan. They had sailed south to the islands around New Guinea, the idea went, later mixing with the population, known as Papuans. Only later did their descendants sail east to Pacific islands.

This theory helped account for the kinds of languages spoken in the Pacific, the agriculture, and styles of pottery, as well as the mix of East Asian and New Guinea DNA found in the islanders.
Dr. Spriggs and other archaeologists provided Dr. Reich with bones from Vanuatu and Tonga, and his team succeeded in recovering DNA where others had failed. And what did it say about the prevailing theory?
“We found genetically that wasn’t right at all,” Dr. Reich said. He and his colleagues published their results last month in the journal Current Biology.
Instead, the people who first arrived on Vanuatu and other Pacific islands came directly from Asia — perhaps Taiwan or the Philippines — without ever stopping in New Guinea. Only later did a wave of Papuans arrive.
“We know now when that wave hits — it hits before 2,400 years ago,” said Dr. Reich. “And it’s a total replacement.”
And that second wave actually was made up of at least two migrations. The Papuans who came to what is now Vanuatu probably sailed from the Bismarck Islands. But the Papuans who arrived further east, in Polynesia, came from other islands, possibly New Britain.
As of last month, Dr. Reich’s team has published about three-quarters of all the genome-wide data from ancient human remains in the scientific literature. But the scientists are only getting started.
They also have retrieved DNA from about 3,000 more samples. And the lab refrigerators are filled with bones from 2,000 more denizens of prehistory.
Dr. Reich’s plan is to find ancient DNA from every culture known to archaeology everywhere in the world. Ultimately, he hopes to build a genetic atlas of humanity over the past 50,000 years.
“I try not to think about it all at once, because it’s so overwhelming,” he said.
Correction: March 20, 2018
An earlier version of this article misstated the given name of a mathematician. He is Nick Patterson, not Neil.