When the two dignitaries landed with their entourage at DFW International Airport, security agents rushed them through customs and helped them into a pair of waiting black vans. As their chauffeurs rolled toward downtown Dallas, a police escort trailed behind.
The guests are unlike any that have visited North Texas. They flew in from South Africa and have been dead for more than 250,000 years. Now their dismembered skeletons lay inside a half-dozen pieces of carry-on luggage and one cargo crate.
Nicknamed “Neo” and “Karabo,” these early human fossils are the stars of the Perot Museum of Nature and Science’s “Origins: Fossils from the Cradle of Humankind,” which opened Oct. 19 and runs through March 22.
They mark two of the greatest fossil discoveries in history, including two of the most complete early human skeletons. This is the fossils’ first time on public display outside their homeland, and they are exclusively in Dallas.
Precious cargo
The exhibition is both precise in its details and profound in its meaning. Visitors will be taken through the story of the fossils’ dramatic discoveries in 2008 and 2013, and learn how their very existence alters our understanding of human evolution.
It’s also a working exhibition. Scientists from around the country will rotate through a glassed-in lab to study the fossils firsthand. Other researchers will analyze newly obtained CT scans of a rock believed to hold the rest of Karabo. They hope to then 3D print the bones and add them to Karabo’s skeleton piece by piece, as viewers look on.
“They are obviously priceless heritage objects,” says Lee Berger, the paleoanthropologist who discovered both sets of fossils. He says the responsibility of carrying them across the world on airplanes is “terrifying.”
Berger is standing at this moment in the international arrivals hall at DFW Airport, his boyish face contrasting with his prematurely white hair. Moments before, Perot Museum CEO Linda Silver had greeted him with a hug. At Berger’s feet sits a black plastic briefcase that holds Karabo’s skull.
Berger has barely stopped grinning since getting off the plane. He and a handful of colleagues had sat nursing their drinks on the 24-hour flight, shuddering at every shake or drop of turbulence. But the priceless fossils had survived, nested in custom-fitted foam liners and stored in overhead bins.
The discoveries have elevated Berger, a professor at Johannesburg’s University of the Witwatersrand, into an international celebrity. If ever there were an Indiana Jones in real life, it might be Berger, who has the charisma and the props to match. His work has been featured in prominent scientific journals like Science, on the covers of National Geographic and Scientific American, on newspaper front pages and in documentaries.
As significant as his discoveries have been, some colleagues have criticized what they see as his penchant for publicity. Paleoanthropologists have traditionally toiled in isolation for years before disclosing their finds in peer-reviewed journals. Berger, by contrast, has live-tweeted his expeditions and allowed journalists to cover them as they happened. He does this, he says, because he believes science should be transparent and engaging, a goal he hopes to further with “Origins.”
The discoveries
Berger found the first of the two skeletons, Karabo, while exploring with his son, Matthew, and their dog about 30 miles northwest of Johannesburg. They were in an area of limestone hills and olive groves called the Cradle of Humankind, where many early human relatives have been discovered.
“Dad, I think I found a fossil!” his son yelled. The then-9-year-old stood near a rock with a yellowish, fingerlike protrusion.
Berger recognized it as a human-like collarbone, a fossil so fragile and rare that only about a half dozen have ever been found. Trying to maintain his scientific skepticism, he turned the rock over to examine it more closely and glimpsed something even more unmistakable: a jawbone with a small canine tooth.
“When I saw that sticking out of the back of the rock, I instantly knew that this was something very special,” says Berger.
As he speaks, he is standing on this day in a small windowless room on the lower level of the Perot Museum. The cases filled with the fossils he and his son had found — and many more — sit open on countertops, their contents exposed like the insides of exotic fruit.
It turned out that his young son had found the remains of a male his own age.
The fossils belonged to a previously unknown species of early human relative that the senior Berger named Australopithecus sediba. It had lived 2 million years ago, right around the time that our own genus, Homo, first emerged. And it had an intriguing mishmash of features: a small brain, ape-like arms and heels, but human-like hands and pelvis.
Within about a year, Berger’s team had amassed one of the most complete early human relative skeletons ever assembled.
That discovery alone could have made Berger’s career. But five years later, he found another new species.
Late one night, two cavers came to Berger’s house in Johannesburg and showed him photos of bones they had found as they explored a twisty span of underground pathways. Berger saw that these likely belonged to hominins — members of the human lineage that share more traits with people than with apes. He put together an international team to retrieve the finds.
The trove of fossils they brought to the surface is unprecedented in scale: They have unearthed more than 20 individuals of a species that the scientific team named Homo naledi. Like sediba, naledi was an unusual mix of ancestral and more human-like traits. However, naledi lived much more recently — 300,000 years ago.
Berger and his colleagues brought the most complete naledi skeleton, that of an adult male nicknamed Neo, to Dallas.
“Either discovery would be very significant on its own,” says John Kappelman, an anthropologist at the University of Texas at Austin who specializes in human evolution. “To have both of them come through is remarkable.”
Naledi’s body is slender and upright, with hands and feet that resemble those of humans, only more curved, suggesting it was an adept climber of trees or rocks. And while its brain, about the size of an orange or grapefruit, was far smaller than a human’s, it had an enlarged area associated with speech.
“We don’t know whether it could talk,” Berger says. “But it could have had a more complex language than just an animal language.”
Together, the two species shake up our understanding of the human family tree.
“Human evolution isn’t a linear process of one species leads to the next, leads to the next, and sediba and naledi reinforce that,” says Becca Peixotto, an archaeologist who climbed through the South African cave system to recover many of naledi’s bones and now directs the Perot Museum’s Center for the Exploration of the Human Journey.
Scientists now think it likely that modern and primitive species existed side by side at times in the past, in some cases even exchanging genes through interbreeding, passing down various combinations of traits until our human combo took hold. Berger likens this pattern of evolution to that of a braided stream.
“I think it’s one of the most important hypotheses we have now,” says UT’s Kappelman. He says finds like Homo naledi suggest early species persisted far longer than scientists previously thought.
From Africa to Dallas
Berger’s road to Dallas was forged about 10 years ago when he met philanthropist Lyda Hill at the annual National Geographic Explorer’s Festival in Washington, D.C. The story he told about sediba’s discovery captivated her. “He is a remarkable storyteller and you feel like you are there,” she says via email. She returned to the symposium some years later, and this time he told the story of Neo.
“I walked up to him after his talk and said, ‘You are going to change the textbooks. You probably need some support.’” Lyda Hill Philanthropies has supported Berger’s work ever since.
Because Hill also supports the Perot Museum, she helped bring the two together. Last year, the museum formalized its partnership with Berger and the University of the Witwatersrand, appointing Berger as an adviser to its new Center for the Exploration of the Human Journey. Shortly afterward, the museum opened its Being Human Hall that included an expanded evolution exhibit featuring casts of naledi’s and sediba’s skulls and a virtual reality exploration of the cave system where naledi was found. The museum also hired archaeologist Peixotto.
Last year, Perot Museum CEO Silver and board director Hernan Saenz traveled to Johannesburg to meet with Berger and plan future collaborations. They asked him, “If you could do something extraordinary, what would you do?”
Berger replied, “I would love to bring original fossils to Dallas and the Perot Museum, because no one would ever consider doing that!”
Early human skeletons rarely leave Africa. The last one to do so was “Lucy,” our famous 3.2 million-year-old relative from Ethiopia, that went on tour in 2007.
Berger was also drawn to Dallas because of his Southern roots. His father was a Texas oil wildcatter, and Berger grew up in rural Georgia. The middle of the country, he said, is often overlooked when it comes to exhibitions on human evolution.
“All of the major exhibits around human origins tend to go to the upper East Coast or the upper West Coast,” Berger says, “and the rest of America tends to be ignored.”
To help compensate for that, the museum will bring scientists involved with fossil research to schools and local libraries. It is also hosting a one-day workshop for educators on how to teach human evolution — a subject that 60 percent of K-to-12 educators either omit or underplay, according to a 2010 survey reported in the journal Science.
“Teaching evolution, let alone human evolution, here in Texas is challenging,” says John Mead, a middle school biology teacher at St. Mark’s School of Texas who will serve as an instructor in the workshop. “It’s not a topic that most biology teachers are overly comfortable with.” The “Origins” exhibit, he said, allows teachers to be exposed to the story of human evolution in a way they haven’t been before.
Underground astronauts
Discovering bones is one thing, of course; retrieving them is quite another. A strange and compelling twist in this story involves a team of spelunking women scientists.
In 2013, Berger posted a call on Facebook for “skinny and preferably small” individuals with experience in caving and archaeology or paleontology. “They must not be claustrophobic,” he added.
Peixotto replied to the post and became one of six women whom Berger dubbed “underground astronauts.” They would would have to navigate a tortuous path below ground through passageways with names like “Dragon’s Back,” “The Chute” and “Superman’s Crawl.”
At the Perot Museum, visitors can squeeze through the same tiny pinch points — one is just 7 inches wide — that Peixotto navigated to retrieve naledi.
She practiced for the expedition by learning to crawl, inflate her lungs and maneuver her body beneath her IKEA bed — the only piece of furniture in her apartment that was precisely 7 inches off the ground.
The end of ‘great secrecy’
Even before Berger knew exactly what lay inside those caves outside Johannesburg, he invited reporters and filmmakers from National Geographic and NOVA to follow his expedition. His team also posted updates on social media so the general public and fellow scientists could follow along.
That openness sets him apart from many of his peers, who prefer to work slowly and guard their finds closely until they publish results. “Historically in this field people practice great secrecy on the fossils, sometimes for decades,” said UT’s Kappelman.
Berger also made 3D files of naledi available online, so researchers and other fossil lovers could print and examine their own copies of its skull.
Starting this weekend, however, museum-goers will be treated to the real thing. They will come eye-socket to eye-socket with relatives that lived before our genes settled into a pattern that enabled us to sail the world, build skyscrapers, invent iPhones and create virtual tribes instead of real ones.
To those who worry that humanity has grown more fragmented than ever, the “Origins” exhibit may seem timely: It marks a diplomatic mission from the past that reminds us of our common ancestry.
Details
'Origins: Fossils from the Cradle of Humankind" runs Oct. 19 to March 22 at the Perot Museum of Nature and Science, 2201 N. Field St., perotmuseum.org
THE STORY OF A SKULL
For the first year of their excavation, Lee Berger and his team were missing sediba’s skull. Then Berger found an upper arm bone in a block of rock and took it back to his university to have a fossil preparator work on it. As his colleague picked away the rock, Berger saw part of a facial bone emerge. Assuming it was a fragmented face, he called up his wife, a radiologist, and rushed the rock over to the hospital where she worked. In between patients, they loaded it into a CT scanner, then sat and waited by the monitor. “The first image that came out was this slice of perfect, whole skull,” said Berger. “It was literally sitting a millimeter below the rock, and the rock was just big enough to have concealed the whole skull inside of it. I couldn’t believe it. Complete skulls like that are completely unheard of, and I realized I was looking at something really extraordinary.” — A.K.
