In Georgia, discoveries provide clues to evolution
The forested bluff that overlooks this sleepy Georgian hamlet seems an unlikely portal to the mysteries surrounding the dawn of man.
Think human evolution, and one conjures up the wind-swept savannas and badlands of East Africa’s Great Rift Valley. Georgians may claim their ancestors made Georgia the cradle of wine 8,000 years ago, but the cradle of mankind lies 3,300 miles away, at Tanzania’s famous Olduvai Gorge.
But it is here in the verdant uplands of southern Georgia that paleoanthropologist David Lordkipanidze has been unearthing one of the largest and most significant troves of prehistoric human fossils ever found outside the Great Rift Valley. His work has begun to change fundamental beliefs about human evolution, and about early man’s migration from Africa.
Lordkipanidze’s latest findings, partial skeletons 1.77 million years old and described in Nature magazine this fall, paint a portrait of small-framed early humans with primitive brains but longer legs, well-suited for long-distance walking.
Why they left Africa remains a mystery. But the Dmanisi fossils provide ample evidence that when mankind’s ancestors did leave Africa, they trekked through the Fertile Crescent and made their way to the lush highlands at the foot of the Caucasus Mountains.
“The Dmanisi fossils are no doubt the earliest hominid fossils in Europe,” Lordkipanidze said. “They are the first immigrants. They could be ancestors for any European or Asian population.”
Lordkipanidze believes his team’s findings at Dmanisi fill crucial gaps in the puzzle of mankind’s rootstock. Though not yet accepted by the scientific community as a separate species, Lordkipanidze says “Dmanisi man” could be a link between two stages of early man, the primitive, ape-like Homo habilis and the more human-like Homo erectus.
But for Lordkipanidze, the Dmanisi fossils are invaluable for a different reason: They have etched tiny Georgia into the annals of science, creating recognition that can rev up interest in science in a nation still reeling economically from the 1991 collapse of the Soviet Union.
“What is Georgia for much of the world? For a lot of people, it’s the birthplace of Stalin,” said the tall, soft-spoken 44-year-old Georgian. “Not many people know about our country. Now we’re making a name for Georgia through archaeology.”
There were archaeological digs at Dmanisi long before Lordkipanidze began his work. Excavations in 1936 revealed the stonewalled ruins of a medieval Georgian city, once a bustling way station along the Silk Road. The ruins included a citadel atop a promontory wedged between the Mashavera and Phinezauri rivers.
Erosion caused by the rivers made Dmanisi an ideal site to look beneath the medieval ruins and peer further back in time. In 1983, Georgian paleontologist Abesalom Vekua discovered the jaw fragment of a prehistoric rhinoceros in one of the citadel’s grain cellars. Its age, 1 million years, suggested that the site had significance far beyond its value as a window on the Middle Ages.
The following year, paleontologists discovered primitive stone tools at Dmanisi, raising the possibility of a presence of prehistoric man. The tools appeared to be akin to those found in East Africa, dispelling beliefs that prehistoric humans had to have developed more advanced stone tools before leaving Africa.
In the summer of 1991, Lordkipanidze began working at Dmanisi. Only 27, he had enticing offers to work in Germany and France, but he chose to return to his homeland, which was besieged by economic and political strife.
“I never hesitated,” said Lordkipanidze, director of the Georgian National Museum in Tbilisi. “It’s not anything extraordinary if you follow your country through good times and bad times. And I knew Dmanisi was important. How important, I couldn’t say back then. But I knew.”
On the last day of the 1991 dig, Lordkipanidze and his team found a prehistoric human jawbone underneath the bones of a saber-tooth cat. Lordkipanidze and his colleagues put the jaw’s age at about 1.6 million years and presented their findings to the world’s paleoanthropology community that year. Their findings drew skepticism from peers who doubted humans could have left Africa earlier than a million years ago.
“For the scientific community, it was difficult to accept the notion of finding something so old here in Georgia,” Lordkipanidze says.
After eight years of fruitless digging, Lordkipanidze erased all doubt about Dmanisi’s importance with findings of two 1.7-million-year-old skulls in 1999, another jaw fragment in 2000, and from 2001 to 2006, the skeletal remains of three adults and an adolescent.
Collectively, they are the oldest set of early hominid fossils outside Africa.
The variety of bones found at Dmanisi -- skulls, ribs, vertebrae, femurs, arm bones, a shoulder blade -- gave Lordkipanidze’s team a wealth of information rarely produced at early-hominid digs. With so many clues, he could begin envisioning Dmanisi’s prehistoric inhabitants.
The skull’s size fits between those of Homo habilis and Homo erectus, suggesting it could be a link between the two species, Lordkipanidze says. Its primitive arms and hands were built to climb trees, but the length of its legs suggested the ability to walk long distances. They were carnivores, a characteristic that would require the ability to be on the move to find new sources of food.
Dmanisi’s yield of fossils from 1999 to 2006 has startled Lordkipanidze’s peers, who work in a field that often requires decades of digging to produce a few fragments.
“It’s not one of these sites where you get one or two skulls or fragments,” said Jeffrey Schwartz, an anthropology professor at the University of Pittsburgh. “In the time that David has been working there, he’s found numerous fossils. It’s incredible.”
Paleoanthropologists haven’t reached a consensus on whether the Dmanisi hominid fossils represent a new species of early man. Lordkipanidze isn’t even sure himself. Much of the evidence points to Dmanisi man being a new species, but it also could be a subspecies of Homo erectus.
If science eventually dubs Dmanisi man a new species, Lordkipanidze has a tentative name: Homo georgicus. “I think Homo georgicus will appear one day, maybe five years or in 10 years.”
