Remarkable finds are changing beliefs about human evolution and migration from Africa

DMANISI, Georgia - The forested bluff that overlooks this sleepy Georgian hamlet seems an unlikely portal into 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 famed Olduvai Gorge.

But it is here in the verdant uplands of southern Georgia that David Lordkipanidze, a paleoanthropologist, has been unearthing one of the largest and most significant troves of prehistoric human fossils ever found outside of the Great Rift Valley. In doing so, he has begun to change fundamental beliefs about human evolution, and about early human's migration out of 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, more humanlike legs, well-suited for long-distance walking.

Why they left Africa remains a mystery. But the Dmanisi fossils provide ample evidence that when humankind's ancestors did leave Africa, they first 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 humankind'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 human, the primitive, apelike Homo habilis and the more humanlike Homo erectus.

A boost for his country

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 archeology."

Long before Lordkipanidze began his work at Dmanisi, the site buzzed with archeological digs. Excavations in 1936 revealed the stone-walled 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 into the Middle Ages.

The following year, paleontologists discovered primitive stone tools at Dmanisi, raising the possibility of a presence of prehistoric human. 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 (pronounced lord-keh-pa-NEED-ze) began working at Dmanisi. Then only 27, he had enticing offers to work in Germany and France, but he chose to return to his homeland at a time when Georgia 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-toothed 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 later 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 of Africa.

Abundant clues

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.

The skull's size fits between 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."

A consensus among paleoanthropologists has not been reached on whether the Dmanisi hominid fossils represent a new species of early human. 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.

"Understanding what you have can take years," Lordkipanidze explained on a sunny afternoon as he walked the rim of a wide, square pit where most of the fossils were found. "What's our job? It's the reconstruction of crime stories. And you have no [witnesses], no one can tell you what happened. So you have to guess, analyze and compare. But human fossils from this time period are very rare, so it's very difficult to compare with other bones. That's why it takes a long time."

Lordkipanidze appears braced to put in the time. A permanent steel roof is being built over the dig site, an improvement over the makeshift tarp roofs the team relied on in previous years. With the new roof, digs will go on for three months instead of eight weeks.

The site is being transformed into a kind of living museum, with steps and boardwalks that will take visitors from the medieval ruins, through a section of the site where Bronze Age pottery, tools and artifacts were found, and then to the large pit where the hominid digs take place.