Thursday, January 11, 2007

Earliest evidence of modern humans in Europe

Modern humans who first arose in Africa had moved into Europe as far back as about 45,000 years ago, according to a new study by an international research team led by the Russian Academy of Sciences and the University of Colorado at Boulder.

The evidence consists of stone, bone and ivory tools discovered under a layer of ancient volcanic ash on the Don River in Russia some 250 miles south of Moscow, said John Hoffecker, a fellow of CU-Boulder's Institute of Arctic and Alpine Research. Thought to contain the earliest evidence of modern humans in Europe, the site also has yielded perforated shell ornaments and a carved piece of mammoth ivory that appears to be the head of a small human figurine, which may represent the earliest piece of figurative art in the world, he said.

"The big surprise here is the very early presence of modern humans in one of the coldest, driest places in Europe," Hoffecker said. "It is one of the last places we would have expected people from Africa to occupy first."

A paper by Michael Anikovich and Andrei Sinitsyn of the Russian Academy of Sciences, Hoffecker, and 13 other researchers was published in the Jan. 12 issue of Science.

The excavation took place at Kostenki, a group of more than 20 sites along the Don River that have been under study for many decades. Kostenki previously has yielded anatomically modern human bones and artifacts dating between 30,000 and 40,000 years old, including the oldest firmly dated bone and ivory needles with eyelets that indicate the early inhabitants were tailoring animal furs to help them survive the harsh climate.

Most of the stone used for artifact construction was imported from between 60 miles and 100 miles away, while the perforated shell ornaments discovered at the lowest levels of the Kostenki dig were imported from the Black Sea more than 300 miles away, he said. "Although human skeletal remains in the earliest level of the excavation are confined to isolated teeth, which are notoriously difficult to assign to specific human types, the artifacts are unmistakably the work of modern humans," Hoffecker said.The sediment overlying the artifacts was dated by several methods, including an analysis of an ash layer deposited by a monumental volcanic eruption in present-day Italy about 40,000 years ago, Hoffecker said. The researchers also used optically stimulated luminescence dating -- which helps them determine how long ago materials were last exposed to daylight -- as well as paleomagnetic dating based on known changes in the orientation and intensity of Earth's magnetic field and radiocarbon calibration.

Anatomically modern humans are thought to have arisen in sub-Saharan Africa around 200,000 years ago.

Kostenki also contains evidence that modern humans were rapidly broadening their diet to include small mammals and freshwater aquatic foods, an indication they were "remaking themselves technologically," he said. They may have used traps and snares to catch hares and arctic foxes, exploiting large areas of the environment with relatively little energy. "They probably set out their nets and traps and went home for lunch," he said.

While there is some evidence Neanderthals once occupied the plains of Eastern Europe, they seem to have been scarce or absent there during the last glacial period when modern humans arrived, he said. The lack of competitors like the Neanderthals might have been the chief attraction to the area and the reason why modern humans first entered this part of Europe, Hoffecker said.

"Unlike the Neanderthals, modern humans had the ability to devise new technologies for coping with cold climates and less than abundant food resources," he said. "The Neanderthals, who had occupied Europe for more than 200,000 years, seem to have left the back door open for modern humans. "

The ivory artifact believed to be the head of a small figurine, discovered during the 2001 field season, was broken and perhaps never was finished by the person who began crafting it more than 40,000 years ago, said Hoffecker. "This is a really interesting piece," he said. "If confirmed, it will be the oldest example of figurative art ever discovered."

Buried under 10 feet to 15 feet of silt, the artifacts at Kostenki include blades, scrapers, drills and awls, as well as sturdy antler digging tools known as mattocks that resemble crude pick-axes, he said. Mattocks have been found at other Old World sites and the arctic and were used to dig large pits for the storage of foods and fuel, although traces of such pits have yet to turn up at the lowest levels of Kostenki, he said.

Large animal remains at Kostenki include mammoth, woolly rhinoceros, bison, horses, moose and reindeer. A bone chemistry analysis from 30,000-year-old human remains indicates a high consumption of freshwater aquatic foods -- either water birds, fish, or both -- more evidence for efficient food gathering techniques, he said.

Except for some early sites in the Near East, the oldest evidence modern humans outside of Africa comes from the Australian continent roughly 50,000 years ago, said Hoffecker, who was awarded an honorary doctorate from the Russian Academy of Sciences in 2006. Several modern human sites in south-central Europe may be almost as old as Kostenki, he said.

1 comment:

Jonathan Kantrowitz said...

Archaeologists find earliest evidence of modern humans in Eastern Europe

A University of Arizona archaeologist is a member of a team of scientists that has uncovered new evidence that modern humans moved out of Africa and occupied parts of eastern Europe as early as 45,000 years ago.

The Russian Academy of Sciences and the University of Colorado at Boulder, and including Vance T. Holliday, a UA professor of anthropology and geosciences, excavated three and worked on six of the more than two dozen ancient sites along the Don River, about 240 miles south of Moscow, Russia. Their discovery is published in the current (Jan. 12) issue of the journal Science ("Early Upper Paleolithic in Eastern Europe and Implications for the Dispersal of Modern Humans").

The excavations are located in the villages of Kostenki and Borshchevo, on the low terraces just above the Don River, overlooking a broad valley. Holliday says the uplands at Kostenki closely resemble rural Iowa. The area also has a number of natural springs and seeps that would have been an important source of fresh water for both the humans and the animals they hunted.

While there is little human skeletal evidence except for a few teeth, other artifacts found at Kostenki - including stone tools and elegant beadwork and figurines made from shells and ivory - are consistent with Upper Paleolithic humans. Stone used for tools were imported from quarries at least 60 miles away. The animal remains on site indicate that these people were technologically adept at hunting a variety of small and large game - hares, foxes, birds, fish and a number of very large animals, including mammoth.

The notion that modern people lived that long ago in what was then a sub-Arctic region intrigued Holliday, who analyzed the stratigraphy of the sites. Some of the digs are several meters deep in places, covered by silt from centuries of repeated flooding. Bones and artifacts have been exposed there for centuries, and scientific archaeology missions have dug there since 1879.

Getting a precise fix on the age of the sites is a bit complicated. Radiocarbon dating and a technique called OSL, or optically stimulated luminescence - measuring the time an artifact was last exposed to sunlight - offer varying levels of certainty.

But Holliday says the key is a thin layer of volcanic ash overlaying the oldest modern sites. The ash deposit is evidence of a very large volcanic eruption known to have occurred in Italy about 40,000 years ago, guaranteeing that anything underneath is older.

"OSL goes back much farther than C14, but it isn't as reliable as C14, so the ash provide a nice check on the OSL dates from levels beyond the reliability of C14 as well as being a superb marker bed and dating tool in its own right," Holliday says.

There are older deposits of artifacts below the settlements created by humans, likely belonging to Neanderthals, although no skeletal evidence of them remains either. Neanderthals roamed across Ice Age Europe for 200,000 years and largely vanished as modern humans advanced out of Africa through the Middle East and into central Asia and Europe.