The information collected allowed the scientists to piece together a picture of the ancient climate, environment, and migration of prehistoric peoples in the eastern Sahara over the past 12,000 years.
Among their findings, the researchers provide further evidence that the human exodus from the desert about 5,000 years ago is what laid the foundation for the first pharaohs' rule.
"Egypt is a gift of the Nile, as Herodotus said, as many people still think today," Kröpelin said, referring to the 5th-century B.C. Greek historian. "But at the same time also it is a gift of the desert."
"Without the tradition and the know-how and the knowledge of the desert, probably the Egyptian pharaonic civilization wouldn't have emerged as it did."
For example, pottery was first invented in Africa in the Egyptian Sahara at the same time, if not before, it was developed in the Middle East.
"[Pottery] is the first modern plastic, one of the most important inventions in human history," Kröpelin said.
The innovation provided the economic basis for the Neolithic revolutiona period of human cultural development about 5,200 to 4,500 years ago.
Pottery vessels enabled nomadic peoples to preserve and store food and thus settle down (photo: excavating ancient Egyptian pottery).
"It was really a very, very big step in human evolution, and this happened in the desert," Kröpelin said. "Only when the desert dried out, this condition was brought to the Nile Valley."
Adding Some Meat
In their study, Kröpelin and Kuper also describe how pastoral cultures moved along with the desert's southern march.
The ancient peoples' progress helped sow aspects of farming, particularly domestic animal herding, throughout Africa (explore an interactive atlas of the human journey out of Africa).
David Phillipson, a professor of African archaeology, directs the Museum of Archaeology and Anthropology at the University of Cambridge in England.
The study "adds a great deal of meat and detail to something which has been envisaged for a little while," he said.
"And it's extremely useful to have this, because it enormously increases the amount of basic data on which the conclusions are drawn.
"As the Sahara dried and became less suited and eventually unsuited to habitation, people ultimately had to move out, whether it be southward or to the east into the Nile Valley," Phillipson said.
"And this [study] helps [us] to understand the apparent rather sudden development of intensive settlement by sophisticated societies in the Nile Valley 'round about five or six thousand years ago."
Free Email News Updates
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).
SOURCES AND RELATED WEB SITES