Once green, prehistoric Arabia drew early humans from Africa

WASHINGTON (AP) — Huw Groucutt passes rolling sand dunes as far as his eye can see when traveling to archaeological sites in the northern Arabian Peninsula. But the same desert regions were once intermittently lush and green, attracting early humans and large animals such as hippopotamuses migrating out of Africa to linger at ancient lakes, new evidence suggests.

Until a decade ago, the Arabian Peninsula was a blank spot on the map for scientists trying to reconstruct the story of early human evolution and movements out of Africa. Much more is known about early human settlements in the Levant region — modern-day Israel, Jordan, Lebanon and parts of Syria — where extensive archaeological research has been carried out for more than a century.

But the Arabian Peninsula may have also played an important role as a bridge between Africa and Eurasia, a study published Wednesday in the journal Nature suggests.

“Arabia has not been part of the story of early human migration because so little work was done there before,” said co-author Michael Petraglia, a paleolithic archaeologist at the Max Planck Institute for the Science of Human History in Jena, Germany. The research team included scientists from Germany, Saudi Arabia, Australia, the United Kingdom and elsewhere.

The impetus to look closely for archeological remains in the region came from satellite imagery that revealed traces of prehistoric lakes in now-arid regions. “We noticed color patterns made by ancient lakes — sand dunes are kind of orange-colored, while ancient lakes are tinted white or gray,” said Groucutt, who is also based at the Max Planck Institute.

Extensive excavations over a decade revealed stone tools from multiple periods of prehistoric settlement by early human groups, the oldest 400,000 years ago....