Is the Arabian Gulf the Cradle of Civilisation? Yes, postulates Dr Jeffrey Rose, archaeologist and researcher at the University of Birmingham, UK, in a recently published paper. Rose's paper summarises the theories that are now gaining ground and causing considerable excitement among Middle Eastern archaeologists and historians: that the shallow waters of the Gulf may well hide evidence of the earliest human migrations out of Africa.

Around 8,000 years ago, when the last Ice Age drew to a close, rising sea levels resulting from the melting of the ice caused the Indian Ocean to break through a natural barrier in what is now known as the Straits of Hormuz. In what must have been the mother of all waterfalls, sea water poured through the gap and over a period of some 200 years flooded what had been a fertile plain, watered by rivers including the Tigris and Euphrates in what is now Iraq, and springs which welled up from an aquifer through the karstic limestone which lines the basin. Such springs, known as khawakh in local Arabic, still exist to this day and are thought to have given rise to the name Bahrain - 'two seas', ie salt and fresh water.

During the Pleistocene period, which ended around 12,000 years ago, the inhabitants of Arabia were among the first anatomically modern humans to branch from the common ancestral population that first appeared in East Africa some 190,000 years ago.

The Arabian Gulf is an elongated basin some 250km in width and around 1,000km in depth. It is bounded to the west by the deserts of the Arabian peninsula, to the east by the Zagros mountain range and to the north by the Mesopotamian floodplain. The sea is one of the shallowest in the world, averaging only 35m in depth. During the glacial period in the northern continents sea level worldwide was 120m lower than in the modern era, and along the basin of the Gulf ran a prehistoric river, the Shatt-Al-Arab, discharging into the Indian Ocean at the Straits of Hormuz.

It is inconceivable, given the nature of much of the harsh surrounding landscape, that early humans did not make use of the most precious of all commodities: plentiful fresh water. Rose theorises that this well-watered fertile land could have seen human occupation for over 100,000 years. From about 74,000 years ago until 8,000 years ago the Arabian Gulf oasis formed the southern tip of what is known as the 'Fertile Crescent'. The low-lying floodplain of the Shatt-Al-Arab included not only the river itself but two sizeable lakes, and a mosaic of springs, mangrove swamps and estuaries.

Modern archaeology in Eastern Arabia dates back only to the beginning of the oil era, ie about 60 years ago. It got off to a false start with the Danish expedition to Qatar in the 1960s, designating as Paleolithic what they regarded as early examples of stone tools. Then came the French scientific expedition a decade later. Based on their excavations at sites around Al Khor, they dismissed the Danes' tentative dating and postulated that the whole assemblage of stone tools in Qatar was no older than the Neolithic period, ie around 7,000 years before the present era.

For many years most scholars accepted the dating put forward by the French expedition. It was known, from carbon dating of charcoal found the Yaftah Cave in the Zagros Mountains in Iran, that humans were occupying the cave 35,000 years ago, but the first indication of an early human presence in Eastern Arabia was in 2005, when a rock shelter in the UAE being investigated by a joint Emirate of Sharjah/Tubingen University expedition yielded small hand axes, hammer blades and bifacial foliates that clearly pre-dated lithics from the Neolithic period. Then in 2009 the discovery of a surface scatter of stone tools at Ras 'Ushayriq on the north-west coast of Qatar caused a radical re-assessment of the dates of the earliest human occupation of the Gulf region.

In the last decade, archaeologists have identified over 60 settlements along the shores of the Gulf, dating to about 7,500 years ago. The scattered camps of Neolithic hunter-gatherers were already known, but these were settlements, occupied by modern people who built permanent stone houses, made fine decorated pottery and sophisticated 'pressure-flaked' tools of flint, grew crops, domesticated animals, constructed sea-worthy boats and established long-distance trading networks. Where did they come from? Such civilisations do not spring up overnight, and Rose believes that evidence of preceding populations is missing because it is hidden beneath the Gulf. He said, "These new colonists may have come from the heart of the Gulf, displaced by rising water levels that plunged the once fertile landscape beneath the waters of the Indian Ocean."

"It is no coincidence," he went on, "that the founding of such remarkably well developed communities along the shoreline corresponds with the flooding of the Gulf basin around 8,000 years ago."

Water was vital to human settlement. Much later, in the Bronze Age when the Dilmun civilisation flourished in the Gulf, the Sumerian legend of the god Enki and his consort Ninhursag relates, "For Dilmun... I will create long waterways, rivers and canals, whereby water will flow to quench the thirst of all beings and bring abundance to the land." On the island of Bahrain, only after the oil era brought an increased population which drained the aquifers near the surface, did these canals cease to flow and the springs of fresh water fail.

There is evidence that humans could have been in the region even before the Arabian Gulf oasis suffered its catastrophic flooding. Recently, sites in Oman and Yemen have produced a type of stone tool very different from those in the East African tradition. They bear affinities with Levantine and Zagros stone tool assemblages. This suggests that human beings could have been established in the south of the Arabian Peninsula as long ago as 100,000 years, or even longer. To such early migrants, the fresh water of the Arabian Gulf and the green trees and vegetation would have been a sanctuary amid the barren desert landscapes.
It may well be that deep beneath the busy shipping lanes which now criss-cross the waters of the Arabian Gulf may lie vital pieces of the human evolutionary puzzle. Meanwhile, a project between the Qatar Museums Authority and The University of Birmingham, directed by Dr Richard Cuttler, is undertaking research into this former landscape to investigate the former environments and archaeological remains within the Arabian Gulf.