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| Human World on Feb 01, 2011

New timeline for first early human exodus out of Africa

Ancient artifacts found in the Arabian Peninsula, dating back to 100,000 years ago, indicate that modern humans first left Africa much earlier than thought.

An international team of researchers have released a study suggesting that modern humans first left Africa much earlier than researchers previously believed. They’ve unearthed artifacts in the United Arab Emirates dating back 100,000 years and implying that humans could have arrived on the Arabian Peninsula as early as 125,000 years ago — directly from Africa rather than via the Nile Valley or the Near East, as researchers have suggested in the past.

Evidence of this ancient journey was found in the discovery of primitive hand-axes, as well as several kinds of scrapers and perforators, excavated at the Jebel Faya archaeological site in the United Arab Emirates. These tools resemble the types used by early modern humans in East Africa. A technique known as luminescence dating placed the artifacts between 100,000 to 125,000 years old.

View of northern Jebel Faya from the north-east. Image © Science/AAAS

The timeline and dispersal of the first modern humans out of Africa has been a subject of great controversy. Most evidence had pointed to that journey occurring about 60,000 years ago, with the first humans leaving Africa to travel along the Mediterranean Sea and the Arabian coast.

Simon Armitage, the lead author of the research paper released in the 28 January issue of Science, from the University of London, said,

These ‘anatomically modern’ humans — like you and me — had evolved in Africa about 200,000 years ago and subsequently populated the rest of the world. Our findings should stimulate a re-evaluation of the means by which we modern humans became a global species.

The excavation team, led by Hans-Peter Uerpmann from Eberhard Karls University in Tübingen, Germany, also studied climatic and sea level changes in that region during the last interglacial period, about 130,000 years ago. The lower sea level during that time would have exposed a land bridge between Arabia and the Horn of Africa, now known as the Bab al-Mandab Strait. This would have allowed over-land travel at the start of the last interglacial period. Back then, the Arabian Peninsula was not an arid desert. A wet climate created denser plant growth as well as networks of rivers and lakes. That terrain would have provided a way for early humans to arrive to Arabia from Africa, then continue on to the Fertile Crescent — an area extending from the Mediterranean Sea to the Persian Gulf — and India.

The location of Jebel Faya, United Arab Emirates. The dashed line represents land exposure due to the lower sea level during the last interglacial period. Image courtesy of Science/AAAS.

Armitage continued:

Archaeology without ages is like a jigsaw with the interlocking edges removed — you have lots of individual pieces of information but you can’t fit them together to produce the big picture. At Jebel Faya, the ages reveal a fascinating picture in which modern humans migrated out of Africa much earlier than previously thought, helped by global fluctuations in sea-level and climate change in the Arabian Peninsula.

Thus the search for human origins and movements on Earth’s various continents continues. This international team – which unearthed ancient artifacts in the United Arab Emirates – now believes that humans could have arrived on the Arabian Peninsula as early as 125,000 years ago.

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