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"Out of Africa" --Which Way Did Humans Migrate?

Sahara-space_L5zyc_69

It is a widely held and scientifically viable belief that humans originated in sub-Saharan Africa some 150 to 200 thousand years ago. However our migration away from there, to populate immediate areas and, later, the planet, is currently conjecture.

Archaeological evidence has thrown up question marks for previous explanations. Tracking mitochondrial DNA has shown travel patterns across the entire planet. But no one migration explanation has been able to properly explain all the evidence.

Looking at a map of Africa, sub-Saharan Africa is everything that is not the Sahara Desert. A massive expanse, the Sahara is the planet’s largest hot desert (second largest desert after Antarctica). To travel across it to where humans ended up is a massive challenge today.

But the team from Bristol University has suggested that wetter conditions existed much further north than previously believed. As a result, a wet corridor through Libya might have existed, allowing for early human migrations to avoid what we know as today’s Sahara.

"Space-born radar images showed fossil river channels crossing the Sahara in Libya, flowing north from the central Saharan watershed all the way to the Mediterranean,” said Anne Osborne, lead author on the study. “Using geochemical analyses, we demonstrate that these channels were active during the last interglacial period. This provides an important water course across this otherwise arid region."

The researchers traced the isotopic composition of snail shells taken from two sites in the fossil river channels and from shells of planktonic microfossils in the Mediterranean. Despite being hundreds of kilometers from the volcanic rocks in the mountains of the Saharan watershed, previously believed to the limit of the wet region in our early ancestors time, these shells had a distinctly volcanic signature that could only be explained by water flowing from the volcanic mountains.

Dr Derek Vance, senior author on the paper, added: "The study shows, for the first time, that monsoon rains fed rivers that extended from the Saharan watershed, across the northern Sahara, to the Mediterranean Sea. These corridors rivalled the Nile Valley as potential routes for early modern human migrations to the Mediterranean shores."

The Daily Galaxy via http://www.eurekalert.org

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Images: A map showing the sample locations mentioned here, plus other images of the Sahara,  https://www.bris.ac.uk/fluff/u/inclel/hLpdnnvzzmnVVGYNlnETAAy1/

Comments

This is fascinating to me not so much for the alleged human migration pattern as for the ancient geography. I'd love to see a map of these prehistoric rivers.

blacks headed to the project, whites to the burbs.

World leaders gathering in Italy for a summit this week will be able to don parkas designed by Belstaff, the maker of the movie star's jackets if things get stormy.

kash | July 05, 2011 at 06:41 PM>>>>>>>

"and the ignorant who believe in Race based on color". Perhaps you should find out just how much "BLACK" DNA still flows in your veins.

Never forget where ya come from sonny boy!

p.s.

How's those "projects" looking at 1600 Penn. Ave. working out for ya?

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