Oldest Known Human Remains Extend our History Back by 100,000 Years - say what?

Adding to a recent string of discoveries that are rewriting the narrative of human evolution, fossils of a number of ancient human individuals that were unearthed in Morocco have been dated to more than 300,000 years ago. this find pushes evidence for the age of Homo sapiens back by roughly 100,000 years, and also shows that our ancient ancestors were much better traveled than previously assumed.

The fossils in question were excavated from the Jebel Irhoud cave, located 62 miles west of modern-day Marrakesh, and included the remains of five individuals, along with flint tools and the remains of their campfires. The skulls of the individuals bore faces that were unmistakably that of modern humans; although despite having a brain of similar size to other H. sapiens, the cranium was somewhat flattened and elongated towards the rear, unlike the more spherical braincase we see today.

The researchers were surprised to find that the group's tools dated to between 280,00 to 350,000 years ago -- roughly one-third older than modern humans were assumed to be. The previously oldest known remains were 200,000 years old, and found in Ethiopia, prompting the scientific community to assume that the area they were found in was the origin of humanity. But aside from being separated by 1,000 centuries, the remains found in Morocco and Ethiopia are on opposite sides of the African continent: with the far older remains being found 5,600 kilometers (3,500 miles) away from the previously-assumed eldest fossils, this raises the question of where modern humans actually originated from.

"What people, including myself, used to think was that there was a cradle of humankind in East Africa about 200,000 years ago, and all modern humans descend from that population," explains Philipp Gunz, with the Max Planck Institute for Evolutionary Anthropology. "The new finds indicate that Homo sapiens is much older and had already spread across all of Africa by 300,000 years ago. They really show that the African story of our species was more complex than what we used to think." 

• Image Credit:
• Taken at the David H. Koch Hall of Human Origins at the Smithsonian Natural History Museum. flickr.com

• News Source:
• theatlantic.com

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MYSTERY: Northern Forests Are Crucial Carbon Sink

Giant, Mysterious Body of Water Found Under China Desert

  by Patrick J. Kiger

The Tarim basin in China’s northwestern Xinjiang province, which covers about 350,000 square miles, is one of the driest places you could imagine. Surrounded by mountains that block the passage of moist air from the ocean, it doesn’t get much rainfall — less than 4 inches annually. And the shallow, silt-laden Tarim river doesn’t provide much water, either.

Paradoxically, though, Chinese scientists have discovered  that the Tarim basin actually has an enormous supply of water — 10 times the amount in all five of North America’s Great Lakes combined, in fact. The problem is that the water in a gigantic aquifer that they describe as an underground ocean. It’s too salty for the region’s impoverished residents to use, but it apparently plays a role in helping to slow climate change.

The findings were reported in a recent article in Geophysical Research Letters.

“This is a terrifying amount of water,” professor Li Yan, who led the study at the Chinese Academy of Sciences’ Xinjiang Institute of Ecology and Geography in Urumqi, the Xinjiang capital, told the South China Morning Post. “Our estimate is a conservative figure — the actual amount could be larger.”

The scientists actually discovered the immense underground ocean while investigating carbon dioxide absorption by the region.  Ain Nature Climate Change, which found that the Mojave Desert acts as a carbon sink, suggested that the world’s deserts might play a role similar to oceans and forests in soaking up and storing some of the excess carbon emissions from human activity.

The Chinese scientists obtained deep underground water samples from nearly 200 locations in the basin and measured the carbon dioxide in them, and then compared it to the levels in the snowmelt that gradually seeps into the ground from the surrounding mountains.
The area’s alkaline soil helps the carbon dioxide to dissolve into the water, Li said.
Li described the carbon dioxide-rich water in the ground as “like a can of Coke.”  If the aquifer were somehow opened, “all the greenhouse gas will escape into the atmosphere.”
A separate study by German scientists found that the region’s underground water may actually be getting saltier, as a result of massive cotton farming in the region and resulting agricultural runoff.