Friday, October 19, 2007

Earliest Evidence of Modern Humans Discovered

via ScienceDaily, new evidence has been uncovered at a site near Pinnacle Point in South Africa that pushes back the origin of modern humans to 160,00 years ago. Droughts during this period may have forced human populations to coastal areas where they supplmented their diets with a variety of shellfish and other marine resources.

"Our findings show that at 164,000 years ago in coastal South Africa humans expanded their diet to include shellfish and other marine resources, perhaps as a response to harsh environmental conditions," notes Curtis Marean, a professor in ASU's School of Human Evolution and Social Change. "This is the earliest dated observation of this behavior."

These early humans also exhibited the use of bladelet technology thought to have not occurred until 70,000 years ago, and the team also discovered evidence of the use of red ochre, a pigment used for ritual behavior that has been thought to also date from the same later period as the bladelet use.

"These new findings not only move back the timeline for the evolution of modern humans, they show that lifestyles focused on coastal habitats and resources may have been crucial to the evolution and survival of these early humans."

The period from 195,000 to around 125,000 years ago was heavily glaciated, and much of the continent of Africa experienced repeated severe droughts. In fact, it is thought that there might have been as few as 5 or 6 sites on the continent capable of supporting early modern humans, and the researchers studied ocean currents, climate data, geological formations and other evidence to theorize where a probable location would be located. These finds also extends back into time the period when early people began to utilize marine resources by as much as 40,000 years.

"Generally speaking, coastal areas were of no use to early humans -- unless they knew how to use the sea as a food source" says Marean. "For millions of years, our earliest hunter-gatherer relatives only ate terrestrial plants and animals. Shellfish was one of the last additions to the human diet before domesticated plants and animals were introduced."

Before, the earliest evidence for human use of marine resources and coastal habitats was dated about 125,000 years ago. "Our research shows that humans started doing this at least 40,000 years earlier. This could have very well been a response to the extreme environmental conditions they were experiencing," he says."

With the knowledge of how to exploit ocean resources, the coastal areas of the continent would have allowed long distance human migrations, and the use of bladelets as compound stone tools as well as the use of pigments for symbolic purposes is often tied to the development of human cognitive functions and human lanaguage skills. These developments had also been tied to the later 70,000 before present period as well. Human language and communications skills are thought to have greatly aided early human survival by allowing cooperative behvior and the establishment of trade and exchange networks between groups of our early ancestors.

"This evidence shows that Africa, and particularly southern Africa, was precocious in the development of modern human biology and behavior. We believe that on the far southern shore of Africa there was a small population of modern humans who struggled through this glacial period using shellfish and advanced technologies, and symbolism was important to their social relations. It is possible that this population could be the progenitor population for all modern humans," Marean says."

Pretty amazing find, and I'd say it lays a pretty definitive nail in the coffin of the Out of Africa skeptic community being so far in advance of other archaeological finds showcasing evidence of similar behavior.

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