Our ancestors preferred to live on shaky ground

March 4th, 2011 - 12:48 pm ICT by ANI  

Washington, Mar 4 (ANI): A new study has suggested that our earliest ancestors preferred to settle in locations that have something in common with cities like San Francisco, Naples and Istanbul-they are often on active tectonic faults in areas that have an earthquake risk or volcanoes, or both.

Scientists at the University of the Witwatersrand, South Africa, the University of York and the Institut de Physique du Globe Paris (IPGP) have established a link between the shape of the landscape and the habitats preferred by our earliest ancestors.

The four-year study examined the geomorphology (literally the shape of the landscape) around ancient sites in southern Africa.

Lead author, Sally Reynolds, a palaeoanthropologist at Witwatersrand said, “We were stunned when during a fieldwork trip in South Africa in 2007, Professor Geoffrey King and I discovered evidence that hominin sites such as Taung, Sterkfontein and Makapansgat, show landscape features in combinations that are not random, but result from tectonic motions, such as earthquakes.”

Several lines of scientific evidence suggested that Australopithecus was adapted to mixed, or mosaic habitats-landscapes with trees and open grassland, with some wetland marshy areas. The study suggested that it was the type of mosaic environment created by tectonic earth movements near rivers or lakes.

These features including cliffs, sedimented valleys, river gorges and drier plateau areas in close proximity of about 10 kilometres, are created when sections of the earth’s crust move in response to pressure, then blocks of land are lifted up, while others are forced downwards.

When this happens next to a river, the result is the creation of wetland, marshy areas close to drier plateaus and areas of erosion.

King, a tectonic geomorphologist at the IPGP, added: “The original idea was developed in Greece over a decade ago, with the surprising discovery that the sites there were clearly associated with ongoing tectonic activity.

“Even though South Africa appears to be tectonically stable, there are landscape features that indicate that modest levels of activity are preserved in the hard, southern African rocks. This means that the landscape model we developed in Greece is equally applicable to East Africa, and now also to the well-known fossil sites of the South Africa’s Cradle of Humankind World Heritage Site.”

Reynolds added, “Our hominin ancestors would have been unaware of the tectonic influence on their habitats, but instead would have been attracted by the range of food and shelter offered.”

The findings have been published in the Journal of Human Evolution. (ANI)

Related Stories

Tags: , , , , , , , , , , , , , , , , , , ,

Posted in Health Science |