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Earliest ancestor of mordern man found

Finding forefathers
Last Updated 08 September 2011, 18:21 IST
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Painstakingly analysing hundreds of pieces of fossilised bone fragments, unearthed from a South African cave, scientists have come out with a fairly accurate description of the new species which could turn out to be the long sought-after missing link between 3.2 million years old ape-like Lucy (Australopithecus afarensis) and modern human (Home sapiens), whose earliest ancestors was thought to be 1.9 million year old Homo habilis.

The age of the new hominid species (Australopithecus sediba) has been fixed at approximately 1.977 million years, which predates the earliest appearances of human-type traits in the fossil record.

Until now, fossils dated to 1.90 million years ago – and mostly attributed to Homo habilis and Homo rudolfensis – have been considered ancestral to Homo erectus, the earliest undisputed human ancestor. “Au. sediba demonstrates a surprisingly unique combination of features, never before seen in an early human ancestor,” Lee Berger at the University of Witwatersrand in Johannesburg and team leader, said. Details of the new species have been described in five scientific papers published in the journal -Science- on Friday.

The scientists recovered accurate fossils of a hominid hand, undistorted pelvic, foot and ankle skeleton and the skull. Bones representing five different individuals were found at the South African site, Malapa, since 2008.

The first two fossils studied by the researchers belong to a child between 10 and 13 years and a female in her late twenties or early thirties. The individuals along with other animals may have fallen inside a deep cave from where the bodies were washed by a rainstorm into an underground lake. Analysis of the skull cast doubts upon the long-standing theory of gradual brain enlargement during the transition from Australopithecus to Homo.

Instead, the findings corroborates an alternative hypothesis which suggests a reorganisation of neurons in the front portion of the brain to make it more human like – a small brain capable of doing complex tasks inside a small skull.

The hands and feet display a mix of both primitive and modern features. The hands disclose the early ancestors’ ability to climb up trees as well as “precision gripping”, suggesting they began dabbling with tool making. They also had an unique form of bipedal walking.

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(Published 08 September 2011, 18:21 IST)

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