London, July 13 (IANS) Our earliest human ancestors left Africa and colonized East Asia over two million years ago, earlier than previously thought, says a study of ancient tools and bones.
The tools, including a notch, scrapers, cobble, hammer stones and pointed pieces, were discovered in a locality called Shangchen in the southern Chinese Loess Plateau.
The oldest are circa (ca) 2.12 million years old, and are ca. 270,000 years older than the 1.85 million year old skeletal remains and stone tools from Dmanisi, Georgia, which were previously the earliest evidence of humanity outside Africa.
This shows that early humans occupied the Chinese Loess Plateau under different climatic conditions between 1.2 and 2.12 million years ago, the researchers said.
“Our discovery means it is necessary now to reconsider the timing of when early humans left Africa,” said Robin Dennell, Professor at the University of Exeter, UK.
The 80 stone artefacts, described in the journal Nature, were found predominantly in 11 different layers of fossil soils which developed in a warm and wet climate.
A further 16 items were found in six layers of loess that developed under colder and drier conditions. These 17 different layers of loess and fossil soils were formed during a period spanning almost a million years.
All show signs of use — the stone had been intentionally flaked. Most were made of quartzite and quartz that probably came from the foothills of the Qinling Mountains 5-10 kms to the south of the site, and the streams flowing from them.
Fragments of animal bones 2.12 million years old were also found, the researchers said.