sábado, 16 de agosto de 2014

Before they left Africa, early modern humans were 'culturally diverse'

A new study provides fresh insights into the life of early modern humans before they left Africa following a massive comparative study of stone tools.

Stone tools from Kharga Oasis, Egypt, one of the archaeological sites used in the study. Photograph reproduced with kind permission from The British Museum

Researchers have carried out the biggest ever comparative study of stone tools dating to between 130,000 and 75,000 years ago found in the region between sub-Saharan Africa and Eurasia. They have discovered there are marked differences in the way stone tools were made, reflecting a diversity of cultural traditions. The study has also identified at least four distinct populations, each relatively isolated from each other with their own different cultural characteristics.

The research paper also suggests that early populations took advantage of rivers and lakes that criss-crossed the Saharan desert. A climate model coupled with data about these ancient water courses was matched with the new findings on stone tools to reveal that populations connected by rivers had similarities in their cultures. This could be the earliest evidence of different populations ‘budding’ across the Sahara, using the rivers to disperse and meet people from other populations, says the paper published in the journal, Quaternary Science Reviews.

The researchers from the University of Oxford, Kings College London and the University of Bordeaux took over 300,000 measurements of stone tools from 17 archaeological sites across North Africa, including the Sahara. For the first time they combined the stone tool data with a model of the North African environment during that period, which showed that the Sahara was then a patchwork of savannah, grasslands and water, interspersed with desert. They also mapped out known ancient rivers and major lakes, building on earlier research by Professor Nick Drake, one of this paper’s co-authors. [...] ox.ac.uk / Link 2