​Johannesburg, July 13 (IANS) Countering a common perception, a new study suggests that climate change, after all, may not have been directly linked to cultural and technological innovations of Middle Stone Age humans in southern Africa.

The Middle Stone Age marked a period of dramatic change among early humans in southern Africa, and climate change has been postulated as a primary driver for the appearance of technological and cultural innovations such as bone tools, ochre production, and personal ornamentation.

The new study published in the journal PLOS ONE showed that while climate shifts may have influenced human subsistence strategies, it may not have been the driving factor behind innovation.

"While acknowledging that climate and environmental shifts may have influenced human subsistence strategies, the research suggests climate change may not have been the driving factor behind cultural and technological innovations in these localities,” said one of the lead researchers Chris Henshilwood, Professor at University of the Witwatersrand in Johannesburg, South Africa.

The authors of this study carried out analyses of animal remains, shellfish taxa and the stable carbon and oxygen isotope measurements in ostrich eggshell, from two archaeological sites, Blombos Cave and Klipdrift Shelter to acquire data regarding possible palaeoenvironmental conditions in southern Africa at the Middle Stone Age.

For instance, ostrich eggshell carbon and oxygen stable isotope levels may reflect vegetation and water consumption, which in turn vary with rainfall seasonality and amount in this region.

The researchers found that climatic and environmental variation, reflected in ostrich eggshell stable isotope measurements, faunal records, and shellfish indicators, may not have occurred in phase with Middle Stone Age human technological and cultural innovation at these two sites.

"Our results suggest that although climate and environmental changes occurred, they were not coincident with cultural innovations, including personal ornamentation, or the appearance of complex tool-types,” Patrick Roberts from University of Oxford .

"This suggests that we have to consider that other factors drove human innovation at this stage in our species' evolution," Roberts noted.​