Early Human Innovation Linked With Climate Change to Wetter Conditions

In the Middle Stone Age, which ended about 40,000 years ago, early humans living in what is now South Africa made cultural innovations and technological advances during periods of wetter weather, according to a new study from Cardiff University linking climate change and human evolution.

Scientists working along the coast of South Africa studied marine sediment and were able to reconstruct a climate record of the last 100,000 years and compare the variability of climate with the evolution of man.

The research observed that while lands in the Northern Hemisphere were experiencing much colder conditions, and large parts of sub-Saharan Africa experienced very dry conditions, South Africa and the region experienced prolonged periods of rainy conditions.

Archaeological record shows that some of the earliest examples of human culture and technology were found in South Africa; there were notable periods of advancement about 71,500 years ago, and another between 64,000 and 59,000 years ago, according to an AFP report. Examples of the early innovations include the manufacture and use of stone tools and personal adornment with shell jewelry.

"When the timing of these rapidly occurring wet pulses was compared with the archaeological datasets, we found remarkable coincidences,"    Ian Hall, of Cardiff University School of Earth and Ocean Sciences, said in a press statement.

"The occurrence of several major Middle Stone Age industries fell tightly together with the onset of periods with increased rainfall. Similarly, the disappearance of the industries appears to coincide with the transition to drier climatic conditions."

Study co-author Martin Ziegler said that the research shows for the first time the periods of innovation coincided with abrupt climate change.

"We found that South Africa experienced wetter conditions during these periods of cultural advance. At the same time, large parts of sub-Saharan Africa experienced drier conditions, so that South Africa potentially acted as a refugium for early humans," Ziegler told the AFP.

The research, published in the journal Nature Communications