Did abrupt climate change spark human culture?
CARDIFF U. (UK) — Rapid climate change 80,000 to 40,000 years ago, the Middle Stone Age, may have sparked cultural innovation in early modern humans, according to new research.
Scientists studied a marine sediment core off the coast of South Africa and reconstructed terrestrial climate variability over the last 100,000 years. Their research is published this month in Nature Communications.
Martin Ziegler, Cardiff University School of Earth and Ocean Sciences, says: “We found that South Africa experienced rapid climate transitions toward wetter conditions at times when the Northern Hemisphere experienced extremely cold conditions.”
These large Northern Hemisphere cooling events have previously been linked to a change in the Atlantic Ocean circulation that led to a reduced transport of warm water to the high latitudes in the North. In response to this Northern Hemisphere cooling, large parts of the sub-Saharan Africa experienced very dry conditions.
“Our new data however, contrasts with sub-Saharan Africa and demonstrates that the South African climate responded in the opposite direction, with increasing rainfall, that can be associated with a globally occurring southward shift of the tropical monsoon belt.”
Linking climate change with human evolution
Ian Hall, professor at Cardiff University School of Earth and Ocean Sciences, says: “When the timing of these rapidly occurring wet pulses was compared with the archaeological datasets, we found remarkable coincidences.
“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.”
Chris Stringer, a professor London’s Natural History Museum, says: “The correspondence between climatic ameliorations and cultural innovations supports the view that population growth fueled cultural changes, through increased human interactions.”
The South African archaeological record is so important because it shows some of the oldest evidence for modern behavior in early humans. This includes the use of symbols, which has been linked to the development of complex language, and personal adornments made of seashells.
“The quality of the southern African data allowed us to make these correlations between climate and behavioral change, but it will require comparable data from other areas before we can say whether this region was uniquely important in the development of modern human culture,” adds Stringer.
The new study presents the most convincing evidence so far that abrupt climate change was instrumental in this development.
The UK Natural Environment Research Council and the 7th Framework Programme of the European Union funded the study.
Source: Cardiff University
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