Climate Change Propelled Ancient Human Cultural Innovation

It turns out that climate change was good for humans in the past. Scientists have discovered that rapid climate change that occurred almost 80,000 years ago sparked surges in cultural innovation that possibly helped propel early modern humans into a more advanced society.

In order to study the ancient climate of the past, researchers examined a marine sediment core off of the coast of South Africa. Cores are extremely useful when looking at past temperatures; over the years, layers of sediment are laid down with the passing seasons. When scientists core an area, they're essentially taking a several centuries-long sample of the climate of that region. By looking at the different layers, they can then reconstruct the past.

"We found that South Africa experienced rapid climate transitions toward wetter conditions at times when the Northern Hemisphere experienced extremely cold conditions," said Martin Ziegler of the Cardiff University School of Earth and Ocean Sciences in a news release.

While the Northern Hemisphere became extremely cool, sub-Saharan Africa experienced very dry conditions. South Africa, in contrast to both, responded with increasing rainfall that can be associated with a globally occurring southward shift of the tropical monsoon belt. It was obvious that the climate had experienced a drastic shift.

Yet what effect did this shift have on human populations at the time? Researchers examined Middle Stone Age artifacts and what they knew of the ancient histories of these people. More specifically, they looked at the use of symbols and personal adornments made of seashells. They actually found that the occurrence of several major industries occurred with the onset of periods with increased rainfall. Similarly, the disappearance of the industries coincided with the transition to drier conditions.

"The correspondence between climactic ameliorations and cultural innovations supports the view that population growth fuelled cultural changes, through increased human interactions," said Chris Stringer of London's Natural History Museum in a news release.

It's perhaps not surprising that these changes in human populations occurred. After all, modern humans are good at adapting to different environmental conditions. As areas became wetter or drier, humans merely changed their lifestyles in order to survive. What is interesting, though, is the possibility that modern human culture may have emerged during this time period. That said, a bit more research needs to be done in the area.

"The quality of 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," said Stringer.

The findings are published in the journal Nature Communications.