Wet weather helped human culture grow (Update)

May 21, 2013
Wet weather helped human culture grow
Signs of modern human culture - symbolic artefacts from around 75,000 years ago unearthed from Still Bay at Blombos Cave, South Africa: a) bifacial foliate point, b) bone tool, c) engraved ochre, d) shell beads, e) engraved bone. Credit: Christopher Henshilwood

We moan about the wet weather all too often but it may have been crucial in the development of human culture from about 70,000 years onwards, according to scientists reporting in Nature Communications today.

Some of the earliest signs of modern human culture, found in South African archaeological sites from that time, are linked to periods where the climate changed rapidly to wetter conditions, scientists say.

A team led by Martin Ziegler at the School of Earth and Ocean Sciences at Cardiff University and including those at the Natural History Museum and the University of Barcelona, studied a marine sediment core from the coast of South Africa and reconstructed climate variability on land over the last 100,000 years.

During that time, the Northern Hemisphere had phases of extreme cooling, while northern sub-Saharan Africa experienced widespread droughts, and it was often assumed that southern Africa did too. This research suggests, however, that South Africa, rather than being the same as sub-Saharan Africa, responded in the opposite direction with increased rainfall.

The new research shows that known periods of early modern human cultural innovation coincided with brief phases of increased rainfall and humidity between 80,000 and 40,000 years ago, during the Middle Stone Age. Some of these climate switches were very rapid, occurring in decades rather than centuries.

Modern human behaviour

South African archaeological records show some of the oldest evidence for modern human (Homo sapiens) behaviours, suggesting the presence of complex language, innovation and cultural identity. Symbolic expression through engravings, tools and jewellery have been unearthed from sites dated to over 60,000 years old.

What drives inventiveness?

Professor Chris Stringer of the Natural History Museum, who was part of the research team says, 'There is currently much debate about what drives inventiveness in human groups - is it environmental stress, forcing people to innovate to survive, or is it actually improved and stable conditions?

Wet weather helped human culture grow
Archaeological sites in South Africa {Blombos Cave (BBC), Pinnacle Point (PP), Klasies river (KR), Howiesons Poort Shelter (HPS), Sibudu Cave (SC) and Border Cave (BC)}. These sites have evidence of cultural innovations from over 60,000 years ago. Site of marine sediment core (red dot with arrow) studied in this research.

'Some recent research suggests that human populations require a certain minimum level of density and networking between neighbouring groups, or cultural knowledge will actually be lost, rather than gained, through time. The opposite will occur if populations are relatively dense and interacting, as ideas can be built on, with more chance of being conserved.

'The correspondence we find between climatic ameliorations and cultural innovations supports the view that improved climate fuelled population growth, in turn catalysing cultural changes through increased human interactions.

'The quality of the southern African data allowed us to make these correlations between climate and behavioural 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.

Stringer concludes, 'Personally, I think that various areas of the continent contributed to the formation of our species, before we began to spread from Africa about 60,000 years ago.'

The paper is titled "Development of Middle Stone Age innovation linked to rapid climate change."

Explore further: How the ice ages ended

Related Stories

Past tropical climate change linked to ocean circulation

Aug 23, 2012

A new record of past temperature change in the tropical Atlantic Ocean's subsurface provides clues as to why the Earth's climate is so sensitive to ocean circulation patterns, according to climate scientists at Texas A&M ...

How the ice ages ended

May 01, 2013

A study of sediment cores collected from the deep ocean supports a new explanation for how glacier melting at the end of the ice ages led to the release of carbon dioxide from the ocean.

Recommended for you

Magnitude-7.2 earthquake shakes Mexican capital

Apr 18, 2014

A powerful magnitude-7.2 earthquake shook central and southern Mexico on Friday, sending panicked people into the streets. Some walls cracked and fell, but there were no reports of major damage or casualties.

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

Jimee
5 / 5 (1) May 22, 2013
This seems like very important work, if it holds up.
Torbjorn_Larsson_OM
5 / 5 (1) May 22, 2013
Indeed, good model if it holds up. It may also mean that SA locales are not as opportunistic (say, coastal) as seen, but that there will be more spread found.
Benni
1 / 5 (5) May 22, 2013
There was "climate change" 80-40,000 years ago?

That can't be right, the United States was not in existence at the time. It must have been caused by the proliferation of neanderthal European campfires.

More news stories

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

UN weather agency warns of 'El Nino' this year

The UN weather agency Tuesday warned there was a good chance of an "El Nino" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...