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‘Then you start to find the problems with it.’ Atmospheric carbon variations, including variability in the all-important carbon-14, left the method unreliable. that we could begin to correct for some of these variations in radiocarbon production,’ Walker says.Although carbon dating is now more reliable, it has one major drawback: it only goes back 50,000 years, leaving most of human history outside its reach.‘As it formed on top of the painting, it therefore gives you a minimum age of the painting,’ Pike says.This isn’t ideal, but it’s currently the best tool.well, us.‘The great breakthrough in Quaternary archaeology was radiocarbon dating,’ Walker says.Developed by Willard Libby in the 1940s – and winning him the Nobel prize in chemistry in 1960 – the basic principle of radiocarbon dating is simple: living things exchange carbon with their environment until they die.A huge development in the story of humans is ‘modern’ behaviour, or acting like a human as opposed to acting like a two-legged ape – but it’s hard to date.For example, it’s difficult to say exactly when people started to think abstract thoughts or speak to communicate.
At death, the exchange stops, and the carbon-14 then decays with a known half-life, which enables scientists to calculate the time of death.
‘We’re kind of at the mercy of geochemistry.’Pike’s team used this method to give a minimum date to red hand stencils found in a cave in northern Spain called El Castillo, which contains the oldest known cave art in the world. This is long after humans were supposed to become anatomically modern, adding to the evidence suggesting that early anatomically modern humans didn’t necessarily act modern. Anatomically modern humans arrived in northern Spain around 42,000 to 43,000 years ago, and Neanderthals died out between 39,000 and 41,000 years ago.
But because the stencil date is a minimum age, there’s a chance the Neanderthals could have been the artists.
is the only fellowship-trained urologic oncologist practicing between Gainesville and Tampa, Florida.
He is a graduate of the University of South Florida College of Medicine in Tampa, Florida, and completed his urologic residency at the University of Oklahoma Health Science Center in Oklahoma City, Oklahoma.