[but] if you haven’t got organic pigment in there, you can’t use radiocarbon and you’d be destroying the art, which is very valuable.
To take a normal radiocarbon sample would be unduly disruptive,’ he explains.
A portion of the carbon is the radioactive isotope carbon-14.
Instead, Pike’s team turned to uranium-series dating, another radiometric method.Uranium-238 decays through a series of isotopes to uranium-234, which then itself decays to thorium-230.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.The first excavations in the 1950s and 1960s revealed a hub of ancient human activity, spanning thousands of years’ worth of artefacts.
Unfortunately much of it originates from outside radiocarbon dating’s timescale. was almost non-existent,’ says Geoff Duller, a geochronologist from the University of Aberystwyth in Wales.‘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.Yet cave paintings are generally considered to be physical traces of early modern behaviour, because the creation of art requires abstract thought. ‘The reason we started to look at dating cave art was because we had this slight conundrum,’ says Alistair Pike, an archaeologist at the University of Southampton in the UK.‘When we look at genetics, they suggest that modern humans become anatomically modern between 150,000 and 200,000 years ago in Africa.well, us.‘The great breakthrough in Quaternary archaeology was radiocarbon dating,’ Walker says.