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.
Regardless, if there is evidence to find that Neanderthals were artists, dating will be the thing to expose it.
This isn’t ideal, but it’s currently the best tool.It’s possible to measure the ratios of uranium-238/uranium-234 and thorium-230/uranium-238, the latter of which depends on the former.Since only uranium, and not thorium, is present at sample formation, comparing the two ratios can be used to calculate the time passed since the sample formed. Pike’s team are not actually dating the painting itself, but small calcite growths on top of it.Though originally a field reserved for archaeologists, physical scientists like Walker are showing that they also have crucial contributions to make.With the help of new physical and chemical dating methods, scientists are finally beginning to discover how and when archaic species became…well, us.‘The great breakthrough in Quaternary archaeology was radiocarbon dating,’ Walker says.