Radiocarbon dates reveal that New Guinea art is older than thought

Still up north, so this is an automatic post.

Before leaving I found this press release at the University of Arizona. The exciting thing in it isn’t the fact that it’s early, there are plenty of old things in the world. It’s the life-span of the use of the objects. According to Gregory Hodgins “These measured ages imply that a few of the objects were in use for more like 50 to 100 generations.”

There’s certainly no physical reason why the use of many artefacts could span many generations, but often the problem is proving it. Evidence of antler bone at Stonehenge shows that some of the material was old when it was deposited, but nothing like the scale of the age of this art. Thinking about difficult to date material like polished axes, the use of these materials takes on a whole new meaning if we think about them being preserved for this scale of time. Furthermore what does it say now about the act of throwing something like this away? I saw a great presentation by Hannah Lynch at Newcastle comparing polished stone axes to Aston Martins. She concluded that for Neolithic peoples the stone axes would have been even more prestigious. This is magnified almost beyond imagination if they’re being held on such a long scale.

Is this feasible for some prehistoric material in Europe? Off the top of my head I don’t know. I haven’t been reading about the Stone Age recently – but it looks like we could have few creating entirely new social models for interacting with artefacts.

The first question I had reading this though was that the life-span was simply unfeasibly long. I’ve no doubt the radiocarbon dates say they’re that old, but could that be a measurement of contaminated material? Looking at the release I suspect not. If there was contamination from new material I’d expect the dates to appear younger as fresh carbon-14 would be introduced to the pieces.

There’s also a large sample size, 145 pieces, which gives me some confidence. When carbon dates are quoted with an error +/- n years, that’s usually to a 95% confidence. That sounds impressive, but that means that one in twenty dates could be very different to what is real. This is why you need more than one date. The fact that so many pieces are older shows that it’s not a statistical fluke. If 5% of the artefacts had odd dates that might be a different matter.

For the biggest claim even 50 generations seems long, but if you halve that it’s still an enormous length of time for an artefact to be used. “The ages for this art totally change the bias that says Stone Age peoples living in isolated communities do not develop art with that kind of complexity,” Jull, director of the NSF-Arizona AMS Lab, said. I think the biggest difference between us and our stone-age ancestors is that we’re lucky enough to be standing on their shoulders. This kind of find would appear to confirm that. —–