Neanderthals, Aurignacians and carbon dating

On Saturday Camilla and I went a series of five lectures on "Neanderthals and Modern Humans". This was hosted by the Oxford Radiocarbon Accelerator Unit and after the lectures we were given a tour of their lab and got to see the accelerator.

Wil Roebroeks talked about Neanderthals and Paul Pettit about the Aurignacians who followed them. Both avoided talking about the actual transition. Pettit did venture into the debate over symbolic elements of Neanderthal culture, however, putting up a picture of a woman with red lipstick and a feather boa to suggest that use of pigments and feathers by Neanderthals may have been decorative but not symbolic (which got him some flak in audience questions).

A lecture on archaeogenetics by Martin Richards started off slowly but picked up speed. He discussed some of the full genome work - he has generally been sceptical about ancient DNA, but was impressed by the work on the Neanderthal genome - but his own research focuses on mitochondrial DNA from modern populations. He discussed the implications of the haplogroup distributions here for routes out of Africa and other historical scenarios. An analysis of mtDNA from "orang asli" populations in Malaysia finds all three main haplogroups (M, N and R), which might suggest those pre-date a "southern route" migration (or just some introgression).

A talk by William Davies on climate, environment and humans in the last Ice Age was probably the least interesting of the talks, with a lot of fairly general theorising. Basically, environmental changes are spatially and temporally complex - you can't conclude much at all about any specific location in Western Europe from Greenland ice cores - and human responses to them aren't straightforward, so inferring anything from the archaeology is decidedly non-trivial.

At the end Tom Higham described ORAU's own work. They specialise in taking extra steps to avoid contamination of carbon dating samples - using ultrafiltration of bone collagen to weed out anything smaller than 30 kDalton, for example - and they've produced revisions of previous dates associated with the Neanderthal-Cro Magnon transition which seem easier to reconcile with other evidence. (Though the nice tidy appearance of their diagrams results from imposing Bayesian coherence on the order of samples within contexts.)

I wished I'd taken a camera along when we visited the accelerator. There was a radiation counter (running at 1 micro-Sievert/hour), some great warning signs such as "Read manual before opening" on the main acceleration chamber, and a fair bit of duct-tape.

All up it was a good day. There wasn't anything too surprising for me, but it was good to catch up on the latest thinking about the end of the Neanderthals (where my last reading was the decade-old The Neanderthal's Necklace), more general topics in prehistory, and the state-of-the-art in radiocarbon dating.