Neanderthal radiocarbon problem reported in an article in BBC News 13 Feb 2009. Scientists trying to work out what happened to Neanderthals have made an interesting admission about dating methods. One of the numerous theories about the extinction of Neanderthals is that they died out due to the effects of climate change. Investigating this theory involves dating Neanderthal using radiocarbon dating on remains of fires, as was done in a recent find in a cave in Gibraltar which gave an unexpected recent date. It seems “putting archaeological finds – including the evidence from Gibraltar – in their climatic context is problematic because calendar dates and radiocarbon dates do not exactly match up.” Chronis Tzedakis, of University of Leeds explained: “The radiocarbon chronometer is like a clock that is sometimes running faster, and sometimes stops. So there are differences between radiocarbon years and calendar years, and that complicates trying to work out what is going on with the climate for a given radiocarbon date. The reference archives (Greenland ice cores) that we have for what climate was doing are in calendar years. And the discrepancies can be up to thousands of years apart.”
The report also includes comments from Konrad Hughen, of the Woods Hole Oceanographic Institution, US, who has been working on a climate record in sediments off the Venezuela coast and had taken radiocarbon dates from hundreds of points along the core. Hughen reports that changes in that core were similar to those from Greenland and the western Mediterranean, suggesting the whole North Atlantic system changed in unison when climate flipped back and forth. So the Venezuelan record is a “Rosetta Stone”, with climate and radiocarbon dates written on the same archive. How to resolve the conflict? Dr Hughen suggested circumventing the conversion to calendar years altogether and going straight from radiocarbon years to climate.
Editorial Comment: Tzedakis’ admission reminds us that one of the best known dating methods is not infallible. To admit Carbon 14 sometimes works, and sometimes stops or goes faster, and that it also disagrees with the calendar type approach often by 1000’s of years, and to then have a fellow academic recommend the discarding of calendar clocks in favour of a radiocarbon clock alone that is known to be broken shows us the real problem in dating: when you have an exciting and popular story, don’t let the facts interfere with it. (Ref. chronology, dates, anthropology)
Evidence News, 11 March 2009