The IntCal09 and Marine09 radiocarbon calibration curves have been revised utilizing newly available and updated data sets from ¹⁴C measurements on tree rings, plant macrofossils, speleothems, corals, and foraminifera. The calibration curves were derived from the data using the random walk model (RWM) used to generate IntCal09 and Marine09, which has been revised to account for additional uncertainties and error structures. The new curves were ratified at the 21st International Radiocarbon conference in July 2012 and are available as Supplemental Material at www.radiocarbon.org. The database can be accessed at http://intcal.qub.ac.uk/intcal13/.

Neandertal cave art: It has been suggested that Neandertals, as well as modern humans, may have painted caves. Hoffmann et al. used uranium-thorium dating of carbonate crusts to show that cave paintings from three different sites in Spain must be older than 64,000 years. These paintings are the oldest dated cave paintings in the world. Importantly, they predate the arrival of modern humans in Europe by at least 20,000 years, which suggests that they must be of Neandertal origin. The cave art comprises mainly red and black paintings and includes representations of various animals, linear signs, geometric shapes, hand stencils, and handprints. Thus, Neandertals possessed a much richer symbolic behavior than previously assumed. Science , this issue p. 912

Dating Cave Paintings: A number of caves in Europe contain exquisite ancient art. Most of the art has been thought to be produced during the time of last glaciation by recently arrived modern humans, but dating of the art has been problematic because the art contains only minimal amounts of carbon for radiocarbon dating. Pike et al. (p. 1409 ; see the cover; see the Perspective by Hellstrom ) have now obtained U-series dates on the calcite crusts that formed over the art from 11 caves in northwestern Spain. The ages from three caves are older than 35,000 years ago, and one dates to nearly 41,000 years ago. The earliest art used primarily red and was relatively formless; animal depictions appeared later. This dating is near the time of the arrival of modern humans and, because Neandertals were also present, complicates identifying the artists.

The peopling of Tibet: The date of the first permanent human occupation of the high Tibetan Plateau has been estimated at about 3600 years ago, when agriculture became established. Meyeret al.used several dating techniques to analyze sediments at a high-altitude site (4270 m) where human handprints and footprints have been found. Their analysis indicates occupation of the plateau 7400 years ago and possibly earlier. These dates are consistent with the genetic history of Tibetans and suggest that a permanent preagricultural peopling of the plateau was enabled by the wetter regional climate at that time.Science, this issue p.64