Precise single-grain 40Ar/39 Ar dating of a cold to warm climate transition in Central Europe

RECENT advances in 40Ar/39Ar dating1,2 have made it possible to date individual K-feldspar grains from Pleistocene tephra, a capability that greatly improves the reliability and temporal resolving power of the method. Here we apply these new techniques to the dating of a phonolite tephra from the East Eifel volcanic field in West Germany, which is sandwiched between loess and palaeosol (alfisol) deposits, and which was therefore erupted during the transition from a glacial to an interglacial period. Our age estimate for this transition is 215±4 kyr (1 σ), which has important implications for the marine δ18O timescale and for models of global climate change during the Pleistocene. The results show that single-grain dating can detect and compensate for the large quantities of xenocrystic contaminants which are found in many tephra deposits. This technique could be used to date the tephra layers found in marine sediment cores and the results could greatly enhance the reliability of the marine δ18O timescale for more rigorous Fourier analysis testing of the Milankovitch hypothesis

Strong differences between Neanderthals and AMHs cannot be inferred from ethnographic evidence for skill and learning in hunting

The majority of analyses of hominin learning processes focus on stone tools. However, stone tool production is just one of many skills that were important for forager survival and success in the past, of which hunting strategies are one of the few documented in the Palaeolithic record. This chapter focuses on hunting skills, as a supplement to lithic studies addressing learning processes in Neanderthals and anatomically modern humans. Based on the ethnographic record, the content to be learned while hunting includes a wide range of different sorts of skills and information, some of which are situation specific. The similarities and relatively subtle differences in the record for hunting behaviour between the Middle and Upper Palaeolithic make it unlikely that there was a substantial contrast in the content to be learned or processes involved in acquiring hunting skills. Among contemporary hunters, various older individuals undertake some teaching and also frequently provide small tools, take children on hunting trips, and tell hunting stories. Children enthusiastically engage in their own hunting exploits and games with weapons. The widespread distribution of such activities suggests benefits for the speed and quality of learning, among other factors. It is not unlikely that AMH and Neanderthals, for whom hunting was an important skill, also employed some of these processes.Human Origin