The Laacher See-eruption (12,920 BP) and material culture change at the end of the Allerød in Northern Europe

A number of recent papers have argued that summed probability distributions of radiocarbon dates calibrated with the CALPAL software package can be used to identify population trends in prehistory. For instance, Gamble et al. (Gamble, C., Davies, W., Pettitt, P., Richards, M., 2004. Climate change and evolving human diversity in Europe during the last glacial. Philosophical Transactions of the Royal Society of London, Series B 359, 243–254; Gamble, C., Davies, W., Pettitt, P., Richards, M., 2005. The archaeological and genetic foundations of the European population during the Late Glacial: implications for 'agricultural thinking'. Cambridge Archaeological Journal 15, 193–223.) have demonstrated that during the European Late Glacial, demography was more variable than hitherto acknowledged. Building on this work, this paper presents evidence that the large, but so far largely ignored eruption of the Laacher See-volcano, located in present-day western Germany and dated to 12,920 BP, had a dramatic impact on forager demography all along the northern periphery of Late Glacial settlement and precipitated archaeologically visible cultural change. In Southern Scandinavia, these changes took the form of technological simplification, the loss of bow-and-arrow technology, and coincident with these changes, the emergence of the regionally distinct Bromme culture. Groups in north-eastern Europe appear to have responded to the eruption in similar ways, but on the British Isles and in the Thuringian Basin populations contracted or relocated, leaving these areas largely depopulated already before the onset of the Younger Dryas/GS-1 cooling. Demographic models are used to link these changes to the Laacher See-eruption and this research demonstrates that we cannot sideline catastrophic environmental change in our reconstructions of prehistoric culture history.     

A Review of Swahili Archaeology

The Swahili people have been viewed as of Persian/Arabic or Cushitic-speaking origin. Scholars have used historical and archaeological data to support this hypothesis. However, linguistic and recent archaeological data suggest that the Swahili culture had its origin in the early first centuries AD. It was the early farming people who settled on the coast in the last centuries BC who first adopted iron technology and sailing techniques and founded the coastal settlements. The culture of the iron-using people spread to the rest of the coast of East Africa, its center changing from one place to another. Involvement in transoceanic trade from the early centuries AD contributed to the prosperity of the coastal communities as evidenced by coastal monuments. More than 1500 years of cultural continuity was offset by the arrival of European and Arab colonizers in the seventeenth and nineteenth centuries AD. Le peuple Swahili a souvent été consideré comme un peuple dont la langue avait pour origine le Perse/Arabe ou le Cushite. Les chercheurs ont utilisé des donées historiques et archéologiques afin de supporter cette hypothese. Cependant l'étude linguistique de cette langue, ainsi que de nouvelles découvertes archéologiques suggérent que la culture Swahili trouve son origine au début de l'ère chrétienne. Ils furent les premiers fermiers à s'installer le long du littoral, fondant des villages côtiers, vers les premiers siécles de notre ère, les premiers aussi à adopter les techniques du fer et les techniques de navigation. La culture du fer s'étendit rapidement au reste des côtes d'Afrique de l'Est, son centre se déplaçant d'un endroit à un autre. Leur implication dans le commerce océanique contrbua à la prosperité de leur communautés côtières, mise en évidence notamment par les monuments le long du littoral. Plus de 1500 ans de continuité culturelle pris fin à l'arrivé des colonisateurs Européens et Arabes de dixseptième et dixhuitième siècles.     

Solution Techniques for Large Regional Partitioning Problems

This paper presents procedures for use in electoral districting and related applications. A region is to be divided into a number of “territories” formed as aggregates of discrete spatial units, subject to constraints on territory size and on intraterritorial connectivity, so as to minimize the total length of territory perimeters. The procedures are based on a hill-climbing principle, with progressively rigorous application of the connectivity and territory-size constraints. Computational tests indicate that the best of the procedures provide an effective trade-off between solution quality and computational efficiency.