Experimental assessment of plan-view and profile-view gross-edge curvature on stone flake slicing efficiency

Separating two or more aspects of an object via cutting was likely an important factor in the origin and evolution of flaked stone technology. In recent years experiments have demonstrated that several stone tool attributes can influence different kinds of cutting behaviour: slicing, cleaving, scraping, sawing, drilling, piercing and abrading. Here we experimentally assessed the role of stone flake plan- and profile-view gross-edge curvature in a controlled slicing task. We also assessed the role of edge length. A total of 21 participants, using 252 stone flakes with distinct gross-edge curvatures and edge lengths, were asked to cut through a standardized substrate, and their efficiency in the task was measured over time. Flakes with longer edge lengths increased the efficiency of the cutting task, but increasing either plan- or profile-view edge curvature decreased the efficiency of the cutting task. These results have implications for the emergence of particular tool forms or reduction sequences throughout the Pleistocene, and may in part explain why certain forms were favoured by Paleolithic people, leading to their convergent evolution or widespread transmission.     

On the ‘Arab Inequality Puzzle’: The Case of Egypt

This article surveys and discusses prominent protagonists of the debate on socio-economic inequality in the Arab region, with a special focus on the World Bank and Egypt. According to official data, the region holds remarkably low Gini coefficients in a context of declining inequality. This contradicts the popular perception of high social inequality as a major cause of regional protests since the Arab Spring; hence the reference to a ‘puzzle’ in mainstream literature. The debate about the reality of social inequality in the region has developed since 2011 — particularly in regard to Egypt, where income and consumption data are periodically collected by means of household surveys. Inequality measures based on this method alone, while income taxation data are inaccessible, are highly questionable and conflict with various observations and calculations based on other indicators such as national accounts, executive income or house prices. Yet, the World Bank upholds official inequality findings in portraying the Arab upheaval as the revolt of a ‘middle class’ that aspires to greater business freedom, in consonance with the neoliberal worldview.     

Rapid loss of endogenous DNA in pig bone buried in five different environments

The rate at which endogenous DNA from differently prepared (butchered, boiled and baked) compact pig bones degrades in five different Danish terrestrial and marine environments over 12 months was investigated. Although > 70% of the estimated endogenous mtDNA is lost after just four weeks of exposure, no cytosine deamination of DNA was recognised. A correlation between the presence of oxygen and the amount of preserved DNA was observed. The results provide valuable information on the interaction between the endogenous DNA and the depositional environment in the early stages of bone diagenesis, which can be a support in the interpretation of the initial diagenetic pathways of archaeological bone.