The origins of herding practices in southern Africa remain controversial. The first appearance of domesticated caprines in the subcontinent is thought to be c. 2000 years BP; however, the origin of this cultural development is still widely debated. Recent genetic analyses support the long-standing hypothesis of herder migration from the north, while other researchers have argued for a cultural diffusion hypothesis where the spread of herding practices took place without necessarily implicating simultaneous and large population movements. Here we document the Later Stone Age (LSA) site of Leopard Cave (Erongo, Namibia), which contains confirmed caprine remains, from which we infer that domesticates were present in the southern African region as early as the end of the first millennium BC. These remains predate the first evidence of domesticates previously recorded for the subcontinent. This discovery sheds new light on the emergence of herding practices in southern Africa, and also on the possible southward routes used by caprines along the western Atlantic coast.

The saturated sapwood permeability (k) of jack pine (Pinusbanksiana Lamb.) from stands of different ages and site qualities was measured using a constant water flow apparatus. Saturated sapwood permeability at the base of the live crown (BLC) increased with age and reached a plateau just beyond 4 × 10−12 m2. The rate at which this plateau was reached, however, was dependent on site quality. Such age-related increases in k can partially explain how trees can maintain similar daytime leaf water potentials at different stages of stand development. Within age-classes 15 and 35, k at BLC was greater on the better-quality sites and was strongly correlated with both diameter and height growth. For age-class 120, k at BLC was not significantly different among sites. Saturated sapwood permeability at BLC could be predicted from age and site quality, using a negative exponential function (R2 = 0.66). The ability to predict changes in k with stand development has potential for improving leaf area estimates derived from sapwood area -leaf area correlations. Sapwood conductance from ground level to the upper third of the crown decreased with age for good-quality sites and increased with age for poor-quality sites. It corresponded to the pattern of average annual height growth over the last 5 years (R2 = 0.61). The number of annual rings contributing to the sapwood at a given age was independent of site quality. This suggests that the historical reconstruction of a tree's leaf area and growth efficiency is possible even after the formation of significant amounts of heartwood.

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The African origin of modern humans is the center of a large debate. Discoveries of anatomically modern human fossils in Sub-Saharan Africa correlated to lithic and faunal artifacts show that a "modern Behavior" is associated with the emergence of Homo sapiens. Even though the traits to define this modernity are sometimes difficult to apprehend, the study of the Middle Stone Age cultural phase is important for understanding the origin and evolution of the cognitive capacity of modern humans. Porc-Epic Cave in Ethiopia has a long sequence of Upper Pleistocene occupation. Several thousand bone and lithic artifacts were excavated during three major field excavations (1933, 1974,). The lithic assemblage reveals that the relationship between humans and their environment is well organized and that the African terminology is sometimes difficult to apply. This paper proposes a synthesis of all the data, studies and conclusions I have made from the analysis of lithic materials from the 1933 and 1975-76 excavations in order to integrate Porc-Epic into the current debate of MSA and modern human Behavior. L'origine de l'Homme moderne en Afrique fait l'objet actuellement d'un large débat. Les décourvertes de fossiles d'Homo sapiens en Afrique sub-saharienne associésà des industries lithiques montrent que, en parallèleà l'émergence de cette nouvelle espèce humaine, un comportement dit moderne s'est développé. Le Middle Stone Age est donc une période culturelle charnière dans l'évolution comportementale de l'homme. La grotte du Porc-Épic, enÉthiopie, est un témoignage de cetteère avec un remplissage pléistocène supérieur contenant des dizaines de milliers de restes fauniques et lithiques. L'étude de son important assemblage lithique révèle que le rapport de l'hommeà la matière età son environnement 178 Pleurdeau est très organisé et que le terminologie culturelle africaine est parfois difficileà utiliser.

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The anatomical characteristics of sapwood from the base of the live crown of trees from 11 jack pine stands (Pinusbanksiana Lamb.) of different age and site quality were related to the patterns of change of longitudinal sapwood permeability (k) previously observed to occur among these stands. Tracheid length (Lt) increased rapidly from a minimum of 1.9 mm to a plateau of around 3.6 mm as stand age and site quality (productivity class) increased. Sapwood relative water content (Rs) measured before saturation ranged from 78 to 85% for the majority of trees. Samples taken from trees growing on poor sites, however, exhibited significantly lower values of Rs, which probably resulted in their remaining below saturation during the determination of sapwood permeability. The lower Rs values were assumed to be reflective of more adverse water balances during the growing season associated with rapidly drained and (or) shallow soils. Tracheid lumen diameter (Dl) was positively correlated with k within age-classes 15 and 35, but not thereafter. The initial relation between Dl, and k is thought to be associated with corresponding increases in the area of pit membranes, which determines the number of pores within a pit membrane. Values of k were never more than 60% of the values calculated by Poiseuille's law for ideal capillaries (kc) and were generally less than 40%. Values of k tended to approach kc with increasing Lt and decreasing Dl. Overall, Poiseuille's law by itself could not explain the changes in the hydraulic properties of jack pine sapwood with stand development. However, Lt and Rs could together account for 72% of the variation in k. Young stands that had different k depending on site quality generally had corresponding differences in Lt, Rs, and (or) Dl. Mature stands that had reached maximum k on all quality sites no longer showed differences in Lt, Rs, or Dl.

Namibia is one of the southern African countries hosting the richest rock art heritage, with thousands of rock paintings. Although numerous studies investigated their distribution, style, and possible meaning, few are known about the materials used to perform these paintings. Our in situ study aimed at identifying the diversity of pigments and alterations of some rock paintings in the northwestern part of the Erongo (Namibia). It relies on extensive pXRF analyses of 35 figures from eight rock art sites of the area. Despite common limits of in situ pXRF analyses, the extensive number of figures analyzed and the original data treatment that we performed pioneered the first scientific analyses of the pigments from rock painting sites in the Erongo Mountains. Furthermore, the study also confirmed the presence of iron oxide pigments on a portion of wall exposed during the excavations carried out at the archeological site of Leopard Cave and of possibly datable alterations over several paintings, paving the way to future chronological analyses of past tradition of rock paintings in Central Namibia.