Journal of Anthropological Sciences最新文献

North Africa features some of the earliest manifestations of the Middle Stone Age (MSA) and fossils of our species, Homo sapiens, as well as early examples of complex culture and the long distance transfer of exotic raw materials. As they are elsewhere, lithics (i.e., stone tools) present by far the most abundant source of information on this cultural period. Given the importance of North Africa in human origins, understanding the character and distribution of MSA lithics is therefore crucial, as they shed light on early human behaviour and culture. However, the lithics of the North African MSA are poorly understood, and their technological variability is frequently obfuscated by regionally specific nomenclatures, often repeated without criticism, and diverse methods of analysis that are often incompatible. Characterising dynamic technological innovations as well as apparent technological stasis remains challenging, and many narratives have not been tested quantitatively. This significantly problematizes hypotheses of human evolution and dispersals invoking these data that extend beyond North Africa. This paper therefore presents a description of the lithics of the North African MSA, including their technological characteristics, chronology, spatial distribution and associated research traditions. A range of interpretations concerning early H. sapiens demography in North Africa are then re-evaluated in the light of this review, and the role and power of lithic data to contribute to such debates is critically assessed.

The Longobard necropolis of Povegliano Veronese dates from the 6th to the 8th centuries AD. Among the 164 tombs excavated, the skeleton of an older male shows a well-healed amputated right forearm. The orientation of the forearm fracture suggests an angled cut by a single blow. Reasons why a forearm might be amputated include combat, medical intervention, and judicial punishment. As with other amputation cases reported in literature, this one exhibits both healing and osteoblastic response. We argue that the forelimb stump morphology suggests the use of a prosthesis. Moreover, dental modification of RI2 shows considerable wear and smoothing of the occlusal surface, which points to dental use in attaching the prosthesis to the limb. Other indications of how this individual adjusted to his amputated condition includes a slight change in the orientation of the right glenoid fossa surface, and thinning of right humeral cortical bone. This is a remarkable example in which an older male survived the loss of a forelimb in pre-antibiotic era. We link archaeological remains found in the tomb (buckle and knife) with the biological evidence to show how a combined bioarchaeological approach can provide a clearer interpretation of the life history of an individual.

This paper proposes that the distinctively human capacity for cumulative, adaptive, open-ended cultural evolution came about through two temporally-distinct cognitive transitions. First, the origin of Homo-specific culture over two MYA was made possible by the onset of a finer-grained associative memory that allowed episodes to be encoded in greater detail. This in turn meant more overlap amongst the distributed representations of these episodes, such that they could more readily evoke one another through self-triggered recall (STR). STR enabled representational redescription, the chaining of thoughts and actions, and the capacity for a stream of thought. Second, fully cognitive modernity following the appearance of anatomical modernity after 200,000 BP, was made possible by the onset of contextual focus (CF): the ability to shift between an explicit convergent mode conducive to logic and refinement of ideas, and an implicit divergent mode conducive to free-association, viewing situations from radically new perspectives, concept combination, analogical thinking, and insight. This paved the way for an integrated, creative internal network of understandings, and behavioral modernity. We discuss feasible neural mechanisms for this two-stage proposal, and outline how STR and CF differ from other proposals. We provide computational evidence for the proposal obtained with an agent-based model of cultural evolution in which agents invent ideas for actions and imitate the fittest of their neighbors' actions. Mean fitness and diversity of actions across the artificial society increased with STR, and even more so with CF, but CF was only effective if STR was already in place. CF was most effective following a change in task, which supports its hypothesized role in escaping mental fixation. The proposal is discussed in the context of transition theory in the life sciences.

Anthropologists have long been interested in explaining patterns of variation in human physical form, in both present-day and ancient humans. Starting in the 1950s, their explanations became more firmly rooted in evolutionary theory, but they have typically focused on adaptive accounts. Neutral explanations - those grounded in models of evolution by mutation, genetic drift, and gene flow rather than natural selection - provide an alternative to adaptive explanations, and in recent years, neutral models have become an important tool for researchers investigating the evolution of human physical form. Neutral models have implications for many areas of biological anthropology, including using morphology to reconstruct the histories and migrations of recent human populations, using morphology to infer the evolutionary relationships among hominin taxa, and clarifying how natural selection has acted on physical form throughout human evolution. Their application to anthropological questions has stimulated biological anthropologists to more seriously consider the roles of history and chance in human evolution. In light of the growing importance of neutral explanations in biological anthropology, the goal here is to provide an introduction to neutral models of phenotypic evolution and their application to human physical form.