The Ratcliff Site in southwestern Virginia lies in a small second-order stream valley filled with approximately 3.5 m of organic-rich deposits that contain bones of mammoth, mastodon, deer (or antelope), logs, and plant macrofossils. Radiocarbon analyses indicate the age of the organic-rich sediment ranges from > 44,000 to 29,100 14C yr BP, a time period with no fossil remains reported in this region of the Appalachians. Analyses of field observations, textural data, organic carbon content, and plant macrofossils indicate that the organic-rich sediments contain interbedded standing-water and debris-flow deposits. Up to 6 m of oxidized debris-flow sediments bury the organic-rich sediments. The presence of Rubus parviflorus (Thimble Berry) throughout the deposit indicates the site had a boreal environment from > 44,000 to 29,100 14C yr BP. Plant macrofossil evidence indicates the uplands had stands of spruce/jack-pine forests while the valley contained ponds and associated wetlands. Three debris flows occurred at the site between approximately 38,000 and 29,000 14C yr BP, suggesting a recurrence interval for major storms of approximately 3000 yr, even though the apparent stability of the boreal environment implies a climate not conducive to catastrophic rainstorms. This conflicting combination of features suggests that during the middle Wisconsinan this area experienced generally cool climates, dominated by polar air masses, but was punctuated by relatively brief warm periods marked by incursions of tropical air masses.

Recognising elements of a ‘modern’ mind or complex cognition in Stone Age archaeology is difficult and often disputed. A key question is whether, and in what way, the thinking of Homo sapiens differs from that of other species/sub-species of hominins. We argue that if the question of whether the modern mind is different from that of our ancestors or other members of the hominin family is to be fully explored, some focus should fall on technologies and behaviours unique to H. sapiens.

We examine the development of stable bimetal interfaces in nanolayered composites in severe plastic deformation. Copper-niobium multilayers of varying layer thicknesses from several micrometers to 10 nanometers (nm) were fabricated via accumulative roll bonding (ARB). Investigation of their 5-parameter character and atomic scale structure finds that when layer thicknesses refine well below one micrometer, the interfaces self-organize to a few interface orientation relationships. With atomic scale and crystal plasticity modeling, we identify that the two controlling factors that determine whether an interface is stable under high strain rolling are orientation stability of the bicrystal and interface formation energy. A figure-of-merit is introduced that not only predicts the development of the prevailing interfaces but also explains why other interfaces did not develop. Through a suite of nanomechanical and bulk test results, we show that ARB composites containing these stable interfaces are found to have exceptional hardness (∼4.5 GPa) and strength (∼2 GPa).

Carey leaves unaddressed an important evolutionary puzzle: In the absence of a numeral list, how could a concept of natural number ever have arisen in the first place? Here we suggest that the initial development of natural number must have bootstrapped on a material culture scaffold of some sort, and illustrate how this might have occurred using strings of beads.

From the perspective of evolutionary theory, we believe it makes more sense to view the sex differences in spatial cognition as being an evolutionary by-product of selection for optimal rates of fetal development. Geary does not convince us that his proposed selective factors operated with “sufficient precision, economy, and efficiency.” Moreover, the archaeological evidence does not support his proposed evolutionary scenario.

Cognitive neuroscience provides a powerful perspective on the brain and cognition from which archaeologists can begin to document the evolution of the human mind. The following essay uses the Hohlenstein-Stadel figurine as a starting point to demonstrate the two kinds of conclusion open to an evolutionary cognitive archaeology: first, describing features of the cognitive life-world at specific points in human evolution, in this case central Europe 32,000 years ago, and second identifying the evolutionary timing and contexts for specific cognitive abilities, in this case various components of concept formation. We argue that the abstract concept underpinning the Hohlenstein-Stadel figurine resulted initially from an effortful (attentive) linking of ‘animal’ and ‘person’ concepts via the working memory network of the frontal and parietal lobes. These ‘animal’ and ‘person’ concepts themselves were largely unconscious folk biological categories generated by a parietal network that had evolved earlier, probably by the time of the earliest Homo sapiens. These in turn rest on even older, basic ontological categories of ‘animate’ and ‘manipulable’ objects that are temporal lobe networks, and which evolved much earlier still, perhaps with the advent of Homo erectus.