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Although many species display behavioural traditions, human culture is unique in the complexity of its technological, symbolic and social contents. Is this extraordinary complexity a product of cognitive evolution, cultural evolution or some interaction of the two? Answering this question will require a much better understanding of patterns of increasing cultural diversity, complexity and rates of change in human evolution. Palaeolithic stone tools provide a relatively abundant and continuous record of such change, but a systematic method for describing the complexity and diversity of these early technologies has yet to be developed. Here, an initial attempt at such a system is presented. Results suggest that rates of Palaeolithic culture change may have been underestimated and that there is a direct relationship between increasing technological complexity and diversity. Cognitive evolution and the greater latitude for cultural variation afforded by increasingly complex technologies may play complementary roles in explaining this pattern.

Niche theory, the oldest, most established community assembly model, predicts that in sympatry, the realized niche will contract due to negative interspecific interactions, but fails to recognize the effects of positive interactions on community assembly. The stress gradient hypothesis predicts that positive interactions expand realized niches in stressful habitats. We tested the predictions of the stress gradient hypothesis in a cobble beach model system across both physical and biological stress gradients. We transplanted seven common littoral species within, adjacent to, and below Spartina alterniflora cordgrass stands in control, cage control, predator exclusion cage, shade, and shaded predator exclusion cage treatments to test the hypothesis that cordgrass expands intertidal organism habitats. On cobble beaches, cordgrass ameliorates physical and predation stresses, expanding the distribution and realized niches of species to habitats in which they cannot live without facilitation, suggesting that niche theory and species distribution models should be amended to accommodate the role of positive interactions in community assembly.

South Asia is rich in Lower Paleolithic Acheulian sites. These have been attributed to the Middle Pleistocene on the basis of a small number of dates, with a few older but disputed age estimates. Here, we report new ages from the excavated site of Attirampakkam, where paleomagnetic measurements and direct ²⁶Al/¹⁰Be burial dating of stone artifacts now position the earliest Acheulian levels as no younger than 1.07 million years ago (Ma), with a pooled average age of 1.51 ± 0.07 Ma. These results reveal that, during the Early Pleistocene, India was already occupied by hominins fully conversant with an Acheulian technology including handaxes and cleavers among other artifacts. This implies that a spread of bifacial technologies across Asia occurred earlier than previously accepted.

High-resolution images of the surface of asteroid Itokawa from the Hayabusa mission reveal it to be covered with unconsolidated millimeter-sized and larger gravels. Locations and morphologic characteristics of this gravel indicate that Itokawa has experienced considerable vibrations, which have triggered global-scale granular processes in its dry, vacuum, microgravity environment. These processes likely include granular convection, landslide-like granular migrations, and particle sorting, resulting in the segregation of the fine gravels into areas of potential lows. Granular processes become major resurfacing processes because of Itokawa's small size, implying that they can occur on other small asteroids should those have regolith.

This study presents an experimental study to improve the mechanical properties of a concrete cobble using statistical software. First, an experimental design was carried out using a statistical software to obtain the different mixtures of cement with additives such as clay and ashes from ceramic kilns and then optimize the number of tests to evaluate the mechanical properties of a cobble block with different percentages of additives. Finally, the results have shown that with a mixture composed of 93.3% of concrete, 3.33% of clay, and 3.33% of ashes, it was possible to obtain the highest compressive strength with 99% compliance.

Deep-sea corals are fragile and long-lived species that provide important habitat for a variety of taxa. The rarity ofin situobservations in deep waters off Newfoundland, Canada, motivated the first extensive deep-sea research cruise to that region in 2007. We conducted 7 dives in 3 canyons (Haddock Channel, Halibut Channel, and Desbarres Canyon) with ROPOS (Remotely Operated Platform for Ocean Science). Over 160 000 coral colonies were enumerated and, of the 28 species found,Acanella arbuscula,Pennatulaspp., andFlabellumspp. were most frequently observed. The largest coral observed wasKeratoisis grayiat over 2 m in height. Corals spanned the entire depth range sampled (351 to 2245 m) and inhabited all bottom types surveyed, but boulder and cobble habitats were most species-rich. Assemblages differed significantly with depth class and bottom type. The unique assemblage at outcrops was strongly driven by the presence ofDesmophyllum dianthus.Keratoisis grayi,D. dianthus, andAnthomastusspp. were largely absent in mud-sand habitats. Sea pen meadows covered large tracts of muddy seafloor spanning >1 km.Acanella arbusculaandFlabellumspp. characterised large coral fields with abundant corals but relatively low species richness. These results highlight not only the importance of hard structure in determining patterns of coral distributions, abundances, and assemblages, but also the need to focus conservation efforts on a variety of habitats to ensure protection for the full suite of deep-sea coral species.

This article reviews the archaeology and chronology of the Chinese Upper Paleolithic and the human fossils attributed to this period. The onset of the Upper Paleolithic in China dates to ca. 35,000-30,000 years ago and is marked by the appearance of a few body decorations and well-shaped bone tools that were added to stone tool assemblages, including core-and-flake tools in North China and cobble tools in South China. The proliferation of blade assemblages in northwest China is interpreted as the cultural impact or the physical presence of bearers of blade industries from western Eurasia. The ensuing appearance of microblade assemblages in North China by 23,000-22,000 years ago reflects the use of local siliceous crystalline nodules by a population that recognized the advantages of this raw material. At that time in South China, prehistoric artisans continued to shape their stone objects from the available flat river cobbles. During the later part of the Chinese Upper Paleolithic (ca. 21,000-10,000 BP), foragers also made bone tools, antler objects, pottery, and shell tools, which laid the technological foundations for the early Neolithic period. One difficulty in this research is that human fossils are rare. Few are well dated and morphological, cultural, and biological interpretations are hotly debated. Our review attempts to facilitate the understanding of a poorly known period in Chinese archaeology and its place in human cultural evolution.

The pervasive impact of invasive species has motivated considerable research to understand how characteristics of invaded communities, such as native species diversity, affect the establishment of invasive species. Efforts to identify general mechanisms that limit invasion success, however, have been frustrated by disagreement between landscape-scale observations that generally find a positive relationship between native diversity and invasibility and smaller-scale experiments that consistently reveal competitive interactions that generate the opposite relationship. Here we experimentally elucidate the mechanism explaining the large-scale positive associations between invasion success and native intertidal diversity revealed in our landscape-scale surveys of New England shorelines. Experimental manipulations revealed this large-scale pattern is driven by a facilitation cascade where ecosystem-engineering species interact nonlinearly to enhance native diversity and invasion success by alleviating thermal stress and substrate instability. Our findings reveal that large-scale diversity-invasion relationships can be explained by small-scale positive interactions that commonly occur across multiple trophic levels and functional groups. We argue that facilitation has played an important but unrecognized role in the invasion of other well studied systems, and will be of increasing importance with anticipated climate change.

Shear strength of sandy gravel with cobbles is difficult to determine for usually an in situ test needs to be performed. Six group of in situ tests were conducted to investigate the shear strength of sandy gravel with cobbles. However, the inner friction angle was highly underestimated compared with those from the other methods. This failure result could be explained comprehensively. The strength parameters were also investigated using a DCP test, an experimental method and a theoretical method. Moreover, a numerical simulation method was also used to determine the failure mode of the in situ test. Through comprehensive comparison of these results, the soil failure mechanism in the tests did not follow the direct shear failure but did follow the bearing-capacity failure model. The bottom boundary could not provide enough capacity during the test; hence, the shear strength was underestimated. Moreover, the in situ test results could be explained through the Meyerhof bearing-capacity theory on shallow foundations subjected to inclined loads. With increasing normal load, the horizontal force decreased, resulting in a small inner-friction angle. The theoretical result of the inner-friction angle of sandy gravel with cobbles was 42 ~ 47.5° in these test, which coincided with the numerical simulation and empirical methods.