Modeling a primate technological niche

The ability to modify the environment through the transport of tools has been instrumental in shaping the evolutionary success of humans. Understanding the cause-and-effect relationships between hominin behavior and the environment ultimately requires understanding of how the archaeological record forms. Observations of living primates can shed light on these interactions by investigating how tool-use behaviors produce a material record within specific environmental contexts. However, this requires reconciling data derived from primate behavioral observations with the time-averaged nature of the Plio-Pleistocene archaeological record. Here, we use an agent-based model to investigate how repeated short-distance transport events, characteristic for primate tool use, can result in significant landscape-scale patterning of material culture over time. Our results illustrate the conditions under which accumulated short-distance transport bouts can displace stone tools over long distances. We show that this widespread redistribution of tools can also increase access to tool require resources over time. As such, these results elucidate the niche construction processes associated with this pattern of tool transport. Finally, the structure of the subsequent material record largely depends on the interaction between tool transport and environmental conditions over time. Though these results have implications for inferring hominin tool transports from hominin archaeological assemblages. Furthermore, they highlight the difficulties with connecting specific behavioral processes with the patterning in the archaeological record

Use-wear and residue analysis of pounding tools used by wild capuchin monkeys (Sapajus libidinosus) from Serra da Capivara (Piauí, Brazil)

Bearded capuchin monkeys (Sapajus libidinosus) from Serra da Capivara National Park (Brazil), perform the widest range of activities using stone tools of all the non-human tool-using primates. The behaviours behind this range of tool-use have been closely documented, but little is known about the characteristics of the tools themselves. Here we redress this imbalance and adopt an archaeological perspective to the analysis of capuchin pounding tools. We apply, for the first time, systematic microscopic techniques to the analysis of capuchin stone tools used for digging, cracking cashew nuts and seed processing to characterise their damage patterns combined with residue spatial distribution and micro-remains analysis. This work presents a standardized methodology for future primate archaeological use-wear studies as well as forming a reference collection which can be used to identify different activities within the primate archaeological record. Furthermore, understanding the archaeologically visible traces of primate percussive behaviours represents an initial step in developing a methodology to investigate if similar activities were practiced by early hominins and to help identify these activities in the Plio-Pleistocene archaeological record

Towards Real-World Applications of ServiceX, an Analysis Data Transformation System

One of the biggest challenges in the High-Luminosity LHC (HL- LHC) era will be the significantly increased data size to be recorded and analyzed from the collisions at the ATLAS and CMS experiments. ServiceX is a software R&D project in the area of Data Organization, Management and Access of the IRIS- HEP to investigate new computational models for the HL- LHC era. ServiceX is an experiment-agnostic service to enable on-demand data delivery specifically tailored for nearly-interactive vectorized analyses. It is capable of retrieving data from grid sites, on-the-fly data transformation, and delivering user-selected data in a variety of different formats. New features will be presented that make the service ready for public use. An ongoing effort to integrate ServiceX with a popular statistical analysis framework in ATLAS will be described with an emphasis of a practical implementation of ServiceX into the physics analysis pipeline.Comment: 8 pages, 3 figures, 2 listings, 1 table, submitted to the 25th International Conference on Computing in High Energy & Nuclear Physic

Distance-decay effect in stone tool transport by wild chimpanzees

Stone tool transport leaves long-lasting behavioural evidence in the landscape. However, it remains unknown how large-scale patterns of stone distribution emerge through undirected, short-term transport behaviours. One of the longest studied groups of stone-tool-using primates are the chimpanzees of the Taï National Park in Ivory Coast, West Africa. Using hammerstones left behind at chimpanzee Panda nut-cracking sites, we tested for a distance-decay effect, in which the weight of material decreases with increasing distance from raw material sources. We found that this effect exists over a range of more than 2 km, despite the fact that observed, short-term tool transport does not appear to involve deliberate movements away from raw material sources. Tools from the millennia-old Noulo site in the Taï forest fit the same pattern. The fact that chimpanzees show both complex short-term behavioural planning, and yet produce a landscape-wide pattern over the long term, raises the question of whether similar processes operate within other stone-tool-using primates, including hominins. Where hominin landscapes have discrete material sources, a distance-decay effect, and increasing use of stone materials away from sources, the Taï chimpanzees provide a relevant analogy for understanding the formation of those landscapes

The Perception Of Walking Speed In A Virtual Environment

Studies of locomotion in virtual environments assume that correct geometric principles define the relationship between walking speed and environmental flow. However, we have observed that geometrically correct optic flow appears to be too slow during simulated locomotion on a treadmill. Experiment 1 documents the effect in a head-mounted display. Experiment 2 shows that the effect is eliminated when the gaze is directed downward or to the side, or when the walking speed is slow. Experiment 3 shows that the effect is unchanged by stride length. Experiment 4 verifies that the effect is not attributable to image jitter. The change in perceived speed from straight ahead to side or down gaze coincides with a shift from expanding optic flow to lamellar flow. Therefore, we hypothesize that lamellar flow is necessary for accurate speed perception, and that a limited field of view eliminates this cue during straight-ahead gaze