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Isolated indigenous societies who actively avoid sustained peaceful contact with the outside world are critically endangered. Last year, "Tanaru", the lone surviving man of his tribe for at least 35 years, died in Southwest Amazonia, marking the latest cultural extinction event in a long history of massacres, enslavement, and epidemics. Yet in the upper reaches of the Amazon Basin, dozens of resilient isolated tribes still manage to survive. Remote sensing is a reliable method of monitoring the population dynamics of uncontacted populations by quantifying the area cleared for gardens and villages, along with the fire detections associated with the burning of those clearings. Remote sensing also provides a method to document the number of residential structures and village fissioning. Only with these longitudinal assessments can we better evaluate the current no-contact policies by the United Nations and governments, along with the prospects for the long-term survival of isolated tribes. While the world's largest isolated indigenous metapopulation, Pano speakers in Acre, Brazil, appears to be thriving, other smaller isolated populations disconnected from metapopulations continue to be extremely vulnerable to external threats. Our applied anthropological conservation approach is to provide analyses of publicly available remote sensing datasets to help inform policies that enhance the survival and well-being of isolated cultural groups. [ABSTRACT FROM AUTHOR]

The evolution of the hominin hand has been widely linked to the use and production of flaked stone tool technologies. After the earliest handheld flake tools emerged, shifts in hominin hand anatomy allowing for greater force during precision gripping and ease when manipulating objects in-hand are observed in the fossil record. Previous research has demonstrated how biometric traits, such as hand and digit lengths and precision grip strength, impact functional performance and ergonomic relationships when using flake and core technologies. These studies are consistent with the idea that evolutionary selective pressures would have favoured individuals better able to efficiently and effectively produce and use flaked stone tools. After the advent of composite technologies during the Middle Stone Age and Middle Palaeolithic, fossil evidence reveals differences in hand anatomy between populations, but there is minimal evidence for an increase in precision gripping capabilities. Furthermore, there is little research investigating the selective pressures, if any, impacting manual anatomy after the introduction of hafted composite stone technologies ('handles'). Here we investigated the possible influence of tool-user biometric variation on the functional performance of 420 hafted Clovis knife replicas. Our results suggest there to be no statistical relationships between biometric variables and cutting performance. Therefore, we argue that the advent of hafted stone technologies may have acted as a 'performance equaliser' within populations and removed (or reduced) selective pressures favouring forceful precision gripping capabilities, which in turn could have increased the relative importance of cultural evolutionary selective pressures in the determination of a stone tool's performance. [ABSTRACT FROM AUTHOR]

We investigate 3D size-segregation in a granular avalanche. A thin bi-disperse avalanche is brought to rest within a confined geometry, forming a stationary deposit. The front of the stationary deposit propagates upslope as a shock in the flow thickness. The shock freezes the segregation state of the disperse avalanche at a given point into the deposit. 3D magnetic resonance images of the deposit have been acquired to obtain particle distribution characteristics. Significant gradients in lateral and downstream concentration profiles are observed. Initially, faster evolution of the segregation state occurs at the walls, with the core remaining closer to the inlet conditions. Ultimately, at larger flow distances, a core rich in large particles develops, with layers of predominantly small particles at the side-walls and base. Evidence from both graded and inversely graded inlet conditions suggests that the avalanches converge to the same stable segregation state for distances larger than ∼ 1300 large particle diameters. Crucially, the pure-small-particle layers that form at the base of the flows, whilst initially varying in thickness, converge towards the same constant thickness by the chute’s end wall. Although the non-constant thickness of the pure-small-particle layer at smaller flow distances is not always reported in prior work on chute avalanches, there is a good qualitative agreement on the evolution of the segregation state down the chute with prior studies. [ABSTRACT FROM AUTHOR]