First GIS analysis of modern stone tools used by wild chimpanzees (Pan troglodytes verus) in Bossou, Guinea, West Africa

Stone tool use by wild chimpanzees of West Africa offers a unique opportunity to explore the evolutionary roots of technology during human evolution. However, detailed analyses of chimpanzee stone artifacts are still lacking, thus precluding a comparison with the earliest archaeological record. This paper presents the first systematic study of stone tools used by wild chimpanzees to crack open nuts in Bossou (Guinea-Conakry), and applies pioneering analytical techniques to such artifacts. Automatic morphometric GIS classification enabled to create maps of use wear over the stone tools (anvils, hammers, and hammers/anvils), which were blind tested with GIS spatial analysis of damage patterns identified visually. Our analysis shows that chimpanzee stone tool use wear can be systematized and specific damage patterns discerned, allowing to discriminate between active and passive pounders in lithic assemblages. In summary, our results demonstrate the heuristic potential of combined suites of GIS techniques for the analysis of battered artifacts, and have enabled creating a referential framework of analysis in which wild chimpanzee battered tools can for the first time be directly compared to the early archaeological record.Leverhulme Trust [IN-052]; MEXT [20002001, 24000001]; JSPS-U04-PWS; FCT-Portugal [SFRH/BD/36169/2007]; Wenner-Gren Foundation for Anthropological Researc

Comparison of Outcome After Percutaneous Mitral Valve Repair With the MitraClip in Patients With Versus Without Atrial Fibrillation

Percutaneous mitral valve repair with the MitraClip is an established treatment for patients with mitral regurgitation (MR) who are inoperable or at high risk for surgery. Atrial Fibrillation (AF) frequently coincides with MR, but only scarce data of the influence of AF on outcome after MitraClip is available. The aim of the current study was to compare the clinical outcome after MitraClip treatment in patients with versus without atrial fibrillation. Between January 2009 and January 2016, all consecutive patients treated with a MitraClip in 5 Dutch centers were included. Outcome measures were survival, symptoms, MR grade, and stroke incidence. In total, 618 patients were treated with a MitraClip. Patients with AF were older, had higher N-terminal B-type natriuretic peptide levels, more tricuspid regurgitation, less often coronary artery disease and a better left ventricular function. Survival of patients treated with the MitraClip was similar for patients with AF (82%) and without AF (non-AF; 85%) after 1 year (p = 0.30), but significantly different after 5-year follow-up (AF 34%; non-AF 47%; p = 0.006). After 1 month, 64% of the patients with AF were in New York Heart Association class I or II, in contrast to 77% of the patients without AF (p = 0.001). The stroke incidence appeared not to be significantly different (AF 1.8%; non-AF 1.0%; p = 0.40). In conclusion, patients with AF had similar 1-year survival, MR reduction, and stroke incidence compared with non-AF patients. However, MitraClip patients with AF had reduced long-term survival and remained more symptomatic compared with those without AF.</p

The ‘mosaic habitat’ concept in human evolution: past and present

The habitats preferred by hominins and other species are an important theme in palaeoanthropology, and the ‘mosaic habitat’ (also referred to as habitat heterogeneity) has been a central concept in this regard for the last four decades. Here we explore the development of this concept – loosely defined as a range of different habitat types, such as woodlands, riverine forest and savannah within a limited spatial area– in studies of human evolution in the last sixty years or so. We outline the key developments that took place before and around the time when the term ‘mosaic’ came to wider palaeoanthropological attention. To achieve this we used an analysis of the published literature, a study of illustrations of hominin evolution from 1925 onwards and an email survey of senior researchers in palaeoanthropology and related fields. We found that the term mosaic starts to be applied in palaeoanthropological thinking during the 1970’s due to the work of a number of researchers, including Karl Butzer and Glynn Isaac , with the earliest usage we have found of ‘mosaic’ in specific reference to hominin habitats being by Adriaan Kortlandt (1972). While we observe a steady increase in the numbers of publications reporting mosaic palaeohabitats, in keeping with the growing interest and specialisation in various methods of palaeoenvironmental reconstruction, we also note that there is a lack of critical studies that define this habitat, or examine the temporal and spatial scales associated with it. The general consensus within the field is that the concept now requires more detailed definition and study to evaluate its role in human evolution

Activity and Habitat Use of Chimpanzees (Pan troglodytes verus) in the Anthropogenic Landscape of Bossou, Guinea, West Africa

Many primate populations inhabit anthropogenic landscapes. Understanding their long-term ability to persist in such environments and associated real and perceived risks for both primates and people is essential for effective conservation planning. Primates in forest–agricultural mosaics often consume cultivars to supplement their diet, leading to potentially negative encounters with farmers. When crossing roads, primates also face the risk of encounters with people and collision with vehicles. Chimpanzees (Pan troglodytes verus) in Bossou, Guinea, West Africa, face such risks regularly. In this study, we aimed to examine their activity budget across habitat types and the influence of anthropogenic risks associated with cultivated fields, roads, and paths on their foraging behavior in noncultivated habitat. We conducted 6-h morning or afternoon follows daily from April 2012 to March 2013. Chimpanzees preferentially used forest habitat types for traveling and resting and highly disturbed habitat types for socializing. Wild fruit and crop availability influenced seasonal habitat use for foraging. Overall, chimpanzees preferred mature forest for all activities. They showed a significant preference for foraging at >200 m from cultivated fields compared to 0–100 m and 101–200 m, with no effect of habitat type or season, suggesting an influence of associated risk. Nevertheless, the chimpanzees did not actively avoid foraging close to roads and paths. Our study reveals chimpanzee reliance on different habitat types and the influence of human-induced pressures on their activities. Such information is critical for the establishment of effective land use management strategies in anthropogenic landscapes

Franco-Japanese and other collaborative contributions to understanding chimpanzee culture at Bossou and the Nimba Mountains

The Japanese approach to science has permitted theoretical leaps in our understanding of culture in non-human animals and challenged human uniqueness, as it is not embedded in the Western traditional dualisms of human/animal and nature/culture. This paper highlights the value of an interdisciplinary approach and combining methodological approaches in exploring putative cultural variation among chimpanzees. I focus particularly on driver ants (Dorylus sp.) and oil palm (Elaeis guineensis) consumption among the Bossou and Nimba chimpanzees, in south-eastern Guinea at the border with Côte d’Ivoire and Liberia, and hand use across different tool use tasks commonly witnessed at Bossou, i.e. ant-dipping, nut-cracking, pestle-pounding, and algae-scooping. Observed variation in resource use was addressed across differing scales exploring both within- and between-community differences. Our findings have highlighted a tight interplay between ecology, social dynamics and culture, and between social and individual learning and maternal contribution to tool-use acquisition. Exploration of hand use by chimpanzees revealed no evidence for individual-level hand or community-level task specialisation. However, more complex types of tool use such as nut-cracking showed distinct lateralization, while the equivalent of a haptic manual action revealed a strong right hand bias. The data also suggest an overall population tendency for a right hand preference. As well as describing these sites’ key contributions to our understanding of chimpanzees and to challenging our perceptions of human uniqueness, this paper also highlights the critical condition and high levels of threats facing this emblematic chimpanzee population, and several questions that remain to be addressed. In the spirit of the Japanese approach to science, I recommend that an interdisciplinary and collaborative research approach can best help us to challenge perceptions of human uniqueness and to further our understanding of chimpanzee behavioural and social flexibility in the face of local social, ecological and anthropogenic changes and threats to their survival

The Advantage of Standing Up to Fight and the Evolution of Habitual Bipedalism in Hominins

BACKGROUND: Many quadrupedal species stand bipedally on their hindlimbs to fight. This posture may provide a performance advantage by allowing the forelimbs to strike an opponent with the range of motion that is intrinsic to high-speed running, jumping, rapid braking and turning; the range of motion over which peak force and power can be produced. METHODOLOGY/PRINCIPAL FINDINGS: To test the hypothesis that bipedal (i.e., orthograde) posture provides a performance advantage when striking with the forelimbs, I measured the force and energy produced when human subjects struck from "quadrupedal" (i.e., pronograde) and bipedal postures. Downward and upward directed striking energy was measured with a custom designed pendulum transducer. Side and forward strikes were measured with a punching bag instrumented with an accelerometer. When subjects struck downward from a bipedal posture the work was 43.70±12.59% (mean ± S.E.) greater than when they struck from a quadrupedal posture. Similarly, 47.49±17.95% more work was produced when subjects struck upward from a bipedal stance compared to a quadrupedal stance. Importantly, subjects did 229.69±44.19% more work in downward than upward directed strikes. During side and forward strikes the force impulses were 30.12±3.68 and 43.04±9.00% greater from a bipedal posture than a quadrupedal posture, respectively. CONCLUSIONS/SIGNIFICANCE: These results indicate that bipedal posture does provide a performance advantage for striking with the forelimbs. The mating systems of great apes are characterized by intense male-male competition in which conflict is resolved through force or the threat of force. Great apes often fight from bipedal posture, striking with both the fore- and hindlimbs. These observations, plus the findings of this study, suggest that sexual selection contributed to the evolution of habitual bipedalism in hominins

Classifying chimpanzee (Pan troglodytes) landscapes across large scale environmental gradients in Africa

Primates are sometimes categorized in terms of their habitat. Although such categorization can be over-simplistic, there are scientific benefits from the clarity and consistency that habitat categorization can bring. Chimpanzees (Pan troglodytes) inhabit various environments, but researchers often refer to ‘forest’ or ‘savanna’ chimpanzees. Despite the wide use of this forest-savanna distinction, clear definitions of these landscapes for chimpanzees, based on environmental variables at study sites or determined in relation to existing bioclimatic classifications, are lacking. The robustness of the forest-savanna distinction thus remains to be assessed. We review 43 chimpanzee study sites to assess how the landscape classifications of researchers fit with the environmental characteristics of study sites and with three bioclimatic classifications. We use scatterplots and Principal Components 15 Analysis to assess the distribution of chimpanzee field sites along gradients of environmental 16 variables (temperature, rainfall, precipitation seasonality, forest cover and satellite-derived 17 Hansen tree cover). This revealed an environmental continuum of chimpanzee study sites 18 from savanna to dense forest, with a rarely acknowledged forest mosaic category in between, 19 but with no natural separation into these three classes and inconsistencies with the bioclimatic 20 classifications assessed. The current forest–savanna dichotomy therefore masks a progression 21 of environmental adaptation for chimpanzees, and we propose that recognizing an additional, 22 intermediate ‘forest mosaic’ category is more meaningful than focusing on the ends of this 23 environmental gradient only. Future studies should acknowledge this habitat continuum, place their study sites on the forest–savanna gradient, and include detailed environmental data to support further attempts at quantification