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International audience; Two models of intra-cortical bone remodeling are presented in this work by accounting for the different time scales. The first model involves change of bone relative density following bone stress modification during short time. The second bone model is based on a combination of Finite Element Analysis and Genetic Algorithms. This model allows to simulate the bone structure evolution through several thousands of generations and by the way shows that mechanical factors control at least in part the phylogenetic signals.; Nous présentons dans ce travail deux modèles de tissu osseux cortical en considérant différentes échelles de temps. La première partie de l'étude est consacrée au remaniement osseux à court terme sous contraintes mécaniques. Ce modèle permet de simuler l'évolution de le densité osseuse suite à des modifications de l'environnement mécanique du tissu cortical sur des rats. La seconde partie présente un modèle d'évolution de la structure anisotropique osseuse en supposant que des facteurs mécaniques contrôlent, du moins en partie, les signaux phylogénétiques. Le modèle biomécanique de cette seconde partie est basé sur l'algorithme génétique et la méthode des éléments finis. Il a été appliqué sur de l'os cortical d'oiseaux.

International audience; Evolutionary algorithms (EAs) use Darwinian principles—selection among random variation and heredity—to find solutions to complex problems. Mostly used in engineering, EAs gain growing interest in ecology and genetics. Here, we assess their usefulness in functional morphology, introducing finite element modelling (FEM) as a simulated mechanical environment for evaluating the ‘fitness' of randomly varying structures. We used this method to identify biomechanical adaptations in bone tissue, a long-lasting problem in skeletal morphology. The algorithm started with a bone tissue model containing randomly distributed vascular spaces. The EA randomly mutated the distribution of vascular spaces, and selected the new structure if its mechanical resistance was increased. After some thousands of generations, organized phenotypes emerged, containing vascular canals and sinuses, mimicking real bone tissue organizations. This supported the hypothesis that natural bone microstructures can result from biomechanical adaptation. Despite its limited faithfulness to reality, we discuss the ability of the EA+FEM method to assess adaptation in a dynamic evolutionary framework, which is not possible in the real world because of the generation times of macro-organisms. We also point out the interesting potential of EAs to simulate not only adaptation, but also concurrent evolutionary phenomenons such as historical contingency.

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The environment of juvenile primates is very challenging. They have to forage and move on the same substrates as adults do and escape the same predators, despite their immature state. In this study, we explore the developmental strategies that may provide effective locomotor abilities early in life. This could provide new insights into the selective pressures acting on juvenile primates and into evolution of primate locomotion. We conducted an ontogenetic study of 36 arboreal gray mouse lemurs from birth to adulthood (6 months of age). The investigated parameters were, for both limbs, (1) grasping behavior during locomotion (i.e., grip postures), (2) grasping performance (i.e., pull strength), and (3) motor coordination (i.e., rotarod test). Our results show that 8-day-old babies are able to climb substrates of various slopes and diameters outside of their nest. Although juveniles cannot successfully complete a motor coordination test before 30 days of age, young individuals display relative pull strengths that are very high or even on par with adults, guaranteeing stability on narrow substrates. These powerful grasps highlight the importance of the grasping function for these juveniles that are not carried and move independently on arboreal substrates shortly after their first week of life. Moreover, the pedal grasping provides a secure grasp on all substrates across ontogeny; however, manual secure grasps decrease during development, being highly used only shortly after birth on vertical and narrow substrates. These results first suggest different functional roles of the hands and feet, with the hind limbs ensuring body balance on the substrates, freeing the upper limbs for manipulation. They further show vertical and narrow branches to be especially challenging, requiring strong grasps, which suggests that they may drive the evolution of strong grasping abilities in primates.

International audience; The Proboscideans, an order of mammals including elephants, are the largest of the Earth lands animals. One probable consequence of the rapid increase of their body size is the development of the trunk, a multitask highly sensitive organ used in a large repertoire of behaviours. The absence of bones in the trunk allows a substantial degree of freedom for movement in all directions, and this ability could underlie individual-level strategies. We hypothesised a stronger behavioural variability in simple tasks, and a correlation between the employed behaviours and the shape and size of the food. The observations of a captive group of African elephants allowed us to create a complete catalogue of trunk movements in feeding activities. We noted manipulative strategies and impact of food item properties on the performed behaviours. The results show that a given item is manipulated with a small panel of behaviours, and some behaviours are specific to a single shape of items. The study of the five main feeding behaviours emphasises a significant variability between the elephants. Each individual differed from every other individual in the proportion of at least one behaviour, and every behaviour was performed in different proportions by the elephants. Our findings suggest that during their lives elephants develop individual strategies adapted to the manipulated items, which increases their feeding efficiency.

Currently, approximately 90% of the human population is right-handed. This handedness is due to the lateralization of the cerebral hemispheres and is controlled by brain areas involved in complex motor tasks such as making stone tools or in language. In addition to describing the evolution of laterality in humans, identifying hand preference in fossil hominids can improve our understanding of the emergence and development of complex cognitive faculties during evolution. Several fields of prehistory like palaeoanthropology or lithic analysis have already investigated handedness in fossils hominins but they face limitations due to either the incomplete or the composite state of the skeleton remains or to results replication or method application failure. Wear analysis could provide new complementary data about hand preference evolution and the development of certain complex cognitive functions using indirect evidence (use traces, micro-scars in particular) of the hand holding the stone tool during use. Controlled experiment has been carried out in order to establish a reference collection of tools used with the left and tools used with the right hand. Wear analysis was performed on this corpus using “classical” microscopic approach and geometric morphometric analysis. A machine learning algorithm, the k-NN method, was applied to verify if use traces (micro-scars) could help determine the hand holding the tool during use. The best model, based on parameters referring to invasiveness of micro-scars, was able to correctly determine the hand holding the tool with 75% accuracy.

Fine prehensile activities are often thought to have been associated with the evolution of the human hand. However, there has been no holistic approach establishing the link between the morphology of the forelimb and grasping ability in living primates. The present study investigated the possible relationships between grasping behaviour and the morphology of the forelimb in strepsirrhines in a phylogenetic context. To do so, grasping behaviour during feeding and the shape of the long bones of the forelimb were analysed for 22 species of strepsirrhines. The data obtained show that there is a phylogenetic signal in forelimb morphology in primates in relation to grasping behaviour, but also that there is a marked co-evolution between grasping behaviour and the shape of the humerus and radius. This latter finding suggests a functional association between grasping and forelimb shape, which in turn suggests that bone shape constrains or facilitates behaviour. This result may permit future inferences to be made regarding this behaviour in extinct species and deserves further examination in more detail.

International audience; Although hand grasping is ubiquitous in primate species, its origins remain uncertain. This is in part because uncertainty about hand skills and grasping strategies persists in strepsirrhines, a monophyletic group of primates located near the base of the primate tree. In this study, we report and discuss our observations of the different grasping strategies adopted by 85 captive individuals belonging to 22 species of strepsirrhines during the grasping of food items of different sizes and consistencies. Our results indicate that although strepsirrhines do not present variability in their hand-grip types (sole whole-hand power grip), they are able to adjust their grasping strategy depending on the properties of the food. Notably, they use the mouth when more precision is needed (i.e. to grasp small items). Moreover, grasping strategies adopted for big items differ depending on food consistency, revealing a new and potentially essential factor to consider in future research on grasping abilities. We believe that by looking across this important set of species in unconstrained standardized conditions, this study provides valuable insight for further comparative research on the potential selective pressures involved in the evolution of hand grasping.

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A major problem of evolution addressed by Darwin, in his Origin of Species (Darwin in On the origin of species. John Murray, London, 1859) is the evolutionary relationship between complex structures and their function, colloquially referred to as form–function relationships. Many of the insights that Darwin contributed to our conceptual framework of evolution are based on careful observations of traits in diverse fossil and extant vertebrates.

International audience; This paper is an introduction to a special issue of the Biological Journal of the Linnean Society (2019, volume 127: issue 3) focused on an interdisciplinary approach to the evolution of grasping and manipulation in tetrapods. Grasping is associated with pronounced morphological, dietary, social and locomotor differentiation, and this prompts several evolutionary questions, including the following. In primates, was the origin and evolution of grasping associated primarily with feeding or with locomotion and other social behaviours? Are some grasping and manipulative abilities unique to humans? What is the variability in grasping and manipulation among primates? What can we learn from other tetrapods? The special issue addresses some of these questions by exploring the ways in which the anatomy, functional morphology, ontogeny and biomechanics of tetrapods enable their hands to carry out diverse functions, such as locomotion and manipulation. We briefly review the possible origin and evolution of grasping and manipulative abilities in tetrapods and then introduce the ten other contributions to the special issue.

The recent interest in animal personality has sparked a number of studies on the heritability of personality traits. Yet, how the sources variance these traits can be decomposed remains unclear. Moreover, whether genetic correlations with life-history traits, personality traits and other phenotypic traits exist as predicted by the pace-of-life syndrome hypothesis remains poorly understood. Our aim was to compare the heritability of personality, life-history and morphological traits and their potential genetic correlations in a small primate (Microcebus murinus). We performed an animal model analysis on six traits measured in a large sample of captive mouse lemurs (N = 486). We chose two personality traits, two life-history traits and two morphological traits to (i) estimate the genetic and/or environmental contribution to their variance, and (ii) test for genetic correlations between these traits. We found modest narrow-sense heritability for personality traits, morphological traits and life-history traits. Other factors including maternal effects also influence the sources of variation in life-history and morphological traits. We found genetic correlations between emergence latency on the one hand and radius length and growth rate on the other hand. Emergence latency was also genetically correlated with birth weight and was influenced by maternal identity. These results provide insights into the influence of genes and maternal effects on the partitioning of sources of variation in personality, life-history and morphological traits in a captive primate model and suggest that the pace-of-life syndrome may be partly explained by genetic trait covariances.

Manual grasping is widespread among tetrapods but is more prominent and dexterous in primates. Whether the selective pressures that drove the evolution of dexterous hand grasping involved the collection of fruit or predation on mobile insects remains an area of debate. One way to explore this question is to examine preferences for manual versus oral grasping of a moving object. Previous studies on strepsirrhines have shown a preference for oral-grasping when grasping static food items and a preference for manual-grasping when grasping mobile prey such as insects, but little is known about the factors at play. Using a controlled experiment with a simple and predictable motion of a food item we tested and compared the grasping behaviours of 53 captive individuals belonging to 17 species of strepsirrhines while grasping swinging food items and static food items. The swinging motion increased the frequency of hand-use for all individuals. Our results provide evidence that the swinging motion of the food is a sufficient parameter to increase hand-grasping in a wide variety of strepsirrhine primates. From an evolutionary perspective, this result gives some support to the idea that hand-grasping abilities evolved under selective pressures associated with the predation of food items in motion. Looking at common grasping pattern across a large set of species, this study provides important insight into comparative approaches to understanding the evolution of food hand-grasping in primates and potentially other tetrapod taxa.

The polytypic Straight-billed Woodcreeper Dendroplex picus (J. F. Gmelin, 1788) is one of the most complex species-groups of Dendrocolaptidae (Aves: Passeriformes), from both the nomenclatural and morphological standpoints. Firstly, its alpha taxonomy is debatable. Virtually all recent works (e.g. Aleixo 2002; Marantz et al . 2003; del Hoyo & Collar 2016) have recognized just two species in the group— Dendroplex picus and Zimmer’s Woodcreeper Dendroplex kienerii (Des Murs, 1856)—although some of the other described taxa possess singular morphological characters and well-defined ranges somewhat isolated from their geographically closest relatives (e.g. Plain-throated Woodcreeper Dendroplex picirostris Lafresnaye, 1847). Secondly, the correct genus to which to allocate taxa presently included in this group ( vide Aleixo 2002) has been controversial. There is a considerable confusion as to which nominal species should be regarded as the type of Dendroplex Swainson, 1827 b . Three species are involved in the dispute (Cory & Hellmayr 1925; Peters 1951; Aleixo et al . 2002; Marantz et al . 2003; Aleixo et al . 2007): Oriolus picus J. F. Gmelin, 1788; Dendrocolaptes guttatus M. H. C. Lichtenstein, 1818; and Dendrocolaptes ocellatus Spix, 1824. Here, we re-examine the nomenclatural issue and show that application of the nomen Dendroplex to the clade comprising the species-group D. picus (Aleixo et al . 2007) is based on a misunderstanding of the application of Article 70.3 of the Code (Anon. 1999) and that Dendrocolaptes ocellatus Spix, 1824, is its real type species. Consequently, the genus Dendroplex Swainson, 1827 b , must be considered a junior synonym of Xiphorhynchus Swainson, 1827 a . Because no generic nomen is currently available for them, we propose a new genus nomen to encompass the species originally described as Oriolus picus J. F. Gmelin, 1788, Dendroplex picirostris Lafresnaye, 1847, and Dendrornis kienerii Des Murs, 1856.

Being given a phylogenetic tree of both extant and extinct taxa in which the fossil ages are the only temporal information (namely, in which divergence times are considered unknown), we provide a method to compute the exact probability distribution of any divergence time of the tree with regard to any speciation (cladogenesis), extinction, and fossilization rates under the Fossilized Birth–Death model. We use this new method to obtain a probability distribution for the age of Amniota (the synapsid/sauropsid or bird/mammal divergence), one of the most-frequently used dating constraints. Our results suggest an older age (between about 322 and 340 Ma) than has been assumed by most studies that have used this constraint (which typically assumed a best estimate around 310–315 Ma) and provide, for the first time, a method to compute the shape of the probability density for this divergence time. [Divergence times; fossil ages; fossilized birth–death model; probability distribution.]

International audience; Introduction: The Mitofusin 2 gene (MFN2), which encodes a mitochondrial membrane protein, is known to be the first cause of autosomal dominant Charcot Marie Tooth disease type 2 (CMT2) with early onset. This gene is involved in typical CMT2A and in more atypical phenotypes as optic atrophy or spastic paraplegia. CMT2 refers to inherited axonal polyneuropathy, which associates progressive peripheral motor and sensory neuropathy, a family history consistent mainly with autosomal dominant inheritance, and normal nerve conduction velocities. Subjects: Between 1999 and 2012, the genetic diagnosis of MFN2 mutation was made in 11 children who were treated in our department for different neurological symptoms. All data including family and personal history data, results of standardized clinical and electrophysiology testing, brain magnetic resonance imaging (MRI), neuro-ophthalmic evaluation, muscle biopsy histopathology and molecular diagnosis were retrospectively analyzed. Results: Five different mutations were found in 6 unrelated families. Three of them have previously been described; the two remaining are new mutations: one of them related a new phenotype. Clinical signs appeared before the age of 6 years in more than half of the patients (54%). The motor deficit was predominant in 8 patients (72%). Two children presented an acute onset of disease that stabilized afterwards; the other children showed a more progressive deterioration that was managed symptomatically. Conclusion: This large pediatric study describes a great interfamilial and intrafamilial phenotypic variability. We recommend screening this gene in pediatric patient with chronic neurologic symptoms such as motor deficit or optic atrophy but also in acute neurologic deficiencies such as subacute polyradiculoneuritis. (C) 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Different factors may have coevolved with hand dexterity such as bipedalism, brain enlargement, language, and the production and use of stone technology. Prehistoric stone tools are thus probably one of the key elements to examine the origin and evolution of these essential functions during human evolution. To gain a better understanding of the variability of traces resulting from use found on stone tools or on the body of the user, to better infer past archaeological tools, and to assess what the tool-using human hand specificities are, it is essential to investigate and describe tool manipulation itself. Studies investigated this question but either focused on static finger postures during grasping, or involved complex kinematic model of the coordination of the fingers necessitating the pose of many markers on the hand excluding the application of the method on non-human species. Here, we propose a new method to describe and quantify the dynamic strategies of tool grip and manipulation without the need of markers. We tested this method on five human subjects who had to make bamboo points using flint flakes. Time-based sequence analysis allowed identifying and describing both consistency and variation among users and types of use depending on the observed variable (e.g., hand contact areas, repositioning). The method proved to be efficient and, to our knowledge, is the only available method to describe and quantify with such detailed level grip and manipulation as dynamic process in both human and non-human primates without high technical constraint.

International audience; Felids show remarkable phenotypic similarities and are conservative in behavioral and ecological traits. In contrast, they display a large range in body mass from around 1kg to more than 300kg. Body size and locomotory specializations correlate to skull, limb and vertebral skeleton morphology. With an increase in body mass, felids prey selection switches from small to large, from using a rapid skull or spine lethal bite for small prey, to sustained suffocating bite for large prey. Dietary specialization correlates to skull and front limbs morphology but no correlation was found on the spine or on the hind limb. The morphology of the sacroiliac junction in relation to ecological factors remained to be described. We are presenting a study of the overall shape of the iliac auricular surface with qualitative and quantitative analyses of its morphology. Our results demonstrate that body mass, prey selection, and bite type, crucially influence the auricular surface, where no significant effect of locomotor specialization was found. The outline of the surface is significantly more elevated dorso-caudally and the joint surface shows an irregular W-shape topography in big cats whereas the surface in small cats is smoother with a C-shape topography and less of an elevated ridge. Biomechanically, we suggest that a complex auricular surface increases joint stiffness and provides more support in heavier cats, an advantage for subduing big prey successfully during a sustained bite.

International audience; bile robots have a head ? A rationale based on behavior, automatic control and signal processing. Abstract. This paper presents an interdisciplinary study of the role of the head in multisensory integration and motor-control organization for the production of voluntary spatial actions. It combines elements from biology and engineering. First, morphological and behavioral characteristics of animals able to perform voluntary spatial actions through evolution are examined. The complexity of state-space representation and observation of multi-joint mobile robots is then described in the context of automatic control, and perception-related characteristics brought by the presence of a head are presented from the perspective of signal processing. Finally, the role of the head in locomotion and manipulation for animals and robots is discussed, paving the way for future robot design.

A whole suite of parameters is likely to influence the behavior and performance of individuals as adults, including correlations between phenotypic traits or an individual's developmental context. Here, we ask the question whether behavior and physical performance traits are correlated and how early life parameters such as birth weight, litter size, and growth can influence these traits as measured during adulthood. We studied 486 captive gray mouse lemurs (Microcebus murinus) and measured two behavioral traits and two performance traits potentially involved in two functions: exploration behavior with pull strength and agitation score with bite force. We checked for the existence of behavioral consistency in behaviors and explored correlations between behavior, performance, morphology. We analyzed the effect of birth weight, growth, and litter size, while controlling for age, sex, and body weight. Behavior and performance were not correlated with one another, but were both influenced by age. Growth rate had a positive effect on adult morphology, and birth weight significantly affected emergence latency and bite force. Grip strength was not directly affected by early life traits, but bite performance and exploration behavior were impacted by birth weight. This study shows how early life parameters impact personality and performance.

Prehension is essential for animal survival and fitness. It is involved in locomotion and feeding behavior and subject to physical and physiological constraints. Studies of prehension in primates have explored the importance of food properties and of the environment, but aging has rarely been studied although prehensile capacity may deteriorate with age in humans. To test the hypothesis that aging affects grasping abilities and to reveal possible behavioral adaptations to this, we quantified behavioral grasping strategies and pull strength in 10 young adult (2–3 yr old) and 10 aged (7–8 yr old) gray mouse lemurs (Microcebus murinus). We assessed grasping strategies in an experimental cage by quantifying grip types used to grasp static and mobile foods. We measured strength using a Kistler triaxial force platform. Our results show that 1) mobile and static foods affected individuals of different ages in similar ways; 2) older individuals used more mouth grasps than young ones; 3) aged individuals made twice as many attempts as young ones when grasping mobile food items but this difference was not significant; and 4) there were no differences in hand grip strength between age classes but young individuals showed a higher foot pull strength compared to old ones. These data suggest that the observed differences in behavior may be due to a decrease in foot grip strength, which in turn influences stability on narrow branches, forcing animals to use their hands to maintain stability and preventing them from using their hands for food-related tasks.

Objectives Humans are known to possess more complex manual abilities than other primates. However, the manual abilities of primates have not been fully explored, and we still do not know if the manipulative abilities we attribute to humans are unique. The aim of this study was to compare the manual function and performance developed by humans, gorillas and orangutans while performing the same experimental tool use task. Materials and Methods The study was conducted on 20 humans, 6 gorillas, and 7 orangutans. Each individual had to use a tool to collect food from a maze during six experimental sessions while maintaining the same unconstrained body posture condition. We quantified the different manual techniques used and the manual performance. Results Each species used different techniques. Humans used bimanual grip techniques, pad-to-pad precision grasping postures, and in-hand movements involving fingertips. Gorillas used unimanual grip techniques and simple in-hand movements while orangutans used a variety of strategies (e.g., hand or mouth). With these techniques, humans performed the task better than both gorillas and orangutans (e.g., by being quicker to collect the food). Discussion This study highlights other ways in which humans’ manual dexterity differs from that of other species and emphasizes the distinct manipulative function of orangutans. The differences between the species could be due to the differing muscular anatomy and morphology of the hands, with hand proportion possibly placing particular biomechanical constraints on each species. The differences between gorillas and orangutans could result from their different locomotor behaviors, and we hypothesize terrestriality facilitates the development of complex manipulation.

The ability to grasp an object is fundamental from an evolutionary perspective. Involved in many daily activities, grasping has been extensively studied in primates and other mammals. Yet, other groups of tetrapods, including anurans, have also evolved significant forelimb prehensile capacities that are often thought to have originated in an arboreal context. However, grasping is also observed in aquatic species. Yet, how aquatic frogs use their forelimbs to capture and manipulate prey remains largely unknown. The aim of this study is to explore how the grasping and manipulation of food items in aquatic frogs is impacted by food properties such as size and mobility. To do so we use the aquatic frog Xenopus laevis and quantified the use of the hands and fingers while processing mobile and stationary prey of different sizes (small, intermediate, and large prey). Our results show that X. laevis is able to individualize the digits and that the mobility and the length of the prey significantly influence the kind of grasping pattern used. Grasping abilities are thus not specific to terrestrial, nor arboreal species. These results illustrate how prey properties impact grasping and manipulation strategies in an aquatic frog and shed further light on the ecological contexts that may have given rise to the origin of grasping in frogs.

The feet are the only contact between the body and the substrate in limbed animals and as such they provide a crucial interface between the animal and its environment. This is especially true for bipedal and arboreal species living in a complex three-dimensional environment that likely induces strong selection on foot morphology. In birds, foot morphology is highly variable, with different orientations of the toes, making it a good model for the study of the role of functional, developmental, and phylogenetic constraints in the evolution of phenotypic diversity. Our data on the proportions of the phalanges analyzed in a phylogenetic context show that two different morphological patterns exist that depend mainly on habitat and toe orientation. In the anisodactyl foot, the hallux is the only backward-oriented toe and is enlarged in climbing species and reduced in terrestrial ones. Moreover, a proximo-distal gradient in phalanx size is observed depending on the degree of terrestriality. In the two other cases (heterodactyl and zygodactyl) that have two toes that point backward, the hallux is rather small in contrast to the other backward-pointing toe, which is enlarged. The first pattern is convergent and common among tetrapods and follows rules of skeletal development. The second pattern is unique for the clade and under muscle–morphogenetic control. In all cases, the functional result is the same tool, a pincer-like foot.

1: Here we describe a novel design to obtain three dimensional data on the movements of aquatic organisms at depths of up to 140 meters. 2: The setup consists of two synchronized high-speed cameras fixed to two articulated arms. 3: The setup was successfully used to film and quantify the locomotion of coelacanths (Latimeria chalumnae) living at a depth of about 120 meters in Sodwana Bay, South Africa. As an example, the detailed motion of the dorsal fin is presented here. 4: This setup can be used for any underwater applications that require synchronized video recordings of medium to large sized animals. This article is protected by copyright. All rights reserved.

Stone artifacts are the most numerous remains provided by early Holocene sites in Southeast Asia. They are thus of prime importance to understand better human behaviors of this region. However, they are typo-technologically difficult to characterize and consist mainly of informal flakes. This paper presents an innovative approach focusing on form and function to better assess the prehistoric use of stone tools in the region using a sample of flakes from the cave of Song Terus, Java, Indonesia. The integration of morphological description, usewear and morphometric analysis (Elliptical Fourier Analysis) allows a detailed characterization of tool use not possible with other methods. We demonstrate that a specific form of stone flake is not related to a particular function and vice versa. Our results show that tool production was not oriented towards the production of flakes of specific form, or to the production of flake blanks that could be modified by retouch but was a system where the control of flake shape was relaxed in favor of the selection of flakes suitable for particular tasks either during reduction or once core reduction had concluded.

The origin and evolution of manual grasping remain poorly understood. The ability to cling requires important grasping abilities and is essential to survive in species where the young are carried in the fur. A previous study has suggested that this behaviour could be a pre-adaptation for the evolution of fine manipulative skills. In this study we tested the co-evolution between infant carrying in the fur and manual grasping abilities in the context of food manipulation. As strepsirrhines vary in the way infants are carried (mouth vs. fur), they are an excellent model to test this hypothesis. Data on food manipulation behaviour were collected for 21 species of strepsirrhines. Our results show that fur-carrying species exhibited significantly more frequent manual grasping of food items. This study clearly illustrates the potential novel insights that a behaviour (infant carrying) that has previously been largely ignored in the discussion of the evolution of primate manipulation can bring.

Many wild primates experience long-term limb disability, and their ability to cope with disability has implications for survival and fitness. We quantified the arboreal feeding and postural behaviors of adult chimpanzees to study the consequences of physical limb disabilities. We collected behavioral data for a total of 8 mo on chimpanzees at Sebitoli, Kibale National Park, Uganda, focusing on the time spent feeding, common feeding tree species, body postures, and substrate use. Of the 51 chimpanzees we observed, 16 (31%) exhibited limb anomalies, which varied in form and severity. Disabled chimpanzees climbed as high as chimpanzees without disabilities and did not differ from nondisabled chimpanzees in the amount they used feeding tree species. Adult chimpanzees with severe hand disability spent significantly more time feeding than nondisabled individuals. In addition, manually disabled adults did not suspend themselves from branches during feeding as frequently as nondisabled adults and used larger substrates for gripping and sitting than nondisabled adults. These results indicate that disabled individuals compensate to carry out feeding activities in trees.

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International audience; Previous quantitative assessments of the crocodylians' dermal bone ornamentation (this ornamentation consists of pits and ridges) has shown that bone sculpture results in a gain in area that differs between anatomical regions: it tends to be higher on the skull table than on the snout. Therefore, a comparative phylogenetic analysis within 17 adult crocodylian specimens representative of the morphological diversity of the 24 extant species has been performed, in order to test if the gain in area due to ornamentation depends on the skull morphology, i.e. shape and size. Quantitative assessment of skull size and shape through geometric morphometrics, and of skull ornamentation through surface analyses, produced a dataset that was analyzed using phylogenetic least-squares regression. The analyses reveal that none of the variables that quantify ornamentation, be they on the snout or the skull table, is correlated with the size of the specimens. Conversely, there is more disparity in the relationships between skull conformations (longirostrine vs. brevirostrine) and ornamentation. Indeed, both parameters GApit (i.e. pit depth and shape) and OArelat (i.e. relative area of the pit set) are negatively correlated with snout elongation, whereas none of the values quantifying ornamentation on the skull table is correlated with skull conformation. It can be concluded that bone sculpture on the snout is influenced by different developmental constrains than on the skull table and is sensible to differences in the local growth ‘context' (allometric processes) prevailing in distinct skull parts. Whatever the functional role of bone ornamentation on the skull, if any, it seems to be restricted to some anatomical regions at least for the longirostrine forms that tend to lose ornamentation on the snout.

Behavior varies among individuals and is flexible within individuals. However, studies of behavioral syndromes and animal personality have demonstrated that animals can show consistency in their behavior and as such may be restricted in their behavioral responses. Like any other trait, including morphology, performance, or physiology, personality is now considered an important component of ecology and may have fitness consequences. Moreover, in some species personality correlates with other traits, as predicted in the context of a recent theoretical framework postulating that individual differences in growth and body size can affect behavior through effects on growth–mortality tradeoffs. This “pace of life” hypothesis predicts that animals that explore more should be larger and have higher growth rates than those that explore less. We tested for associations between morphology and a behavioral trait in a captive colony of gray mouse lemurs (Microcebus murinus). We used open-field tests to evaluate exploration behavior and measured a series of morphological traits in 72 individuals (32 males and 40 females). Our results show that the latency to start exploring correlates positively with adult body size and body weight at birth. These data provide evidence for a link between morphology and behavior in this species, thus supporting predictions of dispersal models but diverging from the predictions of the “pace of life” model.

The gaits of five Ostriches Struthio camelus, seven Emus Dromaius novaehollandiae, two Greater Rheas Rhea americana, two Southern Cassowaries Casuarius casuarius and one Brown kiwi Apteryx australis were filmed at zoological parks. Locomotor parameters were measured using footprints on sandy tracks and video records. Osteological measurements were made on skeletons of the pelvic limbs. All of these terrestrial birds shift from wallking to running at a relative speed below 1. However, they show two different locomotor patterns: the Brown Kiwi increases its speed by increasing its stride length, mainly by increasing the protraction angle. Its hindlimbs make a flexed jointed chain system, its centre of mass is anterior, its femurs are long and the knees act in yield whereas the distal joints act in propulsion. Other ratites, particularly Ostriches, increase their speed by increasing frequency. Their centre of mass is close to the hip, their hindlimbs have an extended jointed chain system with a short erect femur, maximizing a gravity-powered system.

Grasping is a widespread behavior among tetrapod vertebrates. In primates, the hands and feet are involved in many tasks including arboreal locomotion and food acquisition. Yet, the origin and the evolution of prehensile capacities, which are highly diversified across this group, remain open for inquiry. Some researchers suggest that grasping evolved in an arboreal habitat consisting of fine branches associated with insect predation and/or fruit and flower exploitation. However, few studies have tested the importance of arboreal conditions and diet, e.g., frugivorous, omnivorous, on the use of the hands in food grasping. The aim of this study was to link substrate use and food grasping strategies quantitatively to test hypotheses concerning primate grasping origins. We studied a species often described as a good ecological model to study the origin of grasping in primates, Microcebus murinus, and quantified its spontaneous substrate use (diameter and orientation) in an unconstrained environment while presenting them with different food types (static and mobile). We show that 1) Microcebus murinus appears to be an opportunistic rather than a specialist user of fine branches as suggested previously, at least under laboratory conditions; and 2) food properties had an impact on the use of the hands vs. the mouth, with the hands being used more for the grasping of mobile prey. Our results are consistent with hypotheses for primate origins that propose adaptations to both a narrow branch environment and visually directed prey capture with the hands. However, additional studies in the wild are needed to understand better the origin and increased use of the hands in primates grasping and manipulation.

Primates, and particularly humans, are characterized by superior manual dexterity compared with other mammals. However, drawing the biomechanical link between hand morphology/behaviour and functional capabilities in non-human primates and fossil taxa has been challenging. We present a kinematic model of thumb–index precision grip and manipulative movement based on bony hand morphology in a broad sample of extant primates and fossil hominins. The model reveals that both joint mobility and digit proportions (scaled to hand size) are critical for determining precision grip and manipulation potential, but that having either a long thumb or great joint mobility alone does not necessarily yield high precision manipulation. The results suggest even the oldest available fossil hominins may have shared comparable precision grip manipulation with modern humans. In particular, the predicted human-like precision manipulation ofAustralopithecus afarensis, approximately one million years before the first stone tools, supports controversial archaeological evidence of tool-use in this taxon.

Approximately 90% of the human population is right-handed. The emergence of this hand preference in humans is thought to be linked to the ability to execute complex tasks and habitual bipedalism. In order to test these hypotheses, the present study explored, for the first time, hand preference in relation to both body posture (seated and bipedal) and task complexity (bimanual coordination and two tool use tasks of different complexity) in bonobos (Pan paniscus). Few studies have explored the effects of both posture and task complexity on handedness, and investigations with bonobos are scarce, particularly studies on tool use. Our study aims to overcome such a gap by addressing two main questions: 1) Does a bipedal posture increase the strength of hand preference and/or create a directional bias to the use of the right hand? 2) Independent of body posture, does task complexity increase the strength of the hand preference and/or create a directional bias to the use of the right hand? Our results show that independent of body posture, the more complex the task, the more lateralization occurred. Moreover, subjects tended to be right-handed for tasks involving tool use. However, posture had no significant effect on hand preference in the tasks tested here. Therefore, for a given task, bonobos were not more lateralized in a bipedal posture than in a seated one. Task complexity might thus have contributed more than bipedal posture to the emergence of human lateralization and the preponderance of right-handedness, although a larger sample size and more data are needed to be conclusive.

In spite of the fact that the potential usefulness of bone histology in systematics has been discussed for over one and a half centuries, the presence of a phylogenetic signal in the variation of histological characters has rarely been assessed. A quantitative assessment of phylogenetic signal in bone histological characters could provide a justification for performing optimizations of these traits onto independently generated phylogenetic trees (as has been done in recent years). Here we present an investigation on the quantification of the phylogenetic signal in the following bone histological, microanatomical, and morphological traits in a sample of femora of 35 species of sauropsids: vascular density, vascular orientation, index of Haversian remodeling, cortical thickness, and cross-sectional area (bone size). For this purpose, we use two methods, regressions on distance matrices tested for significance using permutations (a Mantel test) and random tree length distribution. Within sauropsids, these bone microstructural traits have an optimal systematic value in archosaurs. In this taxon, a Mantel test shows that the phylogeny explains 81.8% of the variation of bone size and 86.2% of the variation of cortical thickness. In contrast, a Mantel test suggests that the phylogenetic signal in histological traits is weak: although the phylogeny explains 18.7% of the variation of vascular density in archosaurs, the phylogenetic signal is not significant either for vascular orientation or for the index of Haversian remodeling. However, Mantel tests seem to underestimate the proportion of variance of the dependent character explained by the phylogeny, as suggested by a PVR (phylogenetic eigenvector) analysis. We also deal with some complementary questions. First, we evaluate the functional dependence of bone vascular density on bone size by using phylogenetically independent contrasts. Second, we perform a variation partitioning analysis and show that the phylogenetic signal in bone vascular density is not a by-product of phylogentic signal in bone size. Finally, we analyze the evolution of cortical thickness in diapsids by using an optimization by squared change parsimony and discuss the functional significance of this character in terms of decreased buoyancy in crocodiles and mass saving in birds. These results are placed in the framework of the constructional morphology model, according to which the variation of a character in a clade has a historical (phylogenetic) component, a functional (adaptive) component, and a structural (architectural) component.

Serotonin (5-HT) immunoreactive (-ir) profiles within the isthmo-optic nucleus (ION) of the centrifugal visual system (CVS) were studied in the pigeon using light microscopic immunohistofluorescent and electron microscopic immunocytochemical pre-embedding techniques. The brainstem origin of the 5-HT input upon the ION was determined by combining 5-HT immunohistofluorescence (FITC) and retrograde transneuronal tracing after intraocular injection of Rhodamine beta-isothiocyanate. The light microscopic results showed that 5-HT endings were mainly localised within the neuropillar zones of the ventral ION. The 5-HT-ir cell bodies, belonging to a lateral extension of the dorsal raphe system, were observed within the same region as the centrifugal ectopic neurons (EN) underlying the ION and some displayed dendritic processes which penetrated the nucleus. Double-labeled neurons, representing 5-HT-ir afferents to the ION, were identified only within the n. linearis caudalis region of the ventral raphe. The electron microscopic results confirmed the presence of 5-HT-ir dendritic processes within the ventral part of the nucleus and showed that they were contacted by axon terminals belonging to intrinsic interneurons. The functional organisation of the ION and the possible contribution of serotonergic raphe afferents and efferents are discussed in relation to present hypotheses linking the avian CVS to mechanisms of visual attention.

Among the many hand preference studies on nonhuman primates, several have demonstrated the effect of diverse action demands on the direction and magnitude of hand preference. However, few studies have assessed hand preference in the natural repertoire of motor behaviours in nonhuman primates, especially in actions that differ in velocity. Nevertheless, velocity is involved in the coordination between the upper limb joints and could be related to cerebral hemispheric specialization. Indeed, depending on the velocity, some joints, and so some muscles, are used more than others. The purpose of this study was to quantify hand preference across various natural actions to evaluate how the nature of the action modifies hand preference in capuchin and squirrel monkeys. First, we observed seven female tufted capuchin monkeys during spontaneous foraging, performing fast actions (pounding and capturing fast-moving prey) and slow actions (picking fruit, carrying, tapping and catching slow-moving prey). Second, we observed seven squirrel monkeys performing fast actions (capturing fast-moving prey) and slow actions (picking fruit and catching slow-moving prey) in their enclosure. The results showed that (1) capturing fast-moving prey and pounding were associated with a left-hand preference and (2) slow actions were associated with variable hand preferences. Fast manual actions may elicit consistent hand preference. Given that many nonhuman primates use fast actions to capture prey, this possibility deserves further investigation. If this finding is confirmed, a novel link between motor control processes and hand preference can be pursued.

A report from the First International Phylogenetic Nomenclature Meeting recently published in Cladistics conveys several misconceptions about the PhyloCode and presents an erroneous interpretation of discussions that took place at that meeting. Contrary to Pickett’s assertions, the PhyloCode is designed to name clades, not paraphyletic groups; the rejection of ranks has never been a fundamental principle of phylogenetic nomenclature; and specifiers under the PhyloCode differ in several ways from types under rank-based nomenclature. � The Willi Hennig Society 2005.

Morphology can be adaptive through its effect on performance of an organism. The effect of performance may, however, be modulated by behavior; an organism may choose a behavioral option that does not fully utilize its maximum performance. Behavior may therefore be decoupled from morphology and performance. To gain insight into the relationships between these levels of organization, we combined morphological data on defensive structures with measures of defensive performance, and their utilization in defensive behavior. Scorpion species show significant variation in the morphology and performance of their main defensive structures; their chelae (pincers) and the metasoma ("tail") carrying the stinger. Our data show that size-corrected pinch force varies to almost two orders of magnitude among species, and is correlated with chela morphology. Chela and metasoma morphology are also correlated to the LD50 of the venom, corroborating the anecdotal rule that dangerously venomous scorpions can be recognized by their chelae and metasoma. Analyses of phylogenetic independent contrasts show that correlations between several aspects of chela and metasoma morphology, performance and behavior are present. These correlations suggest co-evolution of behavior with morphology and performance. Path analysis found a performance variable (pinch force) to partially mediate the relationship between morphology (chela aspect ratio) and behavior (defensive stinger usage). We also found a correlation between two aspects of morphology: pincer finger length correlates with the relative "thickness" (aspect ratio) of the metasoma. This suggests scorpions show a trade-off between their two main weapon complexes: the metasoma carrying the stinger, and the pedipalps carrying the chelae.

Human beings have been credited with unparalleled capabilities for digital prehension grasping. However, grasping behaviour is widespread among tetrapods. The propensity to grasp, and the anatomical characteristics that underlie it, appear in all of the major groups of tetrapods with the possible exception of terrestrial turtles. Although some features are synapomorphic to the tetrapod clade, such as well-defined digits and digital musculature, other features, such as opposable digits and tendon configurations, appear to have evolved independently in many lineages. Here we examine the incidence, functional morphology, and evolution of grasping across four major tetrapod clades. Our review suggests that the ability to grasp with the manus and pes is considerably more widespread, and ecologically and evolutionarily important, than previously thought. The morphological bases and ecological factors that govern grasping abilities may differ among tetrapods, yet the selective forces shaping them are likely similar. We suggest that further investigation into grasping form and function within and among these clades may expose a greater role for grasping ability in the evolutionary success of many tetrapod lineages. Fil: Sustaita, Diego. University Of Connecticut; Estados Unidos Fil: Pouydebat, Emmanuelle. Centre National de la Recherche Scientifique; Francia. Museum National d'Histoire Naturelle; Francia Fil: Manzano, Adriana Silvina. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina Fil: Abdala, Virginia Sara Luz. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Hertel, Fritz. California State University; Estados Unidos Fil: Herrel, Anthony. Centre National de la Recherche Scientifique; Francia. Museum National d'Histoire Naturelle; Francia

Grasping is essential for primates in numerous behaviors. A variety of different grasping techniques are used for obtaining food. Among humans, several studies have shown that the properties of the objects such as the size or the form influence grasp patterns. In addition, other works have tested the individual variability through grasping strategies and age and several studies have revealed some similarities between great apes and humans in grip types. Finally, results on hand preference are still equivocal and, for non-human primates, object parameters and age effect are rarely tested together, even though it is a methodological aspect important to consider. The study sought to determine whether grip type varied according to the age of the subject, the species (human versus chimpanzee), the size of the object and the hand used. Frame-by-frame analysis of hand contact strategies and statistical results indicated that (1) adults of both species used fewer contact strategies than juveniles and that there was a greater variability of contacts for small than for large objects (2) young juvenile chimpanzees and human children follow a similar grip types development, i.e. more frequent use of precision grips with age (3) juvenile chimpanzees used all five categories of grip and the adults used the "thumb-fingerpad(s)" more than the "precision grips" in addition to the "power grip" and (4) a right hand preference was greater for the grasping of small objects with "precision grips" in adults for both species. These results are discussed in relationship with neurology, morphology and grasping evolution.

International audience; Feeding behavior is known to be modulated as prey properties change. During prey capture, external prey properties, including size and mobility, are likely some of the most important components in predator–prey interactions. Whereas prey size has been demonstrated to elicit modulation of jaw movements during capture, how prey speed affects the approach and capture of prey remains unknown. We quantified the kinematics associated with movements of both the feeding and locomotor systems during prey capture in a lizard, Gerrhosaurus major, while facing prey differing in size and mobility (newborn mice, grasshoppers, and mealworms). Our data show that the feeding and locomotor systems were recruited differently in response to changes in the size or speed of the prey. The timing of jaw movements and of the positioning of the head are affected by changes in prey size—and speed, to a lesser extent. Changes in prey speed resulted in concomitant changes in the speed of strike and an early and greater elevation of the neck. External prey properties, and prey mobility in particular, are relevant in predator–prey interactions and elicit specific responses in different functional systems.

Evolution by natural selection has resulted in a remarkable diversity of organism morphologies that has long fascinated scientists and served to establish the first relations among species. Despite the essential role of morphology as a phenotype of species, there is not yet a formal, mathematical scheme to quantify morphological phenotype and relate it to both the genotype and the underlying developmental genetics. Herein we demonstrate that the morphological diversity in the beaks of Darwin’s Finches is quantitatively accounted for by the mathematical group of affine transformations. Specifically, we show that all beak shapes of Ground Finches (genus Geospiza ) are related by scaling transformations (a subgroup of the affine group), and the same relationship holds true for all the beak shapes of Tree, Cocos, and Warbler Finches (three distinct genera). This analysis shows that the beak shapes within each of these groups differ only by their scales, such as length and depth, which are genetically controlled by Bmp4 and Calmodulin . By measuring Bmp4 expression in the beak primordia of the species in the genus Geospiza , we provide a quantitative map between beak morphology and the expression levels of Bmp4 . The complete morphological variation within the beaks of Darwin’s finches can be explained by extending the scaling transformations to the entire affine group, by including shear transformations. Altogether our results suggest that the mathematical theory of groups can help decode morphological variation, and points to a potentially hierarchical structure of morphological diversity and the underlying developmental processes.

The evolution of the precision grips, in which an object is held between the distal surfaces of thumb and fingers and the power grip, in which an object is grasped with the palm, is poorly understood in spite of hypothesis stipulating an evolution from power toward precision grips. In human, numerous studies have shown that the external factors such as the size or the form of an object influenced grasp patterns whereas in non-human primates, those parameters are poorly known. The objective of the present study was to investigate the variation in the use of different grips according to the volume of the object for six primate species representative of the phylogeny: human, chimpanzee, orangutan, macaque, baboon and capuchin. For those species, the grasping patterns were examined during grasping of spherical objects of two different volumes. Frame-by-frame analysis of digit contact strategies indicated: (1) an effect of the species on the category of grasping whatever the volume of the object, (2) a high degree of species variability and (3) no individual difference whatever the species. These results are discussed in relation to its potential contribution to understand the evolution of grasping.

SUMMARYOnly a few studies on quadrupedal locomotion have investigated symmetrical and asymmetrical gaits in the same framework because the mechanisms underlying these two types of gait seem to be different and it took a long time to identify a common set of parameters for their simultaneous study. Moreover,despite the clear importance of the spatial dimension in animal locomotion,the relationship between temporal and spatial limb coordination has never been quantified before. We used anteroposterior sequence (APS) analysis to analyse 486 sequences from five malinois (Belgian shepherd) dogs moving at a large range of speeds (from 0.4 to 10.0 m s–1) to compare symmetrical and asymmetrical gaits through kinematic and limb coordination parameters. Considerable continuity was observed in cycle characteristics,from walk to rotary gallop, but at very high speeds an increase in swing duration reflected the use of sagittal flexibility of the vertebral axis to increase speed. This change occurred after the contribution of the increase in stride length had become the main element driving the increase in speed– i.e. when the dogs had adopted asymmetrical gaits. As the left and right limbs of a pair are linked to the same rigid structure, spatial coordination within pairs of limbs reflected the temporal coordination within pairs of limbs whatever the speed. By contrast, the relationship between the temporal and spatial coordination between pairs of limb was found to depend on speed and trunk length. For trot and rotary gallop, this relationship was thought also to depend on the additional action of trunk flexion and leg angle at footfall.

We analyzed 51 adult pelvis (25 women, 26 men) by the software DE-VISU conceived by one of us, J. Hecquet. It allows the description of the pelvis as the keystone of the articular system linking vertebral column, pelvis and lower limbs. The variations of the sagittal pelvic parameter, “angle of incidence” (mean 54°), are mainly responsible of individual variation in sagittal spine curves. The extreme values of incidence (32°-76°) correspond to pathological situations. This angle was discovered by radiological observations. We elucidated the morphological components of this angle : a high angle of incidence, associated with a strong lumbar curvature, is correlated to a strong sacral slope, a curved sacrum, a low position of the sacrum in relation to iliac crests. A low angle of incidence, associated with a weak lumbar curvature, is correlated to a weak sacral slope, a rectilinear sacrum, a high sacral position in relation to iliac crests. The performances of the software DE-VISU gave results far superior to those we obtained by geometric morphometry. It benefits from previous studies and publications of the authors on rachis, pelvis and lower limb. Ability to represent each pelvic joint, particularly the two coxo-femoral joints, was crucial. Calculation of centers, radii, directional axes and covering arches of the acetabula allowed to quantify the parameters of their three-dimensional orientation. We put in light for the fist time these parameters. The angles of acetabular anteversion, inclination and covering arch revealed their high variations. These parameters establish the relationship between pelvis and mechanical axes of lower limbs through the femoral angles : angle of anteversion of the femoral neck, cervico-diaphyseal angle and bicondylar angle. DE-VISU introduced for the first time a “systemic analysis” of the pelvis : it is no longer considered as an isolated object but as a piece of an integrated articular system.

More data are provided on the recently described temnospondyl Iberospondylus schultzei from the Upper Carboniferous (Stephanian C) of the Spanish Puertollano Basin. It represents the only known occurrence of a Paleozoic stegocephalian in a Spanish basin. This taxon appears to be more closely related to eryopoids and dissorophoids than to edopoids, as shown by four synapomorphies. However, decay index and bootstrap analyses show that the presented phylogeny, like other recently published phylogenies of temnospondyls, is not robust. Recently published phylogenetic data do not resolve the position of Dendrerpeton in temnospondyl phylogeny. Iberospondylus appears to have lived in the coastal marine environment in which it was preserved. The Spanish material supports the suggestion that the temnospondyls were sometimes coastal, near-marine animals. The widely held idea that many temnospondyls possessed a tympanum is poorly documented; the stapes of this group is always more massive than that of similarly-sized extant tetrapods that possess a tympanum. Other arguments presented to support the presence of a tympanum in temnospondyls appear to be invalid. Therefore, the widely held thesis that a tympanum was present in temnospondyls is questioned.

This study aims to explore a new method for the comparison of hind limb movements in two types of athletic specialities (sprint and middle-distance running). The Procrustes method, which combines quantitative, visual and statistical features, is applied to the shape of the ankle and knee cyclograms by considering as a fixed point the mobile hip landmark. Procrustes superimposition of twenty-five cyclograms (10 for sprinters and 15 for middle-distance runners) was supplemented by statistical procedures (principal component analysis, discriminant function) to seek the main invariants and variant key-events of the dynamics of the running cycle. Cyclogram patterns are more a response to the technical requirements of the athletic speciality than to constraints imposed by morphology (hind limb length) and the runner's speed. The results provided useful gait indicators which may be used by trainers and athletes for assessment and improvement of running style aiming at strategies optimally adapted to the discipline.