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Nature Communications Jan 2021Humans maintain extensive social ties of varying preferences, providing a range of opportunities for beneficial cooperative exchange that may promote collective action...
Humans maintain extensive social ties of varying preferences, providing a range of opportunities for beneficial cooperative exchange that may promote collective action and our unique capacity for large-scale cooperation. Similarly, non-human animals maintain differentiated social relationships that promote dyadic cooperative exchange, but their link to cooperative collective action is little known. Here, we investigate the influence of social relationship properties on male and female chimpanzee participations in a costly form of group action, intergroup encounters. We find that intergroup encounter participation increases with a greater number of other participants as well as when participants are maternal kin or social bond partners, and that these effects are independent from one another and from the likelihood to associate with certain partners. Together, strong social relationships between kin and non-kin facilitate group-level cooperation in one of our closest living relatives, suggesting that social bonds may be integral to the evolution of cooperation in our own species.
Topics: Animals; Behavior, Animal; Cooperative Behavior; Female; Group Processes; Humans; Male; Pan troglodytes; Social Behavior; Social Dominance
PubMed: 33483482
DOI: 10.1038/s41467-020-20709-9 -
Philosophical Transactions of the Royal... Oct 2010Until recently, the last common ancestor of African apes and humans was presumed to resemble living chimpanzees and bonobos. This was frequently extended to their... (Review)
Review
Until recently, the last common ancestor of African apes and humans was presumed to resemble living chimpanzees and bonobos. This was frequently extended to their locomotor pattern leading to the presumption that knuckle-walking was a likely ancestral pattern, requiring bipedality to have emerged as a modification of their bent-hip-bent-knee gait used during erect walking. Research on the development and anatomy of the vertebral column, coupled with new revelations from the fossil record (in particular, Ardipithecus ramidus), now demonstrate that these presumptions have been in error. Reassessment of the potential pathway to early hominid bipedality now reveals an entirely novel sequence of likely morphological events leading to the emergence of upright walking.
Topics: Animals; Biomechanical Phenomena; Fossils; Gait; Hip; Hominidae; Humans; Knee; Lumbar Vertebrae; Pan troglodytes
PubMed: 20855303
DOI: 10.1098/rstb.2010.0112 -
PloS One 2014Endogenous retroviruses (ERVs), eukaryotic transposable elements, exist as proviruses in vertebrates including primates and contribute to genomic changes during the...
Endogenous retroviruses (ERVs), eukaryotic transposable elements, exist as proviruses in vertebrates including primates and contribute to genomic changes during the evolution of their host genomes. Many studies about ERVs have focused on the elements residing in the human genome but only a few studies have focused on the elements which exist in non-human primate genomes. In this study, we identified 256 chimpanzee-specific endogenous retrovirus copies (PtERVs: Pan troglodyte endogenous retroviruses) from the chimpanzee reference genome sequence through comparative genomics. Among the chimpanzee-specific ERV copies, 121 were full-length chimpanzee-specific ERV elements while 110 were chimpanzee-specific solitary LTR copies. In addition, we found eight potential retrotransposition-competent full-length chimpanzee-specific ERV copies containing an intact env gene, and two of them were polymorphic in chimpanzee individuals. Through computational analysis and manual inspection, we found that some of the chimpanzee-specific ERVs have propagated via non-classical PtERV insertion (NCPI), and at least one of the PtERVs may have played a role in creating an alternative transcript of a chimpanzee gene. Based on our findings in this study, we state that the chimpanzee-specific ERV element is one of the sources of chimpanzee genomic variations, some of which might be related to the alternative transcripts in the chimpanzee population.
Topics: Animals; Endogenous Retroviruses; Genetic Variation; Genome; Humans; Pan troglodytes; Terminal Repeat Sequences
PubMed: 24987855
DOI: 10.1371/journal.pone.0101195 -
American Journal of Physical... Dec 2017Studies on grasping and limb posture during arboreal locomotion in great apes in their natural environment are scarce and thus, attempts to correlate behavioral and...
OBJECTIVES
Studies on grasping and limb posture during arboreal locomotion in great apes in their natural environment are scarce and thus, attempts to correlate behavioral and habitat differences with variation in morphology are limited. The aim of this study is to compare hand use and forelimb posture during vertical climbing in wild, habituated mountain gorillas (Gorilla beringei beringei) and semi-free-ranging chimpanzees (Pan troglodytes) to assess differences in the climbing styles that may relate to variation in hand or forelimb morphology and body size.
MATERIALS AND METHODS
We investigated hand use and forelimb posture during both ascent and descent vertical climbing in 15 wild mountain gorillas and eight semi-free-ranging chimpanzees, using video records obtained ad libitum.
RESULTS
In both apes, forelimb posture was correlated with substrate size during both ascent and descent climbing. While climbing, both apes used power grips and diagonal power grips, including three different thumb postures. Mountain gorillas showed greater ulnar deviation of the wrist during vertical descent than chimpanzees, and the thumb played an important supportive role when gorillas vertically descended lianas.
DISCUSSION
We found that both apes generally had the same grip preferences and used similar forelimb postures on supports of a similar size, which is consistent with their overall similarity in hard and soft tissue morphology of the hand and forelimb. However, some species-specific differences in morphology appear to elicit slightly different grasping strategies during vertical climbing between mountain gorillas and chimpanzees.
Topics: Animals; Anthropology, Physical; Female; Forelimb; Gorilla gorilla; Hand; Locomotion; Male; Pan troglodytes; Posture; Species Specificity
PubMed: 28872656
DOI: 10.1002/ajpa.23303 -
American Journal of Primatology Dec 2009The two species of Pan, bonobos and common chimpanzees, have been reported to have different social organization, cognitive and linguistic abilities and motor skill,... (Comparative Study)
Comparative Study
The two species of Pan, bonobos and common chimpanzees, have been reported to have different social organization, cognitive and linguistic abilities and motor skill, despite their close biological relationship. Here, we examined whether bonobos and chimpanzee differ in selected brain regions that may map to these different social and cognitive abilities. Eight chimpanzees and eight bonobos matched on age, sex and rearing experiences were magnetic resonance images scanned and volumetric measures were obtained for the whole brain, cerebellum, striatum, motor-hand area, hippocampus, inferior frontal gyrus and planum temporale. Chimpanzees had significantly larger cerebellum and borderline significantly larger hippocampus and putamen, after adjusting for brain size, compared with bonobos. Bonobos showed greater leftward asymmetries in the striatum and motor-hand area compared with chimpanzees. No significant differences in either the volume or lateralization for the so-called language homologs were found between species. The results suggest that the two species of Pan are quite similar neurologically, though some volumetric and lateralized differences may reflect inherent differences in social organization, cognition and motor skills.
Topics: Animal Communication; Animals; Brain; Female; Magnetic Resonance Imaging; Male; Motor Skills; Organ Size; Pan paniscus; Pan troglodytes; Social Behavior
PubMed: 19760676
DOI: 10.1002/ajp.20741 -
Philosophical Transactions of the Royal... Nov 2013The chimpanzee (Pan troglodytes) is well-known in both nature and captivity as an impressive maker and user of tools, but recently the New Caledonian crow (Corvus... (Comparative Study)
Comparative Study Review
The chimpanzee (Pan troglodytes) is well-known in both nature and captivity as an impressive maker and user of tools, but recently the New Caledonian crow (Corvus moneduloides) has been championed as being equivalent or superior to the ape in elementary technology. I systematically compare the two taxa, going beyond simple presence/absence scoring of tool-using and -making types, on four more precise aspects of material culture: (i) types of associative technology (tools used in combination); (ii) modes of tool making; (iii) modes of tool use; and (iv) functions of tool use. I emphasize tool use in nature, when performance is habitual or customary, rather than in anecdotal or idiosyncratic. On all four measures, the ape shows more variety than does the corvid, especially in modes and functions that go beyond extractive foraging. However, more sustained field research is required on the crows before this contrast is conclusive.
Topics: Animals; Crows; Pan troglodytes; Tool Use Behavior
PubMed: 24101630
DOI: 10.1098/rstb.2012.0422 -
Current Biology : CB Jul 2014Chimpanzees' use of gesture was described in the first detailed field study [1, 2], and natural use of specific gestures has been analyzed [3-5]. However, it was...
Chimpanzees' use of gesture was described in the first detailed field study [1, 2], and natural use of specific gestures has been analyzed [3-5]. However, it was systematic work with captive groups that revealed compelling evidence that chimpanzees use gestures to communicate in a flexible, goal-oriented, and intentional fashion [6-8], replicated across all great ape species in captivity [9-17] and chimpanzees in the wild [18, 19]. All of these aspects overlap with human language but are apparently missing in most animal communication systems, including great ape vocalization, where extensive study has produced meager evidence for intentional use ([20], but see [21, 22]). Findings about great ape gestures spurred interest in a potential common ancestral origin with components of human language [23-25]. Of particular interest, given the relevance to language origins, is the question of what chimpanzees intend their gestures to mean; surprisingly, the matter of what the intentional signals are used to achieve has been largely neglected. Here we present the first systematic study of meaning in chimpanzee gestural communication. Individual gestures have specific meanings, independently of signaler identity, and we provide a partial "lexicon"; flexibility is predominantly in the use of multiple gestures for a specific meaning. We distinguish a range of meanings, from simple requests associated with just a few gestures to broader social negotiation associated with a wider range of gesture types. Access to a range of alternatives may increase communicative subtlety during important social negotiations.
Topics: Animal Communication; Animals; Gestures; Pan troglodytes
PubMed: 24998524
DOI: 10.1016/j.cub.2014.05.066 -
Nature Communications Aug 2017In contrast to a wealth of human studies, little is known about the ontogeny and consistency of empathy-related capacities in other species. Consolation-post-conflict...
In contrast to a wealth of human studies, little is known about the ontogeny and consistency of empathy-related capacities in other species. Consolation-post-conflict affiliation from uninvolved bystanders to distressed others-is a suggested marker of empathetic concern in non-human animals. Using longitudinal data comprising nearly a decade of observations on over 3000 conflict interactions in 44 chimpanzees (Pan troglodytes), we provide evidence for relatively stable individual differences in consolation behaviour. Across development, individuals consistently differ from one another in this trait, with higher consolatory tendencies predicting better social integration, a sign of social competence. Further, similar to recent results in other ape species, but in contrast to many human self-reported findings, older chimpanzees are less likely to console than are younger individuals. Overall, given the link between consolation and empathy, these findings help elucidate the development of individual socio-cognitive and -emotional abilities in one of our closest relatives.Non-human animals are known to exhibit behaviours suggestive of empathy, but the development and maintenance of these traits is unexplored. Here, Webb and colleagues quantify individual consolation tendencies over 10 years across two chimpanzee groups and show evidence of consistent 'empathetic personalities'.
Topics: Aggression; Animals; Emotions; Empathy; Female; Grooming; Male; Pan troglodytes; Social Behavior; Time Factors
PubMed: 28819207
DOI: 10.1038/s41467-017-00360-7 -
Scientific Reports Dec 2020Advances in the field of social network analysis facilitate the creation of multiplex networks where several interaction types can be analysed simultaneously. In order...
Advances in the field of social network analysis facilitate the creation of multiplex networks where several interaction types can be analysed simultaneously. In order to test the potential benefits of this approach, we investigated the sociability of atypically raised chimpanzees by constructing and analysing 4-layered multiplex networks of two groups of former pet and entertainment chimpanzees (Pan troglodytes). These networks are based on four social interaction types (stationary vicinity, affiliative behaviour, allogrooming, passive close proximity) representing low- to high-level interaction types in terms of sociability. Using the tools provided by the MuxViz software, we could assess and compare the similarity and information gain of each these social interaction types. We found some social interaction types to be more similar than other ones. However, each social interaction type imparted different information. We also tested for a possible impact of the chimpanzees' biographical background on the social interaction types and found affiliative behaviour as well as allogrooming to be affected by adverse early life experiences. We conclude that this multiplex approach provides a more realistic framework giving detailed insight into the sociability of these chimpanzees and can function as a tool to support captive care management decisions.
Topics: Animals; Confidence Intervals; Female; Linear Models; Male; Pan troglodytes; Pets; Social Behavior
PubMed: 33262388
DOI: 10.1038/s41598-020-77950-x -
American Journal of Physical... Jun 2019The emergence of human-unique cognitive abilities has been linked to our species' extended juvenile period. Comparisons of cognitive development across species can...
OBJECTIVES
The emergence of human-unique cognitive abilities has been linked to our species' extended juvenile period. Comparisons of cognitive development across species can provide new insights into the evolutionary mechanisms shaping cognition. This study examined the development of different components of spatial memory, cognitive mechanisms that support complex foraging, by comparing two species with similar life history that vary in wild ecology: bonobos (Pan paniscus) and chimpanzees (Pan troglodytes).
MATERIALS AND METHODS
Spatial memory development was assessed using a cross-sectional experimental design comparing apes ranging from infancy to adulthood. Study 1 tested 73 sanctuary-living apes on a task examining recall of a single location after a 1-week delay, compared to an earlier session. Study 2 tested their ability to recall multiple locations within a complex environment. Study 3 examined a subset of individuals from Study 2 on a motivational control task.
RESULTS
In Study 1, younger bonobos and chimpanzees of all ages exhibited improved performance in the test session compared to their initial learning experience. Older bonobos, in contrast, did not exhibit a memory boost in performance after the delay. In Study 2, older chimpanzees exhibited an improved ability to recall multiple locations, whereas bonobos did not exhibit any age-related differences. In Study 3, both species were similarly motivated to search for food in the absence of memory demands.
DISCUSSION
These results indicate that closely related species with similar life history characteristics can exhibit divergent patterns of cognitive development, and suggests a role of socioecological niche in shaping patterns of cognition in Pan.
Topics: Aging; Animals; Anthropology, Physical; Biological Evolution; Cognition; Female; Male; Pan paniscus; Pan troglodytes; Spatial Memory
PubMed: 30973969
DOI: 10.1002/ajpa.23833