Publications

the nature of prosociality in chimpanzees.	an important debate centres around the nature of prosociality in nonhuman primates. chimpanzees help other individuals in some experimental settings, yet they do not readily share food. one solution to this paradox is that they are motivated to help others provided there are no competing interests. however, benefits to recipients could arise as by-products of testing. here we report two studies that separate by-product from intended helping in chimpanzees using a go/no-go paradigm. actors in one ...	2016	27996969
sequential information in a great ape utterance.	birdsong is a prime example of acoustically sophisticated vocal behaviour, but its complexity has evolved mainly through sexual selection to attract mates and repel sexual rivals. in contrast, non-human primate calls often mediate complex social interactions, but are generally regarded as acoustically simple. here, we examine arguably the most complex call in great ape vocal communication, the chimpanzee (pan troglodytes schweinfurthii) 'pant hoot'. this signal consists of four acoustically dist ...	2016	27910886
assessing the manipulative potentials of monkeys, apes and humans from hand proportions: implications for hand evolution.	the hand structure possesses a greater potential for performing manipulative skills than is typically observed, whether in humans or non-human anthropoids. however, a precise assessment of the potential manipulative skills of hands has been challenging, which hampers our understanding of the evolution of manipulative abilities in anthropoid hands. here, we establish a functional model to quantitatively infer the manipulative potentials of anthropoid hands based on hand proportions. our results r ...	2016	27903877
limb bone structural proportions and locomotor behavior in a.l. 288-1 ("lucy").	while there is broad agreement that early hominins practiced some form of terrestrial bipedality, there is also evidence that arboreal behavior remained a part of the locomotor repertoire in some taxa, and that bipedal locomotion may not have been identical to that of modern humans. it has been difficult to evaluate such evidence, however, because of the possibility that early hominins retained primitive traits (such as relatively long upper limbs) of little contemporaneous adaptive significance ...	2016	27902687
getting to the bottom of face processing. species-specific inversion effects for faces and behinds in humans and chimpanzees (pan troglodytes).	for social species such as primates, the recognition of conspecifics is crucial for their survival. as demonstrated by the 'face inversion effect', humans are experts in recognizing faces and unlike objects, recognize their identity by processing it configurally. the human face, with its distinct features such as eye-whites, eyebrows, red lips and cheeks signals emotions, intentions, health and sexual attraction and, as we will show here, shares important features with the primate behind. chimpa ...	2016	27902685
the effects of tradition on problem solving by two wild populations of bearded capuchin monkeys in a probing task.	the effects of culture on individual cognition have become a core issue among cultural primatologists. field studies with wild populations provide evidence on the role of social cues in the ontogeny of tool use in non-human primates, and on the transmission of such behaviours over generations through socially biased learning. recent experimental studies have shown that cultural knowledge may influence problem solving in wild populations of chimpanzees. here, we present the results from a field e ...	2016	27881763
a human reproductive approach to the study of infertility in chimpanzees: an experience at leon's zoological park, mexico.	great apes are mammals close to humans in their genetic, behavioral, social and evolutionary characteristics and new genomic information is revolutionizing our understanding of evolution in primates. however, all these species are endangered. while there are many global programs to protect these species, the international union for conservation of nature (iucn) projects that in a near future the wild populations will decrease significantly. nowadays, the relevance of captive populations of great ...	2016	27872723
nut cracking tools used by captive chimpanzees (pan troglodytes) and their comparison with early stone age percussive artefacts from olduvai gorge.	we present the results of a series of experiments at the kumamoto sanctuary in japan, in which captive chimpanzees (pan troglodytes) performed several nut cracking sessions using raw materials from olduvai gorge, tanzania. we examined captive chimpanzee pounding tools using a combination of technological analysis, use-wear distribution, and micro-wear analysis. our results show specific patterns of use-wear distribution across the active surfaces of pounding tools, which reveal some similarities ...	2016	27870877
review of in vivo bone strain studies and finite element models of the zygomatic complex in humans and nonhuman primates: implications for clinical research and practice.	the craniofacial skeleton is often described in the clinical literature as being comprised of vertical bony pillars, which transmit forces from the toothrow to the neurocranium as axial compressive stresses, reinforced transversely by buttresses. here, we review the literature on bony microarchitecture, in vivo bone strain, and finite-element modeling of the facial skeleton of humans and nonhuman primates to address questions regarding the structural and functional existence of facial pillars an ...	2016	27870351
elastic properties of chimpanzee craniofacial cortical bone.	relatively few assessments of cranial biomechanics formally take into account variation in the material properties of cranial cortical bone. our aim was to characterize the elastic properties of chimpanzee craniofacial cortical bone and compare these to the elastic properties of dentate human craniofacial cortical bone. from seven cranial regions, 27 cylindrical samples were harvested from each of five chimpanzee crania. assuming orthotropy, axes of maximum stiffness in the plane of the cortical ...	2016	27870344
the biomechanics of zygomatic arch shape.	mammalian zygomatic arch shape is remarkably variable, ranging from nearly cylindrical to blade-like in cross section. based on geometry, the arch can be hypothesized to be a sub-structural beam whose ability to resist deformation is related to cross sectional shape. we expect zygomatic arches with different cross sectional shapes to vary in the degree to which they resist local bending and torsion due to the contraction of the masseter muscle. a stiffer arch may lead to an increase in the relat ...	2016	27870343
genomics: disclose the influence of human specific genetic variation on the evolution and development of cerebral cortex.	cerebral cortex, whose complexity of structure and function has derived from human specific genetic variation, is the most advanced nerve center of human, controlling the cognitive ability which distinguishes human from any other creatures. using genomics technology, molecular mechanisms of cerebral cortex development and evolution have been disclosed. in this review, we summarize how genomics technologies are used in exploring the influence of human specific genetic variation on cerebral cortex ...	2016	27867146
reflections of the social environment in chimpanzee memory: applying rational analysis beyond humans.	in cognitive science, the rational analysis framework allows modelling of how physical and social environments impose information-processing demands onto cognitive systems. in humans, for example, past social contact among individuals predicts their future contact with linear and power functions. these features of the human environment constrain the optimal way to remember information and probably shape how memory records are retained and retrieved. we offer a primer on how biologists can apply ...	2016	27853606
play-solicitation gestures in chimpanzees in the wild: flexible adjustment to social circumstances and individual matrices.	social play is a frequent behaviour in great apes and involves sophisticated forms of communicative exchange. while it is well established that great apes test and practise the majority of their gestural signals during play interactions, the influence of demographic factors and kin relationships between the interactants on the form and variability of gestures are relatively little understood. we thus carried out the first systematic study on the exchange of play-soliciting gestures in two chimpa ...	2016	27853603
distribution of a chimpanzee social custom is explained by matrilineal relationship rather than conformity.	high-arm grooming is a form of chimpanzee grooming in which two individuals mutually groom while each raising one arm. palm-to-palm clasping (ppc) is a distinct style of high-arm grooming in which the grooming partners clasp each other's raised palms. in wild communities, samples of at least 100 observed dyads grooming with raised hands showed ppc frequencies varying from <5% (m group, mahale) to >30% dyads grooming (kanyawara, kibale), and in a large free-ranging sanctuary group, the frequency ...	2016	27839974
reply to schmidt and tomasello: chimpanzees as natural team-players.		2016	27791163
how chimpanzees cooperate: if dominance is artificially constrained.		2016	27791161
social support reduces stress hormone levels in wild chimpanzees across stressful events and everyday affiliations.	stress is a major cause of poor health and mortality in humans and other social mammals. close social bonds buffer stress, however much of the underlying physiological mechanism remains unknown. here, we test two key hypotheses: bond partner effects occur only during stress (social buffering) or generally throughout daily life (main effects). we assess urinary glucocorticoids (ugc) in wild chimpanzees, with or without their bond partners, after a natural stressor, resting or everyday affiliation ...	2016	27802260
the impact of linked selection in chimpanzees: a comparative study.	levels of nucleotide diversity vary greatly across the genomes of most species owing to multiple factors. these include variation in the underlying mutation rates, as well as the effects of both direct and linked selection. fundamental to interpreting the relative importance of these forces is the common observation of a strong positive correlation between nucleotide diversity and recombination rate. while indeed observed in humans, the interpretation of this pattern has been difficult in the ab ...	2016	27678122
broader impacts: international implications and integrative ethical consideration of policy decisions about us chimpanzee research.	recent decisions and unprecedented evaluative processes about research with chimpanzees (pan troglodytes) by the us national institutes of health (nih) continue to attract widespread attention by the public, media, and scientific community. over the past 5 years, actions by the nih and the united states fish and wildlife services, have significantly truncated valuable scientific research and jeopardized future research. from a global perspective, the decisions have broad consequences for researc ...	2016	27434183
chimpanzees in an anthropogenic landscape: examining food resources across habitat types at bossou, guinea, west africa.	many primate populations occur outside protected areas in fragmented anthropogenic landscapes. empirical data on the ecological characteristics that define an anthropogenic landscape are urgently required if conservation initiatives in such environments are to succeed. the main objective of our study was to determine the composition and availability of chimpanzee (pan troglodytes verus) food resources across fine spatial scales in the anthropogenic landscape of bossou, guinea, west africa. we ex ...	2016	27332064
divergence and rewiring of regulatory networks for neural development between human and other species.	neural and brain development in human and other mammalian species are largely similar, but distinct features exist at the levels of macrostructure and underlying genetic control. comparative studies of epigenetic regulation and transcription factor (tf) binding in humans, chimpanzees, rodents, and other species have found large differences in gene regulatory networks. a recent analysis of the cistromes of rest/nrsf, a critical transcriptional regulator for the nervous system, demonstrated that r ...	2016	27900343
elevation of alanine aminotransferase activity occurs after activation of the cell-death signaling initiated by pattern-recognition receptors ‎but before activation of cytolytic effectors in nk or cd8+ t cells in the liver during acute hcv infection.	pattern-recognition receptors (prrs) promote host defenses against hcv infection by binding to their corresponding adapter molecules leading to the initiation of innate immune responses including cell death. we investigated the expression of prr genes, biomarkers of liver cell-death, and t cell and nk cell activation/inhibition-related genes in liver and serum obtained from three experimentally infected chimpanzees with acute hcv infection, and analyzed the correlation between gene expression le ...	2016	27788241
the molecular basis of human brain evolution.	humans are a remarkable species, especially because of the remarkable properties of their brain. since the split from the chimpanzee lineage, the human brain has increased three-fold in size and has acquired abilities for vocal learning, language and intense cooperation. to better understand the molecular basis of these changes is of great biological and biomedical interest. however, all the about 16 million fixed genetic changes that occurred during human evolution are fully correlated with all ...	2016	27780052
foundations of cumulative culture in apes: improved foraging efficiency through relinquishing and combining witnessed behaviours in chimpanzees (pan troglodytes).	a vital prerequisite for cumulative culture, a phenomenon often asserted to be unique to humans, is the ability to modify behaviour and flexibly switch to more productive or efficient alternatives. here, we first established an inefficient solution to a foraging task in five captive chimpanzee groups (n = 19). three groups subsequently witnessed a conspecific using an alternative, more efficient, solution. when participants could successfully forage with their established behaviours, most indivi ...	2016	27775061
the apportionment of tooth size and its implications in australopithecus sediba versus other plio-pleistocene and recent african hominins.	australopithecus sediba is characterized further by providing formerly unpublished and refined mesiodistal and buccolingual crown measurements in the mh1 and mh2 specimens. after size correction, these data were compared with those in other fossil and recent samples to facilitate additional insight into diachronic hominin affinities.	2016	27402184
antibody responses to prime-boost vaccination with an hiv-1 gp145 envelope protein and chimpanzee adenovirus vectors expressing hiv-1 gp140.	over 2 million individuals are infected with hiv type 1 (hiv-1) each year, yet an effective vaccine remains elusive. the most successful hiv-1 vaccine to date demonstrated 31% efficacy. immune correlate analyses associated hiv-1 envelope (env)-specific antibodies with protection, thus providing a path toward a more effective vaccine. we sought to test the antibody response from novel prime-boost vaccination with a chimpanzee-derived adenovirus (adc) vector expressing a subtype c env glycoprotein ...	2016	27525550
lateralization and performance asymmetries in the termite fishing of wild chimpanzees in the goualougo triangle, republic of congo.	the nearly universal right hand preference manifested by human populations is one of the most pronounced manifestations of population-level lateralization. morphological and archeological evidence indicate that this behavioral specialization may have emerged among our hominin ancestors. whether population-level behavioral asymmetries are evident in non-human animals remains a topic of considerable scientific debate, with the most consistent evidence of population-level trends emerging from studi ...	2016	27310151
chimpanzee females queue but males compete for social status.	dominance hierarchies are widespread in animal social groups and often have measureable effects on individual health and reproductive success. dominance ranks are not static individual attributes, however, but instead are influenced by two independent processes: 1) changes in hierarchy membership and 2) successful challenges of higher-ranking individuals. understanding which of these processes dominates the dynamics of rank trajectories can provide insights into fitness benefits of within-sex co ...	2016	27739527
genome sequences of polyomaviruses from the wild-living red colobus (piliocolobus badius) and western chimpanzee (pan troglodytes verus).	we identified with pcr and sequencing the full genomes of the recently discovered pan troglodytes verus polyomavirus 8 and piliocolobus badius polyomavirus 2 in a western chimpanzee and a western red colobus free-ranging in taï national park of côte d'ivoire.	2016	27738028
a single nucleotide polymorphism in human apobec3c enhances restriction of lentiviruses.	humans express seven human apobec3 proteins, which can inhibit viruses and endogenous retroelements through cytidine deaminase activity. the seven paralogs differ in the potency of their antiviral effects, as well as in their antiviral targets. one apobec3, apobec3c, is exceptional as it has been found to only weakly block viruses and endogenous retroelements compared to other apobec3s. however, our positive selection analyses suggest that apobec3c has played a role in pathogen defense during pr ...	2016	27732658
human lice in paleoentomology and paleomicrobiology.	lice are a classic example of cospeciation. human lice confirm this cospeciation with lice specialized in hominids which differ from those of gorillas and chimpanzees. head lice and body lice seem to belong to closely related species with different ecotypes and a different geographical distribution which may reflect population movements. paleo-entomology allows us in some cases to trace the migrations of archaic human populations. the analysis of lice found on mummies in egypt and south america ...	2016	27726759
tool transfers are a form of teaching among chimpanzees.	teaching is a form of high-fidelity social learning that promotes human cumulative culture. although recently documented in several nonhuman animals, teaching is rare among primates. in this study, we show that wild chimpanzees (pan troglodytes troglodytes) in the goualougo triangle teach tool skills by providing learners with termite fishing probes. tool donors experienced significant reductions in tool use and feeding, while tool recipients significantly increased their tool use and feeding af ...	2016	27725706
chimpanzees can visually perceive differences in the freshness of foods.	colour vision in primates is believed to be an adaptation for finding ripe fruit and young leaves. the contribution of the luminance distribution, which influences how humans evaluate the freshness of food, has not been explored with respect to the detection of subtle distinctions in food quality in non-human primates. we examined how chimpanzees, which are closely related to humans, perceive the freshness of foods. the findings suggest that chimpanzees were able to choose fresher cabbage based ...	2016	27708365
neocortical grey matter distribution underlying voluntary, flexible vocalizations in chimpanzees.	vocal learning is a key property of spoken language, which might also be present in nonhuman primate species, such as chimpanzees (pan troglodytes), to a limited degree. while understanding the origins of vocal learning in the primate brain may help shed light on the evolution of speech and language, little is still known regarding the neurobiological correlates of vocal flexibility in nonhuman primates. the current study used voxel-based morphometry (vbm) to assess whether the cerebral cortex o ...	2016	27703216
disruption of an evolutionarily novel synaptic expression pattern in autism.	cognitive defects in autism spectrum disorder (asd) include socialization and communication: key behavioral capacities that separate humans from other species. here, we analyze gene expression in the prefrontal cortex of 63 autism patients and control individuals, as well as 62 chimpanzees and macaques, from natal to adult age. we show that among all aberrant expression changes seen in asd brains, a single aberrant expression pattern overrepresented in genes involved synaptic-related pathways is ...	2016	27685936
differences and similarities between human and chimpanzee neural progenitors during cerebral cortex development.	human neocortex expansion likely contributed to the remarkable cognitive abilities of humans. this expansion is thought to primarily reflect differences in proliferation versus differentiation of neural progenitors during cortical development. here, we have searched for such differences by analysing cerebral organoids from human and chimpanzees using immunohistofluorescence, live imaging, and single-cell transcriptomics. we find that the cytoarchitecture, cell type composition, and neurogenic ge ...	2016	27669147
from stem cells to comparative corticogenesis: a bridge too far?	it has been hypothesized that the higher number of neurons in human cortex compared to the chimpanzee and other primate species is key to high cognitive function. are human cortical precursors endowed with specific properties that drive greater neuronal expansion than in other non-human primates? otani et al. 2016 addressed this issue taking advantage of comparative in vitro corticogenesis models based on human, chimpanzee and macaque pluripotent stem cells. clonal analysis revealed a heterochro ...	2016	27668246
fifteen new species of penicillium.	we introduce 15 new species of penicillium isolated from a diverse range of locations, including canada, costa rica, germany, italy, new zealand, tanzania, usa and the dry valleys of antarctica, from a variety of habitats, including leaf surfaces in tropical rain forests, soil eaten by chimpanzees, infrabuccal pockets of carpenter ants, intestinal contents of caterpillars and soil. the new species are classified in sections aspergilloides (1), canescentia (2), charlesia (1), exilicaulis (3), lan ...	2016	27616792
a partial e3 deletion in replication-defective adenoviral vectors allows for stable expression of potentially toxic transgene products.	adenovirus (ad) is used extensively for construction of viral vectors, most commonly with deletion in its e1 and/or e3 genomic regions. previously, our attempts to insert envelope proteins (env) of hiv-1 into such vectors based on chimpanzee-derived ad (adc) viruses were thwarted. here, we describe that genetic instability of an e1- and e3-deleted adc vector of serotype c6 expressing env of hiv-1 can be overcome by reinsertion of e3 sequences with anti-apoptotic activities. this partial e3 delet ...	2016	27604324
familiar face + novel face = familiar face? representational bias in the perception of morphed faces in chimpanzees.	highly social animals possess a well-developed ability to distinguish the faces of familiar from novel conspecifics to induce distinct behaviors for maintaining society. however, the behaviors of animals when they encounter ambiguous faces of familiar yet novel conspecifics, e.g., strangers with faces resembling known individuals, have not been well characterised. using a morphing technique and preferential-looking paradigm, we address this question via the chimpanzee's facial-recognition abilit ...	2016	27602275
variation in the molecular clock of primates.	events in primate evolution are often dated by assuming a constant rate of substitution per unit time, but the validity of this assumption remains unclear. among mammals, it is well known that there exists substantial variation in yearly substitution rates. such variation is to be expected from differences in life history traits, suggesting it should also be found among primates. motivated by these considerations, we analyze whole genomes from 10 primate species, including old world monkeys (owm ...	2016	27601674
in-group defense, out-group aggression, and coordination failures in intergroup conflict.	intergroup conflict persists when and because individuals make costly contributions to their group's fighting capacity, but how groups organize contributions into effective collective action remains poorly understood. here we distinguish between contributions aimed at subordinating out-groups (out-group aggression) from those aimed at defending the in-group against possible out-group aggression (in-group defense). we conducted two experiments in which three-person aggressor groups confronted thr ...	2016	27601640
chimpanzees can point to smaller amounts of food to accumulate larger amounts but they still fail the reverse-reward contingency task.	the reverse-reward contingency task presents 2 food sets to an animal, and they are required to choose the smaller of the 2 sets in order to receive the larger food set. intriguingly, the majority of species tested on the reverse-reward task fail to learn this contingency in the absence of large trial counts, correction trials, and punishment techniques. the unique difficulty of this seemingly simple task likely reflects a failure of inhibitory control which is required to point toward a smaller ...	2016	27598059
normalization of human rna-seq experiments using chimpanzee rna as a spike-in standard.	normalization of human rna-seq experiments employing chimpanzee rna as a spike-in standard is reported. human and chimpanzee rnas exhibit single nucleotide variations (snvs) in average 210-bp intervals. spike-in chimpanzee rna would behave the same as the human counterparts during the whole ngs procedures owing to the high sequence similarity. after discrimination of species origins of the ngs reads based on snvs, the chimpanzee reads were used to read-by-read normalize biases and variations of ...	2016	27554056
fecal carbon and nitrogen isotopic analysis as an indicator of diet in kanyawara chimpanzees, kibale national park, uganda.	the shorter-term overview from feces provides scope to investigate dietary fluctuations. we assess the correlation of stable isotopic fecal values with recorded seasonal diet of 10 adult chimpanzees (p. t. schweinfurthii) of the kanyawara community (kibale national park, uganda) and whether fecal nitrogen levels (%n) indicate a change in crude protein intake.	2016	27553783
complete mitochondrial genome of the nigeria-cameroon chimpanzee, pan troglodytes ellioti (primates: hominidae).	chimpanzees are especially suited to teach us about ourselves, both in terms of their similarities and differences with human, and such important similarities and differences have also been noted for the incidence and severity of several major human diseases. in the present work, we report the entire mitochondrial genome of the nigeria-cameroon chimpanzee (pan troglodytes ellioti) for the first time. results shows that this mitogenome is 16,559 bp long and consists of 13 protein-coding genes, 22 ...	2016	25350739
blood cell telomere lengths and shortening rates of chimpanzee and human females.	slower rates of aging distinguish humans from our nearest living cousins. chimpanzees rarely survive their forties while large fractions of women are postmenopausal even in high-mortality hunter-gatherer populations. cellular and molecular mechanisms for these somatic aging differences remain to be identified, though telomeres might play a role. to find out, we compared telomere lengths across age-matched samples of female chimpanzees and women.	2016	24633909
development, diet and dynamism: longitudinal and cross-sectional predictors of gut microbial communities in wild baboons.	gut bacterial communities play essential roles in host biology, but to date we lack information on the forces that shape gut microbiota between hosts and over time in natural populations. understanding these forces in wild primates provides a valuable comparative context that enriches scientific perspectives on human gut microbiota. to this end, we tested predictors of gut microbial composition in a well-studied population of wild baboons. using cross-sectional and longitudinal samples collected ...	2016	25818066
trading up: chimpanzees (pan troglodytes) show self-control through their exchange behavior.	self-control is defined as the ability or capacity to obtain an objectively more valuable outcome rather than an objectively less valuable outcome though tolerating a longer delay or a greater effort requirement (or both) in obtaining that more valuable outcome. a number of tests have been devised to assess self-control in non-human animals, including exchange tasks. in this study, three chimpanzees (pan troglodytes) participated in a delay of gratification task that required food exchange as th ...	2016	26325355
[the emergence of ebola virus in humans: a long process not yet fully understood].	since 1976 ebola virus regularly has caused small deadly outbreaks in central africa, usually controlled in a few months. for the first time, an ebola epidemic of exceptional magnitude dramatically engulfed several countries in west africa since december 2013. major failures of implementing measures to prevent human-to-human transmissions are the main cause of this large-scale ebola outbreak. after about one-week incubation period, the ebola virus disease is characterized by a sudden onset of hi ...	2016	27509685
hippocampal pruning as a new theory of schizophrenia etiopathogenesis.	pruning in neurons has been suggested to be strongly involved in schizophrenia's (skz) etiopathogenesis in recent biological, imaging, and genetic studies. we investigated the impact of protein-coding genes known to be involved in pruning, collected by a systematic literature research, in shaping the risk for skz in a case-control sample of 9,490 subjects (psychiatric genomics consortium). moreover, their modifications through evolution (humans, chimpanzees, and rats) and subcellular localizatio ...	2016	25902861
a neuronal aging pattern unique to humans and common chimpanzees.	lipofuscin pigment accumulation is among the most prominent markers of cellular aging in postmitotic cells. the formation of lipofuscin is related to oxidative enzymatic activity and free radical-induced lipid peroxidation. in various mammals such as rat, dog, macaque as well as in cheirogaleid primates, most of the large neurons, such as cerebellar purkinje cells and neocortical pyramidal cells, show heavy lipofuscin accumulation in adulthood. in contrast, a well-known yet poorly studied featur ...	2016	25381006
erythrocytes from ggta1/cmah knockout pigs: implications for xenotransfusion and testing in non-human primates.	pig erythrocytes are potentially useful to solve the worldwide shortage of human blood for transfusion. domestic pig erythrocytes, however, express antigens that are bound by human preformed antibodies. advances in genetic engineering have made it possible to rapidly knock out the genes of multiple xenoantigens, namely galactose α1,3 galactose (agal) and n-glycolylneuraminic acid (neu5gc). we have recently targeted the ggta1 and cmah genes with zinc finger endonucleases resulting in double knock ...	2016	24986655
raising the bar: the implications of the iom report on the use of chimpanzees in research.		2016	23138427
[cloning and gene expression of alpha-3/4-fucosyltransferase lewis in the chimpanzee] .		2016	11000864
social models enhance apes' memory for novel events.	nonhuman primates are more likely to learn from the actions of a social model than a non-social "ghost display", however the mechanism underlying this effect is still unknown. one possibility is that live models are more engaging, drawing increased attention to social stimuli. however, recent research with humans has suggested that live models fundamentally alter memory, not low-level attention. in the current study, we developed a novel eye-tracking paradigm to disentangle the influence of soci ...	2017	28106098
recombinant adenoviruses displaying matrix 2 ectodomain epitopes on their fiber proteins as universal influenza vaccines.	influenza is a zoonotic disease that poses severe threats to public health and the global economy. reemerging influenza pandemics highlight the demand for universal influenza vaccines. we developed a novel virus platform using extracellular domain iv of the matrix 2 protein (m2e), adc68-f3m2e, by introducing three conserved m2e epitopes into the hi loop of the chimpanzee adenovirus (adv) fiber protein. the m2e epitopes were expressed sufficiently on the adv virion surface without affecting fiber ...	2017	28100621
automated face detection for occurrence and occupancy estimation in chimpanzees.	surveying endangered species is necessary to evaluate conservation effectiveness. camera trapping and biometric computer vision are recent technological advances. they have impacted on the methods applicable to field surveys and these methods have gained significant momentum over the last decade. yet, most researchers inspect footage manually and few studies have used automated semantic processing of video trap data from the field. the particular aim of this study is to evaluate methods that inc ...	2017	28095593
a comparative and evolutionary analysis of the cultural cognition of humans and other apes.	the comparative and evolutionary analysis of social learning and all manner of cultural processes has become a flourishing field. applying the 'comparative method' to such phenomena allows us to exploit the good fortunate we have in being able to study them in satisfying detail in our living primate relatives, using the results to reconstruct the cultural cognition of the ancestral forms we share with these species. here i offer an overview of principal discoveries in recent years, organized thr ...	2017	28065215
evolution of transcript modification by n(6)-methyladenosine in primates.	phenotypic differences within populations and between closely related species are often driven by variation and evolution of gene expression. however, most analyses have focused on the effects of genomic variation at cis-regulatory elements such as promoters and enhancers that control transcriptional activity, and little is understood about the influence of post-transcriptional processes on transcript evolution. post-transcriptional modification of rna by n(6)-methyladenosine (m(6)a) has been sh ...	2017	28052920
social learning and culture in child and chimpanzee.	a few decades ago, we knew next to nothing about the behavior of our closest animal relative, the chimpanzee, but long-term field studies have since revealed an undreamed-of richness in the diversity of their cultural traditions across africa. these discoveries have been complemented by a substantial suite of experimental studies, now bridging to the wild through field experiments. these field and experimental studies, particularly those in which direct chimpanzee-child comparisons have been mad ...	2017	28051932
morphological integration of the cranium in homo, pan, and hylobates and the evolution of hominoid facial structures.	modern humans diverge from other extant hominids (chimpanzees, gorillas, and orangutans) in a series of craniofacial morphological features. like hylobatids, they possess a face with a reduced subnasal prognathism that is associated with a globular basicranium. these traits are not independent, as the skull is a complex integrated structure. the aim of the present study is to determine relationships between the face and the basicranium in two hominid genera (homo and pan) and a hylobatid genus ( ...	2017	28035660
oxytocin reactivity during intergroup conflict in wild chimpanzees.	intergroup conflict is evident throughout the history of our species, ubiquitous across human societies, and considered crucial for the evolution of humans' large-scale cooperative nature. like humans, chimpanzee societies exhibit intragroup coordination and coalitionary support during violent intergroup conflicts. in both species, cooperation among group members is essential for individuals to gain access to benefits from engaging in intergroup conflict. studies suggest that a contributive mech ...	2017	28028227
aged chimpanzees exhibit pathologic hallmarks of alzheimer's disease.	alzheimer's disease (ad) is a uniquely human brain disorder characterized by the accumulation of amyloid-beta protein (aβ) into extracellular plaques, neurofibrillary tangles (nft) made from intracellular, abnormally phosphorylated tau, and selective neuronal loss. we analyzed a large group of aged chimpanzees (n = 20, age 37-62 years) for evidence of aβ and tau lesions in brain regions affected by ad in humans. aβ was observed in plaques and blood vessels, and tau lesions were found in the form ...	2017	28888720
information seeking about tool properties in great apes.	evidence suggests that great apes engage in metacognitive information seeking for food items. to support the claim that a domain-general cognitive process underlies ape metacognition one needs to show that selective information seeking extends to non-food items. in this study, chimpanzees (pan troglodytes) and orangutans (pongo abelii) either had to determine the location of a desired food item or a property of a non-food item (length of a tool). we manipulated whether subjects received prior in ...	2017	28883523
lotus birth, a holistic approach on physiological cord clamping.	the positive effects of delayed cord clamping (dcc) has been extensively researched. dcc means: waiting at least one minute after birth before clamping and cutting the cord or till the pulsation has stopped. with physiological clamping and cutting (pcc) the clamping and cutting can happen at the earliest after the pulsation has stopped. with a lotus birth, no clamping and cutting of the cord is done. a woman called clair lotus day imitated the holistic approach of pcc from an anthropoid ape in 1 ...	2017	28882580
chimpanzees recognize their own delayed self-image.	unlike mirror self-recognition, recognizing one's own image in delayed video footage may indicate the presence of a concept of self that extends across time and space. while humans typically show this ability around 4 years of age, it is unknown whether this capacity is found in non-human animals. in this study, chimpanzees performed a modified version of the mark test to investigate whether chimpanzees could remove stickers placed on the face and head while watching live and delayed video image ...	2017	28878955
do juveniles help or hinder? influence of juvenile offspring on maternal behavior and reproductive outcomes in wild chimpanzees (pan troglodytes).	compared to great apes, humans maintain a relatively rapid reproductive pace despite long periods of dependency. this seemingly contradictory set of traits is made possible by weaning offspring before nutritional independence and alloparents who help provide care. in traditional societies, this help may be provided to mothers in part by their juvenile offspring who carry, supervise, or provision younger siblings. in contrast to humans, chimpanzees (pan troglodytes) are nutritionally independent ...	2017	28874268
expression of myosin heavy chain isoforms mrna transcripts in the temporalis muscle of common chimpanzees (pan troglodytes).	the common chimpanzee (pan troglodytes) is the primate that is phylogenetically most closely related to humans (homo sapiens). in order to shed light on the anatomy and function of the temporalis muscle in the chimpanzee, we have analyzed the expression patterns of the mrna transcripts of the myosin heavy chain (myhc) isoforms in different parts of the muscle.	2017	28865772
dental development in homo naledi.	humans' prolonged somatic development and life history are unique among primates, yet their evolutionary origins remain unclear. dental development has been used as a proxy to reconstruct life history evolution in the hominin clade and indicates a recent emergence of the human developmental pattern. here, we analyse tooth formation and eruption in two developing dentitions of homo naledi, a late-surviving, morphologically mosaic hominin species. deciduous dental development is more similar to hu ...	2017	28855415
effects of sex and early rearing condition on adult behavior, health, and well-being in captive chimpanzees (pan troglodytes).	scientific evaluation of management strategies for captive species is part of the establishment of best practices for animal welfare. here we report the effects of sex, rearing, and a sex-by-rearing interaction on adult, captive chimpanzees' (pan troglodytes) behavior, health, well-being, personality, and orientation towards humans based on multiple methods (observation, animal records, and surveys). chimpanzees raised in three conditions, mother-reared (mr), standard nursery (st) and an experim ...	2017	28851632
analysis of 62 hybrid assembled human y chromosomes exposes rapid structural changes and high rates of gene conversion.	the human y-chromosome does not recombine across its male-specific part and is therefore an excellent marker of human migrations. it also plays an important role in male fertility. however, its evolution is difficult to fully understand because of repetitive sequences, inverted repeats and the potentially large role of gene conversion. here we perform an evolutionary analysis of 62 y-chromosomes of danish descent sequenced using a wide range of library insert sizes and high coverage, thus allowi ...	2017	28846694
hepatitis c virus indirectly disrupts dna damage-induced p53 responses by activating protein kinase r.	many dna tumor viruses promote cellular transformation by inactivating the critically important tumor suppressor protein p53. in contrast, it is not known whether p53 function is disrupted by hepatitis c virus (hcv), a unique, oncogenic rna virus that is the leading infectious cause of liver cancer in many regions of the world. here we show that hcv-permissive, liver-derived hepg2 cells engineered to constitutively express microrna-122 (hepg2/mir-122 cells) have normal p53-mediated responses to ...	2017	28442604
spray dried human and chimpanzee adenoviral-vectored vaccines are thermally stable and immunogenic in vivo.	cold chain-free vaccine technologies are needed to ensure effective vaccine delivery and coverage, particularly in resource-poor countries. however, the immunogenicity and thermostability of spray dried live viral vector-based vaccines such as recombinant adenoviral-vectored vaccines remain to be investigated. to address this issue, we have spray dried human adenoviral (adhu5)- and chimpanzee adenoviral (adch68)-vectored tuberculosis vaccines in a mannitol and dextran matrix. spray dried powders ...	2017	28438408
the predictive nature of transcript expression levels on protein expression in adult human brain.	next generation sequencing methods are the gold standard for evaluating expression of the transcriptome. when determining the biological implications of such studies, the assumption is often made that transcript expression levels correspond to protein levels in a meaningful way. however, the strength of the overall correlation between transcript and protein expression is inconsistent, particularly in brain samples.	2017	28438116
trabecular mapping: leveraging geometric morphometrics for analyses of trabecular structure.	trabecular microstructure of limb bone epiphyses has been used to elucidate the relationship between skeletal form and behavior among mammals. such studies have often relied on the analysis of a single volume of interest (voi). here we present a method for evaluating variation in bone microstructure across articular surfaces by leveraging sliding semilandmarks.	2017	28432829
biochemical, cellular, physiological, and pathological consequences of human loss of n-glycolylneuraminic acid.	about 2-3 million years ago, alu-mediated deletion of a critical exon in the cmah gene became fixed in the hominin lineage ancestral to humans, possibly through a stepwise process of selection by pathogen targeting of the cmah product (the sialic acid neu5gc), followed by reproductive isolation through female anti-neu5gc antibodies. loss of cmah has occurred independently in some other lineages, but is functionally intact in old world primates, including our closest relatives, the chimpanzee. al ...	2017	28423240
k-mer content, correlation, and position analysis of genome dna sequences for the identification of function and evolutionary features.	in genome analysis, k-mer-based comparison methods have become standard tools. however, even though they are able to deliver reliable results, other algorithms seem to work better in some cases. to improve k-mer-based dna sequence analysis and comparison, we successfully checked whether adding positional resolution is beneficial for finding and/or comparing interesting organizational structures. a simple but efficient algorithm for extracting and saving local k-mer spectra (frequency distributio ...	2017	28422050
early clinical xenotransplantation experiences-an interview with thomas e. starzl, md, phd.	dr thomas e. starzl, who died on march 4, 2017, was one of the great pioneers of organ transplantation. he was also a pioneer in the field of xenotransplantation. in 1964, he carried out baboon kidney transplants in six patients with terminal renal disease for whom no living or deceased donor became available; graft survival was for 19-60 days, the grafts being lost largely through continuous complement activation. between 1966 and 1974, he carried out one ex vivo liver perfusion and three ortho ...	2017	28421681
erratum to: the laminar organization of the motor cortex in monodactylous mammals: a comparative assessment based on horse, chimpanzee, and macaque.		2017	28421276
primates, lice and bacteria: speciation and genome evolution in the symbionts of hominid lice.	insects with restricted diets rely on symbiotic bacteria to provide essential metabolites missing in their diet. the blood-sucking lice are obligate, host-specific parasites of mammals and are themselves host to symbiotic bacteria. in human lice, these bacterial symbionts supply the lice with b-vitamins. here, we sequenced the genomes of symbiotic and heritable bacterial of human, chimpanzee, gorilla, and monkey lice and used phylogenomics to investigate their evolutionary relationships. we find ...	2017	28419279
natural mortality and cause of death analysis of the captive chimpanzee (pan troglodytes): a 35-year review.	we present the spontaneous causes of mortality for 137 chimpanzees (pan troglodytes) over a 35-year period. a record review of the pathology database was performed and a primary cause of mortality was determined for each chimpanzee. the most common causes of mortality were as follows: cardiomyopathy (40% of all mortalities), stillbirth/abortion, acute myocardial necrosis, chimpanzee-induced trauma, amyloidosis, and pneumonia. five morphologic diagnoses accounted for 61% of mortalities: cardiomyo ...	2017	28418090
hsv-1/hsv-2 infection-related cancers in bantu populations driving hiv-1 prevalence in africa: tracking the origin of aids at the onset of the 20th century.	at the onset of the 20th century, ancient clinical observations of cancer epidemics in bantu populations of sub-saharan africa were discovered. they were reported from 1914 to 1960, but remained unexplained. in 1983, in san francisco, calif., usa, cancer epidemics were related to infections by the human immunodeficiency virus type 1 (hiv-1) known as aids disease. yet since 1996, it is known that hiv-1 strains are not the only ones involved. in sub-saharan africa, recurrent orobuccal herpes simpl ...	2017	28413399
ischial form as an indicator of bipedal kinematics in early hominins: a test using extant anthropoids.	human ischia contrast with those of great apes in being craniocaudally short and dorsally projecting. this configuration is thought to facilitate greater hip extension in humans during bipedal locomotion. this link has been used to infer kinematics in early hominins, but the consequences of variation in ischial configuration for gait remain uncertain. kinematic data for a limited sample of extant nonhuman primates demonstrate that there is variation in hip extension in these taxa during bipedal ...	2017	28406569
lower ilium evolution in apes and hominins.	elucidating the pelvic morphology of the pan-homo last common ancestor (lca) is crucial for understanding ape and human evolution. the pelvis of ardipithecus ramidus has been the basis of controversial interpretations of the lca pelvis. in particular, it was proposed that the lower ilium became elongate independently in the orangutan and chimpanzee clades, making these taxa poor analogues for the pelvis of the lca. this study examines the variation in relative lower ilium height between and with ...	2017	28406561
elucidation of developmental patterns of marmoset corpus callosum through a comparative mri in marmosets, chimpanzees, and humans.	the corpus callosum (cc) is present in all primate brains and is the major white matter tract connecting the cerebral hemispheres for integration of sensory, motor and higher-order cognitive information. the midsagittal area of the cc has frequently been used as a sensitive biomarker of brain development. although the marmoset has been considered as an alternative non-human primate model for neuroscience research, the developmental patterns of the cc have not been explored. the present longitudi ...	2017	28400206
mammalian alox15 orthologs exhibit pronounced dual positional specificity with docosahexaenoic acid.	mammalian lipoxygenases (lox) have been implicated in cell differentiation and in the pathogenesis of inflammatory, hyperproliferative and neurological diseases. although the reaction specificity of mammalian lox with n-6 fatty acids (linoleic acid, arachidonic acid) has been explored in detail little information is currently available on the product patterns formed from n-3 polyenoic fatty acids, which are of particular nutritional importance and serve as substrate for the biosynthesis of pro-r ...	2017	28400162
superoxide dismutase 1 is positively selected to minimize protein aggregation in great apes.	positive (adaptive) selection has recently been implied in human superoxide dismutase 1 (sod1), a highly abundant antioxidant protein with energy signaling and antiaging functions, one of very few examples of direct selection on a human protein product (exon); the molecular drivers of this selection are unknown. we mapped 30 extant sod1 sequences to the recently established mammalian species tree and inferred ancestors, key substitutions, and signatures of selection during the protein's evolutio ...	2017	28389720
non-dietary analytical features of chimpanzee scats.	non-dietary aspects of ape scats such as scat weight and diameter are correlated with age and sex of defaecator for gorillas and orangutans. defaecation rates of primates, including apes, illuminate their role as primary seed dispersers. we assess if non-dietary features of scats for east african chimpanzees (pan troglodytes schweinfurthii) reveal such insights for members of the kanyawara community in kibale national park, uganda. our objective is to see if such data yield useful perspectives f ...	2017	28378197
applying wet sieving fecal particle size measurement to frugivores: a case study of the eastern chimpanzee (pan troglodytes schweinfurthii).	fecal particle size (fps) as quantified by wet sieving analysis is a measure of chewing efficiency relevant for the understanding of physiological adaptations and constraints in herbivores. fps has not been investigated systematically in frugivores, and important methodological problems remain. in particular, food items that are not chewed may skew estimates of fps. we address such methodological issues and also assess the influence of diet type and age on fps in wild chimpanzees.	2017	28374441
development of novel vaccines against infectious diseases based on chimpanzee adenoviral vector.	vaccination is considered to be the most effective method of preventing infectious or other diseases. adenovirus (ad) is one the most promising vectors in vaccine research and development. it can induce not only potent humoral but also cellular immune responses, and has therefore been widely applied in basic and translational studies. chimpanzee ad is a rare serotype circulating in humans. this circumvents the problem of preexisting immunity to human ad serotypes, enhancing chimpanzee ad prospec ...	2017	28374240
favorable ecological circumstances promote life expectancy in chimpanzees similar to that of human hunter-gatherers.	demographic data on wild chimpanzees are crucial for understanding the evolution of chimpanzee and hominin life histories, but most data come from populations affected by disease outbreaks and anthropogenic disturbance. we present survivorship data from a relatively undisturbed and exceptionally large community of eastern chimpanzees (pan troglodytes schweinfurthii) at ngogo, kibale national park, uganda. we monitored births, deaths, immigrations, and emigrations in the community between 1995 an ...	2017	28366199
ardipithecus ramidus and the evolution of language and singing: an early origin for hominin vocal capability.	in this paper we analyse the possibility that the early hominin ardipithecus ramidus had vocal capabilities far exceeding those of any extant non-human primate. we argue that erect posture combined with changes in craniofacial morphology, such as reduced facial and jaw length, not only provide evidence for increased levels of pro-sociality, but also increased vocal ability. reduced length of the face and jaw, combined with a flexed cranial base, suggests the larynx in this species was situated d ...	2017	28363458
is music enriching for group-housed captive chimpanzees (pan troglodytes)?	many facilities that house captive primates play music for animal enrichment or for caregiver enjoyment. however, the impact on primates is unknown as previous studies have been inconclusive. we conducted three studies with zoo-housed chimpanzees (pan troglodytes) and one with group-housed chimpanzees at the national centre for chimpanzee care to investigate the effects of classical and pop/rock music on various variables that may be indicative of increased welfare. study one compared the behavi ...	2017	28355212
probing the evolutionary history of human bitter taste receptor pseudogenes by restoring their function.	lineage-specific gene losses can be driven by selection or environmental adaptations. however, a lack of studies on the original function of species-specific pseudogenes leaves a gap in our understanding of their role in evolutionary histories. pseudogenes are of particular relevance for taste perception genes, which encode for receptors that confer the ability to both identify nutritionally valuable substances and avoid potentially harmful substances. to explore the role of bitter taste pseudog ...	2017	28333344
bayesian analysis of evolutionary divergence with genomic data under diverse demographic models.	we present a new bayesian method for estimating demographic and phylogenetic history using population genomic data. several key innovations are introduced that allow the study of diverse models within an isolation-with-migration framework. the new method implements a 2-step analysis, with an initial markov chain monte carlo (mcmc) phase that samples simple coalescent trees, followed by the calculation of the joint posterior density for the parameters of a demographic model. in step 1, the mcmc s ...	2017	28333230
technical intelligence and culture: nut cracking in humans and chimpanzees.	according to the technical intelligence hypothesis, humans are superior to all other animal species in understanding and using tools. however, the vast majority of comparative studies between humans and chimpanzees, both proficient tool users, have not controlled for the effects of age, prior knowledge, past experience, rearing conditions, or differences in experimental procedures. we tested whether humans are superior to chimpanzees in selecting better tools, using them more dexteriously, achie ...	2017	28332189
variation in the insulin-like growth factor 1 gene in primates.	insulin-like growth factor 1 (igf1) is a multifunctional peptide that is involved in a wide range of physiological and pathophysiological processes in many animal species, ranging from somatic growth in children to metabolism and tissue regeneration and repair in adults. the igf1 gene is under multifactorial regulation in the few species in which it has been studied, with major control being exerted by growth hormone through a gene expression pathway involving inducible binding of the stat5b tra ...	2017	28324014
developmental changes in feeding behaviors of infant chimpanzees at mahale, tanzania: implications for nutritional independence long before cessation of nipple contact.	weaning of chimpanzees is considered to occur at 4-5-years-old with complete cessation of nipple contact and timing of reconception calculated by inter-birth interval minus gestation length. this is also the basis of "early weaning" in humans (i.e., approximately 2.5-years-old). however, recent studies of the survival of orphans and the first molar (m1) eruption in wild chimpanzees have predicted that infants move toward nutritional independence at 3-years-old. therefore, this study aimed to inv ...	2017	28319268