Publications

comprehension of iconic gestures by chimpanzees and human children.	iconic gestures-communicative acts using hand or body movements that resemble their referent-figure prominently in theories of language evolution and development. this study contrasted the abilities of chimpanzees (n=11) and 4-year-old human children (n=24) to comprehend novel iconic gestures. participants learned to retrieve rewards from apparatuses in two distinct locations, each requiring a different action. in the test, a human adult informed the participant where to go by miming the action ...	2016	26448391
production of grooming-associated sounds by chimpanzees (pan troglodytes) at ngogo: variation, social learning, and possible functions.	chimpanzees (pan troglodytes) use some communicative signals flexibly and voluntarily, with use influenced by learning. these signals include some vocalizations and also sounds made using the lips, oral cavity, and/or teeth, but not the vocal tract, such as "attention-getting" sounds directed at humans by captive chimpanzees and lip smacking during social grooming. chimpanzees at ngogo, in kibale national park, uganda, make four distinct sounds while grooming others. here, i present data on two ...	2016	26546459
environmental variables across pan troglodytes study sites correspond with the carbon, but not the nitrogen, stable isotope ratios of chimpanzee hair.	diet influences the stable isotope ratios of carbon and nitrogen (δ(13) c and δ(15) n values) in animal tissue; but here we explore the influences of particular aspects of the local environment on those values in chimpanzees (pan troglodytes). in this article we present new δ(13) c and δ(15) n values in gombe chimpanzees using hairs collected from night nests in 1989. then, we explore the influence of environmental factors by comparing our gombe data to those from eight additional pan study site ...	2016	26513527
towards a computational comparative neuroprimatology: framing the language-ready brain.	we make the case for developing a computational comparative neuroprimatology to inform the analysis of the function and evolution of the human brain. first, we update the mirror system hypothesis on the evolution of the language-ready brain by (i) modeling action and action recognition and opportunistic scheduling of macaque brains to hypothesize the nature of the last common ancestor of macaque and human (lca-m); and then we (ii) introduce dynamic brain modeling to show how apes could acquire g ...	2016	26482863
the degradome database: expanding roles of mammalian proteases in life and disease.	since the definition of the degradome as the complete repertoire of proteases in a given organism, the combined effort of numerous laboratories has greatly expanded our knowledge of its roles in biology and pathology. once the genomic sequences of several important model organisms were made available, we presented the degradome database containing the curated sets of known protease genes in human, chimpanzee, mouse and rat. here, we describe the updated degradome database, featuring 81 new prote ...	2016	26553809
an observation of a severely disabled infant chimpanzee in the wild and her interactions with her mother.	we report the physical and behavioral development of one severely disabled female infant chimpanzee (pan troglodytes schweinfurthii) of the well-habituated m group in the mahale mountains national park. we documented interactions between the infant and its mother and with other group members. congenital disabilities occur in many primate species, including chimpanzees. however, there have been only a few case studies of congenitally disabled chimpanzee infants and no reports examining how a chim ...	2016	26553203
asymmetries in the production of self-directed behavior by chimpanzees and gorillas during a computerized cognitive test.	self-directed behaviors (sdbs) are a commonly used behavioral indicator of arousal in nonhuman primates. experimental manipulations, designed to increase arousal and uncertainty, have been used to elicit sdb production in primates. beyond measuring rates of sdb production, researchers have also recorded their lateralized production by primates, thought to reflect laterality of hemispheric brain control and response to emotion. although a handful of such studies exist, all have been conducted wit ...	2016	26577088
integrative genomic analysis of interleukin-36rn and its prognostic value in cancer.	interleukin (il)-36rn, previously known as il1-f5 and il-1δ, shares a 360-kb region of chromosome 2q13 with members of il-1 systems. il-36rn encodes an anti-inflammatory cytokine, il-36 receptor antagonist (il-36ra). in spite of il-36ra showing the highest homology to il-1 receptor (il-1r) antagonist, it differs from the latter in aspects including its binding to il-lrrp2 but not to il-1r1. il-36rn is mainly expressed in epithelial cells and has important roles in inflammatory diseases. in the p ...	2016	26676204
human-specific derived alleles of cd33 and other genes protect against postreproductive cognitive decline.	the individuals of most vertebrate species die when they can no longer reproduce. humans are a rare exception, having evolved a prolonged postreproductive lifespan. elders contribute to cooperative offspring care, assist in foraging, and communicate important ecological and cultural knowledge, increasing the survival of younger individuals. age-related deterioration of cognitive capacity in humans compromises these benefits and also burdens the group with socially costly members. we investigated ...	2016	26621708
genetic and phylogenetic characterization of novel bocaparvovirus infecting chimpanzee.	primate bocaparvoviruses were first described in 2005, since then further human and gorilla bocaparvoviruses have been identified. to uncover diversity of non-human primates' bocaparvoviruses, their phylogenetic relationship and potential to cross the host species barrier, we tested 153 fecal samples from 17 captive primate species. the only one captive female of central chimpanzee (coded cpzh2) has been identified as bocaparvovirus positive. based on the full genome phylogenetic analyses, cpzh2 ...	2016	26616676
how chimpanzees (pan troglodytes) perform in a modified emotional stroop task.	the emotional stroop task is an experimental paradigm developed to study the relationship between emotion and cognition. human participants required to identify the color of words typically respond more slowly to negative than to neutral words (emotional stroop effect). here we investigated whether chimpanzees (pan troglodytes) would show a comparable effect. using a touch screen, eight chimpanzees were trained to choose between two simultaneously presented stimuli based on color (two identical ...	2016	26613593
chimpanzee food preferences, associative learning, and the origins of cooking.	a recent report suggested that chimpanzees demonstrate the cognitive capacities necessary to understand cooking (warneken & rosati, 2015). we offer alternate explanations and mechanisms that could account for the behavioral responses of those chimpanzees, without invoking the understanding of cooking as a process. we discuss broader issues surrounding the use of chimpanzees in modeling hominid behavior and understanding aspects of human evolution.	2016	26659967
nasal temperature drop in response to a playback of conspecific fights in chimpanzees: a thermo-imaging study.	emotion is one of the central topics in animal studies and is likely to attract attention substantially in the coming years. recent studies have developed a thermo-imaging technique to measure the facial skin temperature in the studies of emotion in humans and macaques. here we established the procedures and techniques needed to apply the same technique to great apes. we conducted two experiments respectively in the two established research facilities in germany and japan. total twelve chimpanze ...	2016	26657470
translating chimpanzee personality to humans: investigating the transportability of chimpanzee-derived personality scales to humans.	there is a growing interest in the study of personality in chimpanzees with repeated findings of a similar structure of personality in apes to that found in humans. to date, however, the direct translational value of instruments used to assess chimpanzee personality to humans has yet to be explicitly tested. as such, in the current study we sought to determine the transportability of factor analytically-derived chimpanzee personality scales to humans in a large human sample (n = 301). human info ...	2016	26716761
human-specific increase of dopaminergic innervation in a striatal region associated with speech and language: a comparative analysis of the primate basal ganglia.	the dopaminergic innervation of the striatum has been implicated in learning processes and in the development of human speech and language. several lines of evidence suggest that evolutionary changes in dopaminergic afferents of the striatum may be associated with uniquely human cognitive and behavioral abilities, including the association of the human-specific sequence of the foxp2 gene with decreased dopamine in the dorsomedial striatum of mice. to examine this possibility, we quantified the d ...	2016	26715195
testicular receptor 2, nr2c1, is associated with stem cells in the developing olfactory epithelium and other cranial sensory and skeletal structures.	comparative genomic analysis of the nuclear receptor family suggests that the testicular receptor 2, nr2c1, undergoes positive selection in the human-chimpanzee clade based upon a significant increase in nonsynonymous compared to synonymous substitutions. previous in situ analyses of nr2c1 lacked the temporal range and spatial resolution necessary to characterize cellular expression of this gene from early to mid gestation, when many nuclear receptors are key regulators of tissue specific stem o ...	2016	26712358
the end of chimpanzee research.	in june 2010, rosie, a descendant of the chimpanzees sent into space, and thirteen others were shipped from new mexico to a laboratory in texas for possible use in hepatitis research. they were to be the first group of approximately two hundred chimpanzees to be reintroduced to invasive research. these chimpanzees had been in semiretirement for a decade after being removed from an enormous laboratory that was in egregious violation of the animal welfare act. i, along with many bioethicists, scie ...	2016	27417870
nonhuman primates, human need, and ethical constraints.	"the ethics of infection challenges in primates," by anne barnhill, steven joffe, and franklin miller, is an exceptionally timely contribution to the literature on animal research ethics. animal research has long been both a source of high hopes and a cause for moral concern. when it comes to infection challenge studies with nonhuman primates, neither the hope-to save thousands of human lives from such diseases as ebola and marburg-nor the concern-the conviction that primates deserve especially ...	2016	27417866
animal intuitions.	as described by lori gruen in the perspective column at the back of this issue, federally supported biomedical research conducted on chimpanzees has now come to an end in the united states, although the wind-down has taken longer than expected. the process began with a 2011 institute of medicine report that set up several stringent criteria that sharply limited biomedical research. the national institutes of health accepted the recommendations and formed a committee to determine how best to impl ...	2016	27417859
molecular determinants of gs-9620-dependent tlr7 activation.	gs-9620 is an orally administered agonist of toll-like receptor (tlr)7 currently being evaluated in clinical studies for the treatment of chronic hbv and hiv patients. gs-9620 has shown antiviral efficacy in preclinical models of chronic hepadnavirus infection in woodchuck as well as chimpanzee. however, the molecular determinants of gs-9620-dependent activation of tlr7 are not well defined. the studies presented here elucidate gs-9620 subcellular distribution and characterize its molecular inte ...	2016	26784926
it all adds up …. or does it? numbers, mathematics and purpose.	no chimpanzee knows what a square root is, let alone a complex number. yet not only our closest ape cousins but even some invertebrates, possess a capacity for numerosity, that is the ability to assess relative numerical magnitudes and distances. that numerosity should confer adaptive advantages, such as social species that choose shoal size, is obvious. moreover, it is widely assumed that numerosity and mathematics are seamlessly linked, as would be consistent with darwinian notions of descent ...	2016	26783082
long bone cross-sectional properties reflect changes in locomotor behavior in developing chimpanzees.	recent studies indicate that the locomotor behavior of wild chimpanzees changes during development. before transitioning to quadrupedal knuckle-walking in adulthood, young chimpanzees engage in a significant amount of upper limb loading suspensory behavior. we investigated whether these dramatic changes in locomotion influence the strength and shape of chimpanzee long bones.	2016	26780478
a chimpanzee (pan troglodytes) model of triarchic psychopathy constructs: development and initial validation.	the current work sought to operationalize constructs of the triarchic model of psychopathy in chimpanzees (pan troglodytes), a species well-suited for investigations of basic biobehavioral dispositions relevant to psychopathology. across three studies, we generated validity evidence for scale measures of the triarchic model constructs in a large sample (n=238) of socially-housed chimpanzees. using a consensus-based rating approach, we first identified candidate items for the chimpanzee triarchic ...	2016	26779396
chimpanzees trust their friends.	the identification and recruitment of trustworthy partners represents an important adaptive challenge for any species that relies heavily on cooperation [1, 2]. from an evolutionary perspective, trust is difficult to account for as it involves, by definition, a risk of non-reciprocation and defection by cheaters [3, 4]. one solution for this problem is to form close emotional bonds, i.e., friendships, which enable trust even in contexts where cheating would be profitable [5]. little is known abo ...	2016	26776735
placentophagy in wild chimpanzees (pan troglodytes verus) at bossou, guinea.	despite intensive observation of nonhuman great apes during long-term field studies, observations of great ape births in the wild are rare. research on wild chimpanzees (pan troglodytes verus) at bossou in the republic of guinea has been ongoing for 35 years, yet chimpanzee parturitions have been observed on only two occasions. here we provide information regarding both chimpanzee births, with detailed information from the close observation of one. during this birth, the mother built a day nest ...	2016	26769192
reproductive state and rank influence patterns of meat consumption in wild female chimpanzees (pan troglodytes schweinfurthii).	an increase in faunivory is a consistent component of human evolutionary models. animal matter is energy- and nutrient-dense and can provide macronutrients, minerals, and vitamins that are limited or absent in plant foods. for female humans and other omnivorous primates, faunivory may be of particular importance during the costly periods of pregnancy and early lactation. yet, because animal prey is often monopolizable, access to fauna among group-living primates may be mediated by social factors ...	2016	26767956
maternal effects on offspring stress physiology in wild chimpanzees.	early life experiences are known to influence hypothalamic-pituitary-adrenal (hpa) axis development, which can impact health outcomes through the individual's ability to mount appropriate physiological reactions to stressors. in primates, these early experiences are most often mediated through the mother and can include the physiological environment experienced during gestation. here, we investigate stress physiology of dependent offspring in wild chimpanzees for the first time and examine wheth ...	2016	26757681
cortical cell and neuron density estimates in one chimpanzee hemisphere.	the density of cells and neurons in the neocortex of many mammals varies across cortical areas and regions. this variability is, perhaps, most pronounced in primates. nonuniformity in the composition of cortex suggests regions of the cortex have different specializations. specifically, regions with densely packed neurons contain smaller neurons that are activated by relatively few inputs, thereby preserving information, whereas regions that are less densely packed have larger neurons that have m ...	2016	26729880
safety and immunogenicity of a chimpanzee adenovirus-vectored ebola vaccine in healthy adults: a randomised, double-blind, placebo-controlled, dose-finding, phase 1/2a study.	the ongoing ebola outbreak led to accelerated efforts to test vaccine candidates. on the basis of a request by who, we aimed to assess the safety and immunogenicity of the monovalent, recombinant, chimpanzee adenovirus type-3 vector-based ebola zaire vaccine (chad3-ebo-z).	2016	26725450
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
the potency of nef-mediated serinc5 antagonism correlates with the prevalence of primate lentiviruses in the wild.	the cellular factor serine incorporator 5 (serinc5) impairs hiv-1 infectivity but is antagonized by the viral nef protein. we analyzed the anti-serinc5 activity of nef proteins across primate lentiviruses and examined whether serinc5 represents a barrier to cross-species transmissions and/or within-species viral spread. hiv-1, hiv-2, and siv nefs counteract human, ape, monkey, and murine serinc5 orthologs with similar potency. however, hiv-1 nefs are more active against serinc5 than hiv-2 nefs, ...	2016	27631701
strain-dependent and distinctive t-cell responses to hiv antigens following immunisation of mice with differing chimpanzee adenovirus vaccine vectors.	in vivo vaccination studies are conventionally conducted in a single mouse strain with results, only reflecting responses to a single immunogenetic background. we decided to examine the immune response to an hiv transgene (gag, pol and nef fusion protein) in 3 strains of mice (cba, c57bl/6 and balb/c) to determine the spectrum of responses and in addition to determine whether the serotype of the adenoviral vector used (chad3 and chad63) impacted the outcome of response. our results demonstrated ...	2016	27452864
in silico phylogenomics using complete genomes: a case study on the evolution of hominoids.	the increasing availability of complete genome data is facilitating the acquisition of phylogenomic data sets, but the process of obtaining orthologous sequences from other genomes and assembling multiple sequence alignments remains piecemeal and arduous. we designed software that performs these tasks and outputs anonymous loci (al) or anchored enrichment/ultraconserved element loci (ae/uce) data sets in ready-to-analyze formats. we demonstrate our program by applying it to the hominoids. starti ...	2016	27435933
travel fosters tool use in wild chimpanzees.	ecological variation influences the appearance and maintenance of tool use in animals, either due to necessity or opportunity, but little is known about the relative importance of these two factors. here, we combined long-term behavioural data on feeding and travelling with six years of field experiments in a wild chimpanzee community. in the experiments, subjects engaged with natural logs, which contained energetically valuable honey that was only accessible through tool use. engagement with th ...	2016	27431611
functional divergence of the nuclear receptor nr2c1 as a modulator of pluripotentiality during hominid evolution.	genes encoding nuclear receptors (nrs) are attractive as candidates for investigating the evolution of gene regulation because they (1) have a direct effect on gene expression and (2) modulate many cellular processes that underlie development. we employed a three-phase investigation linking nr molecular evolution among primates with direct experimental assessment of nr function. phase 1 was an analysis of nr domain evolution and the results were used to guide the design of phase 2, a codon-model ...	2016	27075724
chimpanzees, cooking, and a more comparative psychology.	a recent report suggested that chimpanzees demonstrate the cognitive capacities necessary to understand cooking (warneken & rosati, 2015). we offered alternative explanations and mechanisms that could account for the behavioral responses of those chimpanzees, and questioned the manner in which the data were used to examine human evolution (beran, hopper, de waal, sayers, & brosnan, 2015). two commentaries suggested either that we were overly critical of the original report's claims and methodolo ...	2016	27068300
the influence of avpr1a genotype on individual differences in behaviors during a mirror self-recognition task in chimpanzees (pan troglodytes).	the mark/rouge test has been used to assess mirror self-recognition (msr) in many species. despite consistent evidence of msr in great apes, genetic or non-genetic factors may account for the individual differences in behavioral responses that have been reported. we examined whether vasopressin receptor gene (avpr1a) polymorphisms are associated with msr-related behaviors in chimpanzees since vasopressin has been implicated in the development and evolution of complex social relations and cogniti ...	2016	27058969
de novo genes arise at a slow but steady rate along the primate lineage and have been subject to incomplete lineage sorting.	de novo protein-coding gene origination is increasingly recognized as an important evolutionary mechanism. however, there remains a large amount of uncertainty regarding the frequency of these events and the mechanisms and speed of gene establishment. here, we describe a rigorous search for cases of de novo gene origination in the great apes. we analyzed annotated proteomes as well as full genomic dna and transcriptional and translational evidence. it is notable that results vary between databas ...	2016	27056411
sex differences in the relationship between planum temporale asymmetry and corpus callosum morphology in chimpanzees (pan troglodytes): a combined mri and dti analysis.	increases brain size has been hypothesized to be inversely associated with the expression of behavioral and brain asymmetries within and between species. we tested this hypothesis by analyzing the relation between asymmetries in the planum temporale (pt) and different measures of the corpus callosum (cc) including surface area, streamline count as measured from diffusion tensor imaging, fractional anisotropy values and the ratio in the number of fibers to surface area in a sample of chimpanzees. ...	2016	27055947
malignant neoplasia of the sex skin in 2 chimpanzees (pan troglodytes).	this report describes 2 cases of spontaneous malignant neoplasia within the sex skin of aged female chimpanzees. in both cases, the initial presentation resembled nonhealing traumatic wounds to the sex skin, with different degrees of infection, ulceration, and tissue necrosis. histopathology of the lesions confirmed the diagnosis of squamous cell carcinoma in one case and of adenocarcinoma with metastasis in the other. advanced age and previous trauma likely contributed to the development of the ...	2016	27053571
measuring hair cortisol concentrations to assess the effect of anthropogenic impacts on wild chimpanzees (pan troglodytes).	non-human primates face major environmental changes due to increased human impacts all over the world. although some species are able to survive in certain landscapes with anthropogenic impact, their long-term viability and fitness may be decreased due to chronic stress. here we assessed long-term stress levels through cortisol analysis in chimpanzee hair obtained from sleeping nests in northwestern uganda, in order to estimate welfare in the context of ecotourism, forest fragmentation with huma ...	2016	27050418
establishment of an intermittent cold stress model using tupaia belangeri and evaluation of compound c737 targeting neuron-restrictive silencer factor.	previous studies have shown that intermittent cold stress (ics) induces depression-like behaviors in mammals. tupaia belangeri (the tree shrew) is the only experimental animal other than the chimpanzee that has been shown to be susceptible to infection by hepatitis b and c viruses. moreover, full genome sequence analysis has revealed strong homology between host proteins in tupaia and in humans and other primates. tupaia neuromodulator receptor proteins are also known to have a high degree of ho ...	2016	27041457
first observation of dorylus ant feeding in budongo chimpanzees supports absence of stick-tool culture.	the use of stick- or probe-tools is a chimpanzee universal, recorded in all long-term study populations across africa, except one: budongo, uganda. here, after 25 years of observation, stick-tool use remains absent under both natural circumstances and strong experimental scaffolding. instead, the chimpanzees employ a rich repertoire of leaf-tools for a variety of dietary and hygiene tasks. one use of stick-tools in other communities is in feeding on the aggressive dorylus 'army ant' species, con ...	2016	27038810
a novel trim family member, trim69, regulates zebrafish development through p53-mediated apoptosis.	trim69 contains the hallmark domains of a tripartite motif (trim) protein, including a ring-finger domain, b-box domain, and coiled-coil domain. trim69 is structurally and evolutionarily conserved in zebrafish, mouse, rat, human, and chimpanzee. the role of this protein is unclear, however, so we investigated its function in zebrafish development. trim69 is extensively expressed in zebrafish adults and developing embryos-particularly in the testis, brain, ovary, and heart-and its expression decr ...	2016	27031046
impaired air conditioning within the nasal cavity in flat-faced homo.	we are flat-faced hominins with an external nose that protrudes from the face. this feature was derived in the genus homo, along with facial flattening and reorientation to form a high nasal cavity. the nasal passage conditions the inhaled air in terms of temperature and humidity to match the conditions required in the lung, and its anatomical variation is believed to be evolutionarily sensitive to the ambient atmospheric conditions of a given habitat. in this study, we used computational fluid ...	2016	27010321
how comparative psychology can shed light on human evolution: response to beran et al.'s discussion of "cognitive capacities for cooking in chimpanzees".	we recently reported a study (warneken & rosati proceedings of the royal society b, 282, 20150229, 2015) examining whether chimpanzees possess several cognitive capacities that are critical to engage in cooking. in a subsequent commentary, beran, hopper, de waal, sayers, and brosnan learning & behavior (2015) asserted that our paper has several flaws. their commentary (1) critiques some aspects of our methodology and argues that our work does not constitute evidence that chimpanzees can actually ...	2016	27007910
recombination hotspots: models and tools for detection.	recombination hotspots are the regions within the genome where the rate, and the frequency of recombination are optimum with a size varying from 1 to 2kb. the recombination event is mediated by the double-stranded break formation, guided by the combined enzymatic action of dna topoisomerase and spo 11 endonuclease. these regions are distributed non-uniformly throughout the human genome and cause distortions in the genetic map. numerous lines of evidence suggest that the number of hotspots known ...	2016	26991854
species diversity regarding the presence of proximal tubular progenitor cells of the kidney.	the cellular source for tubular regeneration following kidney injury is a matter of dispute, with reports suggesting a stem or progenitor cells as the regeneration source while linage tracing studies in mice seemingly favor the classical theory, where regeneration is performed by randomly surviving cells. we, and others have previously described a scattered cell population localized to the tubules of human kidney, which increases in number following injury. here we have characterized the species ...	2016	26972712
reference in human and non-human primate communication: what does it take to refer?	the concept of functional reference has been used to isolate potentially referential vocal signals in animal communication. however, its relatedness to the phenomenon of reference in human language has recently been brought into question. while some researchers have suggested abandoning the concept of functional reference altogether, others advocate a revision of its definition to include contextual cues that play a role in signal production and perception. empirical and theoretical work on func ...	2016	26971953
human fibroblasts display a differential focal adhesion phenotype relative to chimpanzee.	there are a number of documented differences between humans and our closest relatives in responses to wound healing and in disease susceptibilities, suggesting a differential cellular response to certain environmental factors. in this study, we sought to look at a specific cell type, fibroblasts, to examine differences in cellular adhesion between humans and chimpanzees in visualized cells and in gene expression. we have found significant differences in the number of focal adhesions between prim ...	2016	26971204
daily travel distances of zoo-housed chimpanzees and gorillas: implications for welfare assessments and space requirements.	the degree to which the relatively smaller area of artificial environments (compared with natural habitats) has measureable effects on the behavior and welfare of captive animals has been debated for many years. while there is little question that these spaces provide far less opportunity for natural ranging behavior and travel, less is known about the degree to which captive animals travel within their environments and what factors influence these travel patterns. we intensively studied the mov ...	2016	26968410
cars kill chimpanzees: case report of a wild chimpanzee killed on a road at bulindi, uganda.	roads have broadly adverse impacts on wildlife, including nonhuman primates. one direct effect is mortality from collisions with vehicles. while highly undesirable, roadkills provide valuable information on the health and condition of endangered species. we present a case report of a wild chimpanzee (pan troglodytes schweinfurthii) killed crossing a road in bulindi, uganda, where chimpanzees inhabit forest fragments amid farmland. details of the collision are constructed from eyewitness accounts ...	2016	26960418
a time- and cost-effective strategy to sequence mammalian y chromosomes: an application to the de novo assembly of gorilla y.	the mammalian y chromosome sequence, critical for studying male fertility and dispersal, is enriched in repeats and palindromes, and thus, is the most difficult component of the genome to assemble. previously, expensive and labor-intensive bac-based techniques were used to sequence the y for a handful of mammalian species. here, we present a much faster and more affordable strategy for sequencing and assembling mammalian y chromosomes of sufficient quality for most comparative genomics analyses ...	2016	26934921
isotopic reconstructions of habitat change surrounding the extinction of oreopithecus, the last european ape.	oreopithecus bambolii was the last hominoid to survive in europe. the purpose of this investigation was to reconstruct, through stable isotope analyses, oreopithecus' habitat, subsistence behavior, and changes in habitat that may have led to its extinction.	2016	26932906
chimpanzee accumulative stone throwing.	the study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. here, we describe newly discovered stone tool-use behaviour and ston ...	2016	26923684
variation in carbon isotope values among chimpanzee foods at ngogo, kibale national park and bwindi impenetrable national park, uganda.	stable isotope values in primate tissues can be used to reconstruct diet in the absence of direct observation. however, in order to make dietary inferences, one must first establish isotopic variability for potential food sources. in this study we examine stable carbon isotope (δ(13) c) values for chimpanzee (pan troglodytes) food resources from two ugandan forests: ngogo (kibale national park), and bwindi impenetrable national park. mean δ(13) c values for plant samples are equivalent at both s ...	2016	26918258
dietary options and behavior suggested by plant biomarker evidence in an early human habitat.	the availability of plants and freshwater shapes the diets and social behavior of chimpanzees, our closest living relative. however, limited evidence about the spatial relationships shared between ancestral human (hominin) remains, edible resources, refuge, and freshwater leaves the influence of local resources on our species' evolution open to debate. exceptionally well-preserved organic geochemical fossils--biomarkers--preserved in a soil horizon resolve different plant communities at meter sc ...	2016	26903646
chimpanzee research and conservation in bossou and the nimba mountains: a long-term international collaborative effort in west africa.	the nimba mountains are a west african natural world heritage site located in the range of the guineo-equatorial evergreen rainforest, renowned for its rich biodiversity with a high level of endemism. in 1976, yukimaru sugiyama from kyoto university initiated the long-term study of chimpanzees at bossou, a guinean village situated 5 km from the northern foothills of nimba. this japanese initiative has provided key discoveries and insights on our closest living evolutionary relatives over the 40 ...	2016	26902853
evolution of brain and culture: the neurological and cognitive journey from australopithecus to albert einstein.	fossil and comparative primatological evidence suggest that alterations in the development of prehistoric hominin infants kindled three consecutive evolutionary-developmental (evo-devo) trends that, ultimately, paved the way for the evolution of the human brain and cognition. in the earliest trend, infants' development of posture and locomotion became delayed because of anatomical changes that accompanied the prolonged evolution of bipedalism. because modern humans have inherited these changes, ...	2016	26894688
use of an implantable loop recorder in a chimpanzee (pan troglodytes) to monitor cardiac arrhythmias and assess the effects of acupuncture and laser therapy.	cardiovascular disease is a leading cause of death in captive chimpanzees and is often associated with myocardial fibrosis, which increases the risk of cardiac arrhythmias. in this case report, we present a 36-y-old male chimpanzee (pan troglodytes) diagnosed with frequent ventricular premature complexes (vpc). we placed a subcutaneous implantable loop recorder for continual ecg monitoring to assess his arrhythmias without the confounding effects of anesthetics. during his initial treatment with ...	2016	26884410
robust retention and transfer of tool construction techniques in chimpanzees (pan troglodytes).	long-term memory can be critical to a species' survival in environments with seasonal and even longer-term cycles of resource availability. the present, longitudinal study investigated whether complex tool behaviors used to gain an out-of-reach reward, following a hiatus of about 3 years and 7 months since initial experiences with a tool use task, were retained and subsequently executed more quickly by experienced than by naïve chimpanzees. ten of the 11 retested chimpanzees displayed impressive ...	2016	26881941
using the nimh research domain criteria (rdoc) in human and nonhuman primate research.	in this article, we provide a commentary on kozak and cuthbert ()'s theoretical paper discussing the nimh research domain criteria (rdoc) initiative and on latzman et al. (2016)'s empirical investigation of the rdoc negative valence systems domain in chimpanzees, conducted with experimental procedures across genetic, neurobiological, and behavioral levels of analysis. we discuss the pros and cons of the rdoc approach to research on mental illness as well as the strengths and weaknesses of the im ...	2016	26877128
neuroethology as a translational neuroscience strategy in the era of the nimh research domain criteria.	the article by latzman et al. in the current special issue utilizes a novel dataset consisting of behavioral, brain, and genomic data from a sample of 76 captive chimpanzees to make the case that negative affective expression is influenced by variation in the gene coding for arginine vasopressin receptor 1a (avpr1a), in a sex-linked manner. a novel feature of this study is the ethological approach employed by the authors, i.e., the use of scratching as a behavioral indicator of negative affectiv ...	2016	26877127
displacement behaviors in chimpanzees (pan troglodytes): a neurogenomics investigation of the rdoc negative valence systems domain.	the current study aimed to systematically investigate genetic and neuroanatomical correlates of individual variation in scratching behaviors, a well-validated animal-behavioral indicator of negative emotional states with clear links to the nimh research domain criteria (rdoc) response to potential harm ("anxiety") construct within the negative valence systems domain. utilizing data from a sample of 76 captive chimpanzees (pan troglodytes), we (a) examined the association between scratching and p ...	2016	26877126
no distinction of orthology/paralogy between human and chimpanzee rh blood group genes.	on human (homo sapiens) chromosome 1, there is a tandem duplication encompassing rh blood group genes (hosa_rhd and hosa_rhce). this duplication occurred in the common ancestor of humans, chimpanzees (pan troglodytes), and gorillas, after splitting from their common ancestor with orangutans. although several studies have been conducted on ape rh blood group genes, the clear genome structures of the gene clusters remain unknown. here, we determined the genome structure of the gene cluster of chim ...	2016	26872772
analysis of hair cortisol levels in captive chimpanzees: effect of various methods on cortisol stability and variability.	hair cortisol has been reported to be a useful measure of long-term hypothalamic-pituitary-adrenal (hpa) axis activation in several species. it serves as a practical tool for long-term stress assessment, but it is important to understand the methodological factors that can affects hair cortisol assays to avoid methodological artifacts. to that end, we tested several procedures for measuring cortisol levels in hair collected from captive chimpanzees. the results showed that reproducibility was hi ...	2016	26870668
pitfalls reconstructing the last common ancestor of chimpanzees and humans.		2016	26862165
reply to almécija: a new direction for reconstructing our last common ancestor with chimpanzees.		2016	26862164
bystanders, parcelling, and an absence of trust in the grooming interactions of wild male chimpanzees.	the evolution of cooperation remains a central issue in socio-biology with the fundamental problem of how individuals minimize the risks of being short-changed ('cheated') should their behavioural investment in another not be returned. economic decisions that individuals make during interactions may depend upon the presence of potential partners nearby, which offers co operators a temptation to defect from the current partner. the parcelling model posits that donors subdivide services into parce ...	2016	26856371
differing views: can chimpanzees do level 2 perspective-taking?	although chimpanzees understand what others may see, it is unclear whether they understand how others see things (level 2 perspective-taking). we investigated whether chimpanzees can predict the behavior of a conspecific which is holding a mistaken perspective that differs from their own. the subject competed with a conspecific over two food sticks. while the subject could see that both were the same size, to the competitor one appeared bigger than the other. in a previously established game, th ...	2016	26852383
smoke and mirrors: testing the scope of chimpanzees' appearance-reality understanding.	the ability to make appearance-reality (ar) discriminations is an important higher-order cognitive adaptation in humans but is still poorly understood in our closest primate relatives. previous research showed that chimpanzees are capable of ar discrimination when choosing between food items that appear, due to the effects of distorting lenses, to be smaller or larger than they actually are (krachun, call, & tomasello, 2009). in the current study, we investigated the scope and flexibility of chi ...	2016	26848736
should i stay or should i go? initiation of joint travel in mother-infant dyads of two chimpanzee communities in the wild.	it is well established that great apes communicate via intentionally produced, elaborate and flexible gestural means. yet relatively little is known about the most fundamental steps into this communicative endeavour-communicative exchanges of mother-infant dyads and gestural acquisition; perhaps because the majority of studies concerned captive groups and single communities in the wild only. here, we report the first systematic, quantitative comparison of communicative interactions of mother-inf ...	2016	26833496
social behavior shapes the chimpanzee pan-microbiome.	animal sociality facilitates the transmission of pathogenic microorganisms among hosts, but the extent to which sociality enables animals' beneficial microbial associations is poorly understood. the question is critical because microbial communities, particularly those in the gut, are key regulators of host health. we show evidence that chimpanzee social interactions propagate microbial diversity in the gut microbiome both within and between host generations. frequent social interaction promotes ...	2016	26824072
spontaneous reproductive tract lesions in aged captive chimpanzees.	chimpanzees (pan troglodytes) have served as an important model for studies of reproductive diseases and aging-related disorders in humans. however, limited information is available about spontaneously occurring reproductive tract lesions in aging chimpanzees. in this article, the authors present histopathologic descriptions of lesions identified in the reproductive tract, including the mammary gland, of 33 female and 34 male aged chimpanzees from 3 captive populations. the most common findings ...	2016	26823448
atypical early histories predict lower extraversion in captive chimpanzees.	although much research has been conducted to understand personality development in humans, there remain substantial gaps in our understanding of these processes, particularly in relation to social influences. as such, investigations into personality development in our closest living relative, the chimpanzee, may provide useful insight. we evaluated the impact of early social exposure (to both humans and conspecifics) on personality development by studying 88 chimpanzees, including former pets an ...	2016	26814701
animal behaviour: friendship enhances trust in chimpanzees.	individuals that participate in exchanges with delayed rewards can be exploited if their partners don't reciprocate. in humans, friendships are built on trust, and trust enhances cooperation. new evidence suggests that close social bonds also enhance trust in chimpanzees.	2016	26811894
overexpression of p53 activated by small activating rna suppresses the growth of human prostate cancer cells.	previous research has reported that a particular double-stranded rna, named dsp53-285, has the capacity to induce expression of the tumor suppressor gene tp53 in chimpanzee cells by targeting its promoter. usually, it is the wild-type p53 protein, rather than mutants, which exhibits potent cancer-inhibiting effects. in addition, nonhuman primates, such as chimpanzees, share almost identical genome sequences with humans. this prompted us to speculate whether dsp53-285 can trigger wild-type p53 pr ...	2016	26811691
life history effects on the molecular clock of autosomes and sex chromosomes.	one of the foundational results in molecular evolution is that the rate at which neutral substitutions accumulate on a lineage equals the rate at which mutations arise. traits that affect rates of mutation therefore also affect the phylogenetic "molecular clock." we consider the effects of sex-specific generation times and mutation rates in species with two sexes. in particular, we focus on the effects that the age of onset of male puberty and rates of spermatogenesis have likely had in hominids ...	2016	26811451
spatio-temporal complexity of chimpanzee food: how cognitive adaptations can counteract the ephemeral nature of ripe fruit.	ecological complexity has been proposed to play a crucial role in primate brain-size evolution. however, detailed quantification of ecological complexity is still limited. here we assess the spatio-temporal distribution of tropical fruits and young leaves, two primary chimpanzee (pan troglodytes) foods, focusing on the predictability of their availability in individual trees. using up to 20 years of information on monthly availability of young leaf, unripe and ripe fruit in plant species consume ...	2016	26800493
unidirectional adaptation in tempo in pairs of chimpanzees during simultaneous tapping movement: an examination under face-to-face setup.	many studies have reported a spontaneous nature to synchronized movement in humans and in non-human primates. however, it is not yet clear whether individuals mutually adapt their movement to each other or whether one individual significantly changes to synchronize with the other. in the current study, we examined a directionality of the tempo adaptation to understand an introductive process of interactional synchrony in pairs of chimpanzees. four pairs, consisting of five female chimpanzees, pr ...	2016	26795540
characterization of a cardiorenal-like syndrome in aged chimpanzees (pan troglodytes).	cardiorenal syndrome involves disease and dysfunction of the heart that leads to progressive renal dysfunction. this study investigated the relationship between cardiac and renal disease in 91 aged chimpanzees at the alamogordo primate facility by evaluation of the medical histories, metabolic parameters, functional measurements of the cardiovascular system, clinical pathology, and histopathology focused on the heart and kidney. cardiac fibrosis was the most frequent microscopic finding in 82 of ...	2016	26792841
how chimpanzees cooperate in a competitive world.	our species is routinely depicted as unique in its ability to achieve cooperation, whereas our closest relative, the chimpanzee (pan troglodytes), is often characterized as overly competitive. human cooperation is assisted by the cost attached to competitive tendencies through enforcement mechanisms, such as punishment and partner choice. to examine if chimpanzees possess the same ability to mitigate competition, we set up a cooperative task in the presence of the entire group of 11 adults, whic ...	2016	27551075
human feeding biomechanics: performance, variation, and functional constraints.	the evolution of the modern human (homo sapiens) cranium is characterized by a reduction in the size of the feeding system, including reductions in the size of the facial skeleton, postcanine teeth, and the muscles involved in biting and chewing. the conventional view hypothesizes that gracilization of the human feeding system is related to a shift toward eating foods that were less mechanically challenging to consume and/or foods that were processed using tools before being ingested. this hypot ...	2016	27547550
causal reasoning versus associative learning: a useful dichotomy or a strawman battle in comparative psychology?	the debate about whether or not one could/should ascribe reasoning abilities to animals has deep historical roots and seems very up-to-date in the light of the immense body of new empirical data originating from various species and research paradigms. associative learning (al) seems to be a ubiquitous low-level contender for any cognitive interpretation of animal behavior, mostly because of the assumed mechanistic simplicity and phylogenetic prevalence. however, the implicit assumption that al i ...	2016	27512825
passive acoustic monitoring reveals group ranging and territory use: a case study of wild chimpanzees (pan troglodytes).	assessing the range and territories of wild mammals traditionally requires years of data collection and often involves directly following individuals or using tracking devices. indirect and non-invasive methods of monitoring wildlife have therefore emerged as attractive alternatives due to their ability to collect data at large spatiotemporal scales using standardized remote sensing technologies. here, we investigate the use of two novel passive acoustic monitoring (pam) systems used to capture ...	2016	27507999
cross-cultural sex differences in post-conflict affiliation following sports matches.	the nature of ancestral human social structure and the circumstances in which men or women tend to be more cooperative are subjects of intense debate. the male warrior hypothesis proposes that success in intergroup contests has been vital in human evolution and that men therefore must engage in maximally effective intragroup cooperation [1-3]. post-conflict affiliation between opponents is further proposed to facilitate future cooperation [4], which has been demonstrated in non-human primates [5 ...	2016	27498561
laetoli footprints reveal bipedal gait biomechanics different from those of modern humans and chimpanzees.	bipedalism is a key adaptation that shaped human evolution, yet the timing and nature of its evolution remain unclear. here we use new experimentally based approaches to investigate the locomotor mechanics preserved by the famous pliocene hominin footprints from laetoli, tanzania. we conducted footprint formation experiments with habitually barefoot humans and with chimpanzees to quantitatively compare their footprints to those preserved at laetoli. our results show that the laetoli footprints a ...	2016	27488647
emergence of a homo sapiens-specific gene family and chromosome 16p11.2 cnv susceptibility.	genetic differences that specify unique aspects of human evolution have typically been identified by comparative analyses between the genomes of humans and closely related primates, including more recently the genomes of archaic hominins. not all regions of the genome, however, are equally amenable to such study. recurrent copy number variation (cnv) at chromosome 16p11.2 accounts for approximately 1% of cases of autism and is mediated by a complex set of segmental duplications, many of which ar ...	2016	27487209
the dau cluster: a comparative analysis of 18 rhd alleles, some forming partial d antigens.	the rh system is the most complex and polymorphic blood group system in humans with more than 460 alleles known for the rhd gene. the dau cluster of rhd alleles is characterized by the single-nucleotide change producing the p.thr379met amino acid substitution. it is called the dau-0 allele and has been postulated to be the primordial allele, from which all other alleles of the dau cluster have eventually evolved.	2016	27480171
tepitool: a pipeline for computational prediction of t cell epitope candidates.	computational prediction of t cell epitope candidates is currently being used in several applications including vaccine discovery studies, development of diagnostics, and removal of unwanted immune responses against protein therapeutics. there have been continuous improvements in the performance of mhc binding prediction tools, but their general adoption by immunologists has been slow due to the lack of user-friendly interfaces and guidelines. current tools only provide minimal advice on what al ...	2016	27479659
characterizing abnormal behavior in a large population of zoo-housed chimpanzees: prevalence and potential influencing factors.	abnormal behaviors in captive animals are generally defined as behaviors that are atypical for the species and are often considered to be indicators of poor welfare. although some abnormal behaviors have been empirically linked to conditions related to elevated stress and compromised welfare in primates, others have little or no evidence on which to base such a relationship. the objective of this study was to investigate a recent claim that abnormal behavior is endemic in the captive population ...	2016	27478710
differences in molecular evolutionary rates among micrornas in the human and chimpanzee genomes.	the rise of the primate lineage is accompanied by an outstanding emergence of micrornas, small non-coding rnas with a prominent role in gene regulation. in spite of their biological importance little is known about the way in which natural selection has influenced micrornas in the human lineage. to study the recent evolutionary history of human micrornas and to analyze the signatures of natural selection in genomic regions harbouring micrornas we have investigated the nucleotide substitution rat ...	2016	27474039
kea cooperate better with sharing affiliates.	controlled studies that focus on intraspecific cooperation tasks have revealed striking similarities, but also differences, in abilities across taxa as diverse as primates, fish, and birds. such comparisons may provide insight into the specific socio-ecological selection pressures that led to the evolution of cooperation. unfortunately, however, compared to primates data on birds remain relatively scarce. we tested a new zealand psittaciform, the kea, in a dyadic cooperation task using the loose ...	2016	27473206
animal research. chimpanzee sanctuaries open door to more research.		2016	27471286
form and function of the human and chimpanzee forefoot: implications for early hominin bipedalism.	during bipedal walking, modern humans dorsiflex their forefoot at the metatarsophalangeal joints (mtpjs) prior to push off, which tightens the plantar soft tissues to convert the foot into a stiff propulsive lever. particular features of metatarsal head morphology such as "dorsal doming" are thought to facilitate this stiffening mechanism. in contrast, chimpanzees are believed to possess mtpj morphology that precludes high dorsiflexion excursions during terrestrial locomotion. the morphological ...	2016	27464580
effects of relocation and individual and environmental factors on the long-term stress levels in captive chimpanzees (pan troglodytes): monitoring hair cortisol and behaviors.	understanding the factors associated with the long-term stress levels of captive animals is important from the view of animal welfare. in this study, we investigated the effects of relocation in addition to individual and environmental factors related to social management on long-term stress level in group-living captive chimpanzees by examining behaviors and hair cortisol (hc). specifically, we conducted two studies. the first compared changes in hc levels before and after the relocation of 8 c ...	2016	27463685
faster reproductive rates trade off against offspring growth in wild chimpanzees.	life history theory predicts a trade-off between offspring quality and quantity. among large-bodied mammals, prolonged lactation and infant dependence suggest particularly strong potential for a quality-quantity trade-off to exist. humans are one of the only such species to have been examined, providing mixed evidence under a peculiar set of circumstances, including extensive nutritional provisioning by nonmothers and extrasomatic wealth transmission. here, we examine trade-offs between reproduc ...	2016	27354523
children's and apes' preparatory responses to two mutually exclusive possibilities.	animal brains have evolved to predict outcomes of events in the immediate environment [1-5]. adult humans are particularly adept at dealing with environmental uncertainty, being able to mentally represent multiple, even mutually exclusive versions of the future and prepare accordingly. this capacity is fundamental to many complex future-oriented behaviors [6, 7], yet little is known about when it develops in children [8] and whether it is shared with non-human animals [9]. here we show that chil ...	2016	27345164
copy number variation in tas2r bitter taste receptor genes: structure, origin, and population genetics.	bitter taste receptor genes (tas2rs) harbor extensive diversity, which is broadly distributed across human populations and strongly associated with taste response phenotypes. the majority of tas2r variation is composed of single-nucleotide polymorphisms. however, 2 closely positioned loci at 12p13, tas2r43 and -45, harbor high-frequency deletion (δ) alleles in which genomic segments are absent, resulting in copy number variation (cnv). to resolve their chromosomal structure and organization, we ...	2016	27340135
cpg island evolution in the mammalian dhrs4 gene cluster and its role in the regulation of gene transcription.	the dehydrogenase/reductase (sdr family) member 4 (dhrs4) gene is copied during mammalian evolution; therefore, while only one dhrs4 gene is expressed in the mouse genome, the gene cluster consists of two (dhrs4 and dhrs4l1) and three (dhrs4, dhrs4l2, and dhrs4l1) copies in chimpanzees and humans, respectively. in this study, we explored the possible regulatory mechanism of the dhrs4 gene cluster in mammalian evolution by analyzing the promoter sequence, methylation of cpg islands, and rna expre ...	2016	27323117