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The recent development of methods for constructing directly comparable white matter atlases in primate brains from diffusion MRI allows us to probe specializations unique to humans, great apes, and other primate taxa. Here, we constructed the first white matter atlas of a lesser ape using an ex vivo diffusion-weighted scan of a brain from a young adult (5.5 years) male lar gibbon. We find that white matter architecture of the gibbon temporal lobe suggests specializations that are reminiscent of those previously reported for great apes, specifically, the expansion of the arcuate fasciculus and the inferior longitudinal fasciculus in the temporal lobe. Our findings suggest these white matter expansions into the temporal lobe were present in the last common ancestor to hominoids approximately 16 million years ago and were further modified in the great ape and human lineages. White matter atlases provide a useful resource for identifying neuroanatomical differences and similarities between humans and other primate species and provide insight into the evolutionary variation and stasis of brain organization. [ABSTRACT FROM AUTHOR]

We present the PanAf20K dataset, the largest and most diverse open-access annotated video dataset of great apes in their natural environment. It comprises more than 7 million frames across ∼ 20,000 camera trap videos of chimpanzees and gorillas collected at 18 field sites in tropical Africa as part of the Pan African Programme: The Cultured Chimpanzee. The footage is accompanied by a rich set of annotations and benchmarks making it suitable for training and testing a variety of challenging and ecologically important computer vision tasks including ape detection and behaviour recognition. Furthering AI analysis of camera trap information is critical given the International Union for Conservation of Nature now lists all species in the great ape family as either Endangered or Critically Endangered. We hope the dataset can form a solid basis for engagement of the AI community to improve performance, efficiency, and result interpretation in order to support assessments of great ape presence, abundance, distribution, and behaviour and thereby aid conservation efforts. The dataset and code are available from the project website: PanAf20K [ABSTRACT FROM AUTHOR]

There has been a long debate about the possibility of multiple contemporaneous species of Australopithecus in both eastern and southern Africa, potentially exhibiting different forms of bipedal locomotion. Here, we describe the previously unreported morphology of the os coxae in the 3.67 Ma Australopithecus prometheus StW 573 from Sterkfontein Member 2, comparing it with variation in ossa coxae in living humans and apes as well as other Plio‐Pleistocene hominins. Statistical comparisons indicate that StW 573 and 431 resemble humans in their anteroposteriorly great iliac crest breadth compared with many other early australopiths, whereas Homo ergaster KNM WT 15000 surprisingly also has a relatively anterioposteriorly short iliac crest. StW 573 and StW 431 appear to resemble humans in having a long ischium compared with Sts 14 and KNM WT 15000. A Quadratic Discriminant Function Analysis of morphology compared with other Plio‐Pleistocene hominins and a dataset of modern humans and hominoids shows that, while Lovejoy's heuristic model of the Ardipithecus ramidus os coxae falls with Pongo or in an indeterminate group, StW 573 and StW 431 from Sterkfontein Member 4 are consistently classified together with modern humans. Although clearly exhibiting the classic “basin shaped” bipedal pelvis, Sts 14 (also from Sterkfontein), AL 288‐1 Australopithecus afarensis, MH2 Australopithecus sediba and KNM‐WT 15000 occupy a position more peripheral to modern humans, and in some analyses are assigned to an indeterminate outlying group. Our findings strongly support the existence of two species of Australopithecus at Sterkfontein and the variation we observe in os coxae morphology in early hominins is also likely to reflect multiple forms of bipedality. [ABSTRACT FROM AUTHOR]

Objectives: Low‐energy vertebral fractures are a common health concern, especially in elderly people. Interestingly, African apes do not seem to experience as many vertebral fractures and the low‐energy ones are even rarer. One potential explanation for this difference is the lower bone density in humans. Yet, only limited research has been done on the vertebral bone density of the great apes and these have mainly included only single vertebrae. Hence the study aim is to expand our understanding of the vertebral microstructure of African apes in multiple spinal segments. Materials: Bone density in the vertebral body of C7, T12, and L3 was measured from 32 Pan troglodytes and 26 Gorilla gorilla using peripheral quantitative computed tomography (pQCT). Results: There was a clear difference between the three individual vertebrae and consequently the spinal segments in terms of trabecular density and cortical density and thickness. The variation of these bone parameters between the vertebrae differed between the apes but was also different from those reported for humans. The chimpanzees were observed to have overall higher trabecular density, but gorillas had higher cortical density and thickness. Cortical thickness had a relatively strong association with the vertebral size. Discussion: Despite the similarity in locomotion and posture, the results show slight differences in the bone parameters and their variation between spinal segments in African apes. This variation also differs from humans and appears to indicate a complex influence of locomotion, posture, and body size on the different spinal segments. [ABSTRACT FROM AUTHOR]

The known diversity of European middle and late Miocene hominids has increased significantly during the last decades. Most of these great apes were frugivores in the broadest sense, ranging from soft fruit frugivores most like chimpanzees to hard/tough object feeders like orangutans, varying in size from larger than siamangs (over 17 kg) to larger than most chimpanzees (~60–70 kg). In contrast to the frequent sympatry of hominoids in the early-to-middle Miocene of Africa, in no European Miocene locality more than one hominid taxon has been identified. Here we describe the first case of hominid sympatry in Europe from the 11.62 Ma old Hammerschmiede HAM 5 level, best known from its excellent record of Danuvius guggenmosi. The new fossils are consistent in size with larger pliopithecoids but differ morphologically from any pliopithecoid and from Danuvius. They are also distinguished from early and middle Miocene apes, share affinities with late Miocene apes, and represent a small hitherto unknown late Miocene ape Buronius manfredschmidi. With an estimated body mass of about 10 kg it represents the smallest known hominid taxon. The relative enamel thickness of Buronius is thin and contrasts with Danuvius, whose enamel is twice as thick. The differences between Buronius and Danuvius in tooth and patellar morphology, enamel thickness and body mass are indicative of differing adaptations in each, permitting resource partitioning, in which Buronius was a more folivorous climber. [ABSTRACT FROM AUTHOR]

African apes are humans' closest evolutionary relatives, yet their fossil record is almost nonexistent. Genomics shows that, despite the fact that African ape lineages originated 6–12 million years ago (Ma), the diversity within the living species is very young (<1 Ma), similar in age to the diversity of recent hominin species, such as modern humans and Neanderthals. The hominin fossil record shows deeper and greater diversity compared with that of the African apes, suggesting that, across hominine evolution, they must have experienced a high rate of extinction, with repeated replacements and dispersals. Recent genomic studies also suggest that African apes had higher levels of diversification in earlier periods, and it is likely that a high rate of extinction and replacement occurred. This raises questions about the last common ancestor, the conditions under which apes evolved, and the adaptive and dispersive nature of the current species. We are accustomed to regular announcements of new hominin fossils. There are now some 6000 hominin fossils, and up to 31 species. However, where are the announcements of African ape fossils? The answer is that there are almost none. Our knowledge of African ape evolution is based entirely on genomic analyses, which show that extant diversity is very young. This contrasts with the extensive and deep diversity of hominins known from fossils. Does this difference point to low and late diversification of ape lineages, or high rates of extinction? The comparative evolutionary dynamics of African hominids are central to interpreting living ape adaptations, as well as understanding the patterns of hominin evolution and the nature of the last common ancestor. [ABSTRACT FROM AUTHOR]

Midfacial morphology varies between hominoids, in particular between great apes and humans for which the face is small and retracted. The underlying developmental processes for these morphological differences are still largely unknown. Here, we investigate the cellular mechanism of maxillary development (bone modelling, BM), and how potential changes in this process may have shaped facial evolution. We analysed cross-sectional developmental series of gibbons, orangutans, gorillas, chimpanzees and present-day humans (n = 183). Individuals were organized into five age groups according to their dental development. To visualize each species's BM pattern and corresponding morphology during ontogeny, maps based on microscopic data were mapped onto species-specific age group average shapes obtained using geometric morphometrics. The amount of bone resorption was quantified and compared between species. Great apes share a highly similar BM pattern, whereas gibbons have a distinctive resorption pattern. This suggests a change in cellular activity on the hominid branch. Humans possess most of the great ape pattern, but bone resorption is high in the canine area from birth on, suggesting a key role of canine reduction in facial evolution. We also observed that humans have high levels of bone resorption during childhood, a feature not shared with other apes. [ABSTRACT FROM AUTHOR]

Investigations into the role of selection in the origin of human bipedalism using ape models have relied heavily on behavioral frequency data. However, analysis of video of wild apes has the advantage of capturing the details of the entirety of each rare, brief bipedal bout witnessed, not just the moment detected in observational studies. We used video to explore the behavioral context and effects of several variables on bipedalism across all ages in wild forest-dwelling chimpanzees from Ngogo, Uganda. We found, as in earlier studies, that adult chimpanzees used bipedalism in the context of foraging; however, unlike earlier studies, we found that while foraging was the predominant behavioral context during arboreal bipedalism, terrestrial bipedalism was more varied in contextual composition. We also found that these different behavioral contexts of bipedalism were associated with different variables. Specifically, foraging was associated with arboreality, hand assistance, and adulthood; antagonism was associated with adulthood, locomotion, and males; play was associated with terrestriality and subadulthood; and travel was associated with locomotion and females. Given that several variables influence bipedalism across multiple behavioral contexts in chimpanzees, it is likely that the early evolution of human bipedalism occurred under the influence of numerous factors. This exploratory study thus suggests that more comprehensive models should be used when reconstructing the transition to bipedalism from the Last Common Ancestor of humans and chimpanzees. [ABSTRACT FROM AUTHOR]

The article is a review of the book "Stuff: Humanity's Epic Journey from Naked Ape to Nonstop Shopper" by Chip Colwell. The book explores the history of human interaction with material culture and our relationship with "stuff." It discusses the evolution of toolmaking, the emergence of art and religion, and the rise of consumerism. The author examines how our dependence on material possessions has shaped our society and raises questions about the future of our relationship with "stuff." The review praises the book for its comprehensive approach but notes that it lacks discussion on certain perspectives and the role of museums in addressing overconsumption. [Extracted from the article]

Introduction: Modern humans are the only fully terrestrial ape. AH other apes are partially arboreal, particularly as infants and juveniles. Precocial locomotor development, high frequency of arboreal locomotion in early ontogeny, and increased terrestriality throughout development are ubiquitous amongst the hominines and likely represent the ancestral state. The role of climbing in hominin evolution has been debated for decades, but if hominins climbed regularly then subadults likely relied on it most frequently. Investigating the role of climbing throughout hominin evolution requires reliable developmentally plastic traits that are responsive to locomotor loading and can be identified in the fossil record. Chimpanzees and gorillas provide a natural experiment to examine the relationship between age-related variation locomotor activities and bone structure. Chimpanzees and gorillas are most arboreal during infancy and become more terrestrial throughout development. Gorillas are comparatively more terrestrial and transition to predominantly terrestrial locomotion at an earlier age. This paper has two main objectives. First, to examine if interspecific differences in the rate of locomotor development is reflected in bone structure. Second, to determine if ontogenetic reductions in the frequency of arboreal locomotion correspond to age-related variation in bone structure. Methods: The humerus, tibia, calcaneus, and seventh cervical vertebrae of an ontogenetic series of gorillas and chimpanzees from the Powell Cotton Museum (n = 71) were uCT scanned. Trabecular, cortical, and total bone volume fraction (BV/TV) were calculated in developmentally homologous regions of interest. Results: BV/TV scales with positive allometry throughout ontogeny. The achievement of adult-like locomotor behaviour can be identified by a significant change in the slope of Total.BV/TV with age. Younger, more arboreal individuals have relatively greater upper limb Total.BV/TV relative to the neck and lower limb than older, more terrestrial individuals in gorillas and chimpanzees. More arboreal chimpanzees have relatively more Total.BV/TV in the upper limb relative to the lower limb and neck. Discussion: The correspondence between developmental trajectories of BV/TV and locomotor ontogeny in extant apes suggests that analyses of hominin skeletal ontogeny can provide new insights into the evolution of two characteristic human traits: our slow rate of maturation and the evolution of fully terrestrial bipedalism. [ABSTRACT FROM AUTHOR]

Pierolapithecus catalaunicus (~12 million years ago, northeastern Spain) is key to understanding the mosaic nature of hominid (great ape and human) evolution. Notably, its skeleton indicates that an orthograde (upright) body plan preceded suspensory adaptations in hominid evolution. However, there is ongoing debate about this species, partly because the sole known cranium, preserving a nearly complete face, suffers from taphonomic damage. We 1) carried out a micro computerized tomography (CT) based virtual reconstruction of the Pierolapithecus cranium, 2) assessed its morphological affinities using a series of two-dimensional (2D) and three-dimensional (3D) morphometric analyses, and 3) modeled the evolution of key aspects of ape face form. The reconstruction clarifies many aspects of the facial morphology of Pierolapithecus. Our results indicate that it is most similar to great apes (fossil and extant) in overall face shape and size and is morphologically distinct from other Middle Miocene apes. Crown great apes can be distinguished from other taxa in several facial metrics (e.g., low midfacial prognathism, relatively tall faces) and only some of these features are found in Pierolapithecus, which is most consistent with a stem (basal) hominid position. The inferred morphology at all ancestral nodes within the hominoid (ape and human) tree is closer to great apes than to hylobatids (gibbons and siamangs), which are convergent with other smaller anthropoids. Our analyses support a hominid ancestor that was distinct from all extant and fossil hominids in overall facial shape and shared many features with Pierolapithecus. This reconstructed ancestral morphotype represents a testable hypothesis that can be reevaluated as new fossils are discovered. [ABSTRACT FROM AUTHOR]

Fossil apes from the eastern Mediterranean are central to the debate on African ape and human (hominine) origins. Current research places them either as hominines, as hominins (humans and our fossil relatives) or as stem hominids, no more closely related to hominines than to pongines (orangutans and their fossil relatives). Here we show, based on our analysis of a newly identified genus, Anadoluvius, from the 8.7 Ma site of Çorakyerler in central Anatolia, that Mediterranean fossil apes are diverse, and are part of the first known radiation of early members of the hominines. The members of this radiation are currently only identified in Europe and Anatolia; generally accepted hominins are only found in Africa from the late Miocene until the Pleistocene. Hominines may have originated in Eurasia during the late Miocene, or they may have dispersed into Eurasia from an unknown African ancestor. The diversity of hominines in Eurasia suggests an in situ origin but does not exclude a dispersal hypothesis. An 8.7 million year old ape from Türkiye shows that Mediterranean fossil apes are diverse and part of the first known radiation of hominines (African apes and humans). Our phylogenetic analysis suggests that hominines originate in Europe. [ABSTRACT FROM AUTHOR]

Cooperative behaviors among individuals of numerous species play a crucial role in social interactions. There is a special interest in investigating the occurrence of cooperation among apes because this knowledge could also shed light on evolutionary processes and help us understand the origin and development of cooperation in humans and primates in general. Gibbons are phylogenetically intermediate between the great apes and monkeys, and therefore represent a unique opportunity for comparisons. The aim of the present study was to discover whether or not white-handed gibbons (Hylobates lar) show cooperative behaviors. In order to test for the respective behaviors, the gibbons were presented with a commonly used experimental cooperative rope-pulling task. The gibbons in this study did not exhibit cooperative behaviors during the problem-solving task. However, prior training procedures could not be fully completed, hence this project constitutes only the onset of exploring cooperative behaviors in gibbons. Additional behavioral observations revealed that the gibbons spent significantly more time "out of arm's reach to everyone", suggesting that they are less often involved in social interactions, than other, more cooperative primates. [ABSTRACT FROM AUTHOR]

Since the first discovery of human fossils in the mid‐19th century, two subjects—our phylogenetic relationship to living and fossil apes and the ancestral locomotor behaviors preceding bipedalism—have driven the majority of discourse in the study of human origins. With few fossils and thus limited comparative evidence available to inform or constrain them, morphologists of the 19th and early mid‐20th centuries posited a range of scenarios for the evolution of bipedalism. In contrast, there exists a rich hominin fossil record and the acceptance of Pan (chimpanzees and bonobos) as our closest living relatives is nearly universal, yet consensus about the ancestral condition from which hominins evolved remains elusive. Notably, while the earliest known hominins are generally congruent with parsimonious inferences of an African ape‐like last common ancestor, our more distantly related Miocene ape cousins are frequently invoked as evidence in favor of more complex scenarios that require substantial homoplasy. Debate over these alternatives suggests that how we infer ancestral nodes and weigh evidence to test their relative likelihoods remains a stumbling block. Here we argue that a key contributor to this impasse includes the history of terminology associated with positional behavior, which has become confused over the last century. We aim to clarify positional behavior concepts and contextualize knuckle‐walking and other forms of posture and locomotion chimpanzees and gorillas engage in, while arguing that the presence of homoplasy in ape evolution does not alter the weight of evidence in favor of an African ape‐like evolutionary history of hominins. [ABSTRACT FROM AUTHOR]

Human-animal pathogenic transmissions threaten both human and animal health, and the processes catalyzing zoonotic spillover and spillback are complex. Prior field studies offer partial insight into these processes but overlook animal ecologies and human perceptions and practices facilitating human-animal contact. Conducted in Cameroon and a European zoo, this integrative study elucidates these processes, incorporating metagenomic, historical, anthropological and great ape ecological analyses, and real-time evaluation of human-great ape contact types and frequencies. We find more enteric eukaryotic virome sharing between Cameroonian humans and great apes than in the zoo, virome convergence between Cameroonian humans and gorillas, and adenovirus and enterovirus taxa as most frequently shared between Cameroonian humans and great apes. Together with physical contact from hunting, meat handling and fecal exposure, overlapping human cultivation and gorilla pillaging in forest gardens help explain these findings. Our multidisciplinary study identifies environmental co-use as a complementary mechanism for viral sharing. Here, the authors conduct a multidisciplinary study of human-great ape viral sharing in Cameroon and a European zoo, finding that environmental co-use enables more enteric virome sharing, virome convergence, and adenovirus and enterovirus sharing between Cameroonian humans and apes. [ABSTRACT FROM AUTHOR]

Humans are perhaps the most curious animals on earth, but to what extent our innate motivations for discovering new information are shared with our closest relatives remain poorly understood. To shed light on this question, we presented great apes with two experimental paradigms in which they had to initially choose between an empty opaque cup and a baited opaque cup with rewards invisible to the ape in study 1, or to choose between a transparent cup with rewards or a baited opaque cup with rewards invisible to the ape in studies 2 and 3. We also presented young children with scenarios comparable to the second paradigm (studies 4 and 5). Notably, after the initial choice phase, we presented participants with potential alternatives providing better rewards than the previously secured options. Importantly, those alternatives shared some features with the uncertain options, giving subjects the possibility to relate both options through analogical reasoning. We found that most great apes were not curious about the uncertain options. They only explored those options after they were presented with the alternatives. Children, instead, explored the uncertain options before the alternatives were presented, showing a higher degree of curiosity than the great apes. We argue that differences between children and apes mostly lay in motivational dispositions to explore the unknown. [ABSTRACT FROM AUTHOR]

Reciprocal food exchange is widespread in human societies but not among great apes, who may view food mainly as a target for competition. Understanding the similarities and differences between great apes' and humans' willingness to exchange food is important for our models regarding the origins of uniquely human forms of cooperation. Here, we demonstrate in-kind food exchanges in experimental settings with great apes for the first time. The initial sample consisted of 13 chimpanzees and 5 bonobos in the control phases, and the test phases included 10 chimpanzees and 2 bonobos, compared with a sample of 48 human children aged 4 years. First, we replicated prior findings showing no spontaneous food exchanges in great apes. Second, we discovered that when apes believe that conspecifics have 'intentionally' transferred food to them, positive reciprocal food exchanges (food-for-food) are not only possible but reach the same levels as in young children (approx. 75–80%). Third, we found that great apes engage in negative reciprocal food exchanges (no-food for no-food) but to a lower extent than children. This provides evidence for reciprocal food exchange in great apes in experimental settings and suggests that while a potential mechanism of fostering cooperation (via positive reciprocal exchanges) may be shared across species, a stabilizing mechanism (via negative reciprocity) is not. [ABSTRACT FROM AUTHOR]

Objectives: Morphological variation in African ape carpals has been used to support the idea that Pan and Gorilla evolved knuckle‐walking independently. Little work, however, has focused on the effect of body mass on carpal morphology. Here, we compare carpal allometry in Pan and Gorilla to that of other quadrupedal mammals with similar body mass differences. If allometric trends in Pan and Gorilla carpals mirror those of other mammals with similar body mass variation, then body mass differences may provide a more parsimonious explanation for African ape carpal variation than the independent evolution of knuckle‐walking. Materials and Methods: Three linear measurements were collected on the capitate, hamate, lunate, and scaphoid (or scapholunate) of 39 quadrupedal species from six mammalian families/subfamilies. Relationships between linear measurements and estimated body mass were analyzed using reduced major axis regression. Slopes were compared to 0.33 for isometry. Results: Within Hominidae, higher body mass taxa (Gorilla) have relatively anteroposteriorly wider, mediolaterally wider, and/or proximodistally shorter capitates, hamates, and scaphoids than low body mass taxa (Pan). These allometric relationships are mirrored in most, but not all, mammalian families/subfamilies included in the analysis. Conclusions: Within most mammalian families/subfamilies, carpals of high body mass taxa are proximodistally shorter, anteroposteriorly wider, and mediolaterally wider than those of low body mass taxa. These distinctions may be caused by the need to accommodate relatively higher forelimb loading associated with greater body mass. Because these trends occur within multiple mammalian families/subfamilies, some carpal variation in Pan and Gorilla is consistent with body mass differences. [ABSTRACT FROM AUTHOR]

Gestural communication is crucial for primates. However, little is known about how gestural repertoires emerge through development. We conducted behavioural observations on captive apes, including 18 siamangs (Symphalangus syndactylus), 16 Sumatran orangutans (Pongo abelii), and 19 chimpanzees (Pan troglodytes), to test different hypotheses for the emergence of gestures (i.e., Phylogenetic Ritualization, Ontogenetic Ritualization, Social Negotiation, and Social Transmission hypotheses). Our results showed little variation in individual gestural repertories, and only one idiosyncratic gesture. Moreover, across subjects (N = 53), repertoire size did not increase with age and social centrality. When comparing repertoires across all possible combinations of conspecifics, including apes in different groups (N=273) for the four groups of siamangs and the two of orangutans, repertoire similarity was higher in dyads of the same group than of different groups, but it also increased with more observational effort and lower age difference between group members. Finally, when comparing repertoires across all dyads of conspecifics in the same group (N = 260), we found no differences in repertoire similarity depending on dyadic relationship quality. Overall, these results provide support for the Phylogenetic Ritualization hypothesis, according to which individuals are endowed with complete gestural repertories from birth. These repertoires are largely similar across individuals and groups, although they may be partially refined through social experiences. [ABSTRACT FROM AUTHOR]

In the comparative study of human and nonhuman communication, ape gesturing provided the first demonstrations of flexible, intentional communication outside human language. Rich repertoires of these gestures have been described in all ape species, bar one: us. Given that the majority of great ape gestural signals are shared, and their form appears biologically inherited, this creates a conundrum: Where did the ape gestures go in human communication? Here, we test human recognition and understanding of 10 of the most frequently used ape gestures. We crowdsourced data from 5,656 participants through an online game, which required them to select the meaning of chimpanzee and bonobo gestures in 20 videos. We show that humans may retain an understanding of ape gestural communication (either directly inherited or part of more general cognition), across gesture types and gesture meanings, with information on communicative context providing only a marginal improvement in success. By assessing comprehension, rather than production, we accessed part of the great ape gestural repertoire for the first time in adult humans. Cognitive access to an ancestral system of gesture appears to have been retained after our divergence from other apes, drawing deep evolutionary continuity between their communication and our own. All nonhuman great apes share a large repertoire of gestures, but there are many challenges to observing these gestures in humans. This study, by showing people videos of ape gestures and testing their understanding, reveals that humans may share these gestures too. [ABSTRACT FROM AUTHOR]

The fearful ape hypothesis (FAH) presents an evolutionary-developmental framework stipulating that in the context of cooperative caregiving, unique to human great ape group life, heightened fearfulness was adaptive. This is because from early in human ontogeny fearfulness expressed and perceived enhanced care-based responding and cooperation with mothers and others. This response extends and refines the FAH by incorporating the commentaries' suggestions and additional lines of empirical work, providing a more comprehensive and nuanced version of the FAH. Specifically, it encourages and hopes to inspire cross-species and cross-cultural, longitudinal work elucidating evolutionary and developmental functions of fear in context. Beyond fear, it can be seen as a call for an evolutionary-developmental approach to affective science. [ABSTRACT FROM AUTHOR]

Already as infants humans are more fearful than our closest living primate relatives, the chimpanzees. Yet heightened fearfulness is mostly considered maladaptive, as it is thought to increase the risk of developing anxiety and depression. How can this human fear paradox be explained? The fearful ape hypothesis presented herein stipulates that, in the context of cooperative caregiving and provisioning unique to human great ape group life, heightened fearfulness was adaptive. This is because from early in ontogeny fearfulness expressed and perceived enhanced care-based responding and provisioning from, while concurrently increasing cooperation with, mothers and others. This explanation is based on a synthesis of existing research with human infants and children, demonstrating a link between fearfulness, greater sensitivity to and accuracy in detecting fear in others, and enhanced levels of cooperative behaviors. These insights critically advance current evolutionary theories of human cooperation by adding an early-developing affective component to the human cooperative makeup. Moreover, the current proposal has important cultural, societal, and health implications, as it challenges the predominant view in Western, educated, industrialized, rich, and democratic (WEIRD) societies that commonly construe fearfulness as a maladaptive trait, potentially ignoring its evolutionary adaptive functions. [ABSTRACT FROM AUTHOR]

Book Review: The Chimpanzees of Rubondo Island: Apes Set Free. To conclude, this book undeniably supplements the existing literature on chimpanzee behavioural variation, adding new reports on another - if rather unusual - chimpanzee community. Keywords: Release; Introduction; Pan troglodytes; Captive chimpanzee; Controversy; Panthropology EN Release Introduction Pan troglodytes Captive chimpanzee Controversy Panthropology 421 423 3 07/10/23 20230601 NES 230601 " I The chimpanzees of Rubondo Island i " retraces the fate of a dozen, captive, western chimpanzees who, in the 1960s, were left on an island in East Africa. [Extracted from the article]

Objectives: This study examines how speciation and extinction rates vary across primates, with a focus on the recent macroevolutionary dynamics that have shaped extant primate biodiversity. Materials and methods: Lineage‐specific macroevolutionary rates were estimated for each tip in a tree containing 307 species using a hidden‐state likelihood model. Differences in tip rates among major clades were evaluated using phylogenetic ANOVA. Differences among diurnal, nocturnal, and cathemeral lineages were also evaluated, based on previous work indicating that activity pattern influences primate diversification. Results: Rate variation in extant primates is low within clades and high between clades. As in previous studies, cercopithecoids stand out in having high net diversification rates, driven by high speciation rates and very low extinction rates. Platyrrhines combine high speciation and high extinction rates, giving them high rates of lineage turnover. Strepsirrhines and tarsiids have low rates of speciation, extinction, turnover, and net diversification. Hominoids are intermediate between platyrrhines and the strepsirrhine‐tarsiid group, and there is evidence for differentiation between hominids and hylobatids. Diurnal lineages have significantly higher speciation rates than nocturnal lineages. Conclusions: Recent anthropoid macroevolution has been characterized by marked variation in diversification dynamics among clades. Strepsirrhines and tarsiids are more uniform, despite divergent evolutionary and biogeographic histories. Higher speciation rates in diurnal lineages may be driven by greater ecological opportunity or reliance on visual signals for mate recognition. However, the differences among anthropoids indicate that factors other than activity pattern (e.g., clade competition, historical contingency) have had a more influential role in shaping recent primate diversification. [ABSTRACT FROM AUTHOR]

Primatological research in zoos is increasing globally. Such research allows scientists to study primate biology, behavior, and cognition while helping to advance the welfare of captive primates. Moreover, zoos welcome millions of visitors annually, which creates unique opportunities for public engagement with this research. Reflecting the importance of zoos in the field of primatology, the articles in this special issue showcase the range of primatological research currently being conducted in zoos around the world. With this special issue, I have chosen to focus on research examining primate behavior and cognition, addressing both basic and applied questions. The articles included in this special issue also highlight the array of technologies and methods being used to study zoo‐housed primates. While zoos house a variety of primate species, potentially enabling the testing of under‐studied species or widescale comparative research, great apes are disproportionately represented in current zoo‐based research. Thus, while an interest in conducting research with primates in zoos continues to grow, there are still opportunities to increase the breadth and diversity of this study. Highlights: Primatological research in zoos is increasing globally.Such research allows scientists to study primate biology, behavior, and cognition.This research helps to advance the welfare of captive primates.While zoos house many primate species, apes are disproportionately represented in current zoo research. [ABSTRACT FROM AUTHOR]

Regardless of which synanthropic index is used to calculate which flies or animals are found in association with humans, more studies need to be done in areas where flies have proven to be involved in transmitting human or animal pathogens, such as anthrax or food-borne pathogens. In their excellent paper on flies transmitting the pathogen of yaws, which is a major problem of wild baboons in Tanzania, Knauf et al. [[92]], using DNA sequencing, were able to show that several necrophagous flies contained the pathogens and were involved in the transmission cycle in the study area. This pathogen transfer can occur either by an infectious fly being eaten or by the fly leaving its newly acquired pathogens/parasites via the processes of regurgitation and/or defecation on the food source. Keywords: dipteran diverticulated crop; bio-enhanced pathogen transmission; regurgitation; horizontal transmission of resistance; bats; birds; apes; zoonoses; viruses; emerging infectious diseases EN dipteran diverticulated crop bio-enhanced pathogen transmission regurgitation horizontal transmission of resistance bats birds apes zoonoses viruses emerging infectious diseases N.PAG N.PAG 27 09/27/22 20220901 NES 220901 1. Synanthropic Flies - A Review Including How They Obtain Nutrients, along with Pathogens, Store Them in the Crop and Mechanisms of Transmission. [Extracted from the article]

Gestures are ubiquitous in human communication, involving movements of body parts produced for a variety of purposes, such as pointing out objects (deictic gestures) or conveying messages (symbolic gestures) 1. While displays of body parts have been described in many animals 2 , their functional similarity to human gestures has primarily been explored in great apes 3,4 , with little research attention given to other animal groups. To date, only a few studies have provided evidence for deictic gestures in birds and fish 5,6,7 , but it is unclear whether non-primate animals can employ symbolic gestures, such as waving to mean 'goodbye', which are, in humans, more cognitively demanding than deictic gestures 1. Here, we report that the Japanese tit (Parus minor), a socially monogamous bird, uses wing-fluttering to prompt their mated partner to enter the nest first, and that wing-fluttering functions as a symbolic gesture conveying a specific message ('after you'). Our findings encourage further research on animal gestures, which may help in understanding the evolution of complex communication, including language. Zhu et al. present an alternative explanation for the weaker multisensory illusions in football goalkeepers compared with outfielders and non-athletes, showing that better unisensory precision in goalkeepers can also account for this effect. [ABSTRACT FROM AUTHOR]

Background: The reduction of the chromosome number from 48 in the Great Apes to 46 in modern humans is thought to result from the end-to-end fusion of two ancestral non-human primate chromosomes forming the human chromosome 2 (HSA2). Genomic signatures of this event are the presence of inverted telomeric repeats at the HSA2 fusion site and a block of degenerate satellite sequences that mark the remnants of the ancestral centromere. It has been estimated that this fusion arose up to 4.5 million years ago (Mya). Results: We have developed an enhanced algorithm for the detection and efficient counting of the locally over-represented weak-to-strong (AT to GC) substitutions. By analyzing the enrichment of these substitutions around the fusion site of HSA2 we estimated its formation time at 0.9 Mya with a 95% confidence interval of 0.4-1.5 Mya. Additionally, based on the statistics derived from our algorithm, we have reconstructed the evolutionary distances among the Great Apes (Hominoidea). Conclusions: Our results shed light on the HSA2 fusion formation and provide a novel computational alternative for the estimation of the speciation chronology. [ABSTRACT FROM AUTHOR]

Although curiosity has huge implications for human creativity and learning, its evolutionary roots and function in animals remain poorly understood. Modern humans, who lack natural predators, thrive with curiosity, but our ancestors faced more hazardous environments that would not necessarily favor individual curiosity. Instead, being curious may have undergone selection in interaction with sociality. Our closest living relatives, the great apes (henceforth apes) have evolved facing conditions more like human ancestors and as such, can help us understand the functions of curiosity and its expression in non‐human species. In this study, we defined curiosity as a combination of behavioral traits like neophilia, exploration diversity, and prolonged interest in exploring novelty and compared it, under similar captive environments across four ape species (N = 101): Pan troglodytes, Pan paniscus, Pongo abelii, and Pongo pygmaeus. Results revealed that curiosity followed a linear gradient across the four species in accordance with their sociality. We propose the social curiosity hypothesis to explain the observed pattern, reflecting those individuals in highly social species, like bonobos and chimpanzees, regularly are accompanied by conspecifics, and thereby accustomed to an abundance of social cues, leading to inhibited curiosity when alone, compared to more solitary orangutans. As such, our study implies that ape curiosity evolved interlinked with sociality. Further, a subset of the sample (N = 46) enabled us to examine if curiosity benefits problem‐solving skills, but our data did not support such link. [ABSTRACT FROM AUTHOR]

Afro-Eurasian monkeys originated in the Miocene and are the most species-rich modern primate family. Molecular and fossil data have provided considerable insight into their evolutionary divergence, but we know considerably less about the evolutionary processes that underlie these differences. Here, we apply tests developed from quantitative genetics theory to a large (n > 3000) cranio-mandibular morphometric dataset, investigating the relative importance of adaptation (natural selection) and neutral processes (genetic drift) in shaping diversity at different taxonomic levels, an approach applied previously to monkeys of the Americas, apes, hominins, and other vertebrate taxa. Results indicate that natural selection, particularly for differences in size, plays a significant role in diversifying Afro-Eurasian monkeys as a whole. However, drift appears to better explain skull divergence within the subfamily Colobinae, and in particular the African colobine clade, likely due to habitat fragmentation. Small and declining population sizes make it likely that drift will continue in this taxon, with potentially dire implications for genetic diversity and future resilience in the face of environmental change. For the other taxa, many of whom also have decreasing populations and are threatened, understanding adaptive pressures similarly helps identify relative vulnerability and may assist with prioritising scarce conservation resources. [ABSTRACT FROM AUTHOR]

While Grawunder et al. do not report I f i SB 0 sb values of chimpanzee screams from which formants are estimated, measurements for scream climaxes have elsewhere been reported to be as high as I f i SB 0 sb > 1,500 Hz (Mitani et al., [4]). Indeed, most F SB 1 sb and F SB 2 sb values reported for scream calls (Grawunder et al., [3], p. 9) follow an apparent 1:2 ratio, suggesting that frequencies of two lower-spectrum partials were interpreted as formants. Analysis of nonhuman, great ape vocal behavior may provide insight into the evolution of human speech. [Extracted from the article]

Chip scars in fossil teeth are a lasting evidence that bears on human evolution. Chip dimensions in posterior teeth of hominins, apes and white-lipped peccary (Tayassu pecari) are measured from published occlusal images. The results are plotted as D / D m vs. h / D m , where h , D and D m denote indent distance, chip width and mean tooth crown diameter. The hominin species follow a similar pattern where D / D m monotonically increases up to h / D m ≈ 0.3. The behavior for the apes is characterized by two phases. In the first, h / D m monotonically increases up to h / D m ≈ 0.26 while in the second (h / D m ≈ 0.26 to 0.42), D / D m experiences a drastic change in behavior. The interpretation of chip morphology is assisted by results from controlled spherical indentation tests on extracted human molars. This study shows that in addition to the commonly recognized chipping due to cusp loading, a chip may also initiate from the inner wall of the tooth's central fossa. Accordingly, it is suggested that the chipping in hominins generally initiates from a (worn) cusp while that in apes involves cusp loading up to h / D m ≈ 0.26 and fossa loading thereafter. The behavior for T. pecari is much similar to that of the apes. The fossa chipping is facilitated by a consumption of hard, large-size diet (e.g., plants, roots, barks and nuts) and presence of broad central fossa, conditions that are met in apes. Finally, a simple expression for the critical chipping force P ch due to fossa loading is developed. • Chipping in hominins generally occurs by cusp loading, that in apes also include fossa loading. • A wide fossa breadth or sharp cusps enable fossa type chipping. • It is recommended that chipping prevalence data be given in terms of normalized chip width D / D m vs. indent distance h / D m. • Enamel wear tends to increase chipping frequency and reduce chip size. • The scope of this work can be enhanced by additional good-resolution tooth images. [ABSTRACT FROM AUTHOR]

Intersubjectivity has often been lauded as one of the defining features that separates humans and other extant hominids. Intersubjectivity and empathy are different, yet related, phenomena. The study of emotions and empathy-related abilities can provide insights into the ontogeny and evolution of intersubjectivity. Intersubjectivity, which refers to the capacity to create shared value or connection between individuals, is a complex and multi-faceted phenomenon involving both cognitive and affective components. Intersubjectivity has often been lauded as one of the defining features that separates the social minds and existence of humans and non-human animals. Despite the apparently profound importance of inter-subjectivity for the socio-cognitive functioning of our species, we know surprisingly little about its evolution, nor how its evolution relates to the evolution of other related phenomena, such as empathy. In this review, we embrace the "bottom-up" perspective to consider recent theoretical and empirical advances in the fields of non-human animal cognition and emotion and what they can tell us about how complex socio-emotional capacities evolve. In particular, we focus on great ape species. Given their close phylogenetic relationship to us, great apes (the non-human, extant hominids) offer a unique lens to identify which of our capacities may be evolutionarily derived or phylogenetically shared. [ABSTRACT FROM AUTHOR]

Over the last 30 years, most research on non-human primate gestural communication has been produced by psychologists, which has shaped the questions asked and the methods used. These researchers have drawn on concepts from philosophy, linguistics, anthropology, and ethology, but despite these broad influences the field has neglected to situate gestures into the socio-ecological context in which the diverse species, individuals, and social-units exist. In this review, we present current knowledge about great ape gestural communication in terms of repertoires, meanings, and development. We fold this into a conversation about variation in other types of ape social behaviour to identify areas for future research on variation in gestural communication. Given the large variation in socio-ecological factors across species and social-units (and the individuals within these groups), we may expect to find different preferences for specific gesture types; different needs for communicating specific meanings; and different rates of encountering specific contexts. New tools, such as machine-learning based automated movement tracking, may allow us to uncover potential variation in the speed and form of gesture actions or parts of gesture actions. New multi-group multi-generational datasets provide the opportunity to apply analyses, such as Bayesian modelling, which allows us to examine these rich behavioural landscapes. Together, by expanding our questions and our methods, researchers may finally be able to study great ape gestures from the perspective of the apes themselves and explore what this gestural communication system reveals about apes' thinking and experience of their world. [ABSTRACT FROM AUTHOR]

One Health is a collaborative trans‐disciplinary approach to health; integrating human, animal, and environmental health. The focus is often on infection disease transmission and disease risk mitigation. However, One Health also includes the multidisciplinary and comparative approach to disease investigation and health of humans, animals, and the environment. One key aspect of environmental/ecosystem health is conservation, the maintenance of healthy, actively reproducing wildlife populations. Reproduction and reproductive health are an integral part of the One Health approach: the comparative aspects of reproduction can inform conservation policies or breeding strategies (in situ and ex situ) in addition to physiology and disease. Differences in reproductive strategies affect the impact poaching and habitat disruption might have on a given population, as well as ex situ breeding programs and the management of zoo and sanctuary populations. Much is known about chimpanzees, macaques, and marmosets as these are common animal models, but there is much that remains unknown regarding reproduction in many other primates. Examining the similarities and differences between and within taxonomic groups allows reasonable extrapolation for decision‐making when there are knowledge gaps. For example: (1) knowing that a species has very low reproductive rates adds urgency to conservation policy for that region or species; (2) identifying species with short or absent lactation anestrus allows ex situ institutions to better plan contraception options for specific individuals or prepare for the immediate next pregnancy; (3) recognizing that progestin contraceptives are effective contraceptives, but may be associated with endometrial hyperplasia in some species (in Lemuridae but not great apes) better guides empirical contraceptive choice; (4) recognizing the variable endometriosis prevalence across taxa improves preventive medicine programs. A summary of anatomical variation, endocrinology, contraception, pathology, and diagnostics is provided to illustrate these features and aid in routine physical and postmortem examinations as well as primate management. Research Highlights: Comparative studies highlight differences and similarities that can elucidate natural mechanisms of action and causes of infertility and subfertility.Better physiology and pathology data from in situ populations are needed to complement the available knowledge from ex situ populations.Improved knowledge of factors that can negatively impact reproduction supports conservation efforts. [ABSTRACT FROM AUTHOR]

How did grammar evolve? Perhaps a better way to ask the question is what kind of cognition is needed to enable grammar. The present analysis departs from the observation that linguistic communication is structured in terms of agents and patients, a reflection of how humans see the world. One way to explore the origins of cognitive skills in humans is to compare them with primates. A first approach has been to teach great apes linguistic systems to study their production in subsequent conversations. This literature has revealed considerable semantic competences in great apes, but no evidence for a corresponding grammatical ability, at least in production. No ape has ever created a sentence with an underlying causal structure of agency and patienthood. A second approach has been to study natural communication in primates and other animals. Here, there is intermittent evidence of compositionality, for example, a capacity to perform operations on semantic units, but again no evidence for an ability to refer to the causal structure of events. Future research will have to decide whether primates and other animals are simply unable to see the world as casually structured the way humans do, or whether they are just unable to communicate causal structures to others. This article is categorized under:Cognitive Biology > Evolutionary Roots of CognitionComputer Science and Robotics > Artificial IntelligenceLinguistics > Evolution of Language [ABSTRACT FROM AUTHOR]

Objectives: The morphological characteristics of the thumb are of particular interest due to its fundamental role in enhanced manipulation. Despite its possible importance regarding this issue, the body of the first metacarcapal (MC1) has not been fully characterized using morphometrics. This could provide further insights into its anatomy, as well as its relationship with manipulative capabilities. Hence, this study quantifies the shape of the MC1's body in the extant Homininae and some fossil hominins to provide a better characterization of its morphology. Materials and methods: The sample includes MC1s of modern humans (n = 42), gorillas (n = 27), and chimpanzees (n = 30), as well as Homo neanderthalensis, Homo naledi, and Australopithecus sediba. 3D geometric morphometrics were used to quantify the shape of MC1's body. Results: The results show a clear distinction among the three extant genera. H. neanderthalensis mostly falls within the modern human range of variation. H. naledi varies slightly from modern humans, although also showing some unique trait combination, whereas A. sediba varies to an even greater extent. When classified using a discriminant analysis, the three fossils are categorized within the Homo group. Conclusion: The modern human MC1 is characterized by a distinct suite of traits, not present to the same extent in the great apes, that are consistent with an ability to use forceful precision grip. This morphology was also found to align very closely with that of H. neanderthalensis. H. naledi shows a number of human‐like adaptations, while A. sediba presents a mix of both derived and more primitive traits. [ABSTRACT FROM AUTHOR]

Psychological essentialism is the ability to recognize that the class or kind to which an object belongs remains unaltered despite changes to its superficial perceptual features. It is unclear whether humans are unique in possessing this ability or whether it is present in nonhuman primates. A recent study with three great ape species found suggestive evidence of psychological essentialism, but further research is needed to rule out the alternative explanation that the apes used locational information to pass the test. We tested a bonobo (Pan paniscus) with specialized symbolic skills, Kanzi, using a modified procedure that avoided this alternative explanation. Kanzi passed the test, which required him to indicate which of two superficially identical but essentially different kinds of items was actually the item requested by the experimenter (e.g., successfully indicating the banana when both items looked like carrots). A control test indicated that he had not passed the essentialism test simply by detecting differences in the superficial appearance of the items. Our findings support the conclusion that great apes are capable of psychological essentialism; however, Kanzi is unique in that he is able to comprehend some simple spoken English and use lexigram symbols to communicate with humans. The extent to which these skills contributed to his essentialism is unknown. Further research designed to specify the limits of essentialism in bonobos, and other great apes, that are not symbol-proficient can inform debates about the phylogenetics of essentialism and the role of language in its development and expression. [ABSTRACT FROM AUTHOR]

Several species can detect when they are uncertain about what decision to make—revealed by opting out of the choice, or by seeking more information before deciding. However, we do not know whether any nonhuman animals recognize when they need more information to make a decision because new evidence contradicts an already-formed belief. Here, we explore this ability in great apes and human children. First, we show that after great apes saw new evidence contradicting their belief about which of two rewards was greater, they stopped to recheck the evidence for their belief before deciding. This indicates the ability to keep track of the reasons for their decisions, or 'rational monitoring' of the decision-making process. Children did the same at 5 years of age, but not at 3 years. In a second study, participants formed a belief about a reward's location, but then a social partner contradicted them, by picking the opposite location. This time even 3-year-old children rechecked the evidence, while apes ignored the disagreement. While apes were sensitive only to the conflict in physical evidence, the youngest children were more sensitive to peer disagreement than conflicting physical evidence. [ABSTRACT FROM AUTHOR]

When human infants are intentionally addressed by others, they tend to interpret the information communicated as being relevant to them and worth acquiring. For humans, this attribution of relevance leads to a preference to learn from communication, making it possible to accumulate knowledge over generations. Great apes are sensitive to communicative cues, but do these cues also activate an expectation of relevance? In an observational learning paradigm, we demonstrated to a sample of nonhuman great apes (bonobos, chimpanzees, orangutans; N = 24) how to operate on a food dispenser device. When apes had the opportunity to choose between an effective and an ineffective method in the baseline conditions, the majority of them chose the effective method. However, when the ineffective method was demonstrated in a communicative way, they failed to prioritize efficiency, even though they were equally attentive in both conditions. This suggests that the ostensive demonstration elicited an expectation of relevance that modified apes' interpretation of the situation, potentially leading to a preference to learn from communication, as human children do. [ABSTRACT FROM AUTHOR]

Mountain gorillas are particularly inbred compared to other gorillas and even the most inbred human populations. As mountain gorilla skeletal material accumulated during the 1970s, researchers noted their pronounced facial asymmetry and hypothesized that it reflects a population-wide chewing side preference. However, asymmetry has also been linked to environmental and genetic stress in experimental models. Here, we examine facial asymmetry in 114 crania from three Gorilla subspecies using 3D geometric morphometrics. We measure fluctuating asymmetry (FA), defined as random deviations from perfect symmetry, and population-specific patterns of directional asymmetry (DA). Mountain gorillas, with a current population size of about 1000 individuals, have the highest degree of facial FA (explaining 17% of total facial shape variation), followed by Grauer gorillas (9%) and western lowland gorillas (6%), despite the latter experiencing the greatest ecological and dietary variability. DA, while significant in all three taxa, explains relatively less shape variation than FA does. Facial asymmetry correlates neither with tooth wear asymmetry nor increases with age in a mountain gorilla subsample, undermining the hypothesis that facial asymmetry is driven by chewing side preference. An examination of temporal trends shows that stress-induced developmental instability has increased over the last 100 years in these endangered apes. [ABSTRACT FROM AUTHOR]

Approximately 65% of primate species are facing extinction, with threats including the impacts of linear infrastructures such as roads, railways, and power lines, associated with habitat loss and fragmentation, direct and indirect mortality, and changes in animal behavioral patterns. Nevertheless, this is an often-overlooked topic in primatology, and there is limited information on which regions and species are most affected by linear infrastructures. Here, we provide a global assessment of priority areas and primate species for conservation by integrating information from global-scale open-access data sets on the distributional ranges, traits, and threats to primate species and linear infrastructures, together with a systematic literature review and a questionnaire sent to primatological societies. We produced a bivariate map that reflects the patterns of co-occurrence of the Conservation Value and Infrastructure Density. From this map we highlight Primate Mitigation Areas (regions with high Primate Conservation Value and Infrastructure Density), which are areas where infrastructure mitigation should be prioritized; and the Primate Preservation Areas (regions with high Primate Conservation Value and low Infrastructure Density), which represent areas that should be preserved from further infrastructure development. Primate Mitigation Areas primarily include the Atlantic forest of Brazil, the Guinean forests of West Africa, and most of Southeastern Asia, whereas Primate Preservation Areas are found principally in the Amazon and Congo River basins. Our assessment also produced a list of priority species affected by infrastructures, with the great apes and gibbons ranking highest. Global infrastructure projects, especially the Belt and Road Initiative, can seriously affect both priority areas (particularly preservation areas) and the most vulnerable species, due to the massive sprawl of linear infrastructures and associated human activity. Thus, we call for dedicated strategic environmental and social assessments throughout these different economic corridors within the Belt and Road Initiative planning process, prior to developing the different projects. Our assessment can serve as a tool to coordinate management actions and legislation around the world. [ABSTRACT FROM AUTHOR]

In Africa, relatively few hominoid fossils are known from the late middle Miocene and late Miocene periods corresponding to the time span 13-5.5 million years ago, compared to the preceding and subsequent periods from which several thousand specimens have been reported from many different localities. In Eurasia, in contrast, many hominoid fossils are known from the Late Miocene period from diverse localities scattered from Spain in the west to China in the East. The scarcity of hominoid fossils from this period in Africa lent support to the hypothesis that the ancestors of extant African Apes and hominids may have evolved in Eurasia and then dispersed to Africa during the late Miocene where they gave rise to the extant Gorilla, Pan and Homo lineages. We herein document additional hominoid fossils from Berg Aukas, Namibia, aged ca 12-13 Ma, and rectify the locality data concerning the Niger proto-chimpanzee fossil. The new data indicate that Africa was not devoid of hominoids during the period under discussion, and they support the hypothesis that the extant African Apes and hominids may have evolved autochthonously within the continent. [ABSTRACT FROM AUTHOR]

Modern phylogenetic comparative methods allow us to estimate evolutionary rates of phenotypic change, how these rates differ across clades, and to assess whether the rates remained constant over time. Unfortunately, currently available phylogenetic comparative tools express the rate in terms of a scalar dimension, and do not allow us to determine rate variations among different parts of a single, complex phenotype, or chart realized rate variation directly onto the phenotype. We present a new method which allows the mapping of evolutionary rate variation directly onto three‐dimensional phenotypes, informing on the direction and magnitude of trait change automatically. Implemented using the function rate.map embedded in the R package RRphylo, this method is based on phylogenetic ridge regression rate estimates. Since the latter represent ridge regression slopes, they possess sign and magnitude. In RRphylo, different rates are calculated for different districts of the phenotype, which can then be visualized directly onto the phenotype itself. We present the application of rate.map to the evolution of facial skeleton in Hominoidea, the primate clade inclusive of Homo and the greater apes (including living and fossil taxa). We found that the highly derived, unique shape of the face in modern humans evolved through rapid phenotypic changes affecting the nasal bones, the brow ridge and the maxillary region. The canine fossa, a facial feature unique to Homo sapiens, did not belong to a region of rapid phenotypic change, and could be seen as the by‐product of midface evolution as suggested by previous studies. [ABSTRACT FROM AUTHOR]

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