Roman M Wittig

• Dr rer nat
• Group Leader at Max Planck Institute for Evolutionary Anthropology

This paper introduces the "phonetic equifinality" problem in speech evolution , namely, how similar ostensibly speech-like sounds can be produced by different species, while their execution is still subject to distinct articulatory constraints. Several (nonhuman) great ape vocalizations share acoustic and perceptual similarities with human speech s...

The diversity and composition of mammal communities are strongly influenced by human activities, though these relationships may vary across broad scales. Understanding this variation is key to conservation, as it provides a baseline for planning and evaluating management interventions. We assessed variation in the structure and composition of Afrot...

The arcuate fascicle (AF) is the main fibre tract in the brain for human language. It connects frontal and temporal language areas in the superior and middle temporal gyrus (MTG). The AF’s connection to the MTG was considered unique to humans and has influenced theories of the evolution of language. Here, using high-resolution diffusion MRI of post...

Human attachment theory outlines three organized types: secure, insecure avoidant and insecure resistant, all considered adaptive responses to maternal care for offspring survival. In contrast, disorganized attachment is hypothesized to be maladaptive and therefore uncommon in wild mammals, though this remains untested. We assessed attachment types...

Language is a combinatorial communication system able to generate an infinite number of meanings. Nonhuman animals use several combinatorial mechanisms to expand meanings, but maximum one mechanism is reported per species, suggesting an evolutionary leap to human language. We tested whether chimpanzees use several meaning-expanding mechanisms. We r...

Social learning opportunities shape cognitive skills across species, especially in humans. Although the social environment impacts learning opportunities, the benefits of role model diversity and tolerance on task learning in tool-using species remain poorly understood. To explore these links, we study 2343 peering events (close-range observation o...

During childhood, human speech utterances increase steadily in complexity, length and diversity. In contrast, the vocal repertoire of non-human primates has long been considered fixed from birth. Recent studies showing the acquisition of vocal sequences during ontogeny in chimpanzees and marmosets challenge this view. Here we further explore the po...

Ongoing ecosystem change and biodiversity decline across the Afrotropics call for tools to monitor the state of biodiversity or ecosystem elements across extensive spatial and temporal scales. We assessed relationships in the co‐occurrence patterns between great apes and other medium to large‐bodied mammals to evaluate whether ape abundance serves...

Computer vision analysis of camera trap video footage is essential for wildlife conservation, as captured behaviours offer some of the earliest indicators of changes in population health. Recently, several high-impact animal behaviour datasets and methods have been introduced to encourage their use; however, the role of behaviour-correlated backgro...

Chimpanzees, our closest living relatives, share a vast amount of our genetic code, with the majority of differences found in non-coding regions of the genome. Functional and gene regulatory differences drive phenotypic divergence, including the distinctive brain anatomy of humans compared to chimpanzees and other apes. However, little is known abo...

How populations adapt to their environment is a fundamental question in biology. Yet, we know surprisingly little about this process, especially for endangered species, such as nonhuman great apes. Chimpanzees, our closest living relatives, are particularly notable because they inhabit diverse habitats, from rainforest to woodland-savannah. Whether...

Chimpanzee brain maturation provides an invaluable framework for understanding the evolution of the human brain. We performed ultra-high resolution quantitative magnetic resonance imaging (qMRI) with histological validation on post mortem brains from captive and wild chimpanzees with a broad age range. We mapped developmental myelination and age-re...

An older wild female chimpanzee ( Pan troglodytes ) was found dead with a large calcium oxalate stone in the renal pelvis. Histopathological changes included glomerulosclerosis, interstitial nephritis and fibrosis, focal mineralization, and medial hypertrophy. Urinary albumin‐creatinine‐ratio showed increased values from 15 months before death. Cau...

How populations adapt to their environment is a fundamental question in biology. Yet we know surprisingly little about this process, especially for endangered species such as non-human great apes. Chimpanzees, our closest living relatives, are particularly interesting because they inhabit diverse habitats, from rainforest to woodland-savannah. Whet...

As camera trapping grows in popularity and application, some analytical limitations persist including processing time and accuracy of data annotation. Typically images are recorded by camera traps although videos are becoming increasingly collected even though they require much more time for annotation. To overcome limitations with image annotation...

Objectives Chimpanzees ( Pan troglodytes ) are patrilocal, with males remaining in their natal community and females dispersing when they reach sexual maturity. However, the details of female chimpanzee dispersal, such as their possible origin, are difficult to assess, even in habituated communities. This study investigates the utility of ⁸⁷ Sr/ ⁸⁶...

Long-standing questions about human brain evolution may only be resolved through comparisons with close living evolutionary relatives, such as chimpanzees. This applies in particular to structural white matter (WM) connectivity, which continuously expanded throughout evolution. However, due to legal restrictions on chimpanzee research, neuroscience...

Bacillus cereus biovar anthracis (Bcbva) is an atypical anthrax-causing bacterium, inflicting wildlife fatalities across African rainforest ecosystems. The pathogen’s virulence in one of our closest living relatives, the chimpanzee, together with human serological evidence, suggests Bcbva is zoonotic. While classical B. anthracis-induced anthrax ha...

Bacillus cereus biovar anthracis (Bcbva) is an atypical anthrax-causing bacterium, inflicting wildlife fatalities across African rainforest ecosystems. The pathogen’s virulence in one of our closest living relatives, the chimpanzee, together with human serological evidence, suggests Bcbva is zoonotic. While classical B. anthracis-induced anthrax ha...

Nematodes belonging to the genus Oesophagostomum frequently infect wild chimpanzees ( Pan troglodytes ) across widely separated field sites. Nodular lesions (granulomas) containing Oesophagostomum are commonly seen in the abdomen of infected chimpanzees post‐mortem. At Taï National Park, Côte d'Ivoire, previous studies have identified larvae of a v...

Tool use is considered a driving force behind the evolution of brain expansion and prolonged juvenile dependency in the hominin lineage. However, it remains rare across animals, possibly due to inherent constraints related to manual dexterity and cognitive abilities. In our study, we investigated the ontogeny of tool use in chimpanzees (Pan troglod...

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 ∼\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \us...

To decipher the evolution of the hominoid brain and its functions, it is essential to conduct comparative studies in primates, including our closest living relatives. However, strong ethical concerns preclude in vivo neuroimaging of great apes. We propose a responsible and multidisciplinary alternative approach that links behavior to brain anatomy...

Fine-scale knowledge of the changes in composition and function of the human gut microbiome compared that of our closest relatives is critical for understanding the evolutionary processes underlying its developmental trajectory. To infer taxonomic and functional changes in the gut microbiome across hominids at different timescales, we perform high-...

The social complexity hypothesis for the evolution of communication posits that complex social environments require greater communication complexity for individuals to effectively manage their relationships. We examined how different socially uncertain contexts, reflecting an increased level of social complexity, relate to variation in signalling w...

Bacillus cereus biovar anthracis (Bcbva) is an atypical anthrax-causing bacterium, inflicting wildlife fatalities across African rainforest ecosystems. The pathogen's virulence in one of our closest living relatives, the chimpanzee, together with human serological evidence, suggests Bcbva is zoonotic. While classical B. anthracis-induced anthrax ha...

Advances in viral discovery techniques have led to the identification of numerous novel viruses in human samples. However, the low prevalence of certain viruses in humans raises doubts about their association with our species. To ascertain the authenticity of a virus as a genuine human-infecting agent, it can be useful to investigate the diversific...

Tactical warfare is considered a driver of the evolution of human cognition. One such tactic, considered unique to humans, is collective use of high elevation in territorial conflicts. This enables early detection of rivals and low-risk maneuvers, based on information gathered. Whether other animals use such tactics is unknown. With a unique datase...

The question of how behavioural diversity in humans and other animals is shaped by the combined influence of demography, genetics, culture, and the environment receives much research attention. We take a macro-ecological approach to evaluate how chimpanzee ( Pan troglodytes ) behavioural diversity is spatially structured and associated with genetic...

One universal feature of human language is its versatility in communicating about juxtapositions of everyday events. Versatile combinatorial systems of communication can be selected for if (a) several vocal units are flexibly combined into numerous and long vocal sequences and (b) vocal sequences relate to numerous daily life events. We propose (b)...

The manual processing and analysis of videos from camera traps is time-consuming and includes several steps, ranging from the filtering of falsely triggered footage to identifying and re-identifying individuals. In this study, we developed a pipeline to automatically analyze videos from camera traps to identify individuals without requiring manual...

Mechanisms of inheritance remain poorly defined for many fitness-mediating traits, especially in long-lived animals with protracted development. Using 6,123 urinary samples from 170 wild chimpanzees, we examined the contributions of genetics, non-genetic maternal effects, and shared community effects on variation in cortisol levels, an established...

Uncovering brain-tissue microstructure including axonal characteristics is a major neuroimaging research focus. Within this scope, anisotropic properties of magnetic susceptibility in white matter have been successfully employed to estimate primary axonal trajectories using mono-tensorial models. However, anisotropic susceptibility has not yet been...

The manual processing and analysis of videos from camera traps is time-consuming and includes several steps, ranging from the filtering of falsely triggered footage to identifying and re-identifying individuals. In this study, we developed a pipeline to automatically analyze videos from camera traps to identify individuals without requiring manual...

Characterizing trajectories of the composition and function of hominid gut microbiota across diverse environments and host species can help reveal specific properties of the human microbiota, with possible implications for host evolution and health. Using shotgun metagenomic sequencing, we investigated taxonomic and functional diversity in the gut...

Objectives: Chimpanzees (Pan troglodytes) possess a relatively generalized molar morphology allowing them to access a wide range of foods. Comparisons of crown and cusp morphology among the four subspecies have suggested relatively large intraspecific variability. Here, we compare molar crown traits and cusp wear of two geographically close popula...

The selection pressures that drove dramatic encephalisation processes through the mammal lineage remain elusive, as does knowledge of brain structure reorganisation through this process. In particular, considerable structural brain changes are present across the primate lineage, culminating in the complex human brain that allows for unique behaviou...

The development of the unique, hierarchical, and endless combinatorial capacity in a human language requires neural maturation and learning through childhood. Compared with most non‐human primates, where combinatorial capacity seems limited, chimpanzees present a complex vocal system comprising hundreds of vocal sequences. We investigated how such...

Uncovering brain-tissue microstructure including axonal characteristics is a major neuroimaging research focus. Within this scope, anisotropic properties of magnetic susceptibility in white matter have been successfully employed to estimate primary axonal trajectories using mono-tensorial models. However, anisotropic susceptibility has not yet been...

Feces are a treasure trove in the study of animal behavior and ecology. Stable carbon and nitrogen isotope analysis allows to assess the dietary niches of elusive primate species and primate breastfeeding behavior. However, some fecal isotope data may unwillingly be biased toward the isotope ratios of undigested plant matter, requiring more consist...

One of the many ecosystem services provided by dung beetles is that of secondary seed dispersal. This paper experimentally evaluates the effectiveness of this service using the chimpanzee–dung beetle seed dispersal system in Taï National Park, Côte d’Ivoire. The study focussed on the germination rate and success of four species of seeds contained i...

The ultimate payoff of behaviours depends not only on their direct impact on an individual, but also on the impact on their relatives. Local relatedness—the average relatedness of an individual to their social environment—therefore has profound effects on social and life history evolution. Recent work has begun to show that local relatedness has th...

Early-life experiences, such as maternal care received, influence adult social integration and survival. We examine what changes to social behaviour through ontogeny lead to these lifelong effects, particularly whether early-life maternal environment impacts the development of social communication. Chimpanzees experience prolonged social communicat...

Seed dispersal is a key stage in the life cycle of plants, thus in forest regeneration, especially in the tropics. Chimpanzees are known as important seed dispersers and dung beetles play critical roles in secondary dispersal thus increasing the chance for seed post-dispersal success. Hence, understanding secondary seed dispersal by dung beetles is...

Primates rarely learn new vocalisations, but they can learn to use their vocalizations in different contexts. Such ‘vocal usage learning’, particularly in vocal sequences, is a hallmark of human language, but remains understudied in non-human primates. We assess usage learning in four wild chimpanzee communities of Taï and Budongo Forests by invest...

Seed dispersal is a key stage in the life cycle of plants, thus in forest regeneration, especially in the tropics. Chimpanzees are known as important seed dispersers and dung beetles play critical roles in secondary dispersal thus increasing the chance for seed post-dispersal success. Hence, understanding secondary seed dispersal by dung beetles is...

Knowledge on the population history of endangered species is critical for conservation, but whole-genome data on chimpanzees (Pan troglodytes) is geographically sparse. Here, we produced the first non-invasive geolocalized catalog of genomic diversity by capturing chromosome 21 from 828 non-invasive samples collected at 48 sampling sites across Afr...

We present a novel approach to estimate fiber Orientation Distribution Functions (ODFs) by applying the generalized Constant Solid Angle (CSA) method to High Angular Resolution SUSCEPTIBILITY Imaging (HARSI) data from post-mortem chimpanzee brain. The acquisition details and analytical pipelines are presented and derived susceptibility tensor metri...

Human respiratory pathogens have repeatedly caused lethal outbreaks in wild great apes across Africa, leading to population declines. Nonetheless, our knowledge of potential genomic changes associated with pathogen introduction and spread at the human‐great ape interface remains sparse. Here, we made use of target enrichment coupled with next gener...

Parochial altruism, taking individual costs to benefit the in-group and harm the out-group, has been proposed as one of the mechanisms underlying the human ability of large-scale cooperation. How parochial altruism has evolved remains unclear. In this review paper, we formulate a parochial cooperation model in small-scale groups and examine the mod...

It has long been recognized that the patterning of social interactions within a group can give rise to a social structure that holds very different places for different individuals. Such within-group variation in sociality correlates with fitness proxies in fish, birds, and mammals. Broader integration of this research has been hampered by the lack...

In human warfare, a common territorial tactic is the usage and occupation of areas highly elevated in the landscape, for protection against and early detection of enemies and preparation of ambushes. Elevated areas are thus assumed to confer tactical advantages in inter-group conflicts. Chimpanzee inter-group conflicts resemble in many aspects to s...

The origins of human speech are obscure; it is still unclear what aspects are unique to our species or shared with our evolutionary cousins, in part due to a lack of a common framework for comparison. We asked what chimpanzee and human vocal production acoustics have in common. We examined visible supra-laryngeal articulators of four major chimpanz...

Humans are considered as the main host for Mycobacterium leprae1, the aetiological agent of leprosy, but spillover has occurred to other mammals that are now maintenance hosts, such as nine-banded armadillos and red squirrels2,3. Although naturally acquired leprosy has also been described in captive nonhuman primates4–7, the exact origins of infect...

Here we show that sexual signaling affects patterns of female spatial association differently in chimpanzees and bonobos, indicating its relevance in shaping the respective social systems. Generally, spatial association between females often mirrors patterns and strength of social relationships and cooperation within groups. While testing for propo...

Paleoclimate reconstructions have enhanced our understanding of how past climates have shaped present-day biodiversity. We hypothesize that the geographic extent of Pleistocene forest refugia and suitable habitat fluctuated significantly in time during the late Quaternary for chimpanzees (Pan troglodytes). Using bioclimatic variables representing m...

Mirror self-recognition (MSR) is considered an indicator of self-awareness. Standardized mirror tests reveal compelling evidence for MSR in a few non-human species, including all great apes. However, substantial inter-individual variation of MSR within species resulted in an ongoing methodological controversy, questioning the appropriateness of sta...

Glucocorticoids, such as cortisol, mediate homeostatic processes, allowing individuals to adjust to fluctuating environments. The regulation of circadian cortisol responses, a key homeostatic function, has been shown to be heritable. However, to understand better the role of parental care in shaping physiological functioning in long-lived mammals w...

Understanding variation in host-associated microbial communities is important given the relevance of microbiomes to host physiology and health. Using 560 fecal samples collected from wild chimpanzees (Pan troglodytes) across their range, we assessed how geography, genetics, climate, vegetation, and diet relate to gut microbial community structure (...

Is it possible to slow the rate of ageing, or do biological constraints limit its plasticity? We test the ‘invariant rate of ageing’ hypothesis, which posits that the rate of ageing is relatively fixed within species, with a collection of 39 human and nonhuman primate datasets across seven genera. We first recapitulate, in nonhuman primates, the hi...

The biological embedding model (BEM) suggests that fitness costs of maternal loss arise when early-life experience embeds long-term alterations to hypothalamic-pituitary-adrenal (HPA) axis activity. Alternatively, the adaptive calibration model (ACM) regards physiological changes during ontogeny as short-term adaptations. Both models have been test...

In recent years, new applications of microremain dietary analysis using dental calculus as a source of dietary data on ancient human subsistence and behaviours have accelerated. The dental calculus of contemporary human and non-human populations with known diets have been used as reference datasets, including the chimpanzees of Taï National Park (C...

Dental wear analyses have been widely used to interpret the dietary ecology in primates. However, it remains unclear to what extent a combination of wear analyses acting at distinct temporal scales can be beneficial in interpreting the tooth use of primates with a high variation in their intraspecific dietary ecology. Here, we combine macroscopic t...

Significance Mammals harbor diverse communities of gut microbes. The assembly and evolution of the bacterial components of these communities are influenced by host evolutionary histories and social behavior. Little is known about the ecological and evolutionary origins of the phages infecting these bacteria. We explore drivers of phage community as...

Viruses closely related to human pathogens can reveal the origins of human infectious diseases. Human herpes simplexvirus type 1 (HSV-1) and type 2 (HSV-2) are hypothesized to have arisen via host-virus co-divergence and cross-species transmission. We report the discovery of novel herpes simplexviruses during a large-scale screening of fecal sample...

Signalling plays an important role in mediating social interactions in many animal species. For example, during approaches certain species produce ‘greetings’, which can take the form of vocal or visual signals, which reduce the probability of aggressive interactions and/or facilitate affiliation when approaching each other. However, in species whe...

A major question in evolutionary science is how did language evolve? Syntax, as the core of language, combines meaning-bearing units (words) into hierarchical structures, thereby creating new meanings. Some other mammals and birds combine meaning-bearing vocalisations, but no documented examples exist of non-human animals combining more than two me...

A Correction to this paper has been published: https://doi.org/10.1038/s41467-021-21010-z.

Predictability of social interactions can be an important measure for the social complexity of an animal group. Predictability is partially dependent on how consistent interaction patterns are over time: does the behavior on 1 day explain the behavior on another? We developed a consistency measure that serves two functions: detecting which interact...

Humans maintain extensive social ties of varying preferences, providing a range of opportunities for beneficial cooperative exchange that may promote collective action and our unique capacity for large-scale cooperation. Similarly, non-human animals maintain differentiated social relationships that promote dyadic cooperative exchange, but their lin...

Socioecological theories predict that, in mammals, feeding and mating competitions affect male and female energetic conditions differently but energetic studies investigating both sexes simultaneously are rare. We investigated the effect of socioecological factors on the energetic conditions of male and female western chimpanzees, a long-lived spec...

The cover image is based on the Paper Systematic mapping of developmental milestones in wild chimpanzees by Aisha C. Bründl et al., https://doi.org/10.1111/desc.12988. (c) Liran Samuni, Tai Chimpanzee Project

Noninvasive samples as a source of DNA are gaining interest in genomic studies of endangered species. However, their complex nature and low endogenous DNA content hamper the recovery of good quality data. Target capture has become a productive method to enrich the endogenous fraction of noninvasive samples, such as faeces, but its sensitivity has n...