Human Evolution Research Articles

Gestural Iconicity and Alignment as Steps in the Evolution of Language

AbstractStudies of the evolution of language rely heavily on comparisons to nonhuman primates, particularly the gestural communication of nonhuman apes. Differences between human and ape gestures are largely ones of degree rather than kind. For example, while human gestures are more flexible, ape gestures are not inflexible. In this piece, I closely consider two features of the gestural communication of apes and humans that might display differences in kind: iconicity and temporal alignment. Iconicity has long played a privileged role in theories of gestural language origins, the proposal being that it provided a steppingstone into language through a stage of pantomime. However, iconicity is not as easy as it seems. Evidence from co‐speech gestures of hearing children and from homesign suggests that iconic reference is both cognitively complex and slow to develop in humans. There is no conclusive evidence that nonhuman apes understand or produce iconic gestures; some gestures may appear iconic to human observers but the apes themselves may not understand the similarity between form and meaning. Far from providing an easy pathway into the emergence of symbolic communication, iconicity relies on sophisticated capacities for analogy and abstraction, ones often lacking in apes and young children. Temporal alignment between gesture and vocalization is another area that may show sharp contrasts between adult humans and apes, though data here is sparser. I discuss the tight synchronization of gesture and speech that emerges over the first year of life in human children and contrast it with gesture and vocalization in apes, which typically are described as overlapping but not simultaneous. Human ancestors probably communicated in ways similar to other apes, but the dual emergence of the ability to use iconic reference and the alignment of hand and mouth may have set our ancestors down a unique evolutionary road toward language.

Lithic analysis in African archaeology: Advances and key themes

AbstractStone artifacts (lithics) preserve for extended periods; thus they are key evidence for probing the evolution of human technological behaviors. Africa boasts the oldest record of stone artifacts, spanning 3.3 Ma, rare instances of ethnographic stone tool‐making, and stone tool archives from diverse ecological settings, making it an anchor for research on the long‐term temporal and spatial trends in human evolution. This paper reviews the application of scientific methods for studying African stone artifacts and highlights several popular research themes on the continent, including the origins of flaked stone technology, hunter‐gatherer mobility and landscape use, technological variability, function, biocultural evolution, and ancient human cognition. We conclude by outlining some key challenges to future lithic research in Africa.

Imprint of ancestral and modern threats in human mind – experience of fear, disgust, and anger

IntroductionThreats to our survival are often posed by the environment in which humans have evolved or live today. Animal and human ancestors developed complex physiological and behavioral response systems to cope with two types of threats: immediate physical harm from predators or conspecifics, triggering fear, and the risk of infections from parasites and pathogens leading to the evolution of the behavioral immune system (BIS) with disgust as the key emotion. Here we ask whether the BIS has adapted to protect us from pandemic risks or poisoning by modern toxic substances.MethodsWe have developed a survey comprised of 60 vignettes describing threats evoking fear and disgust belonging to one of the three main categories of threats: (1) ancestral, (2) modern, and (3) pandemic of airborne disease. Each vignette was evaluated on a 7-point Likert scale based on fear, disgust, and anger. Respondents also completed an assessment battery.ResultsThe results show that the strongest fear is triggered by modern threats (electricity, car accidents), while the highest disgust is evoked by ancient threats (body waste products, worms). Disgust does not respond to modern threat stimuli such as toxic substances or radioactivity as these evoke mainly fear and anger. A discriminant factor analysis classified nine out of 10 pandemic disgust vignettes into the ancestral disgust category, convincingly assigning the pandemic disgust threats to the ancestral type. Gender, age, and type of education were significant moderators of emotional responses across all threat categories.DiscussionOur study reveals that while fear is more context-dependent, particularly triggered by modern threats, disgust operates on an evolutionarily hardwired basis, making it less effective against contemporary risks. Furthermore, disgust experienced during a pandemic outbreak is more closely aligned with ancestral disgust-related threats tapping into evolutionary ancient survival circuits of the BIS. However, as disgust declines with age, the brain must adaptatively shift the emotional processing from disgust to fear to protect older adults from contamination risks. Finally, our study reveals that pandemic fear is better predicted by specific behaviors rather than general anxiety, suggesting a need for new assessments.

Expansion of a conserved architecture drives the evolution of the primate visual cortex

Human brain evolution is marked by a disproportionate expansion of cortical regions associated with advanced perceptual and cognitive functions. While this expansion is often attributed to the emergence of novel specialized brain areas, modifications to evolutionarily conserved cortical regions also have been linked to species-specific behaviors. Distinguishing between these two evolutionary outcomes has been limited by the ability to make direct comparisons between species. Here, we addressed this limitation by examining the expansion of the human visual cortex relative to macaques using a common functional architecture: retinotopy. Our findings revealed that human visual cortex expansion is primarily driven by increases in the surface area of a visual map architecture present in macaques rather than an increase in the number of individual areas. This expansion was not uniform, with higher-order areas, particularly in the parietal cortex, exhibiting the largest growth. Comparisons between neonate and adult humans revealed that these relative areal size differences were already established at birth. A meta-analysis of neuroimaging studies indicated that the most expanded areas are associated with advanced cognitive functions beyond visual processing. These results suggest that human perceptual and cognitive adaptations may be rooted in the expansion of evolutionarily conserved cortical architecture, with modifications even in the sensory cortex contributing to the broader cognitive functions characteristic of human behavior.

Structural polymorphism and diversity of human segmental duplications.

Segmental duplications (SDs) contribute significantly to human disease, evolution and diversity but have been difficult to resolve at the sequence level. We present a population genetics survey of SDs by analyzing 170 human genome assemblies (from 85 samples representing 38 Africans and 47 non-Africans) in which the majority of autosomal SDs are fully resolved using long-read sequence assembly. Excluding the acrocentric short arms and sex chromosomes, we identify 173.2 Mb of duplicated sequence (47.4 Mb not present in the telomere-to-telomere reference) distinguishing fixed from structurally polymorphic events. We find that intrachromosomal SDs are among the most variable, with rare events mapping near their progenitor sequences. African genomes harbor significantly more intrachromosomal SDs and are more likely to have recently duplicated gene families with higher copy numbers than non-African samples. Comparison to a resource of 563 million full-length isoform sequencing reads identifies 201 novel, potentially protein-coding genes corresponding to these copy number polymorphic SDs.

Highly accurate Korean draft genomes reveal structural variation highlighting human telomere evolution.

Given the presence of highly repetitive genomic regions such as subtelomeric regions, understanding human genomic evolution remains challenging. Recently, long-read sequencing technology has facilitated the identification of complex genetic variants, including structural variants (SVs), at the single-nucleotide level. Here, we resolved SVs and their underlying DNA damage-repair mechanisms in subtelomeric regions, which are among the most uncharted genomic regions. We generated ∼20×high-fidelity long-read sequencing data from three Korean individuals and their partially phased high-quality de novo genome assemblies (contig N50: 6.3-58.2 Mb). We identified 131138 deletion and 121461 insertion SVs, 41.6% of which were prevalent in the East Asian population. The commonality of the SVs identified among the Korean population was examined by short-read sequencing data from 103 Korean individuals, providing the first comprehensive SV set representing the population based on the long-read assemblies. Manual investigation of 19 large subtelomeric SVs (≥5 kb) and their associated repair signatures revealed the potential repair mechanisms leading to the formation of these SVs. Our study provides mechanistic insight into human telomere evolution and can facilitate our understanding of human SV formation.

Modulating vertebrate physiology by genomic fine-tuning of GPCR functions.

G protein-coupled receptors (GPCRs) play a crucial role as membrane receptors, facilitating the communication of eukaryotic species with their environment and regulating cellular and organ interactions. Consequently, GPCRs hold immense potential in contributing to adaptation to ecological niches and responding to environmental shifts. Comparative analyses of vertebrate genomes reveal patterns of GPCR gene loss, expansion, and signatures of selection. Integrating these genomic data with insights from functional analyses of gene variants enables the interpretation of genotype-phenotype correlations. This review underscores the involvement of GPCRs in adaptive processes, presenting numerous examples of how alterations in GPCR functionality influence vertebrate physiology or, conversely, how environmental changes impact GPCR functions. The findings demonstrate that modifications in GPCR function contribute to adapting to aquatic, arid, and nocturnal habitats, influencing camouflage strategies, and specializing in particular dietary preferences. Furthermore, the adaptability of GPCR functions provides an effective mechanism in facilitating past, recent, or ongoing adaptations in animal domestication and human evolution and should be considered in therapeutic strategies and drug development.

The quest for scientific objectivity: comment on Luke Glowacki's (2024) “The controversial origins of war and peace: Apes, foragers, and human evolution”

The quest for scientific objectivity: comment on Luke Glowacki's (2024) “The controversial origins of war and peace: Apes, foragers, and human evolution”

Advancing paleoanthropology beyond default nulls.

While we are sympathetic with Stibbard-Hawkes' approach, we disagree with the proposal to switch to a "cognitively modern" null for all Homo species. We argue in favor of a more evidence-driven approach, inspired by recent debates in comparative cognition. Ultimately, parsing the contributions of different genetic and extra-genetic factors in human evolution is more promising than setting a priori nulls.

Material culture both reflects and causes human cognitive evolution.

Our commentary suggests that different materialities (fragile, enduring, and mixed) may influence cognitive evolution. Building on Stibbard-Hawkes, we propose that predictive brains minimise errors and seek information, actively structuring environments for epistemic benefits. This perspective complements Stibbard-Hawkes' view.

Evolutionary Changes in Oral Regions (Temporomandibular Joint)

Background: Evolution represents a gradual developmental process that forms the foundation of modern science, widely recognized as a scientific theory supported by various fields of research. One observable example of evolution in the oral cavity is the third molar (molar 3). In ancient times, third molars erupted normally due to larger jaw sizes. However, as human jaws evolved and became smaller, third molar impaction—a pathological condition where a tooth fails to erupt properly—has become increasingly common. Impaction occurs due to limited space and improper jaw angulation, which create gaps between teeth that trap food debris and increase the risk of dental complications. Odontectomy is a surgical procedure used to remove unerupted, partially erupted teeth, or retained roots that cannot be extracted using conventional techniques. Materials and Methods: This study employed a systematic literature review method, gathering data from PubMed, ScienceDirect, Google Scholar, and ResearchGate. Keywords included "Evaluation of teeth," "Temporomandibular Joint Evolution," "Impacted Third Molars," and "Human Dentition Evolution." Relevant studies published between 1991 and 2023 were selected based on inclusion criteria that focused on the evolution of teeth and temporomandibular joint (TMJ). Results and Conclusion: The study identifies significant evolutionary changes in the oral region, particularly in the TMJ, influenced by shifts in dietary habits, environmental factors, and human adaptability. The reduction in jaw size and altered chewing mechanics have contributed to the increased prevalence of impacted third molars (M3s), resulting in complications such as pericoronitis, cyst formation, and neuralgic pain [19,20]. Evolutionary adaptations in the TMJ enabled functional demands like speaking, chewing, and swallowing, but also increased susceptibility to disorders such as temporomandibular joint dysfunction (TMD) [1,11]. These findings highlight the critical role of evolutionary biology in understanding and addressing contemporary oral health issues. Future research should focus on developing targeted treatment strategies and preventive measures to mitigate challenges associated with these evolutionary adaptations.

Technical, social, psychological and ethical aspects of human-robot collaboration: a case study of the 'Robin Heart' medical robot

Objectives: The purpose of the research is to draw attention to the need for comprehensive scientific reflection on the technical, social, psychological and ethical aspects of human-machine cooperation on the example of the Robin Heart medical robot. Methods: The conclusions presented in the article are the result of non-reactive research based on the analysis of secondary sources - scientific literature. The method of scientific inference was inductive. Sources of information used to write this article, are interdisciplinary in nature: in the field of management sciences, psychology, sociology, ethics, management sciences and medical physics. Results: the value of the analysis is the author's assumption that medical robots (including "Robin Heart") are part of the "technology system". We point out the connections between humans (agent 1; agent 2) and technological artifacts (agent 3). The first agent is a person working in a medical facility, functioning in various roles: robot creator, programmer, device owner, operator, robot trainer. The second agent is a patient using a medical service. The third agent is a robot equipped with AI. It can be treated in two ways: as a significant "extension" of human abilities, or as an autonomous entity of medical action. Conclusions: The use of robots is another consequence of human evolution. We move from the stage of ordinary use to the stage of cooperation with them. Improving the human-machine relationship will probably dominate many years of activity of multi-disciplinary teams combining humanistic, biological and technical approaches. The obtained results show that it is necessary to build awareness of the technology system based on a holistic view that considers the integration of interdisciplinary achievements.

Muscle synergy in several locomotor modes in chimpanzees and Japanese macaques, and its implications for the evolutionary origin of bipedalism through shared muscle synergies

Recent evidence indicates that human ancestors utilized a combination of quadrupedal walking, climbing, and bipedal walking. Therefore, the origin of bipedalism may be linked to underlying mechanisms supporting diverse locomotor modes. This study aimed to elucidate foundations of varied locomotor modes from the perspective of motor control by identifying muscle synergies and demonstrating similarities in synergy compositions across different locomotor modes in chimpanzees and Japanese macaques. Four muscle synergies were extracted for bipedal and quadrupedal walking in both the chimpanzees and macaques, as well as for vertical climbing in the chimpanzees. Bipedal walking synergies were generally analogous to those observed in quadrupedal walking and vertical climbing. Specifically, the bipedal walking synergies during the stance and swing phase in the chimpanzees were substitutable with those of vertical climbing and quadrupedal walking, respectively. For the macaque, not all bipedal walking synergies exhibited similarities to quadrupedal walking synergies, likely due to instability during the single support phase of bipedalism. These findings suggest that synergies from vertical climbing and quadrupedal walking might be transferred to bipedal walking, as seen in the chimpanzees, and that this sharing of synergies might form a foundation for a diverse range of locomotor capacities including bipedal walking.

Functions of microcephalin in neurogenesis and human brain evolution

Primary microcephaly is a brain growth disorder of which the main phenotypic hallmarks is a reduction of brain size with varying degrees of intellectual disability. MCPH1 is the first gene reported to cause primary microcephaly. Microcephalin (MCPH1), the encoded protein product, has been implicated in various cellular processes deregulation of which can negatively affects neurogenesis. In our review we will discuss the clinical cases of MCPH1 primary microcephaly and summarize the knowledge about the functions of MCPH1 employing animal models with mutations in various domains of MCPH1. We also pay special attention to the role of MCPH1 in in the evolution of the human brain.

THE IMPACT OF ONLINE EDUCATION ON STUDENTS’ KNOWLEDGE OF HUMAN EVOLUTION

In the 2020/21 school year, education changed overnight due to the COVID-19 pandemic. The aim of this study was to explore the impact of the lockdown on students’ knowledge of evolution. Two student groups were compared; both covered the same subject matter, and only the implementation differed: either online or in class. The sample consisted of 476 participants, 15 to 16 years old. Data were collected with a questionnaire using a 5-point Likert scale. Contrary to expectations, there were no significant differences in knowledge between the online and in-class groups. The reasons for this remain unclear. The impact of some contextual factors was also tested. There were no significant differences in students’ performance concerning maternal education, and only two concerning paternal education. Males scored better than females. Knowledge of human evolution did not correlate with religiosity. However, it did correlate with acceptance of evolution and attitudes toward biology. The online educated group and the in-school educated group differed significantly in most correlations between contextual factors. Further studies should be carried out on students that experienced the lockdown to better understand its consequences, especially if these are long lasting. Keywords: COVID-19 pandemic, evolution acceptance, attitudes toward biology, students’ religiosity, parents’ education, students’ gender

Stone Selection by Wild Chimpanzees Shares Patterns with Oldowan Hominins

The use of broad tool repertoires to increase dietary flexibility through extractive foraging behaviors is shared by humans and their closest living relatives (chimpanzees, Pan troglodytes). However, comparisons between tool use in ancient human ancestors (hominins) and chimpanzees are limited by differences in their toolkits. One feature shared by primate and hominin toolkits is rock selection based on physical properties of the stones and the targets of foraging behaviors. Here, we document the selectivity patterns of stone tools used by wild chimpanzees to crack nuts at Bossou, Guinea, through controlled experiments that introduce rocks unknown to this population. Experiments incorporate specific rock types because previous studies document hominin selection of these lithologies at Kanjera South 2 Ma. We investigate decisions made by chimpanzees when selecting stones that vary in their mechanical properties-features not directly visible to the individual. Results indicate that the selection of anvils and hammers is linked to task-specific mechanical properties. Chimpanzees select harder stones for hammers and softer stones for anvils, indicating an understanding of specific properties for distinct functions. Selectivity of rock types suggests that chimpanzees assess the appropriate materials for functions by discriminating these 'invisible' properties. Adults identify mechanical properties through individual learning, and juveniles often reused the tools selected by adults. Selection of specific rock types may be transmitted through the reuse of combinations of rocks. These patterns of stone selection parallel what is documented for Oldowan hominins. The processes identified in this experiment provide insights into the discrete nature of hominin rock selection patterns in Plio-Pleistocene stone artifact production.

Zewnętrzne ślady pamięciowe społeczności paleolitycznych

This article explores the Paleolithic era through the lens of art and memory. Specifically, it focuses on the memory category, particularly the memory trace/ engram, to better understand the role that Paleolithic art may have played for communities during that time. Paleolithic art can be seen as a kind of memory trace, carrying information and knowledge about behaviors and actions that were transmitted through it. The deliberate placement of images in an external environment was a significant milestone in the cultural and social evolution of hominids.

PUBLIC SERVICES - EFFECTIVE MEANS OF PUBLIC AUTHORITIES FOR SUSTAINABLE DEVELOPMENT

Sustainable development has become a more and more common concept in the current background of social, economic, legal realities that concern not only the evolution of Romania in the coming years, but the evolution of the whole humanity. Romania, as a member state of the United Nations (UN) and the European Union (EU), has signed up to the 17 Sustainable Development Goals (SDGs) of the 2030 Agenda, adopted by the UN General Assembly Resolution A/RES/70/1 at the UN Summit on Sustainable Development in September 2015. The EU Council Conclusions, adopted on June 20, 2017, "A sustainable future for Europe: the EU response to the 2030 Agenda for Sustainable Development" is the policy document committed by the EU Member States on the implementation of the 2030 Agenda for Sustainable Development. In this background, each country involved has sought to regulate as best as possible the levers to achieve these goals. This study attempts to answer the question whether public services in Romania and not only, in an improved formula, can represent real mechanisms towards a sustainable development of the society

Tracing the Evolution of Human Immunity Through Ancient DNA.

Infections have imposed strong selection pressures throughout human evolution, making the study of natural selection's effects on immunity genes highly complementary to disease-focused research. This review discusses how ancient DNA studies, which have revolutionized evolutionary genetics, increase our understanding of the evolution of human immunity. These studies have shown that interbreeding between modern humans and Neanderthals or Denisovans has influenced present-day immune responses, particularly to viruses. Additionally, ancient genomics enables the tracking of how human immunity has evolved across cultural transitions, highlighting strong selection since the Bronze Age in Europe (<4,500 years) and potential genetic adaptations to epidemics raging during the Middle Ages and the European colonization of the Americas. Furthermore, ancient genomic studies suggest that the genetic risk for noninfectious immune disorders has gradually increased over millennia because alleles associated with increased risk for autoimmunity and inflammation once conferred resistance to infections. The challenge now is to extend these findings to diverse, non-European populations and to provide a more global understanding of the evolution of human immunity.

Population Studies and Molecular Mechanisms of Human Radioadaptive Capabilities: Is It Time to Rethink Radiation Safety Standards?

The evolution of man on Earth took place under conditions of constant exposure to background ionizing radiation (IR). From this point of view, it would be reasonable to hypothesize the existence of adaptive mechanisms that enable the human organism to safely interact with IR at levels approximating long-term natural background levels. In some situations, the successful operation of molecular mechanisms of protection against IR is observed at values significantly exceeding the natural background level, for example, in cancer cells. In 15-25% of cancer patients, cancer cells develop a phenotype that is resistant to high doses of IR. While further investigations are warranted, the current evidence suggests a strong probability of observing positive health effects, including an increased lifespan, a reduced cancer risk, and a decreased incidence of congenital pathologies, precisely at low doses of ionizing radiation. This review offers arguments primarily based on a phenomenological approach and critically reconsidering existing methodologies for assessing the biological risks of IR to human health. Currently, in the most economically developed countries, there are radiation safety rules that interpret low-dose radiation as a clearly negative environmental factor. Nowadays, this approach may pose significant challenges to the advancement of radiomedicine and introduce complexities in the regulation of IR sources. The review also examines molecular mechanisms that may play a key role in the formation of the positive effects of low-dose IR on human radioadaptive capabilities.