Early Homo Research Articles

New modern and Pleistocene fossil micromammal assemblages from Swartkrans, South Africa: Paleobiodiversity, taphonomic, and environmental context.

The oldest deposit at the hominin-bearing cave of Swartkrans, South Africa, is the Lower Bank of Member 1, dated to ca. 2.2 million years ago. Excavations of this unit have produced a diverse and extensive mammalian fossil record, including Paranthropus robustus and early Homo fossils, along with numerous Oldowan stone tools. The present study focuses on the taxonomic analysis of the micromammalian fossil assemblage obtained from recent excavations of the Lower Bank, conducted between 2005 and 2010, as part of the Swartkrans Paleoanthropological Research Project. The taxonomic composition of this assemblage is dominated by Mystromys, a rodent indicative of grassland environments. Taphonomic analysis indicates an accumulation of prey by Tyto alba (Barn owl) or a related species. Environments inferred from this evidence reflect an open landscape primarily covered by grassland vegetation, but they also feature components of wooded areas, rocky outcrops, and the proximity of a river. The Swartkrans fossil assemblage is compared with Cooper's D (dated to ca. 1.4Ma) and a modern coprocoenosis of Bubo africanus (spotted eagle-owl) collected within the Swartkrans cave for taxonomic, taphonomic, and paleoecological perspectives. Contrasting fossil and modern micromammalian data provide a better understanding of accumulation processes and facilitate a diachronic reconstruction of changes in climate and landscape evolution. Issues regarding paleoenvironmental reconstruction methodologies based on micromammals are also discussed.

Are we jingling modern hunter-gatherers and early Homo sapiens?

Using modern hunter-gatherers to infer about early Homo sapiens only works if at least (a) modern hunter-gatherers represent an unbiased sample of humanity, and (b) modern hunter-gatherers act in ways similar to the behavior of early Homo sapiens. Both of these are false, leading to the problem of whether we can draw conclusions about early Homo sapiens from modern hunter-gatherers.

Refitting the Context: A Reconsideration of Cultural Change among Early Homo sapiens at Fumane Cave through Blade Break Connections, Spatial Taphonomy, and Lithic Technology

High-resolution stratigraphic frameworks are crucial for unraveling the biocultural processes behind the dispersals of Homo sapiens across Europe. Detailed technological studies of lithic assemblages retrieved from multi-stratified sequences allow archaeologists to precisely model the chrono-cultural dynamics of the early Upper Paleolithic. However, it is of paramount importance to verify the integrity of these assemblages before building explanatory models of cultural change. In this study, multiple lines of evidence suggest that the stratigraphic sequence of Fumane Cave in northeastern Italy experienced minor post-depositional reworking, establishing it as a pivotal site for exploring the earliest stages of the Aurignacian. By conducting a systematic search for break connections between blade fragments and applying spatial analysis techniques, we identified three well-preserved areas of the excavation containing assemblages suitable for renewed archaeological investigations. Subsequent technological analyses, incorporating attribute analysis, reduction intensity, and multivariate statistics, have allowed us to discern the spatial organization of the site during the formation of the Protoaurignacian palimpsest A2–A1. Moreover, diachronic comparisons between three successive stratigraphic units prompted us to reject the hypothesis of techno-cultural continuity of the Protoaurignacian in northeastern Italy after the onset of the Heinrich Event 4. Based on the variability of the lithic and osseous artifacts, the most recent assemblage analyzed, D3b alpha, is now ascribed to the Early Aurignacian, aligning the evidence from Fumane with the current understanding of the development of the Aurignacian across Europe. Overall, this study demonstrates the high effectiveness of the break connection method when combined with detailed spatial analysis and lithic technology, providing a methodological tool particularly amenable to be applied to sites excavated in the past with varying degrees of recording accuracy.

Random forest models highlight early Homo sapiens habitats and their relationship to lithic assemblage composition

Random forest models highlight early Homo sapiens habitats and their relationship to lithic assemblage composition

The Late Villafranchian Absence of Pigs in Europe. Comment on Iannucci, A. The Occurrence of Suids in the Post-Olduvai to Pre-Jaramillo Pleistocene of Europe and Implications for Late Villafranchian Biochronology and Faunal Dynamics. Quaternary 2024, 7, 11

On 2015, after the direct study of the most important Late Villafranchian fossil collections of Europe and Western Asia, including Orce (Spain), Pirro Nord and Upper Valdarno (Italy), Appollonia (Greece), Dmanisi (Georgia) and ‘Ubeidiya (Israel), among others, our team proposed the hypothesis that suids disappeared from Europe during the time span between 1.8 and 1.2 Ma. The implications of our conclusions were significant, the arrival of Early Homo into Western Europe, dated to 1.4 Ma at the site of Barranco León in Orce (Spain), preceded the return of pigs into the continent at 1.2 Ma. This hypothesis has been recently challenged because of the finding of an incomplete metatarsal ascribed to Sus sp., with no clear stratigraphic origin, found in the XIX Century Croizet collection of Peyrolles (France), which is housed in the Natural History Museum, London, together with other weak arguments based on the absence of reliable dating for many Early Pleistocene European sites, and other hypothetical records of pigs, with no real fossil support. We answer all these questions and defend that our 2015 hypothesis is correct.

The species in paleoanthropology

The species is the basic unit of analysis in systematic paleontology. Yet, for most of its history the subfield of paleoanthropology has lacked any coherent concept of what fossil species are, using the species epithet variously at different times – most recently, with the conspicuous effect of minimizing apparent diversity among the hominins. The application of molecular systematic techniques to the analysis of high-latitude early Homo sapiens Linnaeus, 1758 and its contemporaries thus offers a welcome opportunity to reappraise our approaches to species recognition in the rapidly expanding hominin fossil record. But it must be cautioned that evidence for hybridization among documented or hypothesized lineages cannot necessarily be taken as evidence for recoalescence among them, and that “braided stream” models of hominin evolution (which militate against speciation) cannot ­account for the diversity of historically and morphologically differentiated entities we see in that record.

Dental evidence for extended growth in early Homo from Dmanisi

Human life history is characterized by an extended period of immaturity during which there is a disjunction between cerebral and somatic growth rates1. This mode of ontogeny is thought to be essential for the acquisition of advanced cognitive capabilities in a socially complex environment while the brain is still growing2. Key information about when and how this pattern evolved can be gleaned from the teeth of fossil hominins because dental development informs about the pace of life history3–5. Here we show that the first evolutionary steps towards an extended growth phase occurred in the genus Homo at least 1.77 million years ago, before any substantial increase in brain size. We used synchrotron phase-contrast tomography6 to track the microstructural development of the dentition of a subadult early Homo individual from Dmanisi, Georgia. The individual died at the age of 11.4 ± 0.6 years, shortly before reaching dental maturity. Tooth growth rates were high, similar to rates in living great apes. However, the Dmanisi individual showed a human-like delayed formation of the posterior relative to the anterior dentition, and a late growth spurt of the dentition as a whole. The unique combination of great-ape-like and human-like features of dental ontogeny suggests that early Homo had evolved an extended growth phase before a general slow-down in life history, possibly related to biocultural reproduction7 rather than brain growth.

Craniometric variation and the ancestry of modern humans.

Ancient and contemporary DNA provide information about geographic variation in the ancestry of present-day humans. All living populations have ancestry from early Homo sapiens originating in sub-Saharan Africa. Populations of Eurasian descent also have a small amount of Neandertal ancestry. This study examines whether craniometric distances between recent modern human samples reflect this geographic variation in ancestry. Among recent modern humans, Eurasians are expected to be more similar to Neandertals, whereas both sub-Saharan Africans and Eurasians are expected to be equidistant from early H. sapiens. Data on 33 craniometric traits from 2524 recent modern humans were compared with data from the literature for Neandertals and early H. sapiens. Mahalanobis distances were computed for each modern specimen to both the Neandertal and early H. sapiens means. These distances were examined for differences between recent humans from sub-Saharan Africa (N = 373) and those of Eurasian descent (N = 2151). Eurasians as a group are significantly closer than sub-Saharan Africans to Neandertals. There is no significant difference between the distances of sub-Saharan Africans and Eurasians to early H. sapiens. The differences between sub-Saharan Africans and Eurasians for both Neandertals and early H. sapiens are as expected. Although there has been geographic differentiation among recent modern humans, including differences in Neandertal admixture, these differences have not affected overall similarity of recent modern sub-Saharan Africans and Eurasians to the earliest samples of H. sapiens.

Chronometric data and stratigraphic evidence support discontinuity between Neanderthals and early Homo sapiens in the Italian Peninsula

The process by which Palaeolithic Europe was transformed from a Neanderthal-dominated region to one occupied exclusively by Homo sapiens has proven challenging to diagnose. A blurred chronology has made it difficult to determine when Neanderthals disappeared and whether modern humans overlapped with them. Italy is a crucial region because here we can identify not only Late Mousterian industries, assumed to be associated with Neanderthals, but also early Upper Palaeolithic industries linked with the appearance of early H. sapiens, such as the Uluzzian and the Aurignacian. Here, we present a chronometric dataset of 105 new determinations (74 radiocarbon and 31 luminescence ages) from four key southern Italian sites: Cavallo, Castelcivita, Cala, and Oscurusciuto. We built Bayesian-based chronometric models incorporating these results alongside the relative stratigraphic sequences at each site. The results suggest; 1) that the disappearance of Neanderthals probably pre-dated the appearance of early modern humans in the region and; 2) that there was a partial overlap in the chronology of the Uluzzian and Protoaurignacian, suggesting that these industries may have been produced by different human groups in Europe.

Quantifying heterogeneity of hominin environments in and out of Africa using herbivore dental traits

Our own species, Homo sapiens, has been able to invade near-all global ecosystems through a unique form of ecological plasticity. To understand how Homo sapiens have been able to disperse to such a wide range of environments, we need to understand the origins of the characteristic which enabled this, plasticity. Growing evidence indicates that Homo species were already able to occupy a diverse set of environments in the Early Pleistocene, suggesting that the origins of human ecological plasticity have deeper roots than previously anticipated. We analysed the distribution of two dental traits, mean ordinated hypsodonty of large herbivores and proboscidean mesowear, across the mammalian communities at Early Pleistocene hominin sites, to infer the vegetation and climate contexts of these locations. The global distribution of community-level dental traits suggests that, while open grassy vegetation made up a large proportion of the sites, mixed and wooded vegetation was also represented. From our analysis we conclude that Early Pleistocene Homo species were able to exploit habitats with different vegetation types and occupied a range of different environments. In addition to this we found that the distribution of dental traits of mammalian communities in the Eurasian sample was notably different from that of the African sample, suggesting that Homo's dispersal into Eurasia resulted in a niche expansion. Together these findings suggest that Homo in the Early Pleistocene was ecologically plastic and occupied a wide environmental niche space.

Seasonal landscape variability advances Lantian hominin's recognition capacity to strategically adapt to changing environments

Environmental Variability Selection (EVS) is hypothesized for the emergence of early Homo (H.) sapiens with small lithic tools in Africa. Yet, it is unclear how the EVS works when a special hominin group with advanced small lithic tools evolved from the Asian H. erectus with expedient core and flake industry. Lantian loessland in southern Chinese Loess Plateau in North China preserves continuous and concentrated hominin fossil, faunal, pollen, stone tool, paleoclimate, and landform records for last 2 million years (Ma) and is an ideal place to test this hypothesis. We reanalyzed δ13C values of soil organic and inorganic carbon from 2 Lantian loess-paleosol records to partition seasonal climate and habitat changes with synthesized lithic, faunal, and pollen data to seek cluses. We found that Lantian Gongwangling and Chenjiawo H. erectus adapts to woodland-forest habitats, manufacturing Mode 1 stone artifacts foraging subtropical animals in warm and Paleoarctic animals in cool seasons on the low and medium-high rolling loessland, while more advanced Dali hominins adapt to certain steppe-shrubland habitats manufacturing diverse small-sized lithic tools to forage more open-habitat animals in all seasons on hilly landforms. We propose that co-evolution of seasonal habitat variability and changing local landforms in 2.0–0.2 Ma advances Dali hominin's cognitive capacity for strategically using landform morphology for subsistence and manufacture small stone tools for intercepting high fluxes of seasonal resources on highly variable loessland. Seasonal landscape variability and landform evolution is the key in the EVS for the evolution from Asian H. erectus to a more advanced hominin group or species.

Abrupt onset of intensive human occupation 44,000 years ago on the threshold of Sahul

Archaeological evidence attests multiple early dispersals of Homo sapiens out of Africa, but genetic evidence points to the primacy of a single dispersal 70-40 ka. Laili in Timor-Leste is on the southern dispersal route between Eurasia and Australasia and has the earliest record of human occupation in the eastern Wallacean archipelago. New evidence from the site shows that, unusually in the region, sediment accumulated in the shelter without human occupation, in the window 59–54 ka. This was followed by an abrupt onset of intensive human habitation beginning ~44 ka. The initial occupation is distinctive from overlying layers in the aquatic focus of faunal exploitation, while it has similarities in material culture to other early Homo sapiens sites in Wallacea. We suggest that the intensive early occupation at Laili represents a colonisation phase, which may have overwhelmed previous human dispersals in this part of the world.

Assigning a social status from face adornments: an fMRI study.

For at least 150,000 years, the human body has been culturally modified by the wearing of personal ornaments and probably by painting with red pigment. The present study used functional magnetic resonance imaging to explore the brain networks involved in attributing social status from face decorations. Results showed the fusiform gyrus, orbitofrontal cortex, and salience network were involved in social encoding, categorization, and evaluation. The hippocampus and parahippocampus were activated due to the memory and associative skills required for the task, while the inferior frontal gyrus likely interpreted face ornaments as symbols. Resting-state functional connectivity analysis clarified the interaction between these regions. The study highlights the importance of these neural interactions in the symbolic interpretation of social markers on the human face, which were likely active in early Homo species and intensified with Homo sapiens populations as more complex technologies were developed to culturalize the human face.

New fossil Bovidae (Mammalia: Artiodactyla) from Kromdraai Unit P, South Africa and their implication for biochronology and hominin palaeoecology

Kromdraai is a Plio-Pleistocene site located in the Cradle of Humankind (Gauteng Province, South Africa). It has produced diverse and abundant faunal assemblages and key hominin specimens like the holotype of Paranthropus robustus and early Homo. We provide the first taxonomic study of the Bovidae Family from the hominin-bearing Unit P at Kromdraai and discuss its potential to unravel its paleoecological context. We describe the presence of an unknown medium-sized buffalo (Syncerus sp.) that could be closely related to S. acoelotus. The bovid assemblage from Kromdraai Unit P combines older Plio-Pleistocene (Gazella gracilior, Makapania broomi, Numidocapra cf. porrocornutus) and younger Pleistocene taxa (Tragelaphus strepsiceros, Oreotragus oreotragus, Raphicerus campestris, Damaliscus lunatus). Overall, these bovid species indicate a grassland-dominated environment for Unit P. Comparisons with other Plio-Pleistocene South African sites indicate that Australopithecus was associated with woodland and closed-wet environment-adapted taxa, whereas Homo was found in association with bovid species adapted to open and dry environments. In contrast, the assemblages associated with Paranthropus show an extensive range of environmental adaptation among the bovids. The biochronology indicates that Kromdraai Unit P accumulated between 2.9 and 1.8 Ma. If Kromdraai Unit P were to be confirmed to date to the older end of this scale, it would provide the earliest appearance of Paranthropus robustus, Numidocapra, and Damaliscus in southern Africa.

Unravelling human migrations: DISPERSALS Project sheds light on early Homo sapiens' journey

Unravelling human migrations: DISPERSALS Project sheds light on early Homo sapiens' journey DISPERSALS will compare the human occupation and ecology between central Mozambique and eastern and southern Africa using a multi-scale approach based on the study of regional diachronic cultural traits. It will reconstruct regional population patterns, followed by comparative quantitative population genetics combined with GIS computational network analyses. The results will then be integrated through agent-based modelling, based on the incremental creation, elimination, or reorientation of network links to simulate a quantitative framework to study the evolution of population dispersal across southern-eastern Africa. The project will be crucial in providing groundbreaking high-resolution archaeological, chronological and paleoenvironmental data. DISPERSALS will deliver a fundamental perspective on the key processes that triggered migrations and dispersals within Africa and out of Africa, ultimately resulting in the human diaspora over the entire planet.

Finite element analysis of Neanderthal and early Homo sapiens maxillary central incisor

Neanderthal anterior teeth are very large and have a distinctive morphology characterized by robust ‘shovel-shaped’ crowns. These features are frequently seen as adaptive responses in dissipating heavy mechanical loads resulting from masticatory and non-masticatory activities. Although the long-standing debate surrounding this hypothesis has played a central role in paleoanthropology, is still unclear if Neanderthal anterior teeth can resist high mechanical loads or not. A novel way to answer this question is to use a multidisciplinary approach that considers together tooth architecture, dental wear and jaw movements. The aim of this study is to functionally reposition the teeth of Le Moustier 1 (a Neanderthal adolescent) and Qafzeh 9 (an early Homo sapiens adolescent) derived from wear facet mapping, occlusal fingerprint analysis and physical dental restoration methods. The restored dental arches are then used to perform finite element analysis on the left central maxillary incisor during edge-to-edge occlusion. The results show stress distribution differences between Le Moustier 1 and Qafzeh 9, with the former displaying higher tensile stress in enamel around the lingual fossa but lower concentration of stress in the lingual aspect of the root surface. These results seem to suggest that the presence of labial convexity, lingual tubercle and of a large root surface in Le Moustier 1 incisor helps in dissipating mechanical stress. The absence of these dental features in Qafzeh 9 is compensated by the presence of a thicker enamel, which helps in reducing the stress in the tooth crown.

Did climate change make Homo sapiens innovative, and if yes, how? Debated perspectives on the African Pleistocene record

Our enhanced capacity to innovate is a key feature that sets Homo sapiens apart as a species. The Middle Stone Age archaeological record of Pleistocene Africa documents the emergence and elaboration of this capacity, and its relationship to changes in past climate and environments. However, the models and interpretations developed to understand the relationship between early Homo sapiens’ innovativeness and climate change are varied and often contradictory. Here, we review these contrasting interpretations. We contend that while climate change may have influenced early human innovation, it was in an inconsistent and multifaceted way.

Dental morphology in Homo habilis and its implications for the evolution of early Homo

The phylogenetic position of Homo habilis is central to debates over the origin and early evolution of the genus Homo. A large portion of the species hypodigm consists of dental remains, but they have only been studied at the often worn enamel surface. We investigate the morphology of the H. habilis enamel-dentine junction (EDJ), which is preserved in cases of moderate tooth wear and known to carry a strong taxonomic signal. Geometric morphometrics is used to characterise dentine crown shape and size across the entire mandibular and maxillary tooth rows, compared with a broad comparative sample (n = 712). We find that EDJ morphology in H. habilis is for the most part remarkably primitive, supporting the hypothesis that the H. habilis hypodigm has more in common with Australopithecus than later Homo. Additionally, the chronologically younger specimen OH 16 displays a suite of derived features; its inclusion in H. habilis leads to excessive levels of variation.

Ecology and demography of early Homo sapiens: a synthesis of archaeological and climatic data from eastern Africa

ABSTRACT Eastern Africa maintains a key position in debates surrounding the emergence of Homo sapiens across Africa. Extensive research in the region has revealed a rich fossil record in association with a ‘generic’ but variable Middle Stone Age (MSA) material culture, providing an important laboratory for testing hypotheses about the behavioural evolution of our species. For example, multiple archaeological studies of the eastern African MSA note a link between the distribution and density of sites, archaeological diversity and environmental conditions, with ecology and demography often cited as key drivers of cultural evolution. This article formulates new hypotheses using theoretical models of complex fitness landscapes of evolution and reviews the archaeological and climatic records of Middle-late Pleistocene eastern Africa in the light of these ideas. It proposes that evidence from eastern Africa implicates much of the region as a refugial zone within Pleistocene Africa, providing consistently suitable conditions for survival that were characterised by high and changing biodiversity, facilitating population growth and interconnectivity as well as material culture diversification. Interactions between different evolutionary processes likely resulted in the complex cultural mosaic observed across Africa, including the appearance of ‘specific’ innovations against a backdrop of more ‘generic’ MSA elements.

The generic Middle Stone Age: fact or fiction?

ABSTRACT Recent decades have seen a surge of interest in the Middle Stone Age (MSA) as it constitutes the archaeological background to the early evolution of Homo sapiens. Research primacy has been given to rare regional and temporal signatures of MSA technological diversity and material culture, typically in open grassland or sparse savanna regions. These include, for example, the Still Bay, Howiesons Poort, Lupemban and Aterian, all of which can be seen as specific variants of the MSA. Archaeological assemblages apparently lacking distinctive features have received little attention in their own right. Such occurrences can be subsumed under the informal term of a more ‘generic’ MSA. The marginalisation of this material culture is problematic as it dominates the MSA record. The apparent continuity and commonality of generic MSA elements over large spatial and temporal scales also raise manifold questions about the early evolution of our species. As such, a ‘generic’ MSA might be perceived as the common technological and material substrate of early Homo sapiens behaviour and culture. At the same time, we lack quantitative studies that justify subsuming close to 300,000 years of material culture into a single category. This special issue of Azania is based on a symposium at the Sixteenth Congress of the PanAfrican Archaeological Association of Prehistory and Related Studies in Zanzibar (Tanzania) that brought together researchers working in different African regions to scrutinise apparently ‘non-specific’ MSA lithic assemblages across time and space, evaluating their commonality and relevance on different chronological and geographical scales. The six articles in this issue span comparative quantitative studies within and across regions, methodological and theoretical advances to reach these goals and the integration of palaeoecological data. A common interest lies in understanding but also testing the validity of using a ‘generic’ MSA and the general relevance of more specific or generic technological assemblages in the wider framework of modern human cultural and biological evolution.