Late Pleistocene Modern Humans Research Articles

A structural reassessment of the Late Pleistocene femur from Maludong, southwestern China

AbstractObjectiveThe Late Pleistocene partial right femur from Maludong in southwestern China has been attributed characteristics of early Homo, especially from the Early Pleistocene, putatively representing a late surviving archaic population in the region. Assessment of additional traits is warranted given newly described postcrania from the Late Pleistocene of southwestern China and characterized by relatively modern features.Materials and methodsWe used micro computed tomography (μCT) to extract and evaluate cross‐sectional diaphyseal structure. New predictions of Maludong femoral length were generated from a regression analysis of Holocene modern humans. Robusticity and shape at multiple, standard diaphyseal regions of interest (ROI) were compared to those of Pleistocene and Holocene humans from East Asia and beyond.ResultsStandardized torsional rigidities at mid‐proximal and subtrochanteric Maludong ROIs fell within ranges of variation exhibited by multiple comparative groups, and closest to medians of Early and Middle Upper Paleolithic modern humans (E/MUP). For Ix/Iy diaphyseal ratios, Maludong was higher than comparative groups at both ROIs, falling closest to the upper end of the E/MUP range. For Imax/Imin shape ratios, Maludong fell well above group medians at the mid‐proximal ROI and nearest E/MUP and Middle Pleistocene group medians at the subtrochanteric ROI.Discussion and conclusionsIn diaphyseal robusticity and rigidity ratios, Maludong fits within variation exhibited by other Late Pleistocene modern humans. While we did not re‐analyze external features described as archaic‐like, internal structure of the Maludong femur contradicts this characterization and instead supports expanding intrapopulation variability expressed by Late Pleistocene modern humans in East Asia.

Structural properties of humeral diaphyses of East Asian modern humans from the Late Pleistocene to Early Holocene

AbstractObjectivesThis study aims to explore the structural properties along entire humeral diaphyses of Late Pleistocene and Early Holocene East Asian modern humans relative to the contemporaneous Neandertal specimen Regourdou 1 to provide insight into adaptive behaviors within temporal and regional hominin contexts.Materials and methodsThe humeri of three individuals from East Asia securely dated from the Late Pleistocene to Early Holocene were selected: Tianyuan 1, Zhaoguo M1, and Qihe M2. These specimens were scanned using microcomputed tomography to evaluate structural properties: cortical bone thickness (CBT), second moment of area (SMA), external radius (ER), and polar moment of area (J).ResultsThe distribution patterns of CBT, ER, and J were similar across all specimens. However, the magnitude of these variables was notably large in Regourdou 1 right humerus. The SMA, ER, and J of left humerus of Tianyuan 1 were less than that of other East Asian specimens, whereas those from the right humerus of the Qihe M2 individual were slightly larger than two other East Asian individuals. Additionally, the humeral asymmetry of Tianyuan 1 was greater than that of Zhaoguo M1 and Qihe M2.DiscussionCompared to Regourdou 1, East Asian specimens had reduced humeral robusticity. Within East Asia, the Late Pleistocene modern humans exhibit greater humeral asymmetry than the Early Holocene humans, indicating a universal reduction of humeral asymmetry related to technological changes across Eurasia during this time. The current study contributes to developing a more thorough understanding of intergroup humeral structural variation across Eurasia during the Late Pleistocene and Early Holocene.

Estimating crossing success of human agents across sea straits out of Africa in the Late Pleistocene

According to the Out-of-Africa theory, humans originated in Africa and from there expanded into Eurasia. Besides entering Eurasia via a terrestrial route, humans may have used sea straits. These routes would have shaped the subsequent expansions in Eurasia. Sea straits, in particular, are an additional option for entering Eurasia. However, the chances of sea crossings into Eurasia have not yet been quantified. Here, we apply an agent-based model for human water crossing to quantify the crossing success for the Gibraltar Strait, the Sicily Strait, and the Bab-al-Mandab Strait during the Late Pleistocene. The environment of the model consists of geographic explicit reconstructions of the sea straits, including water temperature, current speed and direction, along with terrestrial data of resource distribution and topography. We tested five behavioral scenarios of water movement skills of Late Pleistocene modern humans in a cold phase, represented by the Last Glacial Maximum, and a warm phase, represented by the Last Interglacial. We quantified the impact of water movement skills and climate on the crossing success by the crossing success rate (CSR). Our results show that Africa could be left via the Bab-al-Mandab Strait without specific rafting technology. At low sea level, even passive drifting was sufficient to cross the strait. In contrast, the Gibraltar- and Sicily Strait were barriers to humans without rafting technology.

Initial Upper Palaeolithic humans in Europe had recent Neanderthal ancestry

Modern humans appeared in Europe by at least 45,000 years ago1–5, but the extent of their interactions with Neanderthals, who disappeared by about 40,000 years ago6, and their relationship to the broader expansion of modern humans outside Africa are poorly understood. Here we present genome-wide data from three individuals dated to between 45,930 and 42,580 years ago from Bacho Kiro Cave, Bulgaria1,2. They are the earliest Late Pleistocene modern humans known to have been recovered in Europe so far, and were found in association with an Initial Upper Palaeolithic artefact assemblage. Unlike two previously studied individuals of similar ages from Romania7 and Siberia8 who did not contribute detectably to later populations, these individuals are more closely related to present-day and ancient populations in East Asia and the Americas than to later west Eurasian populations. This indicates that they belonged to a modern human migration into Europe that was not previously known from the genetic record, and provides evidence that there was at least some continuity between the earliest modern humans in Europe and later people in Eurasia. Moreover, we find that all three individuals had Neanderthal ancestors a few generations back in their family history, confirming that the first European modern humans mixed with Neanderthals and suggesting that such mixing could have been common.

Late Pleistocene paleoenvironment of southern China: Clay mineralogical and geochemical analyses from Luna Cave, Guangxi, China

A number of important early Late Pleistocene human fossils have been found in southern China. These new data have contributed to a major revision of the traditional Out of Africa model that argues modern humans did not disperse out of Africa until after 60 ka. At the same time, these findings have attracted increased attention by paleoclimate specialists (e.g., vertebrate paleontologists, sedimentologists) interested in identifying the characteristics and understanding the living environment of the region in which these early Late Pleistocene modern humans lived in. Unfortunately, research focused on the reconstruction of the Late Pleistocene paleoenvironment in southern China is still very limited. Here, we present an analysis of the clay mineral assemblage and geochemical characteristics of the sedimentary deposits from Luna Cave, one of these important early Late Pleistocene modern human sites in southern China. The results from the sedimentological analyses are consistent with previous paleontological and geological studies that showed the paleoclimate was strongly influenced by the East Asian monsoon and that the Late Pleistocene environment was relatively stable warm and humid. Further studies of coeval sites from the region are necessary to determine whether this is a consistent pattern across southern China or specific to the Bubing Basin.

Inner ear morphology of the cioclovina early modern European calvaria from Romania.

The morphology of the human bony labyrinth is thought to preserve a strong phylogenetic signal and to be minimally, if at all, affected by postnatal processes. The form of the semicircular canals is considered a derived feature of Neanderthals and different from the modern human anatomy. Among other hominins, European Middle Pleistocene humans have been found to be most similar to Neanderthals. Early modern humans have been proposed to show a pattern that is distinct, but most similar to that of Holocene people. Here we examine the inner ear structures of the Cioclovina calvaria, one of the earliest reliably dated and relatively complete modern human crania from Europe, in the context of recent and fossil human variation. Bony labyrinths were virtually extracted from CT scans of recent Europeans and Cioclovina. Using univariate and multivariate methods, measurements of the semicircular canals were compared with published measurements of other fossil specimens. Our results show that Cioclovina's inner ear morphology falls within the range of modern variation, with affinities to both Late Pleistocene modern humans and recent Europeans. Using discriminant functions, the sex of the Cioclovina specimen is estimated as male. Results agree with previous work showing that Cioclovina exhibits fully modern cranial morphology.

The Xujiayao 14 Mandibular Ramus and Pleistocene Homo Mandibular Variation

The earlier Late Pleistocene mandibular ramus from Xujiayao (northern China) preserves traits that vary distributionally among western Old World Pleistocene Homo samples and between Early/Middle Pleistocene archaic humans and Late Pleistocene modern humans in eastern Eurasia. Xujiayao 14 presents a lateral mandibular notch crest, an open mandibular foramen, a wide ramus, an asymmetrical mandibular notch, an enlarged superior medial pterygoid tubercle, (probably) a retromolar space, and gonial eversion, as well as an unusual depression in the planum triangulare. The first two traits appear ancestral for Later Pleistocene and recent Homo and are dominant among modern humans. The second two traits largely separate Xujiayao 14 and archaic Homo from modern humans. The next two traits are found in the highest frequency among the Neandertals, although gonial eversion contrasts with Late Pleistocene Neandertals. Xujiayao 14, in the context of Pleistocene and recent Homo samples and the other Xujiayao human remains, therefore provides a morphological mosaic, highlighting regional variation through the Pleistocene.

Storied landscapes makes us (Modern) Human: Landscape socialisation in the Palaeolithic and consequences for the archaeological record

The unusual nature of the Neanderthal archaeological record has attracted the attention of archaeologists for the past 150years. On the one hand, the technical skill apparent in their lithic technology, the practice of symbolic cultural behaviours (such as burials), and their successful survival in harsh environmental conditions for more than 200,000years demonstrate the adaptive success and underlying humanity of the Neanderthal populations. On the other hand, the apparent lack of abundant and repeated use of symbolic material culture has resulted in a number of researchers arguing that these populations were largely incapable of symbolism – a conclusion with significant implications for social organisation. This paper reviews ideas regarding the use of ‘place’ or ‘landscape’ by Neanderthals and argues that the identified differences between the archaeological records of Neanderthals and late Pleistocene Modern Humans is not so much the result of significant variance in cognitive capacities, but rather the use of contrasting approaches to interaction with the physical landscape. ‘Landscape socialisation’ is a Modern Human universal, but what if Neanderthals did not participate in this kind of landscape interaction? Would this difference in behaviour result in the apparently contradictory archaeological record which has been created? The ideas presented in this paper are drawn together as a hypothesis to be developed and tested.

Paleoamerican morphology in the context of European and East Asian late Pleistocene variation: Implications for human dispersion into the new world

Early American crania show a different morphological pattern from the one shared by late Native Americans. Although the origin of the diachronic morphological diversity seen on the continents is still debated, the distinct morphology of early Americans is well documented and widely dispersed. This morphology has been described extensively for South America, where larger samples are available. Here we test the hypotheses that the morphology of Early Americans results from retention of the morphological pattern of Late Pleistocene modern humans and that the occupation of the New World precedes the morphological differentiation that gave rise to recent Eurasian and American morphology. We compare Early American samples with European Upper Paleolithic skulls, the East Asian Zhoukoudian Upper Cave specimens and a series of 20 modern human reference crania. Canonical Analysis and Minimum Spanning Tree were used to assess the morphological affinities among the series, while Mantel and Dow-Cheverud tests based on Mahalanobis Squared Distances were used to test different evolutionary scenarios. Our results show strong morphological affinities among the early series irrespective of geographical origin, which together with the matrix analyses results favor the scenario of a late morphological differentiation of modern humans. We conclude that the geographic differentiation of modern human morphology is a late phenomenon that occurred after the initial settlement of the Americas.

Contributions of biogeochemistry to understanding hominin dietary ecology

Dietary ecology is one key to understanding the biology, lifeways, and evolutionary pathways of many animals. Determining the diets of long-extinct hominins, however, is a considerable challenge. Although archaeological evidence forms a pillar of our understanding of diet and subsistence in the more recent past, for early hominins, the most direct evidence is to be found in the fossils themselves. Here we review the suite of emerging biochemical paleodietary tools based on stable isotope and trace element archives within fossil calcified tissues. We critically assess their contribution to advancing our understanding of australopith, early Homo, and Neanderthal diets within the broader context of non-biogeochemical techniques for dietary reconstruction, such as morphology and dental microwear analysis. The most significant outcomes to date are the demonstration of high trophic-level diets among Neanderthals and Late Pleistocene modern humans in Glacial Europe, and the persistent inclusion of C(4) grass-related foods in the diets of Plio-Pleistocene hominins in South Africa. Such studies clearly show the promise of biogeochemical techniques for testing hypotheses about the diets of early hominins. Nevertheless, we argue that more contextual data from modern ecosystem and experimental studies are needed if we are to fully realize their potential.

Backed tools in Middle Pleistocene central Africa and their evolutionary significance.

The fashioning of stone inserts for composite tools by blunting flakes and blades is a technique usually associated with Late Pleistocene modern humans. Recent reports from two sites in south central Africa (Twin Rivers and Kalambo Falls) suggest that this backed tool technology originated in the later Middle Pleistocene with early or "archaic" Homo sapiens. This paper investigates these claims critically from the perspective of the potential mixing of Middle and Later Stone Age deposits at the two sites and the possible creation of misleading assemblages. The review shows that backed tools form a statistically minor, but technologically significant feature of the early Middle Stone Age of south central Africa. They first appear in the Lupemban industry at approximately 300 ka and remain an element of the Middle Stone Age technological repertoire of the region. Comparisons are made with early backed tool assemblages of east Africa and with the much younger Howiesons Poort industry of southern Africa. The paper concludes that Lupemban tools lack the standardization of the Howiesons Poort backed pieces, but form part of a regionally distinctive and diverse assemblage of heavy and light duty tools. Some modern-like behaviours appear to have emerged by the later Middle Pleistocene in south central Africa.

On the dilatation or compressed liquids, particularly water

According to the Out-of-Africa theory, humans originated in Africa and from there expanded into Eurasia. Besides entering Eurasia via a terrestrial route, humans may have used sea straits. These routes would have shaped the subsequent expansions in Eurasia. Sea straits, in particular, are an additional option for entering Eurasia. However, the chances of sea crossings into Eurasia have not yet been quantified.Here, we apply an agent-based model for human water crossing to quantify the crossing success for the Gibraltar Strait, the Sicily Strait, and the Bab-al-Mandab Strait during the Late Pleistocene. The environment of the model consists of geographic explicit reconstructions of the sea straits, including water temperature, current speed and direction, along with terrestrial data of resource distribution and topography. We tested five behavioral scenarios of water movement skills of Late Pleistocene modern humans in a cold phase, represented by the Last Glacial Maximum, and a warm phase, represented by the Last Interglacial.We quantified the impact of water movement skills and climate on the crossing success by the crossing success rate (CSR). Our results show that Africa could be left via the Bab-al-Mandab Strait without specific rafting technology. At low sea level, even passive drifting was sufficient to cross the strait. In contrast, the Gibraltar- and Sicily Strait were barriers to humans without rafting technology.