Journal of Human Evolution最新文献

The earliest evidence for complex tool use in the archaeological record dates to 3.3 Ma. While wooden tools may have been used by our earliest ancestors, the evidence is absent due to poor preservation. However, insights into possible early hominin wooden tool use can be gained from observing the tool-use practices of our closest living relatives, chimpanzees (Pan troglodytes). By using stone hammers used to crack various nuts, chimpanzees leave a durable material signature comprised of formal tools and associated diagnostic fragments. While the archaeological evidence of chimpanzee wooden tool use is temporary, the combination of stone hammers and wooden anvils can create a more enduring lithic record. This study explores the lithic assemblages associated with wooden and stone anvil use at nut-cracking sites in Taï National Park, Côte d'Ivoire, using technological and use-wear analyses. Our results indicate clear differences in density, fracture patterns, and use-wear in the lithic records between wooden anvil and stone anvil sites. New archaeological excavations at six chimpanzee nut-cracking sites reveal that the anvils' material directly influences the visibility of nut-cracking evidence in the archaeological record. By examining the nature of the lithic signatures associated with wooden anvil and stone anvil use by chimpanzees, we can formulate hypotheses about the probability of such behaviors being preserved and identifiable in the Plio-Pleistocene hominin archaeological record. The variability in material signatures from nut-cracking on different anvils suggests that stone anvils leave a clear archaeological record. Evidence for wooden anvil use is likely underrepresented due to the more ephemeral nature of the associated percussive damage and material signature. It may, however, still be possible, albeit challenging, to identify wooden anvil use in the archaeological record.

A hominin mandible, KNM-ER 63000, and associated vertebrate remains were recovered in 2011 from Area 40 in East Turkana, Kenya. Tephrostratigraphic and magnetostratigraphic analyses indicate that these fossils date to ∼4.3 Ma. KNM-ER 63000 consists of articulating but worn and weathered mandibular corpora, with a broken right M₂ crown and alveoli preserved at other tooth positions. Despite extensive damage, KNM-ER 63000 preserves diagnostic anatomy permitting attribution to Australopithecus anamensis. It can be distinguished from Australopithecus afarensis by its strongly inclined symphyseal axis with a basally convex, ‘cut-away’ external surface, a lateral corpus that sweeps inferomedially beneath the canine-premolar row, and alignment of the canine alveolus with the postcanine axis. KNM-ER 63000 is distinguished from Ardipithecus ramidus by its thick mandibular corpus and large M₂ crown. The functional trait structure and enamel’s stable carbon isotopic composition of the Area 40 large-mammal community suggests an environment comparable to Kanapoi and other ∼4.5–4 Ma eastern African sites that would have offered Au. anamensis access to both C₃ and C₄ food resources. With an age of ∼4.3 Ma, KNM-ER 63000 is the oldest known specimen of Au. anamensis, predating the Kanapoi and Asa Issie samples by at least ∼100 kyr. This specimen extends the known temporal range of Au. anamensis and places it in temporal overlap with fossils of Ar. ramidus from Gona, Ethiopia. The morphology of KNM-ER 63000 indicates that the reconfigured masticatory system differentiating basal hominins from the earliest australopiths existed in the narrow temporal window, if any, separating the two. The very close temporal juxtaposition of these significant morphological and adaptive differences implies that Ar. ramidus was a relative rather than a direct phyletic ancestor of earliest Australopithecus.

The foragers of the southern African Middle Stone Age were among the first humans to adapt their environment and its resources to their needs. They heat-treated stone to alter its mechanical properties, transformed yellow colorants into red pigments and produced moldable adhesive substances from plants. Until now, only Podocarpus conifers have been identified as the botanical origin of Middle Stone Age adhesives. This is curious as these conifers do not produce sticky exudations that could be recognized as potential adhesives. To obtain an adhesive, tar must be made with a technical process based on fire. However, the nature of these technical processes has remained unknown, hampering our understanding of the meaning of this adhesive technology for the cultural evolution of early Homo sapiens. Here, we present the first evidence of a technique used for tar making in the Middle Stone Age. We created an experimental reference collection containing naturally available adhesives along manufactured tars from plants available in the Middle Stone Age and compared these to artifacts using gas chromatography–mass spectrometry and infrared spectroscopy. We found that, in the Howiesons Poort at Sibhudu Cave, tar was made by condensation, an efficient above-ground process. Even more surprisingly, the condensation method was not restricted to Podocarpus. The inhabitants of Sibhudu also produced tar from the leaves of other plants. These tars were then used, either without further transformation or were processed into ochre-based compound adhesives, suggesting that people needed different moldable substances with distinct mechanical properties. This has important implications for our understanding of Middle Stone Age H. sapiens, portraying them as skilled engineers who used and transformed their resources in a knowledgeable way.

Hominoids exhibit a strikingly diverse set of locomotor adaptations—including knuckle-walking, brachiation, quadrumanuous suspension, and striding bipedalism—while also possessing morphologies associated with forelimb suspension. It has been suggested that changes in limb element integration facilitated the evolution of diverse locomotor modes by reducing covariation between serial homologs and allowing the evolution of a greater diversity of limb lengths. Here, I compare limb element integration in hominoids with that of other primate taxa, including two that have converged with them in forelimb morphology, Ateles and Pygathrix. Ateles is part of a clade that, such as hominoids, exhibits diverse locomotor adaptations, whereas Pygathrix is an anomaly in a much more homogeneous (in terms of locomotor adaptations) clade. I find that all atelines (and possibly all atelids), not just Ateles, share reduced limb element integration with hominoids. Pygathrix does not, however, instead resembling other members of its own family. Indriids also seem to have higher limb integration than apes, despite using their forelimbs and hindlimbs in divergent ways, although there is more uncertainty in this group due to poor sample size. These results suggest that reduced limb integration is characteristic of certain taxonomic groups with high locomotor diversity rather than taxa with specific, specialized locomotor adaptations. This is consistent with the hypothesis that reduced integration serves to open new areas of morphospace to those clades while suggesting that derived locomotion with divergent demands on limbs is not necessarily associated with reduced limb integration.

Zooarcheological and geochemical evidence suggests Neanderthals were top predators, but their adherence to a strictly carnivorous diet has been questioned. Recent studies have demonstrated the potential of calcium-stable isotopes to evaluate trophic and ecological relationships. Here, we measure the δ^44/42Ca values in bone samples from Mousterian contexts at Grotte du Bison (Marine Isotope Stage 3, Yonne, France) and Regourdou (Marine Isotope Stage 5, Dordogne, France) in two new Neanderthal individuals, associated fauna, and living local plants. We use a Bayesian mixing model to estimate the dietary composition of these Neanderthal individuals, plus a third one already analyzed. The results reveal three distinct diets: a diet including accidental or voluntary consumption of bone-based food, an intermediate diet, and a diet without consumption of bone-based food. This finding is the first demonstration of diverse subsistence strategies among Neanderthals and as such, reconciles archaeological and geochemical dietary evidence.

The superfamily Cercopithecoidea had a broad spatial distribution and occupied a wide variety of habitats across Europe from the Late Miocene until the Middle Pleistocene. Cercopithecines, such as macaques, showed more flexibility in habitat preferences, whereas colobines tended to be more sensitive to environmental differences. In Romania, only a few Pliocene and Pleistocene fossil sites have yielded primate remains. In this paper, we revise selected specimens previously listed in site reviews, and we describe several unpublished specimens from the Plio–Pleistocene fossil localities of Berești (Mammal Neogene [MN], MN14–MN15), Mălușteni (MN14), Ciuperceni-2 (MN15b), and Betfia (MN18). For each, we provide detailed descriptions, comparisons to other relevant material, and updated taxonomic assignments. We also present an updated biochronology and provide a paleoenvironmental reconstruction based on the taxonomic composition of the faunal assemblages described from these primate localities. The colobine monkey Dolichopithecus ruscinensis, from Berești, Mălușteni, and Ciuperceni-2, was present during the Early Pliocene in Romania. Mesopithecus monspessulanus is also known from Mălușteni, as is Paradolichopithecus sp. The Early Pleistocene site Betfia yielded a molar germ (in crypt; Betfia-XIII) and a deciduous premolar (Betfia-IX), both belonging to a Macaca sylvanus subspecies. Macaca sylvanus ssp. occurrences from Betfia-XIII and Betfia-IX offer an important perspective for understanding the chronostratigraphic range and geographic distribution of this species during the Early Pleistocene. The paleoenvironmental descriptions from Ciuperceni-2 show that primates were distributed in a mosaic habitat, with open and forested areas and a warm Mediterranean climate. This differs from Mălușteni, Berești, and Betfia, where a dry continental phase with an open landscape is inferred. Our review of paleoenvironmental conditions of Romanian primate localities provides a paleoecological framework for understanding the habitat preferences of extinct primates.