Zhoukoudian's Homo erectus teeth provide some clues to the evolution of Homo erectus in South-east Asia
Locality 1, in the Lower Cave of the Zhoukoudian cave complex, China, is one of the most important Middle Pleistocene paleoanthropological and archaeological sites worldwide, with the remains of c. 45 Homo erectus individuals, 98 mammalian taxa, and thousands of lithic tools recovered. Most of the material collected before World War II was lost. However, besides two postcranial elements rediscovered in China in 1951, four human permanent teeth from the ‘Dragon Bone Hill,’ collected by O. Zdansky between 1921 and 1923, were at the time brought to the Paleontological Institute of Uppsala University, Sweden, where they are still stored. This small sample consists of an upper canine (PMU 25719), an upper third molar (PMU M3550), a lower third premolar crown (PMU M3549), and a lower fourth premolar (PMU M3887). Some researchers have noted the existence of morpho-dimensional differences between the Zhoukoudian and the H. erectus dental assemblage from Sangiran, Java. However, compared to its chrono-geographical distribution, the Early to Middle Pleistocene dental material currently forming the Chinese-Indonesian H. erectus hypodigm is quantitatively meager and still poorly characterized for the extent of its endostructural variation. We used micro-focus X-ray tomography techniques of virtual imaging coupled with geometric morphometrics for comparatively investigating the endostructural conformation (tissue proportions, enamel thickness distribution, enamel-dentine junction morphology, pulp cavity shape) of the four specimens stored in Uppsala, all previously reported for their outer features. The results suggest the existence of time-related differences between continental and insular Southeast Asian dental assemblages, the Middle Pleistocene Chinese teeth apparently retaining an inner signature closer to the likely primitive condition represented by the Early Pleistocene remains from Java, while the Indonesian stock evolved toward tooth structural simplification.
Publication date: 10 February 2018
The Bonn-Oberkassel dog remains (Upper Pleistocene and 14223 +- 58 years old) have been reported more than 100 years ago. Recent re-examination revealed the tooth of another older and smaller dog, making this domestic dog burial not only the oldest known, but also the only one with remains of two dogs. This observation brings the total known Magdalenian dogs to nine.
Publication date: 4 February 2018
Paranasal sinuses are highly variable among living and fossil hominins and their function(s) are poorly understood. It has been argued they serve no particular function and are biological ‘spandrels’ arising as a structural consequence of changes in associated bones and/or soft tissue structures. In contrast, others have suggested that sinuses have one or more functions, in olfaction, respiration, thermoregulation, nitric oxide production, voice resonance, reduction of skull weight, and craniofacial biomechanics. Here we assess the extent to which the very large frontal sinus of Kabwe 1 impacts on the mechanical performance of the craniofacial skeleton during biting. It may be that the browridge is large and the sinus has large trabecular struts traversing it to compensate for the effect of a large sinus on the ability of the face to resist forces arising from biting. Alternatively, the large sinus may have no impact and be sited where strains that arise from biting would be very low. If the former is true, then infilling of the sinus would be expected to increase the ability of the skeleton to resist biting loads, while removing the struts might have the opposite effect. To these ends, finite element models with hollowed and infilled variants of the original sinus were created and loaded to simulate different bites. The deformations arising due to loading were then compared among different models and bites by contrasting the strain vectors arising during identical biting tasks. It was found that the frontal bone experiences very low strains and that infilling or hollowing of the sinus has little effect on strains over the cranial surface, with small effects over the frontal bone. The material used to infill the sinus experienced very low strains. This is consistent with the idea that frontal sinus morphogenesis is influenced by the strain field experienced by this region such that it comes to lie entirely within a region of the cranium that would otherwise experience low strains. This has implications for understanding why sinuses vary among hominin fossils.
Publication date: 16 January 2018
Archaeologists investigate the association of fish-hooks in a 12,000 year old Indonesian Island Burial
Fish-hooks discovered among grave goods associated with an adult female burial at the Tron Bon Lei rockshelter on the island of Alor in Indonesia are the first of their kind from a Pleistocene mortuary context in Southeast Asia. Many of the hooks are of a circular rotating design. Parallels found in various other prehistoric contexts around the globe indicate widespread cultural convergence. The association of the fish-hooks with a human burial, combined with the lack of alternative protein sources on the island, suggest that fishing was an important part of the cosmology of this community. The Tron Bon Lei burial represents the earliest-known example of a culture for whom fishing was clearly an important activity among both the living and the dead.
Publication date: 14 January 2018
The earliest figural art known from Greece is dated to the Neolithic period (ca. 8,5 to 5 thousand years ago). A recent study of the petroglyphs at Asphendou Cave on the island of Crete, however, suggests that such art has a much longer history in the Aegean basin. First published over forty years ago, the debate concerning the petroglyphs' age has lain dormant for decades. In light of technological advances in digital imaging and recent archaeological and palaeontological discoveries on the island we re-assess the dating of the petroglyphs and prove that some were made in the Late Pleistocene, or Upper Palaeolithic. Comparison of the iconography to fossil data demonstrates that an extinct endemic deer (Candiacervus) is represented at Asphendou Cave. This is the earliest figural art yet discovered in Greece.
Publication date: 13 January 2018
The Zadar region is exceptionally rich in Middle Palaeolithic materials discovered in the area from Ražanac and Nin to the Zadar islands (Dugi otok, Silba and Pag). Sites correspond closely to raw material choice, as well as typological and technological characteristics of tools. Distinct microlithization is the main factor by which industries such as the Micro-Mousterian are classified. These kinds of materials are also characterized by preserved cortex on the core and tools made on primary and secondary flakes. The abundance and accessibility of smaller sized raw materials led Neanderthal groups to develop techniques that maximized tool size in as efficient manner as possible.
Publication date: 12 January 2018
The lithic assemblages at the Oldowan-Acheulean transition in Bed II of Olduvai Gorge, Tanzania, represent a wide variety of raw materials reflecting both the diversity of volcanic, metamorphic, and sedimentary source materials available in the Olduvai basin and surroundings and the preferences of the tool-makers. A geochemical and petrographic systematic analysis of lava-derived archaeological stone tools, combined with textural and mineralogical characterization of quartzite, chert, and other metamorphic and sedimentary raw materials from two Middle and Upper Bed II sites, has enabled us to produce a comprehensive dataset and characterization of the rocks employed by Olduvai hominins, which is used here to establish a referential framework for future studies on Early Stone Age raw material provenancing. The use of rounded blanks for most lava-derived artifacts demonstrates that hominins were accessing lava in local stream channels. Most quartzite artifacts appear to derive from angular blocks, likely acquired at the source (predominantly Naibor Soit hill), though some do appear to be manufactured from stream-transported quartzite blanks. Raw material composition of the EF-HR assemblage indicates that Acheulean hominins selected high-quality lavas for the production of Large Cutting Tools. On the other hand, the HWK EE lithic assemblage suggests that raw material selectivity was not entirely based on rock texture, and other factors, such as blank shape and availability of natural angles suitable for flaking, played a major role in Oldowan reduction sequences.
Publication date: 12 January 2018
Eight years of excavation work by the Olduvai Geochronology and Archaeology Project (OGAP) has produced a rich vertebrate fauna from several sites within Bed II, Olduvai Gorge, Tanzania. Study of these as well as recently re-organized collections from Mary Leakey's 1972 HWK EE excavations here provides a synthetic view of the faunal community of Olduvai during Middle Bed II at ∼1.7–1.4 Ma, an interval that captures the local transition from Oldowan to Acheulean technology. We expand the faunal list for this interval, name a new bovid species, clarify the evolution of several mammalian lineages, and record new local first and last appearances. Compositions of the fish and large mammal assemblages support previous indications for the dominance of open and seasonal grassland habitats at the margins of an alkaline lake. Fish diversity is low and dominated by cichlids, which indicates strongly saline conditions. The taphonomy of the fish assemblages supports reconstructions of fluctuating lake levels with mass die-offs in evaporating pools. The mammals are dominated by grazing bovids and equids. Habitats remained consistently dry and open throughout the entire Bed II sequence, with no major turnover or paleoecological changes taking place. Rather, wooded and wet habitats had already given way to drier and more open habitats by the top of Bed I, at 1.85–1.80 Ma. This ecological change is close to the age of the Oldowan-Acheulean transition in Kenya and Ethiopia, but precedes the local transition in Middle Bed II.
Publication date: 6 December 2017
Hominins performed a variety of carcass processing activities at two sites in the Olduvai Gorge, Tanzania
In this paper, pounded objects from excavations at HWK EE and EF-HR are presented, which are studied from macro and microscopic perspectives. Analysis of HWK EE revealed one of the largest collections of percussive objects from Olduvai Gorge, while excavations at EF-HR have allowed a team of archaeologists ffom University College London to recover a much wider collection of percussive tools than previously recorded. Differences are observed between the two localities. At the Acheulean site of EF-HR, percussive tools were predominantly used in the production of flakes and large cutting tools (LCTs). At the Oldowan site of HWK EE, the tool repertoire probably related to a wider range of activities, including bone breaking and bipolar knapping. Comparison of these two assemblages, potentially produced by different hominin species, helps provide a wider picture of pounding activities during the Oldowan-Acheulean transition at Olduvai Gorge.
Publication date: 21 November 2017
Migratory activity is a critical factor in shaping processes of biological and cultural change through time. We introduce a method to estimate changes in underlying migratory activity that can be applied to genetic, morphological, or cultural data and is well-suited to samples that are sparsely distributed in space and through time. By applying this method to ancient genome data, we infer a number of changes in human mobility in Western Eurasia, including higher mobility in pre- than post-Last Glacial Maximum hunter–gatherers, and oscillations in Holocene mobility with peaks centering on the Neolithic transition and the beginnings of the Bronze Age and the Late Iron Age. A team of scientists from University College London, including Liisa Loog, Mirna Kovacevic and Mark G. Thomas led to this research.
Publication date: 21 November 2017
Previous dating of the Vi-207 and Vi-208 Neanderthal remains from Vindija Cave (Croatia) led to the suggestion that Neanderthals survived there as recently as 28,000–29,000 B.P. Subsequent dating yielded older dates, interpreted as ages of at least ∼32,500 B.P. We have redated these same specimens using an approach based on the extraction of the amino acid hydroxyproline, using preparative high-performance liquid chromatography (Prep-HPLC). This method is more efficient in eliminating modern contamination in the bone collagen. The revised dates are older than 40,000 B.P., suggesting the Vindija Neanderthals did not live more recently than others across Europe, and probably predate the arrival of anatomically modern humans in Eastern Europe. We applied zooarchaeology by mass spectrometry (ZooMS) to find additional hominin remains. We identified one bone that is Neanderthal, based on its mitochondrial DNA, and dated it directly to 46,200 ± 1,500 B.P. We also attempted to date six early Upper Paleolithic bone points from stratigraphic units G1, Fd/d+G1 and Fd/d, Fd. One bone artifact gave a date of 29,500 ± 400 B.P., while the remainder yielded no collagen. We additionally dated animal bone samples from units G1 and G1–G3. These dates suggest a co-occurrence of early Upper Paleolithic osseous artifacts, particularly split-based points, alongside the remains of Neanderthals is a result of postdepositional mixing, rather than an association between the two groups, although more work is required to show this definitively.
Publication date: 24 September 2017
Ontogenetic studies help us understand the processes of evolutionary change but no one single system defines the ontogeny of an individual. Previous studies of Neanderthals have focused more on the pace than the pattern of growth. Thirteen genetically related Neanderthals have been recovered from the 49 ky site of El Sidrón, Asturias, Spain, including a new juvenile partial skeleton for which there is associated dental, cranial and postcranial material. This individual provides the first opportunity to establish chronological age using dental histology with which to compare growth across the skeleton. A team of scientists based in Madrid (led by CSIC's Antonio Rosas and Luis Ríos) and at UCL (CBD's Christopher Dean) and QMUL (Institute of Dentistry's Helen Liversidge) have together explored the development of this specimen. Maturation of almost all cranio-dental and postcranial elements falls within the expected range of modern humans of this age. However, at around 7.7 years of age, the most striking difference in growth between Neanderthals and modern humans occurs in the vertebral column. The atlas and the mid-thoracic vertebral bodies and neural arches remain unfused and at a stage more typical of a modern 5-6 year old child and so appearing to take longer to establish the larger more capacious adult morphology of the Neanderthal chest. Furthermore, a number of endocranial features suggest that at the time of death brain growth was not yet completed. The implication of these findings is that Neanderthal brain growth and somatic growth must have incorporated changes in both rate and timing that differ slightly from modern humans today in order to achieve their adult size.
Publication date: 22 September 2017
This paper investigates the formation history of the early Acheulean site of EF-HR (Olduvai Gorge, Tanzania). The study focuses on the main site (T2-Main Trench) and adjacent trenches (T12 and T9), which constitute the bulk of the archaeological assemblage recently excavated in the EF-HR area (de la Torre et al., submitted). Site formation processes are investigated through taphonomic proxies and spatial analysis, and consider artifact features, orientation patterns, and topographic data retrieved during archaeological excavation. This enables an assessment of the impact of natural agents on the assemblage and a discussion of the relevance of water disturbance in shaping the structure of the EF-HR archaeological record. The results indicate that fluvial action over the assemblage was significant, although it is likely that EF-HR still preserves areas marginally affected by water sorting and rearrangement. In summary, by applying a novel approach that combines a systematic analysis of artifact attributes with GIS spatial analysis of archaeological remains and topographic features, our study aims to provide a fresh look at the interaction of human and natural agents in the formation of Early Stone Age assemblages at Olduvai Gorge.
Publication date: 18 August 2017
Recent fossil finds have highlighted extensive morphological diversity within our genus, Homo, and the co-existence of a number of species. However, little is known about the evolutionary processes responsible for producing this diversity. Understanding the action of these processes can provide insight into how and why our lineage evolved and diversified. Here, cranial and mandibular variation are examined and diversification from the earliest emergence of our genus at 2.8 Ma until the Late Pleistocene (0.126–0.0117 Ma), using statistical tests developed from quantitative genetics theory to evaluate whether stochastic (genetic drift) versus non-stochastic (selection) processes were responsible for the observed variation. Results show that random processes can account for species diversification for most traits, including neurocranial diversification, and across all time periods. Where selection was found to shape diversification, we show that: 1) adaptation was important in the earliest migration of Homo out of Africa; 2) selection played a role in shaping mandibular and maxillary diversity among Homo groups, possibly due to dietary differences; and 3) Homo rudolfensis is adaptively different from other early Homo taxa, including the earliest known Homo specimen. These results show that genetic drift, and, likely, small population sizes were important factors shaping the evolution of Homo and many of its novel traits, but that selection played an essential role in driving adaptation to new contexts.
Publication date: 30 July 2017
Computer modelling suggests that cannibalism could have been a factor in the extinction of Homo neanderthalensis
After more than 100,000 years of evolutionary success in Western Eurasia, Neanderthals rapidly went extinct between 40,000 and 30,000 years ago, almost coinciding with the spread of Anatomically Modern Homo sapiens (AMHS) in Europe. Several scenarios relate their extinction to competition with AMHS, climatic changes during the last glacial period or a combination of both. Here we propose a much simpler scenario, in which the cannibalistic behaviour of Neanderthals may have played a major role in their eventual extinction. We show that this trait was selected as a common behaviour at moments of environmental or population stress. However, as soon as Neanderthals had to compete with another species that consumed the same resources (AMHS in this case) cannibalism had a negative impact, leading, in the end, to their extinction. To test this hypothesis, an agent-based model computer simulation was used. The model is simple, with only traits, behaviours and landscape features defined and with no attempt to re-create the exact landscape in which Neanderthals lived or their cultural characteristics. The basic agent of our system is a group of individuals that form a community. The most important state variable of the model is the location of the group, coupled with a defined home range and two additional factors: cannibalism and the chance of fission. The result of the simulation shows that cannibalistic behaviour is always selected when resources are scarce and clustered. However, when a non-cannibalistic species (late Pleistocene AMHS) is introduced into the same environment, the cannibalistic species retreats and the new species grows until it has reached the carrying capacity of the system. The cannibalistic populations that still survive are displaced from the richest areas, and live on the borders with arid zones, a situation which is remarkably similar to what we know about the end of the Neanderthals.
Publication date: 23 July 2017