Aggiornamento 11 febbraio

 
  A Neanderthal deciduous human molar with incipient carious infection from the Middle Palaeolithic De Nadale cave, Italy, di J. Arnaud, S. Benazzi, M. Romandini, A. Livraghi, D. Panetta, P. A. Salvadori, L. Volpe, M. Peresani, "American Journal of Physical Anthropology", Volume 162, Issue 2, February 2017, Pages 370–376

The aim of the study is the assessment of Nadale 1, a Neanderthal deciduous tooth recently discovered in Northeastern Italy in the De Nadale cave (Middle Palaeolithic). Together with the clear archaeological context of the site, this study brings new insight on Neanderthal behavior and dental morphological variability.
We used microCT data to provide a morphological description and morphometric analysis (diameter measurements and dental tissue volumes) of the Nadale 1 human tooth. Microwear analysis, taphonomical investigation and caries identification were performed using a stereomicroscope and Scanning Electron Microscope.
In terms of morphology (i.e., incipient tuberculum molare, marked mesial marginal ridge and well-developed mid-trigonid crest connecting the protoconid and the metaconid, deep anterior fovea) and size, Nadale 1 presents features frequently observed in Neanderthal lower first deciduous molars. Microscope investigations reveal the presence of a small pit which could be correlated to an incipient caries.
Nadale 1 expands the Italian Middle Palaeolithic fossil record and provides further information on Neanderthal dm1s in terms of dimensional and morphological variability. Furthermore, the presence of an incipient caries brings further data on Neanderthal diet.

     
  New Tools Identify Key Evolutionary Advantages from Ancient Hominid Interbreeding, di J. Caspermeyer, "Molecular Biology and Evolution", Volume 34, Issue 2, February 2017

Neanderthals. Denisovans. Homo sapiens. Around 50,000 years ago, these hominids not only interbred, but in some cases, modern humans may have also received a special evolutionary advantage from doing so. As more and more data from archaic genomes are becoming available, scientists have become keenly interested in pinpointing these regions to better understand the potential benefits that may have been bestowed to us. One of the most striking recent examples is the EPAS1 gene, which confers a selective advantage in Tibetans by making them less prone to hypoxia at high altitudes. We now know that the Denisovans introduced it into the human gene pool. Inspired by this example, in a new study published in the advanced online edition of Molecular Biology and Evolution, computational biologists Racimo et al. (2016) have developed statistical tools and simulations to successfully identify the signatures of these interbred genomic regions.

     
 

The earliest long-distance obsidian transport: Evidence from the ~200 ka Middle Stone Age Sibilo School Road Site, Baringo, Kenya, di N. Blegen, "Journal of Human Evolution", Volume 103, February 2017, Pages 1–19

This study presents the earliest evidence of long-distance obsidian transport at the ~200 ka Sibilo School Road Site (SSRS), an early Middle Stone Age site in the Kapthurin Formation, Kenya. The later Middle Pleistocene of East Africa (130–400 ka) spans significant and interrelated behavioral and biological changes in human evolution including the first appearance of Homo sapiens. Despite the importance of the later Middle Pleistocene, there are relatively few archaeological sites in well-dated contexts (n < 10) that document hominin behavior from this time period. In particular, geochemically informed evidence of long-distance obsidian transport, important for investigating expansion of intergroup interactions in hominin evolution, is rare from the Middle Pleistocene record of Africa. The SSRS offers a unique contribution to this small but growing dataset. Tephrostratigraphic analysis of tuffs encasing the SSRS provides a minimum age of ∼200 ka for the site. Levallois points and methods of core preparation demonstrate characteristic Middle Stone Age lithic technologies present at the SSRS. A significant portion (43%) of the lithic assemblage is obsidian. The SSRS obsidian comes from three different sources located at distances of 25 km, 140 km and 166 km from the site. The majority of obsidian derives from the farthest source, 166 km to the south of the site. The SSRS thus provides important new evidence that long-distance raw material transport, and the expansion of hominin intergroup interactions that this entails, was a significant feature of hominin behavior ∼200 ka, the time of the first appearance of H. sapiens, and ∼150,000 years before similar behaviors were previously documented in the region.

     
 

The morphology of the enamel–dentine junction in Neanderthal molars: Gross morphology, non-metric traits, and temporal trends, di R. M. G. Martin, J. J. Hublin, P. Gunz, M. M. Skinner, "Journal of Human Evolution", Volume 103, February 2017, Pages 20–44

This study explores the morphological differences between the enamel–dentine junction (EDJ) of maxillary and mandibular molars of Neanderthals (n = 150) and recent modern humans (n = 106), and between an earlier Neanderthal sample (consisting of Pre-Eemian and Eemian Neanderthals dating to before 115 ka) and a later Neanderthal sample (consisting of Post-Eemian Neanderthals dating to after 115 ka). The EDJ was visualised by segmenting microtomographic scans of each molar. A geometric morphometric methodology compared the positioning of the dentine horns, the shape of the marginal ridge between the dentine horns, and the shape of the cervix. We also examined the manifestation of non-metric traits at the EDJ including the crista obliqua, cusp 5, and post-paracone tubercle. Furthermore, we report on additional morphological features including centrally placed dentine horn tips and twinned dentine horns. Our results indicate that EDJ morphology can discriminate with a high degree of reliability between Neanderthals and recent modern humans at every molar position, and discriminate between the earlier and the later Neanderthal samples at every molar position, except for the M3 in shape space. The cervix in isolation can also discriminate between Neanderthals and recent modern humans, except at the M3 in form space, and is effective at discriminating between the earlier and the later Neanderthal samples, except at the M2/M2 in form space. In addition to demonstrating the taxonomic valence of the EDJ, our analysis reveals unique manifestations of dental traits in Neanderthals and expanded levels of trait variation that have implications for trait definitions and scoring.

     
 

The Middle Stone Age human fossil record from Klasies River Main Site, di F. E. Grine, S. Wurz, C. W. Marean, "Journal of Human Evolution", Volume 103, February 2017, Pages 53–78

The paleoanthropological significance of Klasies River Main Site derives from its abundant Middle Stone Age (MSA) archaeological debris and the hominin fossils that have featured in discussions about modern human emergence. Despite their significance, the human remains have yet to be contextualized within the spatial, stratigraphic and geochronological framework of the site. We provide an updated overview of the stratigraphy and geochronology of the site, and review the human fossil record in this context. We also provide the first anatomical interpretations of many of the cranial vault fragments. Five hominin specimens derive from the Upper Member and six from the lowermost LBS Member. The vast majority – nearly 40 cataloged specimens – come from the SAS Member; many of these are from a single stratigraphic horizon in a relatively small area in Cave 1. There is a strong cranial bias to the sample; just over 70% of skeletal remains are from the skull. The postcranial skeleton is poorly represented. Excluding the three metatarsals, there are only three long bones in the sample – a clavicle, a proximal radius, and a proximal ulna. Remarkably, humeral, femoral and tibial diaphyses, which are the most durable elements in terms of cortical bone thickness and density, are absent. However, the proportional representation of hominin remains is reminiscent of the “Klasies Pattern” shown by the MSA large bovid skeletal parts. To some degree, this may reflect the excavation and recovery methods that were employed. The vast bulk of the human fossils represent adults. Only three undoubted juvenile individuals are represented – each by a deciduous tooth. This contrasts with other MSA sites along the southern coast of South Africa, where human remains are predominantly juvenile, usually in the form of (possibly exfoliated) deciduous teeth. However, this apparent dissimilarity may also reflect different excavation techniques.

     
  Evidence for chronic omega-3 fatty acids and ascorbic acid deficiency in Palaeolithic hominins in Europe at the emergence of cannibalism, di J.L. Guil-Guerrero, "Quaternary Science Reviews", Volume 157, 1 February 2017, Pages 176–187

At the Middle-Upper Palaeolithic (M/UP) transition in Western Europe, hominins depended mostly on terrestrial mammals for subsistence, being pointed out that reliance on reindeer (Rangifer tarandus) would have promoted declines in human population densities during that period. Food-composition tables have been compiled for hominins at the M/UP transition, listing protein, fat, energy, different omega-3 fatty acids and ascorbic acid concentrations. These data were used to compute the regular relations between fatty and lean tissues of the main hunted food-animals to meet hominin energy needs. Then, with daily protein intake considered critical, the optimal contribution of the different omega-3 fatty acids from different hunted species to hominin diets were computed. Several faunal assemblages from different human sites at different M/UP periods were used to assess the overall daily intake of the various omega-3 fatty acid classes. The results of the calculations made in this work are quite clear; hominins at the M/UP transition had a deficit of both omega-3 fatty acids and ascorbic acid. Data on human organs summarized here are also conclusive: these contain such nutrients in amounts much higher than reached in the corresponding mammal organs consumed, and thus could have been alternative sources of those nutrients for Palaeolithic hominins. Therefore, nutritional cannibalism detected at such times could have had the function of alleviating these deficits. The evolutionary advantages gained by the consumption of the various omega-3 fatty acids of human origin are also discussed.

     
 

The Aggradational Successions of the Aniene River Valley in Rome: Age Constraints to Early Neanderthal Presence in Europe, di F. Marra , P. Ceruleo, L. Pandolfi, C. Petronio, M. F. Rolfo, L. Salari, January 26, 2017, DOI: http://dx.doi.org/10.1371/journal.pone.0170434 - open access -

We revise the chronostratigraphy of several sedimentary successions cropping out along a 5 km-long tract of the Aniene River Valley in Rome (Italy), which yielded six hominin remains previously attributed to proto- or archaic Neanderthal individuals, as well as a large number of lithic artefacts showing intermediate characteristics somewhere between the local Acheulean and Mousterian cultures. Through a method of correlation of aggradational successions with post-glacial sea-level rises, relying on a large set of published 40Ar/39Ar ages of interbedded volcanic deposits, we demonstrate that deposition of the sediments hosting the human remains spans the interval 295–220 ka. This is consistent with other well constrained ages for lithic industries recovered in England, displaying transitional features from Lower to Middle Paleolithic, suggesting the appearance of Mode 3 during the MIS 9-MIS 8 transition. Moreover, the six human bone fragments recovered in the Aniene Valley should be regarded as the most precisely dated and oldest hominin remains ascribable to Neanderthal-type individuals in Europe, discovered to date. The chronostratigraphic study presented here constitutes the groundwork for addressing re-analysis of these remains and of their associated lithic industries, in the light of their well-constrained chronological picture. (...)

     
 

Brain enlargement and dental reduction were not linked in hominin evolution, di A. Gómez-Robles et alii, January 17, 2017, vol. 114, no. 3, pp. 468–473

The large brain and small postcanine teeth of modern humans are among our most distinctive features, and trends in their evolution are well studied within the hominin clade. Classic accounts hypothesize that larger brains and smaller teeth coevolved because behavioral changes associated with increased brain size allowed a subsequent dental reduction. However, recent studies have found mismatches between trends in brain enlargement and posterior tooth size reduction in some hominin species. We use a multiple-variance Brownian motion approach in association with evolutionary simulations to measure the tempo and mode of the evolution of endocranial and dental size and shape within the hominin clade. We show that hominin postcanine teeth have evolved at a relatively consistent neutral rate, whereas brain size evolved at comparatively more heterogeneous rates that cannot be explained by a neutral model, with rapid pulses in the branches leading to later Homo species. Brain reorganization shows evidence of elevated rates only much later in hominin evolution, suggesting that fast-evolving traits such as the acquisition of a globular shape may be the result of direct or indirect selection for functional or structural traits typical of modern humans.

     
  Discovery adds rock collecting to Neanderthal's repertoire, 17-JAN-2017

An international group that includes a University of Kansas researcher has discovered a brownish piece of split limestone in a site in Croatia that suggests Neanderthals 130,000 years ago collected the rock that stands out among all other items in the cave. "If we were walking and picked up this rock, we would have taken it home," said David Frayer, a professor emeritus of anthropology who was part of the study. "It is an interesting rock." The finding is important, he said, because it adds to other recent evidence that Neanderthals were capable -- on their own -- of incorporating symbolic objects into their culture. The rock was collected more than 100 years ago from the Krapina Neanderthal site, which has items preserved in the Croatian Natural History Museum in Zagreb, where in recent years the research team has re-examined them. (...)
     
  The ecological niche and distribution of Neanderthals during the Last Interglacial, di B. M. Benito et alii, "Journal of Biogeography", Volume 44, Issue 1, January 2017, Pages 51–61

In this paper, we investigate the role of climate and topography in shaping the distribution of Neanderthals (Homo neanderthalensis) at different spatial scales. To this end, we compiled the most comprehensive data set on the distribution of this species during the Last Interglacial optimum (MIS 5e) available to date. This was used to calibrate a palaeo-species distribution model, and analyse variable importance at continental and local scales. (...)

     
  Initial micromorphological results from Liang Bua, Flores (Indonesia): Site formation processes and hominin activities at the type locality of Homo floresiensis, di M. W. Morley et alii, "Journal of Archaeological Science", Volume 77, January 2017, Pages 125–142

Liang Bua, a karstic cave located on the island of Flores in eastern Indonesia, is best known for yielding the holotype of the diminutive hominin Homo floresiensis from Late Pleistocene sediments. Modern human remains have also been recovered from the Holocene deposits, and abundant archaeological and faunal remains occur throughout the sequence. The cave, the catchment in which it is located and the gross aggradational phases of the sediment sequence have all been subject to a great deal of scientific scrutiny since the discovery of the holotype of H. floresiensis in 2003. A recent program of geoarchaeological research has extended analyses of the site’s deposits to the microstratigraphic (micromorphological) level. The stratigraphic sequence in the cave is well defined but complex, comprising interstratified sediments of diverse lithologies and polygenetic origins, including volcanic tephras, fine-grained colluvium, coarse autogenic limestone gravels, speleothems and anthropogenic sediments, such as combustion features. The sedimentological and chemical heterogeneity suggest that processes of site formation and diagenesis varied markedly through time, both laterally and vertically. We present initial results from samples collected in 2014 from an excavation area near the rear of the cave, which yielded radiocarbon ages from charcoal that fill an important temporal gap in the chrono-stratigraphic sequence of previously excavated areas of the site. The results indicate marked changes in site environment and hominin activity during the Late Pleistocene, relating primarily to the degree to which the cave was connected to the hydrogeological system and to the varying intensities of use of the cave by hominins. Importantly, we identify anthropogenic signs of fire-use at the site between 41 and 24 thousand years ago, most likely related to the presence of modern humans.

     
  Two Acheuleans, two humankinds: From 1.5 to 0.85 Ma at Melka Kunture (Upper Awash, Ethiopian highlands), di R. Gallotti, M. Mussi, "JASs Reports-Journal of Anthropological Sciences", Vol. 95 (2017), pp. 1-46

The Acheulean is the longest-lasting human cultural record, spanning approximately 1.5 Ma and three continents. The most comprehensive sequences are found in East Africa, where, in largescale syntheses, the Lower Pleistocene Acheulean (LPA) has often been considered a uniform cultural entity. Furthermore, the emergence and development of Acheulean technology are seen as linked to the emergence and evolution of Homo ergaster/erectus. The criterion for grouping together different lithic assemblages scattered over space and time is the presence of large cutting tools (LCTs), more than of any other component. Their degree of refinement has been used, in turn, as a parameter for evaluating Acheulean development and variability. But was the East African LPA really uniform as regards all components involved in lithic productions? The aim of this paper is to evaluate the techno-economic similarities and differences among LPA productions in a specific micro-regional and environmental context, i.e. at Melka Kunture, in the Ethiopian highlands, and in a specific period of time: between ~1.5 Ma, when some of the earliest Acheulean complexes appeared, and 1.0-0.85 Ma, when LCTs productions became intensive and widespread. Our detailed comparative analyses investigate all aspects and phases of the chaînes opératoires. Since hominin fossil remains were discovered at some of the analyzed sites, we also discuss differences among lithic productions in relation to the changing paleoanthropological record. Our studies show that at Melka Kunture the LPA techno-complexes cannot be grouped into a single uniform entity. The assembled evidence points instead to “two Acheuleans” well-defined by a strong discontinuity in various aspects of techno-economic behaviors. This discontinuity is related to a major step in human evolution: the transition from Homo ergaster/erectus to Homo heidelbergensis. (...)
 

 


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