Francesco D'Errico - Academia.edu (original) (raw)

Papers by Francesco D'Errico

... matériel osseux et leur toujours apporté aide et sympathie Un remerciement particulier va éga... more ... matériel osseux et leur toujours apporté aide et sympathie Un remerciement particulier va également Patrick Auguste Isabelle Margerand et Joëlle Espinel pour leur lecture critique du manuscrit Présentation de l&amp;#x27;étude. 720. FRANCESCO D&amp;#x27;ERRICO ET ANNE-MARIE MOIGNE. ...

Journal of Archaeological Science, 2008

Recently discovered bone implements from Middle Stone Age (MSA) deposits at Sibudu Cave, South Af... more Recently discovered bone implements from Middle Stone Age (MSA) deposits at Sibudu Cave, South Africa, confirm the existence of a bone tool industry for the Howiesons Poort (HP) technocomplex. Previously, an isolated bone point from Klasies River provided inconclusive evidence. This paper describes three bone tools: two points and the end of a polished spatula-shaped piece, from unequivocal HP layers at Sibudu Cave (with ages greater than w61 ka). Comparative microscopic and morphometric analysis of the Sibudu specimens together with bone tools from southern African Middle and Later Stone Age (LSA) deposits, an Iron Age occupation, nineteenth century Bushman hunter-gatherer toolkits, and bone tools used experimentally in a variety of tasks, reveals that the Sibudu polished piece has use-wear reminiscent of that on bones experimentally used to work animal hides. A slender point is consistent with a pin or needle-like implement, while a larger point, reminiscent of the single specimen from Peers Cave, parallels large un-poisoned bone arrow points from LSA, Iron Age and historical Bushman sites. Additional support for the Sibudu point having served as an arrow tip comes from backed lithics in the HP compatible with this use, and the recovery of older, larger bone and lithic points from Blombos Cave, interpreted as spear heads. If the bone point from the HP layers at Sibudu Cave is substantiated by future discoveries, this will push back the origin of bow and bone arrow technology by at least 20,000 years, and corroborate arguments in favour of the hypothesis that crucial technological innovations took place during the MSA in Africa.

Prehistoric human populations were influenced by climate change and resulting environmental varia... more Prehistoric human populations were influenced by climate change and resulting environmental variability and developed a wide variety of cultural mechanisms to deal with these conditions. In an effort to understand the in-Eco-Cultural Niche Modeling of Past Human Populations • 69

Science

also used to image the structure. This apparatus can generate images with atomic resolution by di... more also used to image the structure. This apparatus can generate images with atomic resolution by directly measuring electronic states. UHV allows clean, controlled surface preparation and cryogenic temperatures to help reduce electronic noise and slow molecular motion. Using the same dilution as for the TEM sample preparation, fractal construct 6 in acetonitrile was cast onto a freshly cleaned Au(111) surface. STM images acquired at 6 K ( ) verified a hexagonal pattern of the molecule (12 T 1 nm diameter, and È0.8 nm in height), which was consistent with the computergenerated model of the structure. Tunneling conductance spectra determined for single mole-cules at 6 K showed a 1-eV energy gap. Traces of linear oligomeric as well as larger macrocyclic assemblies (fractoids) were also observed on the STM images (see supporting online material).

PLOS One, 2008

Background: Despite a long history of investigation, considerable debate revolves around whether ... more Background: Despite a long history of investigation, considerable debate revolves around whether Neanderthals became extinct because of climate change or competition with anatomically modern humans (AMH).

Journal of Archaeological Science, 2006

Our knowledge of the migration routes of the first anatomically modern populations colonising the... more Our knowledge of the migration routes of the first anatomically modern populations colonising the European territory at the beginning of the Upper Palaeolithic, of their degree of biological, linguistic, and cultural diversity, and of the nature of their contacts with local ...

Earth and Planetary Science Letters, 2007

Heinrich event 4 (H4) is well documented in the North Atlantic Ocean and the adjacent continents ... more Heinrich event 4 (H4) is well documented in the North Atlantic Ocean and the adjacent continents as a cooling event 39,000 yr before present (BP). To quantify the impact of this event with respect to climate and vegetation over the Iberian Peninsula, we perform numerical experiments using a high-resolution general circulation model forced by sea surface temperatures before and during H4. Our model simulates an expansion of aridity over the peninsula during H4, a desertification of the south, and a replacement of arboreal by herbaceous plants in the north, all of which are in agreement with contemporaneous pollen sequences from marine cores located off the Iberian Peninsula. Our simulations demonstrate that the H4 marine event imprinted drastic changes over Southern Iberia, which would not have favoured its occupation by Anatomically Modern Humans, therefore providing a plausible explanation for the delayed extinction of Neanderthals in this region inferred from the archaeological record.

Journal of World Prehistory, 2003

In recent years, there has been a tendency to correlate the origin of modern culture and language... more In recent years, there has been a tendency to correlate the origin of modern culture and language with that of anatomically modern humans. Here we discuss this correlation in the light of results provided by our first hand analysis of ancient and recently discovered relevant archaeological and paleontological material from Africa and Europe. We focus in particular on the evolutionary significance of lithic and bone technology, the emergence of symbolism, Neandertal behavioral patterns, the identification of early mortuary practices, the anatomical evidence for the acquisition of language, the development of conscious symbolic storage, the emergence of musical traditions, and the archaeological evidence for the diversification of languages during the Upper Paleolithic. This critical reappraisal contradicts the hypothesis of a symbolic revolution coinciding with the arrival of anatomically modern humans in Europe some 40,000 years ago, but also highlights inconsistencies in the anatomically–culturally modern equation and the potential contribution of anatomically “pre-modern” human populations to the emergence of these abilities. No firm evidence of conscious symbolic storage and musical traditions are found before the Upper Paleolithic. However, the oldest known European objects that testify to these practices already show a high degree of complexity and geographic variability suggestive of possible earlier, and still unrecorded, phases of development.

Journal of Archaeological Science, 2002

We submit two reference collections of red deer (Cervus elaphus) canines of known age and sex to ... more We submit two reference collections of red deer (Cervus elaphus) canines of known age and sex to a morphological and metrical study and establish criteria for ageing and sexing. These criteria are applied to the largest Palaeolithic collection of red deer canines used as personal ornaments, associated with the recently discovered multiple burial of the Aven des Iboussières site, in south-eastern France, dated to 10,210 80 . Results reveal sex and age dependent deer hunting strategies and suggest that separate mortality profiles for hinds and stags are necessary to accurately assess the issue of deer hunting by late Upper Palaeolithic and Mesolithic groups. The combined use of zooarchaeological and technological information indicates that pairs of canines were systematically extracted from deer mandibles, perforated and, in some cases, decorated by several members of the group, each leaving on paired teeth distinct traces of his/her gestural behaviour. The large number of unpaired canines suggests that these ornaments circulated in a gift exchange network.

Medical Physics, 1998

A combination of three superheated drop detectors with different neutron energy responses was dev... more A combination of three superheated drop detectors with different neutron energy responses was developed to evaluate dose-equivalent and energy distributions of photoneutrons in a phantom irradiated by radiotherapy high-energy x-ray beams. One of the three detectors measures the total neutron dose equivalent and the other two measure the contributions from fast neutrons above 1 and 5.5 MeV, respectively. In order to test the new method, the neutron field produced by the 10 cm X 10 cm x-ray beam of an 18 MV radiotherapy accelerator was studied. Measurements were performed inside a tissue-equivalent liquid phantom, at depths of 1, 5, 10 and 15 cm and at lateral distances of 0, 10, and 20 cm from the central axis. These data were used to calculate the average integral dose to the radiotherapy patient from direct neutrons as well as from neutrons transmitted through the accelerator head. The characteristics of the dosimeters were confirmed by results in excellent agreement with those of prior studies. Track etch detectors were also used and provided an independent verification of the validity of this new technique. Within the primary beam, we measured a neutron entrance dose equivalent of 4.5 mSv per Gy of photons. It was observed that fast neutrons above 1 MeV deliver most of the total neutron dose along the beam axis. Their relative contribution increases with depth, from about 60% at the entrance to over 90% at a depth of 10 cm. Thus, the average energy increases with depth in the phantom as neutron spectra harden.

Medical Physics, 1993

The superheated drop detector (SDD) consists of thousands of superheated drops dispersed in a sma... more The superheated drop detector (SDD) consists of thousands of superheated drops dispersed in a small vial of gel, which vaporize upon exposure to high LET radiation, thereby providing a directly observable indication of neutron dose. This detector possesses high sensitivity to neutrons and insensitivity to high-energy photons and electrons, making it suitable for the determination of neutron dose equivalent rates around high-energy photon and electron radiotherapy beams. In the present work, the SDD was used to measure the neutron dose equivalent in and around the radiotherapy beams produced by a 32-MeV linear accelerator. For both x-ray and electron beams, the neutron dose profiles were observed to follow the photon/electron radiotherapy beam profiles. For 25-MV x rays, the neutron dose equivalent per photon dose on the central axis increased by a factor of about 3 as field size increased from 5 x 5 to 30 x 30 cm. However, the neutron dose equivalent rate at 50 cm off-axis in the patient plane was essentially independent of field size. The neutron dose equivalent per electron dose was essentially zero for electron beams with energies below 15 MeV, but increased rapidly above 15 MeV. For 25-MeV electrons, neutron dose equivalent on the central axis was about 1/5 that for 25-MV x rays. Analogous to the data for 25-MV x rays, the neutron dose equivalent rate on the central axis of a 25-MeV electron beam exhibited a similar field size dependence and outside the beam it was essentially independent of field size.(ABSTRACT TRUNCATED AT 250 WORDS)

Journal of Human Evolution, 2005

Journal of Human Evolution, 2007

Journal of Human Evolution, 2001