quarta-feira, 29 de junho de 2011

Découverte des plus anciens Hommes modernes du Sud-Est de l'Europe

Paris, 28 JUIN 2011, in http://www2.cnrs.fr

Des restes humains découverts en Crimée (Ukraine) ont été datés de 32 000 ans par une équipe européenne impliquant notamment le CNRS et le département de Préhistoire du Muséum national d'Histoire naturelle (1). Il s'agit du plus ancien témoignage direct de la présence de notre espèce Homo sapiens au Sud-Est de l'Europe. Publiée sur le site de PLoS ONE, cette étude apporte de nouvelles données permettant de retracer la colonisation de l'Europe par les premiers Hommes modernes.

Découvert en 1991 dans le sud montagneux de la Crimée (Ukraine), l'abri sous roche de Buran-Kaya III a été fouillé au cours de plusieurs campagnes. L'une des couches de terrain correspondant au Paléolithique supérieur (2) a ainsi livré 162 fragments d'ossements humains aux côtés d'os d'animaux (essentiellement des antilopes saïga, des renards et des lièvres), d'outils en pierres taillées et en os (3), et d'objets de parure comme des perles en ivoire de mammouth et des coquillages perforés. Une approche pluridisciplinaire a été nécessaire pour analyser ce site, dont le matériel s'avère riche et varié.

La datation au carbone 14 d'un os humain et d'un os de cerf a établi que leurs propriétaires avaient vécu il y a 32 000 ans, ce qui fait de ce site un des plus anciens occupés par l'Homme moderne en Europe. Seuls un site roumain et un site russe s'avèrent plus vieux (34 000 ans pour le site roumain et 33 000 ans pour le russe), tandis que les sites d'Europe occidentale sont tous plus récents. Cette découverte atteste donc l'hypothèse d'une colonisation du continent d'est en ouest par les premiers Hommes anatomiquement modernes. Ces derniers se seraient répandus en Europe par les régions sud-orientales bordant la Mer Noire depuis le Moyen-Orient.

Les ossements humains mis au jour dans l'abri appartiennent à au moins cinq individus : un enfant, deux adolescents et deux adultes. On retrouve essentiellement des morceaux de crâne, des dents, une vertèbre, des fragments de côtes et de phalanges. L'absence d'os longs, comme les fémurs par exemple, d'ordinaire bien préservés, a intrigué les chercheurs. De plus, après le décès, les crânes ont été détachés du reste du corps, comme l'indiquent plusieurs traces de découpe présentes sur plusieurs os. Le traitement des restes osseux étant différent sur les hommes et les animaux, les chercheurs estiment qu'il ne s'agit pas d'un cannibalisme nutritionnel, mais plutôt d'un rituel post mortem. Ils avancent plusieurs hypothèses dans le cadre de pratiques funéraires, soit celle d'un cannibalisme rituel, soit celle d'une désarticulation post mortem du corps afin d'en déposer une partie à un autre endroit. Il s'agit des plus anciennes traces de découpe observées sur des hommes modernes aussi anciens en Europe.

Cette étude a bénéficié du financement de l'ANR Jeunes chercheurs "Mammouths" (sous la direction de Stéphane Péan), du programme ATM "Relations Sociétés - Nature dans le long terme" du MNHN et de l'unité propre du CNRS « Dynamique de l'évolution humaine : individus, populations, espèces ».

Notes :
(1) En France, ont participé les laboratoires suivants : le laboratoire CNRS « Dynamique de l'évolution humaine : individus, populations, espèces » et l'unité « Histoire naturelle de l'Homme préhistorique » (CNRS / MNHN).
(2) Cette période de la Préhistoire est caractérisée par l'arrivée de l'Homme moderne en Europe, le développement de nouvelles techniques (lames, industrie osseuse, propulseur, etc.) et l'explosion de l'art préhistorique. Il se situe entre 35 000 et 10 000 ans avant notre ère.
(3) Ces outils datés de -32 000 ans ont été caractérisés comme appartenant à la culture gravettienne, un complexe culturel qui aurait duré environ de -31 000 à -22 000 ans. Il s'agit des plus anciennes traces de cette culture en Europe.
Références :
The Oldest Anatomically Modern Humans from Far Southeast Europe : Direct Dating, Culture and Behavior. Sandrine Prat, Stéphane C. Péan, Laurent Crépin, Dorothée G. Drucker, Simon J. Puaud, Hélène Valladas, Martina Laznickova-Galetova, Johannes van der Plicht & Alexander Yanevich. PLoS ONE, 6(6):e 20834 . Accès libre en ligne : Consulter le site web

sexta-feira, 24 de junho de 2011

Descobertos os fósseis mais antigos de Homo sapiens na Europa

Quando é que o homem moderno, ou Homo sapiens, a nossa espécie, chegou à Europa vindo da Ásia? O quebra-cabeças da evolução humana ganhou uma nova peça, ao descobrirem-se os fósseis mais antigos do homem moderno na Europa, com 32 mil anos, na Ucrânia.

Foram encontrados ossos e dentes humanos (DR)
Os humanos modernos ou vieram de África, onde apareceram há cerca de 150 mil anos, iniciando a sua diáspora pela Terra há 50 mil anos. Ou surgiram em vários locais, a partir do Homo erectus, que saíra de África há 1,8 milhões de anos. Mas não existiam na Europa, pelo que a descoberta destes fósseis permitirá compreender as migrações dos primeiros humanos modernos e a sua chegada às portas do continente europeu, onde entraram então em contacto com os Neandertais, extintos há 28 mil anos.

O arqueólogo Alexander Yanevich, da Academia Nacional das Ciências da Ucrânia, descobriu vestígios arqueológicos na gruta Buran-Kaya (na cordilheira da Crimeia), que servia de abrigo, e agora publicou os resultados na revista PLoS One. Em escavações, em 2001, 2009 e 2010, encontraram-se duas centenas de fragmentos de ossos humanos e dentes, além de ferramentas líticas, peças de adorno pessoal em marfim e restos de animais.

As datações por radiocarbono concluem que os fósseis humanos têm 32 mil anos: “São as mais antigas provas directas da presença de homens anatomicamente modernos [no Sudeste da Europa], num contexto arqueológico bem documentado”, escreve a equipa de Yanevich.

Os ossos também têm marcas de cortes, o que dá pistas sobre os comportamentos culturais do Homo sapiens: a equipa pensa deverem-se a rituais fúnebres e não a práticas canibais ligadas à alimentação.

In Público 21.06.2011 - 17:03
Por Teresa Firmino

Evolução humana pode ser mais lenta do que se pensava

Estudo deverá ser confirmado em maior escala

Os seres humanos podem estar a evoluir mais lentamente do que se pensava, indicou um estudo sobre mudanças genéticas feito com duas gerações de famílias, realizado no âmbito do projecto CARTaGENE, da Universidade de Montreal, no Canadá.

O código genético compreende seis biliões de nucleótidos ou blocos de construção de DNA, divididos por duas metades, uma herdada do pai e outra da mãe. Até agora, os cientistas acreditavam que os pais contribuíam, cada um, com 100 a 200 mudanças nestes nucleótidos.
Contudo, este novo trabalho aponta para a ocorrência de muito menos mudanças, sendo que, cada pai contribui, em média, com 30 mudanças. "Em princípio, a evolução acontece um terço mais lentamente do que se pensava anteriormente", disse Philip Awadalla, investigador da Universidade de Montreal.

mais em CiênciaHoje

sábado, 18 de junho de 2011

International Conference on Use-Wear analysis | Faro, 2012


First announcement

Dear colleagues,
Taking into account the unquestionable success of the last scientific meetings on the development of use-wear studies in archaeology over the last two decades, we are pleased to announce that we are organizing an International conference on use-wear analysis. Since Verona (2005), “Prehistoric Technology, 40 Years Later: Functional Studies and the Russian Legacy", many projects and data have been developed. Thus, a new meeting will be the perfect setup to present ongoing projects. Subjects are open to all different use-wear approaches, such as theory and method, archaeological artifacts, and residue analysis. The meeting will take place between 10th and 12th October 2012 at the University of Algarve, Portugal. For all those interested researchers there is more information at www.usewear2012.com, the official meeting website.

Time table:
Second announcement and call for papers – 01.October.2011
Third announcement (accommodation, venue, etc.) - 01.January. 2012

Thank you!
Best regards

The coordinators:
Nuno Bicho (UAlg) – nbicho@ualg.pt
Juan Gibaja Bao (CSIC – Barcelona, Spain) - jfgibaja@imf.csic.es
João Marreiros (UAlg) – jmmarreiros@ualg.pt

segunda-feira, 13 de junho de 2011

Journal of Archaeological Science


Arqueologia e identidade do Nordeste de Portugal

Sidrón exportó piezas de sílex

Los investigadores harán un «exhaustivo» estudio a unas herramientas líticas que viajaron por la Cornisa Cantábrica.


Incidir en el estudio de la fábrica del Sidrón, los materiales líticos fabricados por los neandertales que habitaron la gruta piloñesa y para los que usaron el ya denominado sílex de Piloña. Read the rest of this entry »

Los científicos de Atapuerca buscan restos de 1,3 millones de años.

La Junta de Castilla y León ha accedido a instalar un puente provisional sobre el suelo de la “Trinchera del ferrocarril” en la zona de la “Sima del Elefante”, donde aparecieron restos de más de un millón de años en una pequeña cata. Read the rest of this entry »

quinta-feira, 9 de junho de 2011

Web-Exclusive Video: Less Spark, More Smolder?

One good way to learn about the human spark is to investigate a closely related species that lacked it. Alan Alda traveled to a French cave called Roc de Marsal, where Neanderthals sheltered intermittently for tens of thousands of years. The archaeologists who excavate here are becoming experts on Neanderthal life. In this video, Alan quizzes them on what they believe the big differences were between Neanderthals and early modern humans. Harold Dibble, Shannon McPherron, and Dennis Sandgathe explain what they think differentiates Neanderthals from us… and why the human spark might actually have been more of a human smolder.

video

terça-feira, 7 de junho de 2011

Hallada la mejor pelvis neandertal femenina del mundo

Desenterrado en Murcia un esqueleto casi completo de una hembra de 'Homo neanderthalensis'

Excavaciones en la Sima de las Palomas. u. de murcia
Encontrar la tumba intacta de un faraón es para un egiptólogo lo que para un arqueólogo es desenterrar un esqueleto completo de un humano extinto. Y eso es precisamente lo que ha aparecido en una montaña de mármol murciana, el Cabezo Gordo, a seis kilómetros del mar Menor. Allí, un equipo dirigido por el arqueólogo Michael Walker ha hallado el esqueleto casi completo de una mujer neandertal. La hembra fue descubierta en 2006 bajo un montón de grandes piedras, en posición extendida y acostada de lado, con las manos cerca del rostro. Walker, de la Universidad de Murcia, no descarta que tanto esta mujer neandertal como otros dos esqueletos detectados cerca fueran tapados con pedruscos para evitar que las hienas y los leopardos que entonces habitaban Murcia se comieran los cadáveres.

El estudio de los restos fósiles, cuyo hallazgo se publica hoy en la revista PNAS, es una oportunidad única. El esqueleto, completo desde la pantorrilla hasta el cráneo, "permite por primera vez la comparación con exactitud de las dimensiones de un neandertal mediterráneo y las de los neandertales del norte". El primer diagnóstico cumple con el tópico: Tanto la hembra conocida ahora como los restos de otro individuo menos completo hallado en el mismo yacimiento, la Sima de las Palomas del Cabezo Gordo, eran más bajitos que sus hermanos de latitudes más septentrionales. Según Walker, estas dimensiones coincidirían con las de otro ejemplar de la cueva de El Sidrón, en Asturias. Apenas medían metro y medio, aunque mantenían las mismas proporciones de la especie.

"Quizá eran más bajitos"
Sin embargo, el arqueólogo de la Universidad de Murcia no quiere extraer conclusiones precipitadas. "Los restos que tenemos sugieren que los neandertales mediterráneos eran más bajitos, pero en realidad no tenemos ni idea", subraya. "Lo importante de este estudio es que por fin tenemos un esqueleto para comparar", añade.

Los autores, entre los que también figura una de las máximas autoridades en la morfología de los neandertales, el antropólogo estadounidense Erik Trinkaus, destacan que es "el primer esqueleto articulado de un neandertal adulto jamás excavado en el litoral mediterráneo europeo". Además, exponen, posee "la pelvis femenina neandertal más completa del mundo", lo que posibilitará ampliar la información sobre múltiples aspectos de la reproducción de las hembras neandertales.

En la Sima de las Palomas, en el municipio de Torre-Pacheco, han aparecido huesos y dientes de otros seis neandertales. Sin embargo, los investigadores creen que no era una morada fija, ya que hace 40.000 años apenas medía cuatro metros de diámetro y 2,5 de alto.

quinta-feira, 2 de junho de 2011

O passado escondido no Museu Machado de Castro

O Museu Nacional Machado de Castro é palco das escavações arqueológicas da igreja românica de São João, que remonta ao século XII.
A trabalhar nas escavações estão os alunos do mestrado em Arqueologia da UC, uma junção possível graças a uma parceria entre a Universidade e o Museu.

Ancient cave women 'left childhood homes'

"Mrs Ples" is the most famous example of
A. africanus from the Sterkfontein cave site
By Neil Bowdler, Science reporter, BBC News

Analysis of early human-like populations in southern Africa suggests females left their childhood homes, while males stayed at home.

An international team examined tooth samples for metallic traces which can be linked to the geological areas in which individuals grew up.

The conclusion was that while most the males lived and died around the same river valley, the females moved on.

Similar patterns have been observed in chimpanzees, bonobos and modern humans.

Details of the study are published in a letter in Nature.

Isotopic test
The researchers looked at the Sterkfontein and Swartkrans cave sites, north-west of the South African city of Johannesburg.

The sites contain specimens of two distinct early "hominin" species, Australopithecus africanus, a possible direct ancestor of modern humans who lived around 2-3 million years ago, and Paranthropus robustus, who lived some 1.2-2 million years ago, but who is not believed to be our direct ancestor.

They took teeth from eight A.africanus and 11 P.robustus individuals from the cave sites, and removed tiny enamel fragments by laser, to minimise damage.

These fragments were then analysed to test for particular isotopes, or forms, of the metallic element strontium, which can reveal the geological region where individuals were raised.

This is because particular isotopes of strontium dominant within a geological region are digested by individuals living there and incorporated into their tooth enamel.


A third molar from Australopithecus africanus from which a sample was taken for the study
The results showed that the larger teeth, presumed to belong to males, showed most of these individuals lived and died in the region where the Sterkfontein and Swartkrans cave sites are located.

Most of the smaller teeth, presumed to be female, showed that these individuals grew up outside the region.

"What we were trying to do was to find out how these two hominins - two different species living in different time periods - were ranging around and using the landscape in the Sterkfontein valley and beyond," Professor Julia Lee-Thorp of Oxford University told BBC News.

While initial research was aimed at looking at seasonal variations in diet, the isotopic tests pointed them instead to apparent gender variations.

"What [the results] show was that the females were more likely to come from outside the dolomite valley region than the males. It wasn't too far away but it wasn't the same natal group in which they grew up.

"We don't know whether they drifted, or they went across deliberately, or they were abducted; we have no way of knowing that kind of detail, but on the whole most of the females came from somewhere else."

Professor Lee-Thorp said the patterns resemble those seen in chimpanzees, where males tend to stay within the extended family group, hunting together within a single territory, whereas females are forced to leave, possibly to avoid inter-breeding.

But that pattern differs from the one observed in gorillas, where a dominant "silverback" male usually mates with multiple females, and other males are forced to leave the group.

This does not mean, she believes, that the males within these hominin groups were necessarily taking any great role in child-rearing.

"I think that's taking the information too far, quite frankly," she said. "In chimpanzees that doesn't happen. In that case the females are leaving, but the males take little interest in nurturing the children."

Small sample
The sample size is of course very small, with specimens rare and samples for experimentation rarer. The researchers also admit that data from these two separate species living at two separate times was pooled to provide results which were statistically significant.

"We're very obviously constrained by the amount of material we have for destructive analysis," said researcher Professor Darryl de Ruiter of Texas A&M University, during a telephone conference dedicated to the Nature paper.

"In terms of comparing the two species themselves, we did analyse them separately but [the] sample size was so small within these individuals that they were not robust statistics... and we did have to combine these samples in order to get a valid statistical result."

Professor Peter Wheeler of Liverpool John Moores University said that both sample size and methodology were issues to consider.

"You've got to be cautious when drawing conclusions from a relatively small sample. You've got even greater concerns when combining data from more than one species," he said.

However, he said, "if the differences are consistent, then it's extremely interesting and worthy of further work".

He added: "Isotopic work is providing a lot of information about the movement of modern humans in the archaeological record and if people are able to get consistent results further back into prehistory, it could provide information which is potentially useful."

Quaternary International





Shell Midden Research: An Interdisciplinary Agenda for the Quaternary and Social Sciences
Edited by Andrea Balbo, Marco Madella, Ivan Briz Godino and Myrian Álvarez

Lithic Technology



Articles
  • Possible functions of grooved ground stones from Baking Pot, Belize by James J. Aimers, W. James Stemp, and Jaime J. Awe
  • A technological evaluation of the flint blade core reduction sequence at Wadi El-Sheikh, Middle Egyptby Theresa Barket and Robert M. Yohe II
  • On cache recognition: An example from the area of the Chico River (Patagonia, Argentina) by Nora Viviana Franco, Alicia Castro, Natalia Cirigliano, Marilana Martucci, and Agustin Acevedo
  • “I’ll have a flake to go, please”
  • Expedient core technology in the Late Bronze (c. 1100–800 cal BC) and Earliest Iron (c. 800–600 cal BC) ages of eastern England
  • Andrew P. McLaren

BOOK REVIEWS
  • Tools and Economy of the Eneolithic Farmers of South-Eastern Europe, by N.N. Skakun reviewed by Mikhail Zhilin
  • Prehension of Hafting Traces on Flint Tools: A Methodology by Veerle Rots, reviewed by Grant S. McCall

Quaternary Science Reviews






Early Human Evolution in the Western Palaearctic: Ecological Scenarios
Edited by Jose Carrion, James Rose and Chris Stringer

Mesolithic Miscellany



Bicho, N., Cascalheira, J., Marreiros, J., Pereira, T. 2011. The 2008-2010 excavations of Cabeço da Amoreira, Muge, Portugal. Mesolithic Miscellany, Vol. 21, n.º.2: 3-13.