In National Geographic Magazine, edição portuguesa, Julho 2012
terça-feira, 31 de julho de 2012
O Núcleo de Arqueologia e Paleoecologia (NAP) da Universidade do Algarve é uma unidade totalmente dedicada ao desenvolvimento, dinamização e divulgação da investigação no domínio da Arqueologia e da Paleoecologia humana.
Os objectivos do NAP são sobretudo a divulgação da disciplina arqueológica em contextos não científicos; a cooperação em projectos e elaboração de novas propostas de trabalho; a intensificação e dinamização dos contactos com sociedades e associações científicas, nacionais e estrangeiras; e a promoção e organização de reuniões científicas (congressos, conferências, cursos, workshops e demais actividades relacionadas).
Desde a primeira publicação, a 11 de Janeiro de 2009, soma-mos mais de 40.000 acessos...
Obrigados a todos os leitores, apoiantes e amigos que visitam este espaço e a todas as pessoas que directa ou indirectamente contribuem para este projecto. Esperamos poder continuar a merecer a vossa preferência e confiança.
Aqui fica o nosso sincero obrigado!
segunda-feira, 30 de julho de 2012
Sedimentary fluxes and budgets in natural and anthropogenically modified landscapes – Effects of climate change and land-use change on geomorphic processes
Edited by Achim A. Beylich, Armelle Decaulne and Scott Lamoureux
O VI Encuentro de Arqueología Peninsular del Suroesteque se celebrará entre el 4 y 6 de octubre de 2012 en Villafranca de los Barros. Además, la información que se va generando se está colgando AQUI.
|Did modern humans evolve suddenly or over a long period of time?|
Image: Fredrik SandÃ©n/Flickr
Modern humans, Homo sapiens, originated in Africa sometime between 200,000 and 100,000 years ago. I’ve written that sentence many times. But what if it’s wrong? Paleoanthropologist Tim Weaver of the University of California, Davis argues there might be another way to interpret our species’ beginnings. Instead of a discrete origin event, he suggests in the Journal of Human Evolution that our ancestors’ arrival into the world might have been a lengthy process that occurred over hundreds of thousands of years.
Current thinking says the lineages leading to modern humans and Neanderthals split 400,000 years ago. And then 200,000 years later, Homo sapiens suddenly appeared in Africa. There’s a lot of evidence that seems to support the idea. The earliest fossils assigned to our species date to this time period. Mitochondrial DNA inherited through the maternal line backs up the fossil evidence. Modern people’s mitochondrial DNA can all be traced back to a common ancestor, an “Eve,” that lived 200,000 years ago.
But Weaver says these lines of evidence can also support an alternative scenario, in which the evolution of our species plays out over hundreds of thousands of years between the split from Neanderthals and the expansion of humans out of Africa 60,000 to 50,000 years ago. He uses genetics and mathematical methods to argue his case.
First, he shows how modern people’s mitochondrial DNA could all appear to converge at 200,000 years ago without being the result of a speciation event or a population bottleneck at that time. It’s possible, he says, to get the same picture of modern mitochondrial DNA if the population of breeding adults stayed constant 400,000 to 50,000 years ago—and if the size of that population equaled the average (called the harmonic mean) population size of the successive generations experiencing a theoretical bottleneck 200,000 years ago.
Next, he builds a model of physical evolution to show how a long process could lead to the arrival of modern human traits at about 200,000 years ago. The model follows several assumptions about the genetic basis of physical traits. Weaver also assumes changes over time in human physical traits were the result of mutation and genetic drift (random change) rather than natural selection. (He notes that differences between Neanderthal and modern human skulls, for example, don’t appear to be the result of natural selection.) By modeling successive generations from 400,000 years ago to the present, with each generation equaling 25 years, Weaver finds modern human traits should have appeared in the fossil record 165,000 years ago. That date becomes 198,000 years ago when the generation length is increased to 30 years or 132,000 years ago when the generation length is decreased to 20 years. What that means is both an abrupt speciation event or a long process could explain why modern humans seem to appear in the fossil record 200,000 years ago.
Weaver’s purpose with this work, however, is not necessarily to prove that modern human origins was a long, drawn out affair. He writes:
At the moment, both discrete event and lengthy process models appear to be compatible with the available evidence. My goal is simply to show that lengthy process models are consistent with current biological evidence and to heighten awareness of the implications of these models for understanding modern human origins.
One of those implications: If it turns out the arrival of humans was a lengthy process, Weaver says, it means nothing “special” happened 200,000 years ago to cause the birth of our species.
segunda-feira, 23 de julho de 2012
Nota preliminar sobre el IV Seminario de Tecnología Prehistórica (2012): "La agricultura prehistórica: Metodología de investigación"
Dear Colleagues and friends,
With this preliminary note, we want to communicate the future celebration (late fall 2012) of the "IV Prehistoric Technology Seminar", organized by the Institución Mila y Fontanals (CSIC). We beg maximum dissemination of it. On this occasion, the theme will address research methodologies on prehistoric agricultural techniques and technology.Provisional data for the seminar:
- Preliminary title: "IV Prehistoric Technology Seminar: Prehistoric Agriculture: Research Methodology."
- Date of Celebration: 6 to 9 November 2012
- Venue: Institution Mila y Fontanals, CSIC (Barcelona)
Faculty and preliminary titles of the sessions:
- Juan José Ibáñez: El origen de la Agricultura en el Próximo Oriente: Cambio, adopción y proceso de difusión.
- Jesus Emilio González: Técnicas y útiles agrícolas relacionados con el procesado de los cereales
- Juan F. Gibaja: Las técnicas de siega
- Pedro Ferrio Díaz: Los estudios de isótopos aplicados al estudio de la agricultura prehistórica.
- Antonio López: Los análisis polínicos: Procesos agrícolas, territorios de explotación y modificación del paisaje.
- Natalia Alonso: Sistemas de almacenaje. Experimentación y Arqueología.
- Leonor Peña: La Etnoarqueología como medio de aproximación al estudio de las técnicas y sistemas de procesado de los cereales.
- Ramón Buxó: Aproximación al conocimiento sobre la agricultura a partir de los estudios carpológicos.
- Hugo Oliveira: Los estudios genéticos aplicados a las prácticas agrícolas prehistóricas.
- Ferrán Antolín: Análisis cuantitativos y métodos de muestreo en el estudio de semillas.
- Karen Hardy y Les Copeland: El análisis de almidones aplicado al conocimiento de las sociedades agricultoras.
- Marco Madella, Carla Lancelotti y Debora Zurro: Phytoliths as a mean to investigate agricultural plants, systems and tools.
- Welmoed A. Out: Archaeobotany of agricultural societies: the case study of Dutch wetland sites in the process of neolithisation.
- Raquel Piqué y Trinidad Escoriza: Arte rupestre y agricultura.
- Oriol López: Estudio de los palos cavadores empleados en el trabajo agrícola: el caso del asentamiento neolítico de La Draga.
As usual, this seminar involves a special concern for the active participation of the students. In that sense, it will encourage alumni to put together specific issues of their own investigations, in relation to the Seminar's theme (research methodologies in relation to prehistoric agricultural techniques and technology).
In the near future will offer more information.
domingo, 22 de julho de 2012
sexta-feira, 20 de julho de 2012
in Volume 65 Number 4, July/August 2012,
by Nadia Durrani
|The Olympic Park in East London's Lower Lea Valley|
(Courtesy Olympic Delivery Authority)
Summer 2012, and the world’s greatest athletes are gathering in London for the Olympics. In advance of the Games, a square mile of semiderelict land in East London’s Lower Lea Valley has been turned into a fully equipped Olympic Park. This has transformed a run-down industrial district into a leafy urban park containing modern amenities including an athletes’ village, basketball arena, and the Olympic stadium. British law decrees that archaeological assessments must be undertaken before such developments, so between 2007 and 2009, the Olympic Delivery Authority (ODA) archaeologists set to work, digging into London’s past.
|(Courtesy Gary Brown)|
They excavated no fewer than 121 trenches, recovered more than 10,000 artifacts, and revealed evidence of at least 6,000 years of human activity—from the area’s first prehistoric hunters and farmers to World War II defense structures. In addition, they recorded all of the site’s still-standing historic buildings. Alongside this work, thousands of boreholes were sunk deep into the earth, revealing an environmental and geoarchaeological picture of the area over the past 12,000 years.
Completing the task was herculean. Though lying only three miles northeast of the glitz and glamor of central London, just five years ago this was still a neglected and largely unoccupied area. The archaeologists were faced with dilapidated buildings, general construction waste, and a deep accumulation of eighteenth- and nineteenth-century domestic garbage. Much of this garbage had been imported from nearby areas by people wishing to substantially raise the ground in order to settle on what was then low-lying and marshy land. Added to this, an 1844 act ruled that dangerous and so-called “dirty noxious” industries, such as printing works or chemical manufacturers, had to be moved out of central London. Many relocated here, an area already known for its industry. For the archaeologists, this meant that the ground was often chemically contaminated, waterlogged, or indeed both.
Handheld trowels and shovels would not suffice. Simply to break through the layers of city detritus, heavy construction equipment operators removed several hundred tons of soil for each trench, often to a depth of around 15 feet, and in one location, almost 30 feet. Only after the operators got past this recent debris could the team begin to explore the earlier archaeology. This was a mighty task. To avoid any risk of collapse under the weight of the surrounding land, the trenches had to be stepped down, with large trenches at the top narrowing to relatively small areas at the base. “Where trenches were particularly deep, we often had to further secure their sides using steel supports,” explains Gary Brown, fieldwork project manager of Pre-Construct Archaeology. Once the sites were safe, the diggers were kitted up with protective equipment, including disposable overalls, gloves, rubber boots, protective glasses, and even face masks.
Digging in London, with its long and complex history, is always difficult and time-consuming, and these excavations were certainly no exception. However, the results have been worth it. “The archaeology covered a huge swath of time and geography,” says project director Nick Bateman of Museum of London Archaeology. “We now have the first long-term, large-scale picture of life in this part of East London, an area first settled in prehistory, and in more recent times, one that became so significant to the development of the modern city.” Had it not been for the Olympic Park’s construction, this formerly impoverished, waterlogged, outlying part of historic London simply would not have been explored on this scale.
|Some of the excavation trenches were so deep that|
archaeologists ensured they didn’t collapse by creating
a series of steps to distribute the weight of the soil
around them. (Courtesy Olympic Delivery Authority)
According to Simon Wright, head of venues and infrastructure at the ODA, “Not only have we transformed the Olympic Park into the largest urban park to be created in the United Kingdom for more than 100 years, but we have uncovered its past in the process.”
Nadia Durrani is an archaeological editor and writer based in London.
The story of archaeology of the Olympic Park, Renewing the Past: Unearthing the History of the Olympic Park Site, will be available soon. For further details of the excavations, visit learninglegacy.london2012.com.
Tooth analysis shows that european hominins roasted vegetables and may have used medicinal plants.
Neanderthals have long been viewed as meat-eaters. The vision of them as inflexible carnivores has even been used to suggest that they went extinct around 25,000 years ago as a result of food scarcity, whereas omnivorous humans were able to survive. But evidence is mounting that plants were important to Neanderthal diets — and now a study reveals that those plants were roasted, and may have been used medicinally.
The finding comes from the El Sidrón Cave in northern Spain, where the roughly 50,000-year-old skeletal remains of at least 13 Neanderthals (Homo neanderthalensis) have been discovered. Many of these individuals had calcified layers of plaque on their teeth. Karen Hardy, an anthropologist at the Autonomous University of Barcelona in Spain, wondered whether it might be possible to use this plaque to take a closer look at the Neanderthal menu.
Neanderthals were thought to eat only meat,
but investigation of their dental plaque
suggests they consumed cooked plants.
Using plaque to work out the diets of ancient animals is not entirely new, but Hardy has gone further by looking for organic compounds in the plaque. To do this she and a team including Stephen Buckley, an archaeological chemist at the University of York, UK, used gas chromatography and mass spectrometry to analyse the plaque collected from ten teeth belonging to five Neanderthal individuals from the cave.
The plaque contained a range of carbohydrates and starch granules, hinting that the Neanderthals had consumed a variety of plant species. By contrast, there were few lipids or proteins from meat.
Hardy and her colleagues also found, lurking in the plaque of a few specimens, a range of alkyl phenols, aromatic hydrocarbons and roasted starch granules that suggested that the Neanderthals had spent time in smoky areas and eaten cooked vegetables. The results are published today in Naturwissenschaften1.
“The idea that Neanderthals were largely meat-eaters has been hard for me to accept given their membership in a mainly vegetarian clade. It is exciting to see this new set of techniques applied to understanding their palaeo-diet,” says Richard Wrangham, an anthropologist at Harvard University in Cambridge, Massachusetts.
Among the compounds that Hardy found were chemicals from plants such as yarrow and camomile, which taste bitter and have no nutritional value. Genetic analysis has shown2 that Neanderthals had the ability to detect bitter tastes, raising questions about why they would intentionally eat such plants.
Michael Chazan, an anthropologist at the University of Toronto in Canada, suggests that the bitter-tasting plants were used in fire-making, and could have entered the diet as a by-product of cooking. Wrangham, by contrast, proposes that yarrow and camomile were used as seasoning.
Hardy disagrees with Wrangham. “The idea of Neanderthals sitting down for a bowl of salad stretches my imagination and there is no evidence of them having cooking pots, so soups seem unlikely,” she says. Hardy theorizes that the Neanderthals may have used the bitter plants as medicines ― modern herbalists use them as anti-inflamatories and antiseptics. “All modern higher primates make use of medicinal plants, so perhaps Neanderthals did too,” she says.
Regardless of why the Neanderthals consumed plants, perceptions of them and their diets are changing, says Lawrence Straus, an anthropologist at the University of New Mexico in Albuquerque. “As exceptional places like El Sidrón reveal just how wise and flexible Neanderthals were, more and more we are having to ask ourselves, why did they go extinct?”.
Hardy, K. et al. Naturwissenschaften http://dx.doi.org/10.1007/s00114-012-0942-0 (2012).
Lalueza-Fox, C., Gigli, E., de la Rasilla, M., Fortea, J. & Rosas, A. Biol. Lett. 5, 809–811 (2009).
quinta-feira, 19 de julho de 2012
quarta-feira, 18 de julho de 2012
terça-feira, 17 de julho de 2012
No ano em que se comemoram o 2º aniversário da inauguração do Museu do Côa (30/07/2010) e os 16 anos da abertura do Parque Arqueológico (10/08/1996), a Fundação Côa Parque convida-o a participar num conjunto de actividades que vão desde as visitas especiais à arte rupestre passando pela música clássica até à astronomia.
segunda-feira, 16 de julho de 2012
Volume 268, Pages 1-166
3 August 2012
Peat Stratigraphy and Climate Change
Edited by Peter G. Langdon, Paul D. Hughes and Anthony Brown
Volume 269, Pages 1-96
14 August 2012
Inter-disciplinary Perspectives on Indian Paleoanthropology and Prehistory
Edited by Parth R. Chauhan and Rajeev Patnaik
Os progressos da genética podem ter permitido enterrar o machado de guerra num debate histórico: o povoamento da América fez-se a partir da Sibéria por populações vindas da Ásia, mas em três vagas sucessivas e não apenas numa, diz uma equipa internacional de investigadores na revista Nature.
|As populações mais homogéneas geneticamente|
são as da América do Sul (Gregg Newton/Reuters).
Este modelo de povoamento, em três vagas sucessivas, já tinha sido proposto em 1986 por linguistas, mas não foi aceite, na época, pela comunidade científica.
Publicado nesta quarta-feira na revista britânica Nature, um estudo traça a história do património genético das populações nativas americanas, realizado por um consórcio internacional com mais de 60 cientistas. E demonstra que, pelo menos em parte, o modelo de 1986 estava correcto.
Ao analisar o genoma de 500 pessoas oriundas de 52 populações nativas americanas e 17 da Sibéria, com a ajuda de programas informáticos, os investigadores conseguiram obter uma visão de conjunto do seu património genético. A comparação entre mais de 364.000 marcadores genéticos “permitiu estabelecer o grau de diferenciação ou de semelhança genética entre estas populações”, escreve, em comunicado, o Centro Nacional da Investigação Científica (CNRS) de França, que contribuiu para este estudo.
As análises confirmam que a maioria das populações ameríndias resulta de uma vaga de migração vinda da Sibéria há cerca de 15.000 anos, durante uma glaciação que, na época, tornou o estreito de Bering transponível.
Os resultados também salientam a grande diversidade genética entre os indivíduos do Norte da América, enquanto as populações mais homogéneas geneticamente são as da América do Sul.
Mas, acima de tudo, a investigação demonstra a existência de duas outras vagas de povoamento asiático, que ocorreram depois (há entre 15.000 e 5000 anos), o que confirma o modelo proposto em 1986 por Joseph Greenberg, Christy Turner e Stephen Zegura, salienta o CNRS. Estas duas vagas posteriores “ficaram acantonadas no Alasca, Canadá e no Norte dos Estados Unidos”.
E, contrariamente ao que afirmava o modelo de 1986, os novos povoadores integraram-se bem nas populações que já existiam naquelas regiões, formando os povos esquimós, por exemplo.
Qualquer que seja o período em questão, a genética mostra que as populações colonizaram o continente americano em direcção ao sul, seguindo as zonas costeiras e separando-se ao longo da sua dispersão. Depois desta separação, as trocas genéticas entre os diferentes grupos foram muito reduzidas, em especial na América do Sul.
Entre 10 de Agosto e 30 de Setembro de 2012 irá decorrer a 6ª Bienal Internacional de Gravura do Douro 2012. Maioritariamente centrada na Vila de Alijó, com diversas exposições e actividades em diferentes espaços, terá outras exposições e actividades a decorrer noutras cidades e vilas durienses e transmontanas, nomeadamente no Museu do Côa em Vila Nova de Foz Côa, no Museu do Douro na Régua, no Teatro de Vila Real, no Museu do Pão e do Vinho em Favaios, e no Centro de Arte Contemporânea Graça Morais em Bragança.