segunda-feira, 7 de novembro de 2011
The Influence of Late Quaternary Climate-Change Velocity on Species Endemism
B. Sandel,1,2* L. Arge,2 B. Dalsgaard,3 R. G. Davies,4 K. J. Gaston,5 W. J. Sutherland,3 J.-C. Svenning1
1. Ecoinformatics and Biodiversity Group, Department of Bioscience, Aarhus University, Aarhus 8000 C, Denmark.
2. Center for Massive Data Algorithmics (MADALGO), Department of Computer Science, Aarhus University, Aarhus 8000 C, Denmark.
3. Conservation Science Group, Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
4. School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
5. Environment and Sustainability Institute, University of Exeter, Cornwall TR10 9EZ, UK.
The effects of climate change on biodiversity should depend in part on climate displacement rate (climate-change velocity) and its interaction with species’ capacity to migrate. We estimated Late Quaternary glacial-interglacial climate-change velocity by integrating macroclimatic shifts since the Last Glacial Maximum with topoclimatic gradients. Globally, areas with high velocities were associated with marked absences of small-ranged amphibians, mammals, and birds. The association between endemism and velocity was weakest in the highly vagile birds and strongest in the weakly dispersing amphibians, linking dispersal ability to extinction risk due to climate change. High velocity was also associated with low endemism at regional scales, especially in wet and aseasonal regions. Overall, we show that low-velocity areas are essential refuges for Earth’s many small-ranged species.
Artigo em sciencemag.org
quinta-feira, 3 de novembro de 2011
Archaic human ancestry in East Asia
Pontus Skoglund a and Mattias Jakobsson a, b
a Department of Evolutionary Biology and
b Science for Life Laboratory, Uppsala University, 75236 Uppsala, Sweden
Recent studies of ancient genomes have suggested that gene flow from archaic hominin groups to the ancestors of modern humans occurred on two separate occasions during the modern human expansion out of Africa. At the same time, decreasing levels of human genetic diversity have been found at increasing distance from Africa as a consequence of human expansion out of Africa. We analyzed the signal of archaic ancestry in modern human populations, and we investigated how serial founder models of human expansion affect the signal of archaic ancestry using simulations. For descendants of an archaic admixture event, we show that genetic drift coupled with ascertainment bias for common alleles can cause artificial but largely predictable differences in similarity to archaic genomes. In genotype data from non-Africans, this effect results in a biased genetic similarity to Neandertals with increasing distance from Africa. However, in addition to the previously reported gene flow between Neandertals and non-Africans as well as gene flow between an archaic human population from Siberia (“Denisovans”) and Oceanians, we found a significant affinity between East Asians, particularly Southeast Asians, and the Denisova genome—a pattern that is not expected under a model of solely Neandertal admixture in the ancestry of East Asians. These results suggest admixture between Denisovans or a Denisova-related population and the ancestors of East Asians, and that the history of anatomically modern and archaic humans might be more complex than previously proposed.
human origins | ancient DNA
Artigo em pnas.org
quarta-feira, 2 de novembro de 2011
Ancient artist's toolkit a clue to early humans
 |
| Color was mixed in this 100,000-year-old shell. |
A hundred thousand years ago, not long after Homo sapiens emerged as a species, a craftsman - or woman - sat in a cave overlooking the Indian Ocean, crushed a soft rusty red rock, mixed it inside a shell with charcoal and animal marrow, and dabbed it on something - maybe a face, maybe a wall.
Before the person left, he or she stacked the shell and grindstones in a neat pile, where they lay undisturbed for a hundred millennia.
Unearthed in 2008 and described Friday in the journal Science, these paint "toolkits," researchers say, push deeper into human history evidence for artistic impulses and complex, planned behavior.
"They probably understood basic chemistry," said Christopher Henshilwood, the archaeologist who led the discovery team.
Traces of paint on the tools show that the cave dwellers mixed ocher - red or yellow minerals that contain metal oxides - with marrow from bones, charcoal, flecks of quartz and a liquid, probably water. Paint experts at the Louvre in Paris performed the analysis.
With ground ocher as the base, the marrow and charcoal acted as binders. The quartz could have made the compound sticky, while water - in the right amount - provided the proper consistency.
The cave, called Blombos, sits in a cliff on the coast of South Africa about 180 miles east of Cape Town. It shows signs of human use starting 130,000 years ago. The discovery adds to other early artistic treasures at Blombos, including 49 beads smeared with ocher and large pieces of ocher inscribed with cross-hatch patterns that date to 77,000 years ago - widely recognized as the oldest known art.
The cave walls show no paintings, but quickly accreting limestone would have obscured any obvious signs, Henshilwood said.
This article appeared on page A - 5 of the San Francisco Chronicle
in sfgate.com
By Brian Vastag, Washington Post
Friday, October 14, 2011
Unfrozen
There was only one way scientists could unlock the mystery of the famous Iceman.
Take away his ice.
Shortly after 6 p.m. on a drizzling, dreary November day in 2010, two men dressed in green surgical scrubs opened the door of the Iceman's chamber in the South Tyrol Museum of Archaeology in Bolzano, Italy. They slid the frozen body onto a stainless steel gurney. One of the men was a young scientist named Marco Samadelli. Normally, it was his job to keep the famous Neolithic mummy frozen under the precise conditions that had preserved it for 5,300 years, following an attack that had left the Iceman dead, high on a nearby mountain. On this day, however, Samadelli had raised the temperature in the museum's tiny laboratory room to 18°C—64°F.
Photograph by Robert Clark
Mais em nationalgeographic.com
The American Journal of Archaeology publishes quarterly open access book and museum reviews. These reviews are listed in the table of contents of the respective printed issue of the Journal and are available for free download on the Journal's website (www.ajaonline.org).
Below is a list of book reviews published in tandem with our printed October 2011 issue (volume 115, number 4). See the Current Table of Contents (www.ajaonline.org/toc/1154) or click the links below to access the free PDFs. We hope you enjoy.
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Book Reviews
Geography and Ethnography: Perceptions of the World in Pre-Modern Societies
Edited by Kurt A. Raaflaub and Richard J.A. Talbert
Reviewed by Peter S. Allen
http://www.ajaonline.org/online-review-book/985
Body Parts and Bodies Whole: Changing Relations and Meanings
Edited by Katharina Rebay-Salisbury, Marie Louise Stig Sorensen, and Jessica Hughes
Reviewed by Lynne A. Schepartz
http://www.ajaonline.org/online-review-book/986
Dawn of the Metal Age: Technology and Society During the Levantine Chalcolithic
By Jonathan M. Golden
Reviewed by Graham Philip
http://www.ajaonline.org/online-review-book/987
Gräber und Grüfte in Assur. Vol. 1, Von der zweiten Hälfte des 3. bis zur Mitte des 2. Jahrtausends v. Chr.
By Daniel Hockmann
Reviewed by Augusta McMahon
http://www.ajaonline.org/online-review-book/988
Aramaic and Figural Stamp Impressions on Bricks of the Sixth Century B.C. from Babylon
By Benjamin Sass and Joachim Marzahn
Reviewed by Christopher Rollston
http://www.ajaonline.org/online-review-book/989
Flexible Stones: Ground Stone Tools from Franchthi Cave
By Anna Stroulia
Reviewed by Erella Hovers
http://www.ajaonline.org/online-review-book/990
Death Management and Virtual Pursuits: A Virtual Reconstruction of the Minoan Cemetery at Phourni, Archanes
By Constantinos Papadopoulos
Reviewed by Emily Miller Bonney
http://www.ajaonline.org/online-review-book/991
Orchomenos IV: Orchomenos in der mittleren Bronzezeit
By Kalliope Sarri
Reviewed by Michael B. Cosmopoulos
http://www.ajaonline.org/online-review-book/992
Crete in Transition: The Pottery Styles and Island History in the Archaic and Classical Periods
By Brice L. Erickson
Reviewed by Antonis Kotsonas
http://www.ajaonline.org/online-review-book/993
How to Read Greek Vases
By Joan Mertens
Reviewed by T.H. Carpenter
http://www.ajaonline.org/online-review-book/994
La céramique grecque d'Italie méridionale et de Sicile: Productions coloniales et apparentées du VIIIe au IIIe siècle av. J.-C.
By Martine Denoyelle and Mario Iozzo
Reviewed by Robin Osborne
http://www.ajaonline.org/online-review-book/995
Hermeneutik der Bilder: Beiträge zur Ikonographie und Interpretation griechischer Vasenmalerei
Edited by Stefan Schmidt and John H. Oakley
Reviewed by Robin Osborne
http://www.ajaonline.org/online-review-book/996
Corpus Vasorum Antiquorum. Great Britain 25. The British Museum 11: Greek Geometric Pottery
By J. Nicolas Coldstream
Reviewed by Susan Langdon
http://www.ajaonline.org/online-review-book/997
Corpus Vasorum Antiquorum. Germany 87. Munich, Antikensammlungen ehemals Museum Antiker Kleinkunst 15: Attisch Wiessgrundige Lekythen
By Erika Kunze-Götte
Reviewed by Timothy J. McNiven
http://www.ajaonline.org/online-review-book/998
L'architecture grecque. Vol. 3, Habitat, urbanisme et fortifications
By M.C. Hellmann
Reviewed by Lisa Nevett
http://www.ajaonline.org/online-review-book/999
Delphi and Olympia: The Spatial Politics of Panhellenism in the Archaic and Classical Periods
By Michael Scott
Reviewed by Mary Voyatzis
http://www.ajaonline.org/online-review-book/1000
Art in the Era of Alexander the Great: Paradigms of Manhood and Their Cultural Traditions
By Ada Cohen
Reviewed by Sheila Dillon
http://www.ajaonline.org/online-review-book/1001
The Necropolis of Poggio Civitate (Murlo): Burials from Poggio Aguzzo
By Anthony Tuck
Reviewed by Lisa C. Pieraccini
http://www.ajaonline.org/online-review-book/1002
Early Roman Thrace: New Evidence from Bulgaria
Edited by Ian P. Haynes
Reviewed by Emil Nankov
http://www.ajaonline.org/online-review-book/1003
Patrasso colonia di Augusto e le trasformazioni culturali, politiche ed economiche della provincia di Acaia agli inizi dell'età imperiale romana: Atti del convegno internazionale, Patrasso 23–24 marzo 2006
Edited by Emanuele Greco
Reviewed by Amelia Robertson Brown
http://www.ajaonline.org/online-review-book/1004
Houses and Society in the Later Roman Empire
By Kim Bowes
Reviewed by Shelley Hales
http://www.ajaonline.org/online-review-book/1005
Fréjus (Forum Julii): Le Port Antique/ The Ancient Harbour
By Chérine Gébara and Christophe Morhange
Reviewed by R. Scott Moore
http://www.ajaonline.org/online-review-book/1006
Roman Art
By Paul Zanker
Reviewed by Ellen Perry
http://www.ajaonline.org/online-review-book/1018
Saint-Bertrand-de-Comminges. Vol. 4, Le Macellum
By Georges Fabre and Jean-Louis Paillet
Reviewed by Julian Richard
http://www.ajaonline.org/online-review-book/1019
segunda-feira, 31 de outubro de 2011
Arqueologia ao Sul - Ciclo de conferências
O NAP - Núcleo de Arqueologia e Paleoecologia da Universidade do Algarve vem anunciar mais uma das suas conferências Arqueologia ao Sul desta feita com o tema: "Avanços Recentes na Análise de Ossos Queimados e sua Contribuição para a Investigação Arqueológica", por David Gonçalves
quarta-feira, 26 de outubro de 2011
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