Tuesday May 22, 2012
A new research study published in the Proceedings of the National Academy of Sciences on May 21, 2012, reports that the long and varied history of dogs and humans has resulted in a major disconnect between ancient dogs and modern breeds.
One of the few modern breeds of dogs to retain a tiny trace of its genetic origins, the Finnish Spitz was rescued from extinction by a single determined breeder. Photo of Ginger by Noël Zia Lee
Dogs were domesticated from the gray wolf at least 15,000 years ago, although where that happened and whether it happened once or several times is still a controversy. Since domestication occurred while humans were all hunter-gatherers at the time and thus led extensively migrant lifeways, dogs spread with them, and thus these dog populations developed in geographic isolation for a time. Eventually, however, human population growth and trade networks meant people reconnected, and that, say scholars, led to admixture in the dog population. When dog breeds began to be developed about 500 years ago, they were created out of a fairly homogenous gene pool, from dogs with mixed genetic heritages which had been developed in widely disparate locations.
Since the creation of kennel clubs, breeding has been selective: but even that was disrupted by World Wars I and II, when breed populations all over the world were decimated or went extinct: dog breeders have reestablished such breeds using a handful of individuals or combining similar breeds.
Larson G, Karlsson E, Perri A, Webster MT, Ho SYW, Peters J, Stahl PW, Piper PJ, Lingaas F, Fredholm M et al. 2012. New genetic, archeological, and biogeographic perspective on dog domestication. Proceedings of the National Academy of Sciences Early edition.
A couple of news stories:
Friday May 18, 2012
I am not a huge sports fan (having been traumatized by an early fascination with the Chicago Cubs), but I am a huge fan of ballcourts.
Ballcourt at Xcaret, Yucatan Peninsula. Photo by Wired Tourist
Ballcourts are a type of prehistoric structure built for the practice of the Mesoamerican ballgame. The earliest of them dates to ca 1400 BC: versions of the same games are still played in many places in central America today. Ballcourts vary widely in shape and form, and they are found from central Arizona to the Amazon basin in South America.
Small Ballcourt at Lamanai, Belize. Cloud2013
Some of them are enormous, hundreds of feet long; some of them are tiny. Some are rectangular, some I-shaped, some lack any formal stone structure at all. Some games were played for political control, for settling conflicts, for thinning out the ranks of burly aggressive men (the losers often lost their lives), or for reasons we can't even guess at. But to my mind, they are yet another type of site worth investigating.
Carved Stone Ring, Great Ball Court, Chichén Itzá, Mexico. Dolan Halbrook
Monday May 14, 2012
An article in PNAS published on May 14, 2012, describes a fundamental reassessment of the Upper Paleolithic Aurignacian site of Abri Castanet, in the Dordogne region of France, which pushes the date of its artwork back to among the earliest known in the world, about 37,000 years ago.
Cave entrance of Abri Castanet; photo by Père Igor
Abri Castanet was first excavated by pioneer French archaeologist Denis Peyrony in the early decades of the 20th century, and then reopened in the 1990s by Jean Pelegrin and Randall White. Peyrony was convinced that he had identified two separate occupations--an Early Aurignacian one and a Middle Aurignacian one--and in the Middle Aurignacian level he discovered evidence of cave art, specifically animal and abstract vulvar (female sexual organs) representations carved into fragments of the ceiling.
What White's latest research has shown, at least according to the excavators, is that the site has no Middle Aurignacian component to it: all of the artifacts and art date instead to the Early Aurignacian. Abri Castanet's art work is thus similarly dated to that of the marvelous paintings of Chauvet Cave, also in the Dordogne in the Ardache Ardèche valley of France, and, if White and his team are correct, Abri Castanet's art is among the earliest known cave art in the world.
Friday May 11, 2012
A fascinating report in Science today, and featured in an upcoming issue of National Geographic, is that of a newly discovered mural including astronomical tables at the classic Maya site of Xultún.
Trees grow atop a newly discovered mound over a house built by the ancient Maya that contains the rendering of an ancient figure, possibly the town scribe. The research is supported by the National Geographic Society. Photo by Tyrone Turner © 2012 National Geographic
Xultún was a regional capital in the Peten of Guatemala, with an occupation that dates between ca AD 200-800: and on the walls of one of its rooms are painted a list of the movements of heavenly bodies. This story obviously required a photo essay.
For this project, I was thrilled to be able to enlist my former contributing writer Nicoletta Maestri, a student of Maya archaeology completing her PhD who has visited the region on at least one occasion. Our report is based on the Science article, and other materials gleaned from external research. We have not seen the National Geographic article, although most of the photos used in the essay were taken by Tyrone Turner © 2012 National Geographic.
By the way, my favorite thing about this article is that there is evidence that the scribes wrote and corrected their tables over generations, as their observations grew more acute.
Some news items featuring this report:
