Dogs were present in the Americas before the arrival of European colonists, but the origin and fate of these precontact dogs are largely unknown. We sequenced 71 mitochondrial and 7 nuclear genomes from ancient North American and Siberian dogs from time frames spanning ~9000 years. Our analysis indicates that American dogs were not derived from North American wolves. Instead, American dogs form a monophyletic lineage that likely originated in Siberia and dispersed into the Americas alongside people. After the arrival of Europeans, native American dogs almost completely disappeared, leaving a minimal genetic legacy in modern dog populations. The closest detectable extant lineage to precontact American dogs is the canine transmissible venereal tumor, a contagious cancer clone derived from an individual dog that lived up to 8000 years ago.
Archaeological excavations begun at Mayapan in 1996 require re-evaluation of this site, sometimes disparaged as representing “decadent” Postclassic Maya culture. New discoveries show that the site was an international center that incorporated specific symbols in its art from areas as far away as Central Mexico and Oaxaca. Indeed, there is evidence of trade with both areas. Another important Postclassic trade route connected Mayapan to Yucatan's eastern coast and Peten, Guatemala. These connections are reflected in similar ceramics and architecture in the three areas. Revival of Terminal Classic traditions at Mayapan inspired certain architectural constructions and a stela cult marking Katun endings. The Katun-cycle chronologies of the Colonial period provide intriguing evidence that political events at Mayapan may be linked with the site's architectural history. The “founding” of Mayapan may have occurred earlier than the conventionally accepted date ofa.d.1263 (end of Katun 13 Ahau). TheChilam Balam of Chumayelchronicles use of a 24-year Katun instead of a Katun of 20 Tuns, suggesting that the earliest founding event at Mayapan (Katun 8 Ahau) may date back to the eleventh centurya.d.and overlap with the demise of Chichen Itza. Some of Mayapan's earliest architecture is contemporary with Chichen Itza's latest constructions. Several hundred years after Mayapan was founded, there was a renaissance of the Cocom heritage evident in specific architectural forms modeled on those from Chichen Itza.
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