and Damascus could not validate Henri de Contenson's earlier suggestion of a PPNA Aswadian culture. Instead, they found evidence of a fully established PPNB culture at 8700 BC at Aswad, pushing back the period's generally accepted start date by 1,200 years. Similar sites to Tell Aswad in the Damascus Basin of the same age were found at Tell Ramad and Tell Ghoraifé. How a PPNB culture could spring up in this location, practicing domesticated farming from 8700 BC has been the subject of speculation. Whether it created its own culture or imported traditions from the North East or Southern Levant has been considered an important question for a site that poses a problem for the scientific community. Extent Work at the site of 'Ain Ghazal in Jordan has indicated a later Pre-Pottery Neolithic C period, which existed between 8,200 and 7,900 BP. Juris Zarins has proposed that a Circum Arabian Nomadic Pastoral Complex developed in the period from the climatic crisis of 6200 BC, partly as a result of an increasing emphasis in PPNB cultures upon animal domesticates, and a fusion with Harifian hunter gatherers in Southern Palestine, with affiliate connections with the cultures of Fayyum and the Eastern Desert of Egypt. Cultures practicing this lifestyle spread down the Red Sea shoreline and moved east from Syria into southern Iraq. The culture disappeared during the 8.2 kiloyear event, a term that climatologists have adopted for a sudden decrease in global temperatures that occurred approximately 8,200 years before the present, or c. 6200 BC, and which lasted for the next two to four centuries. In the following Munhatta and Yarmukian post-pottery Neolithic cultures that succeeded it, rapid cultural development continues, although PPNB culture continued in the Amuq valley, where it influenced the later development of the Ghassulian culture. Artifacts Around 8000 BCE, before the invention of pottery, several early settlements became experts in crafting beautiful and highly sophisticated containers from stone, using materials such as alabaster or granite, and employing sand to shape and polish. Artisans used the veins in the material to maximum visual effect. Such objects have been found in abundance on the upper Euphrates river, in what is today eastern Syria, especially at the site of Bouqras. These form the early stages of the development of the Art of Mesopotamia. Genetics Pre-Pottery Neolithic B fossils that were analysed for ancient DNA were found to carry the Y-DNA (paternal)