Dutch researcher Eva Kaptijn succeeded in discovering -- based on 100,000 finds -- that the Zerqa Valley in Jordan had been successively inhabited and irrigated for more than 13,000 years. But it was not just communities that built irrigation systems: the irrigation systems also built communities... she has been applying an intensive field exploration technique: 15 metres apart, the researchers would walk forward for 50 metres. On the outward leg, they'd pick up all the earthenware and, on the way back, all of the other material. This resulted in more than 100,000 finds, varying from about 13,000 years to just...