They are where old trade routes of Testificates were along, until the day the Enderdragon hatched. The Enderdragon then created the "evil" mobs such as Zombies and Endermen and Skeletons. This made the poor Testificates become self- sufficiant communites. The only reason the Testificates do not trade after the Enderdragon is dead is because you cannot speak their tounge, and therefore tell them of the danger that has been destroid.
