Ruins of the Temple of the Amphitheatre in the Late Preceramic Period archaeological site of Caral in Peru.  Photo Courtesy: Daniel Sandweiss Early populations shifted from quasi-egalitarian hunter-gatherer societies to communities governed by a centralized authority in the middle to late Holocene, but how the transition occurred still puzzles anthropologists. A University of Maine-led group read more UMaine researchers explore population size, density in rise of centralized power in antiquity – P. Roscoe, D. Sandweiss, E. Robinson