In 1946, explorers stumbled upon two unexpected discoveries in the jungles of Chiapas, Mexico: a treasure of well-preserved Classic Maya murals and a thriving society of indigenous Maya peoples living in the lowland rainforest. Over subsequent decades, these Lacandon Maya were assumed to be the direct descendants of the Classic Maya, who created the spectacular temples and monumental art of the region. As impressive as this lineage may be, Joel Palka...