This is a literary nonfiction book that I am writing and hope to have published.
Threshold: (1) the sill of a doorway; the entrance to a house or building; (2) the point at which a psychological or physiological effect begins to be produced; the starting point of an adventure or experience; (3) the maximum point or upper limit at which a state or condition transitions into another state, usually permanently. – Webster’s New Collegiate Dictionary
Thresholds made us human. A brutal drought likely drove our ape ancestors out of the trees and dying forests into the African savannah, encouraging them to walk upright. The tool-making, meat-eating, cooking, singing, dancing, and story-telling around the campfire that followed over the millennia also represent significant thresholds in our development. So does a transformative genetic bottleneck 75,000 years ago that created our modern behavior, likely the consequence of another devastating drought. Next came the Diaspora out of Africa by a small group of people, freezing weather, cave art, and the start of the warm Holocene epoch. We were ready. We burst across this new threshold – and invented civilization. Nothing was the same ever again. It’s in our nature to explore, adapt, and survive. It’s who we are. It’s where we came from. It’s where we are going – over the next threshold.