Could there have been an entire world of more advanced civilizations than the ones on Earth now prior to an abrupt change in global climate that sent the world back into abrupt Ice Age that lasted approximately 1,300 years? The last Pleistocene Era's age known as the Younger Dryas took place about 14,500 years ago and is theorized to have been caused by an meteor impact. Could this have caused Earth's original advanced civilizations to end? Welcome back to Infinite Rabbit Hole! Infinite Rabbit Hole