“Midi-chlorians are a microscopic life form that resides within all living cells.”— Qui-Gon Jinn, to Anakin Skywalker Star Wars fans know midi-chlorians—the mystical entities that connect living beings to the Force. In the real world, we have a similar “energy mediator”—mitochondria. Ancient symbiosis—like a cosmic legend About 2 billion years ago, mitochondria were free-living bacteria.[…]