Or a a nearby supernova happened to deposit plutonium and other heavy elements in a fine mist over the planet within the last 10 million years... I'm somewhat

Or a a nearby supernova happened to deposit plutonium and other heavy elements in a fine mist over the planet within the last 10 million years... I'm somewhat curious if modern human civilization happened to emerge in the last ~10ky simply because all other time periods since modern humans evolved were too unstable to support civilization.