The universe is populated by a number of sentient races. Some of them are humanoid, while others are so alien that humanity didn't realize that they were sentient for decades. Several sentient races maintain diplomatic relations with Earth's society. Many planets in Noon Universe are inhabited by races identical to humans in all but minor genetic differences. It has been speculated that they were humans who wound up on other worlds due to the Wanderers' manipulations (as "Beetle in the Anthill" shows, that is hardly unprecedented).