Pak Protector - The Pak and Humanity

The Pak and Humanity

In Protector, Niven explains that humans (and all of Earth's primates) are descended from a colony of Pak breeders that were stranded on Earth 2.5 million years ago. The protectors that built the colony ship died when their Tree-of-Life crops failed. The original Pak Breeder population (known to us as Homo habilis) bred and mutated wildly, evolving into modern humans as well as all other Earth primates. All Terran primates would transform into the Protector stage if exposed to Tree-of-Life root (or, more accurately, the symbiotic virus it contains).

In The Ringworld Engineers, the characters find evidence that the Ringworld was built by Pak Protectors (confirmed by the statements of a character in Ringworld's Children who claims to be one of the original builders) and populated by Pak breeders. The Pak Protectors dwindled in numbers until they were no longer able to maintain the genetic purity of the breeder forms and the breeders eventually evolved into all the other hominids of the Ringworld that one sees in Larry Niven's novels.

In Destroyer of Worlds (co-written by Niven and Edward M. Lerner), a human world (and the Pierson's Puppeteers of the Fleet of Worlds) confronts a Pak Protector war fleet. The trailing edge of that Pak fleet, carrying the primary Pak Library, also figures prominently in Betrayer of Worlds, by the same authors.