Editing Pak Protector (section)

== Narrative purpose ==

Niven has written that he invented the Protectors as a [[thought experiment]] to explain the common effects of aging on humans and to create a fictional evolutionary explanation for humans' long lives after females have passed reproductive age.<ref>{{cite book |last=Niven |first=Larry |date=1990 |title=N-Space |url=https://archive.org/details/nspace00nive/page/311 |publisher=[[Tor Books]] |page=[https://archive.org/details/nspace00nive/page/311 311] |isbn=0-312-85089-1 |author-link=Larry Niven }}</ref> Accordingly, most of the positive attributes of Protectors are based on negative human aging effects: swollen joints, decreased muscle-fat ratio, weakening heart, invariant diet, decreasing height, facial atrophy, leathery skin, hair loss, lack of sex drive, and tooth loss are all turned to advantage during the shift from Breeder to Protector.