'Neoteny' is a well-known concept, but what about its opposite? Various writers over the centuries have noted that North African men often appear old and haggard at relatively young ages. Their faces are often rough and craggy in a manner similar to old people, but before old age itself.
What kind of selective breeding pressures would create the opposite of a neotenous appearance? What are the evolutionary advantages of a tribe's men looking old and ugly by the time they are teens?