Who is Andy Randall from Lucifer's Hammer and what is their importance?

Andy is Harvey Randall's son. Andy is on a hiking trip in the mountains with Gordie Vance when the comet strikes. When Harvey finds Andy, he learns that Andy has killed some men in order to rescue a group of young girls, and that he is now paired with one of those. Andy refuses to leave the mountains with his father, and Harvey admits that Andy and those with him might become a new breed of "mountain men."