For several decades, research activities in mobile ad hoc networking have predominantly relied on the notion of serial relays where a data packet hops from one node to another in a serial fashion. Recent research activities in signal processing and information theory suggest that parallel relays have a greater potential than serial relays. In this paper, a significant diversity gain of using parallel relays over serial relays is highlighted, the lifetimes of a single-path route of parallel relays and multi-path routes of serial relays are compared, and the routing overheads for each type of routes are also investigated. This study strongly supports that parallel relays have great advantages over serial relays in dense and mobile ad hoc networks.