"Any hypothesis explaining the evolution of slavery in "Polyergus" must account both for the origin of group raiding with brood capture, and for non-independent colony foundation by queens". Topoff gives an adequate hypothesis to the evolution of "Polyergus" by integrating three processes: queen takeover, olfactory imprinting, and territorial fighting. Here are his main points. A free-living ancestor of Polyergus, that is a scavenger, would band together with others for intraspecific contest. Occasionally a queen invaded colonies of "Formica". Initially the queen drove off the "Formica" queen and workers and appropriated the "Formica" pupae (he gives as example the queens of "Formica wheeleri" that do this now). The killing of the "Formica" queen and adoption by the workers evolved from this. His previous work (which was presented earlier) shows what would have evolved for adaptation to occur: "(1) sharp mandibles for killing the "Formica" queen, (2) a pheromone that reduces aggression from resident workers, (3) a tendency to hold onto the dead "Formica" queen long enough to absorb her odors...". The next step was olfactory imprinting between the two species, a consequence of living one’s life from start to finish in the presence of both species. "Polyergus"’ ancestor then forages and encounters a colony of the same species. Again, they recruit nestmates to a territorial raid. In a brilliant insight, Topoff suggest this trait explains the raiding behavior. The "Polyergus" worker, raised by "Formica" as conspecifics, "identifies individual of "Formica" as belonging to its own species, another territorial raid is incited. Thus from the standpoint of "Polyergus"... slave raids are equivalent to territorial raids". The captured brood is imprinted as well and they become workers in the original nest. As time went on "Our ancestral "Polyergus" could easily slide in the direction of facultative parasitism". Eventually, "Polyergus" ancestors lost the ability to take care of themselves and become the inquiline "Polyergus" we see today.