excellent theories BUT this entire universe is subject to the will of Bungie they ultimately decide. Is Humanity Precursor or Forerunner? then how could the Prophets use the ship on their homeworld if you needed a Biological fingerprint wouldn't that make the Prophets and Humans related? whether we like it or not Bungie could pick any theory and make it the truth in the Halo Universe but i do agree with the genetic memories quite a good argument and if it wasn't up to Bungie i would whole-heartedly agree with you i just simply believe that Bungie can create anything in this Universe and it would be fact maybe the Precursors didn't just own an Empire in the Milky Way? What if it spanned a couple of Galaxies and in one of these Galaxies an Rebellion against empire created a new biological weapon... The Flood so the Precursor Empire (Precursors possibly have their home world in the Milky way) Have sinned by trying to Control other Galaxies and all that submit to them must be cleansed (Forerunners could* descend from these Rebels) and they wish to research what happened to their previous power or something along those lines. EDIT: Forerunners being these descendents of the Floods Creators, The explanation would be the flood gain sentience by 'Infecting' the Loyal Precursors [Edited on 08.10.2010 2:05 PM PDT]