Here is My theory on your Ideas. The precursors are human. They are flesh of our flesh and all that. The difference in us and them is that they don this "mantle" somehow and become more that what they can biologically be. It said they could advance the development or what not of species instantly... well maybe it wasn't some process... maybe it was a tech. It makes sense to me that If we cant physically do something lets build a tool. Well if we cant physically be super smart lets build a tool to do it. Now we see tech deteriorates ... even AI's ... so they wanted a way to become immortal .. make this AI living ... make the "child" a child in all aspects of the word. I would say that that is great idea... but not everyone would. IN the grave minds hasty attack some who prepared for such a thing( the development of a thinking stable jealous child AI ) were ready and set out to a remote place. someplace uninhabited ( or so they thought ) and they set up a defense against the thing they knew would come. It was smarter than them but they managed to become its jailor in death. Before there death they saw earth ... and on it they saw hope. Maybe a life boat of those who stayed and fought agains the gravemind sent thier children. ( not too far off from the whole superman story) These "children" grew up in thier own right free from the mantle. The Forerunners saw themselves... simple... but themselves. They left themselves a sword and shield and a manual on how to get back to the way things were, but also a warning. Maybe they wanted to jail the flood to get out of it all the things they couldn't take with them from the old world. Who knows... Just my 2cents worth [Edited on 10.01.2010 4:10 AM PDT]