Question: If the rings were supposedly activated 100,000 years ago, how did humanity survive?
Support for the Question
The recently released comic shows a human watching Forerunners building. Humans (however primitive) must therefore have been around at the same time as the Forerunners.
The Halo rings were activated approximately 100,000 years ago.<<needs ref>>
Support for the Theory
People are alive today.
Ties to Reality
The story of Noah's Ark seems fitting. Noah was ordered by God to build an ark to save humanity from the "flood." The flood was a cataclysmic event that destroyed all life on Earth except the few kept safe on the ark. Applying this to Halo, the story seems to match quite well. The Forerunners know they are going to die but they wish to save the people of Earth. The activation of the halos relates to when Noah is kept safe in his "ark" from the ravages of the flood. The forerunners have already been considered gods by humans and the Covenant, so the leap is not hard to believe.
Note the terms "Flood" and Ark repeatedly used in both mythologies.