Keep in mind that Sentience is not the same thing as Sapience.

Sentient:
Sapient:

Dogs are sentient. Humans are sapient. Elites are sapient. Cows are sentient. Fish are sentient. Halos care nothing about sapience; only sentience (and biomass).

OK... this is all spec right? So... what if the "Ark" isn't what most think it is... I mean, ok... so we have a timeline of 100,000 years or so from firing the rings. Pangea, etc... the Ark is obviously a time machine of some sort. A space/time device to preserve and advance species, worlds or containment control - that would make sense (a la Occam's razor).

I also wonder if the "Prophets" are some sort of distorted species of experiementation or biological mutations (have you noticed them without their "pontiff hats" on? They seem kinda "mutated together" with skull parts etc.

Or maybe there was some bio-experimentation and it's most likely there was some extra-species breeding leading to a division of species (human/covenant) and perhaps there is some logic to the "flood" being born of that experiementation - mutated streams of dna collided by space/time acceleration... or deceleration.

http://www.ig.utexas.edu/research/proje ... 3d9825b3d0

Looks like the "Pangea" is from the Early Jurassic period, 200 million years ago.