I just finished re-listening to the whole story again. Its amazing the little bits of info you miss the first time through. So my theory about the virus flipping switches in DNA/RNA still stands but I picked up on something I completely missed the first time around regarding the little ones. The scary dude from the Arena tattooed them (the one that got his arm ripped off had a #5 tattooed on it) and trimmed there finger nails into sharp points. We know this cause when they where looking at the arm that got ripped off they talked about its finger nails being filed to sharp points. And in the Hospital we find tattoo equipment and finger nails on the floor and nail files and nail clippers. There are some theories that the "colored one" made these and all the new zombies. I don't think so, I think he is just favoring these new beasts like a new child. For what ever reason he is compelled to care for them, make them special. Maybe they are the whole reason for the virus, to make these little ones and the other special zombies?
You also have to remember that the "colored one" is not the starter of all this. It is happening all over the world and it seemed to happen at the same time. So it is either a crazy accident that this dude got the right dose of virus to became what he is or it was in the design of the virus for certain variations to emerge. These smart/crazy/leader ones being one variant maybe a care giver of sorts, a mother beast? You would have to assume that every epicenter around the world would then have the same kind of set of events. Makes me come back to this being some sort of alien attack to first create as many of us into them and then to start transforming into them, through accelerated mutations, with lots and lots of food for them to eat along the way.
What do you think?