User blog comment:Arbington/The Next Cycle/@comment-2250460-20120802012255/@comment-899316-20120802015155

Actually, given the evolution of the rachni, who were in the exact same situation in their cycle as the varren are in ours, we can easily determine that the varren will evolve. As for the Thresher Maws, I'm going to need some convincing. If they have shown signs of early-stage sentience already, or if there is historic precedent, than I'll consider adding them.