The Origins of Multicellularity Part IV At long last, we return to the exploration of multicellularity that was started a few weeks ago. In Part I, I discussed the fact that multicellularity, the ability of many cells to act as one, is something that can evolve when a single-celled organism experiences selective pressure, like predation. Part II was an exploration of multicellular behaviors, and how organisms that have been traditionally considered unicellular - bacteria and slime molds in...