This "expansion in perspective" leads me to an intersting speculation: If we could quantify the relative complexity of living organisms, we might find that the

This "expansion in perspective" leads me to an intersting speculation: If we could quantify the relative complexity of living organisms, we might find that the difference in complexity between the simplest ancient proto-bacteria and something modern like the leucocyte in the video, or a modern single-cellular eucaryote, is greater than the difference in complexity between the simplest animals with a nervous system and us. On the face of it this might seem absurd (although watching a video like "Inner life of a cell" gives us a hint at how that might be true), but after all evolution has worked on cells for billions of years, and whereas the evolution of multicellular organisms with nervous systems has only been going on for about 600 million years! Just some food for thought...