A gull's butt. Photo by Eliya.Perhaps the grass is always greener on the other side of the evolutionary tree. How often do we wish we could fly, or breathe underwater, or run faster, or change our skin colour to match the décor? We seem to spend comparatively less time recognising the joys of opposable thumbs, self-awareness and bipedalism. Well if that’s the way it is, so be it. Here’s another impressive feature – in this case an organ – shared by many vertebrates, but not us. I give you the cloaca.

Actually I think the phrase “I give you the cloaca” has great potential, either as a compliment (keep reading) or an insult (keep reading). More . . .