Last week I wrote in the New York Times about a fascinating new paper in which scientists described a lamp shell embryo that is, in effect, a swimming eyeball. The paper itself, however, comes in two parts. Along with the part on the swimming eyeball, the scientists also described a later stage of the lamp shell embryo in which it developed simple eyes connected to neurons. It’s primitive version of our own eyes that reveals some interesting things about evolution–particularly about the different photoreceptors that evolved over half a billion years ago for sensing light. At the time, I was struck by the fact that this one paper had two newsworthy insights. So I was glad to see PZ Myer takes up the other half of the story in excellent detail over at Pharyngula. Check it out.