"[On the controversy between and .] [T]he classic case of convergence would be the eye and the human eye, or ian eyes. ...The common ancestor they had had a light sensitive spot, they did have some regulatory genes in common... for example, but that had to effectively independently recruit all the rest of the genes required to make a camera type eye, and that direction of evolutionary travel was in parallel. It was convergent. We even see in some s... a camera-type eye in single-celled critters where there's a retina made from s. There's a made from mitochondria. There's a there. They don't have a brain. I don't know how they use this thing but... plainly it's a camera-type eye. ...It's a of some sort. ...I would see that as a completely independent origin of a camera-type eye, albeit without a brain. I would see the octopus' and mammalian eye as being convergence in the Simon Conway Morris sense... There are certain ways that you can make an eye, that work, and all the steps along the way have to be favored, and... perhaps there are seven or eight... fundamentally different types of eye that we see on earth, and most of them have arisen more than once, always from a common ancestor, generally, that had as a light sensitive pigment. So you're then into an interesting terrain or... How common are the right types of light sensitive pigment? They're chemically not so straight forward."