| Comments |
P.1917 left column 2nd paragraph: "Historical views on eye evolution have flip-flopped, alternately favoring one or many origins. Because members of the opsin gene family are needed for phototransduction in all animal eyes, a single origin was first proposed. But subsequent morphological comparisons suggested that eyes evolved 40 or more times independently (primary source): this finding is based on, among other things, the distinct ontogenetic origins of eyes in different species (ref 33)." |