The Evolution of Eyesight: New Discoveries.
New research suggests that some components of vertebrate vision, such as the protein interphotoreceptor retinoid-binding protein (IRBP), may have been "stolen" from bacteria through horizontal gene transfer, rather than evolving incrementally through family lines. The appearance of IRBP in vertebrate-like eyes over 500 million years ago coincided with the appearance of vertebrate-like eyes. This discovery presents new possibilities for explaining complex biological processes and punctuating eukaryotic evolution by providing immediate functional novelty.