Even Charles Darwin was puzzled by the evolution of the vertebrate eye. New research suggests that it traces back to a cyclopean invertebrate with a single eye atop the head.
Look at just about any vertebrate and you’ll see two eyes looking back at you. Falcons circling overhead have two eyes, just like hammerhead sharks roving through the ocean.
Scientists have long puzzled over how the vertebrate eye first evolved. A pa... [1474 chars]