HOW EVOLUTION INVENTED SIGHT—AND PERFECTED IT

“In reality, no one actually knows the ancestor of all creatures with eyes,” says developmental biologist Walter Gehring of the University of Basel in Switzerland. “But we suspect that it lived about a billion years ago in the sea and had a skin that reacted sensitively to light.” Some starfish, jellyfish, and earthworms still possess an epidermis with light-sensitive cells, presumably comparable to those of our ocular ancestor. Via evolution, nature has adapted the eyes of various animals to their environment—and has equipped them with fascinating features. These are often superior to even the high-tech cameras that have been developed thus far by humans— no wonder, given their developmental period of 1 billion years.