The Eye
In the Victorian era, the complexity of the eye was often cited as proof of “intelligent design”, that God had created the world (and living things). Bill Bryson, in his romp through the human body, aptly titled The Body: A Guide for Occupants , points out that: “It was an odd choice because the eye is really rather the reverse.” First, it is “built back to front”: “The rods and cones that detect light are at the rear, but the blood vessels that keep it oxygenated are in front of them.” Even worse: “There are vessels and nerve fibres and other incidental detritus all over, and your eye has to see through all this.” And: “All the nerve fibres leave the eye via a single channel at the back, resulting in a blind spot… in our field of vision.” If you’re wondering why we don’t see a “gap” in our field of view (corresponding to the blind spot), it’s because “your brain continually fills the void for you”. And since the blind spot is not exactly tiny, it leads...