Mystery of the century, you guys. No, the millenium. All times. A new paper in the journal Brain, Behavior and Evolution has a new answer to the eternal question: why do our fingers and toes get all wrinkly after bathtime? The answer: traction.
The old solution is that wrinkling is simply the result of your fingers and toes absorbing water after a long period of being submerged. But there are problems with this! First: why is it only our fingers and toes that get wrinkly? Second: why is this such an unusual trait among mammals (only humans and macaques get wrinkly)? Third: why, if this is a simple tale of osmosis, do our fingers and toes cease to wrinkle when nerves to them are cut?