Answering the big questions: your wet fingers

Photo courtesy Boise Tourism Bureau.
I cannot tell you how many times a day a complete stranger comes up to me on the sidewalk and asks, "How come my fingers get wrinkly when they're wet?"

I usually ask to see a finger, then grab it and bend it back til the person is writhing in pain. Then I explain:
The wrinkles that develop on wet fingers could be an adaptation to give us better grip in