[pittsburgh]

There's probably a cost to having wrinkly fingers which is why they don't wrinkle immediately.

But if enough of our ancient ancestors fell into bodies of water surrounded by steep, slippery rocks, then the 15-minute delay for gecko fingers to set in would be worth the wait. As long as they could tread water or hold their heads above it long enough, the grippy fingers might have really helped.

Edit: I like katovatzschyn's reasoning even better: http://news.ycombinator.com/item?id=2718662