Humans have special powers!

Sometimes a research headline pops up where you think "What a pointless question" only to find out it's answer is potentially quite interesting. This was probably the most involved I got in the discussion of science at work today.

In the case the headline was "Science tests wrinkled fingers" and is summarised quite well in nature. My instant reaction was that it's obviously just due to the flesh in our fingers absorbing some of the water, so I was quite surprised to find out it seems to be an active process involving constriction of blood vessels. A co-worker instantly cried "Bull5H1t!" and then added "If that was true then  a person with severe nerve damage on one hand wouldn't wrinkle as much their good hand".

I showed him the text from Nature "researchers have known since the 1930s that the effect does not occur when there is nerve damage in the fingers"

My coworker still thinks it's "BS" but was at least vindicated that his hypothetical experiment was tested.

So why do we have wrinkly wet fingers (and toes)? One theory is that it helps us to grip wet objects better. This was shown to be the case when they tested people's ability to handle wet objects when wrinkly fingered. This may actually be evidence for the aquatic ape hypothesis which posits the current human form was due to evolutionary adaptations to a watery environment. Then again, these adaptations could be useful for walking on wet surfaces, a bit like tyre-treads.

One of the scientists commented that for the theory to be more robust they need to find evidence of it in other animals that should benefit from such an adaptation. Currently only macaques show a similar wrinkly finger phenomenon. I suspect it's possibly an adaptation that is only relevant in creatures with "hands and feet" as paws and hooves probably have different ways or have enough grip already. Otters maybe? Although we don't want them getting any extra advantages or this may happen.


It leaves me wondering whether people who've lived in Britain for multiple generations are faster at achieving a more wrinkly finger as it would be an advantage. Given the weather in 2012, I'm wondering if my fingers have become wrinkly enough to climb buildings in a Spider-man style.