8 January 2013
Science puts wrinkled fingers to the test
By Jonathan Amos
Science correspondent, BBC News
The wrinkles may act like the tread on tyres
Science may be getting closer to explaining those prune-like fingers and toes we all get when we sit in a hot bath too long.
UK researchers from Newcastle University have confirmed wet objects are easier to handle with wrinkled fingers than with dry, smooth ones.
They suggest our ancestors may have evolved the creases as they moved and foraged for food in wet conditions.
Their experiments are reported in the Royal Society journal Biology Letters.
These involved asking volunteers to pick up marbles immersed in a bucket of water with one hand and then passing them through a small slot to be deposited by the other hand in a second container.
Volunteers with wrinkled fingers routinely completed the task faster than their smooth-skinned counterparts.
The team found there was no advantage from ridged fingers when moving dry objects. This suggests that the wrinkles serve the specific function of improving our grip on objects under water or when dealing with wet surfaces in general.
For a long time, it was assumed that the wrinkles were simply the result of the skin swelling in water, but recent investigations have actually shown the furrows to be caused by the blood vessels constricting in reaction to the water, which in turn is a response controlled by the body's sympathetic nervous system. (...)
Read more: http://www.bbc.co.uk/news/science-environment-20951232