Why Do We Have Fingerprints? (broadcast Friday, June 12th, 2009)

NIST image.

Why have people evolved fingerprints? The standard answer is that fingerprints increase friction, improving the grip of the fingertips. New research, however, says that may not be the case. In a study published this week in the Journal of Experimental Biology, two researchers in the UK say that fingertip friction is due mainly to the surface area of skin in contact with a surface -- and so the presence of fingerprints will actually reduce fingertip friction in many circumstances. We'll talk with one of the authors about the work, and what alternate reasons there might be for having evolved fingerprints.