Asked by: Anonymous
An obvious answer would be that rough hands grip better than smooth ones, but in fact this is wrong. The ‘dermal ridges’ reduce friction between the skin and other surfaces because they reduce the area of skin in contact. This might be why we get very few blisters on the soles of our feet or the tips of our fingers.
Another reason is that ridges make skin more sensitive. In experiments using rubber-like sensors on artificial fingertips, researchers found grooves produced distinct vibrations when moved across a surface and these vibrations help with sensing.
Why are fingerprints all different? They are probably like cat fur or shell patterns. Given different genes and environments they turn out a little bit different in each person.