Fingerprints

We often say “fingerprints” not just to speak
Of impressions our fingertips make
But also in ref’rence to ridges on those,
Which my lexicons deem a mistake.

The ridges emerge in prenatal month 7.
One’s DNA, fetal location,
Umbilical cord length, and other such factors
Affect every pattern formation.

These patterns are set in the basal cell layer,
So surface skin damage won’t change
Which shape will appear, be it arch, loop, or whorl.
It’s something we can’t rearrange.

A few rare genetic conditions keep fingertips
Smooth so they never leave prints.
Such people have often been sought out by crooks,
As they’d offer detectives few hints.

We doubt that our ridges exist just to help
Tell identical siblings apart,
So why do we have ‘em? The friction to aid
In our grasp was assumed at the start.

More recent experiments showed that the ridges
Ironically hinder our grip.
However, they might work on rough or wet surfaces
After a rain or a dip.

A type of mechanoreceptor, Pacinian
Corpuscles, magnifies touch,
Espec’ly with ridges. It seems hypersensitive
Fingers would help very much.

The one other theory I know of: The ridges
Protect us from damage like blisters.
They might reinforce skin in certain directions
To make them effective resisters.