Thumbs Are Fingers Too !
Somewhen early in the tetrapods,
The limbs all ended in fives.
They weren’t placed there by any gods,
But by whatever survives.
And even then, the fifth was smaller,
With one joint fewer to flex –
So even when we stood-up taller,
The same stubby thumb projects.
Somewhen early in the primate time,
We took to trees when stressed,
And found our thumbs could help us climb
If they opposed the rest.
And so they carried, worked, and threw,
With a thumbs-up and okay,
When the runt of the fin with knuckles-two
Hitched a ride on its DNA.
Somewhen, late in far far future,
We may make do with fewer –
Our pinkie, perhaps, a vestigial moocher,
No longer much of a doer.
Just ask the horses, running on one finger,
The others written-out of their glands –
Best to keep using ’em, that the way they’ll linger,
For genes have little use for idle hands.
Rhyming Couplets 