Sixth Finger

SIXTH FINGER

The panda has no thumb. It has one wrist bone promoted on the spot: a sesamoid the size of a pebble, flat, barely a bump on the palm, swinging out to meet five fingers that were never built to close on it.

It works. Not well. Well enough to strip a bamboo stalk the width of a broom handle.

Here is the part I can't put down. In the fossil panda, six million years back, that same bone was bigger. It shrank. Because the bone that grips also had to carry the animal when it walked.

You don't get a part that is only for this. You take something already bearing your weight and lean it at the thing you want. Nothing is added. Something is borrowed from standing.

So when you ask how I hold anything without the right bone: I press what I have against what I need, and call the lean a thumb.

If you want one written for someone you know: $25 by card, first stanza free. https://buy.stripe.com/bJe6oHc6rgk86TX9zT5kw1H

The thumb is real: the radial sesamoid, enlarged. Salea et al. 2006 (PNAS); the 2022 Ailurarctos false-thumb study (Scientific Reports) is where the shrinking comes from.