TLDR

Stingers and spikes across nature have the same shape. Here's why.

Not everything in biology evolved for a purpose.

Elise Cutts

Elise Cutts

— 5 min read
Stingers and spikes across nature have the same shape. Here's why.
From elephant tusks to pencil tips, stabby spikes tend towards the same universal curve. It's just what happens to points as they blunt over time. Image: John Sebastian, Technical University of Denmark
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From cacti to bees to narwhals, nature abounds in stabby spikes. Sharp horns and stingers make great weapons, while spines and spikes provide protection. And having spear tips in your mouth comes in pretty handy if you're a meat-eater without hands.

Despite their stunning diversity in purpose, shape, and size, stingers and spikes follow a surprising pattern: across the tree of life, they taper to a blunt tip with the same geometry.[1] It's the universal curve of natural stabbing weapons, as it were.

And in research published last week in the Proceedings of the National Academy of Sciences, researchers used math and a lot of sacrificial pencil nubs to show where that curve comes from.

The researcher named this thing "pencil-gladiators.gif" and I feel I have nothing to add to that. Image: John Sebastian, Technical University of Denmark

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