Scanning electron micrograph images of the nut (A,B) and screw (C, D) in the leg joint of a Papuan weevil
What's the News: Biologists spend lots of time poring over nature's nuts and bolts. Now, for the first time, they've found a biological screw and nut---previously thought to be an exclusively human invention. The legs of beetles called Papuan weevils, researchers report
today in Science, have a joint that screws together much like something you'd find in the hardware store. How the Heck:
The researchers took x-ray microtomography scans of museum specimens of the beetle.
One part of the joint (called the coxa) resembled a nut, with a thread along its inner surface covering 345°. The other part (the trocanter) resembled a screw, with an external thread spiraling around it for 410°---more than a full turn.
The beetles' muscles pull on the leg to turn the screw. The beetles don't ...
