How fleas jump (not an Onion story)

February 10, 2011 by Amara D. Angelica

Klingon warrior? No, the anatomy of a flea. (Image: Gregory Sutton)

Well, the 44-year mystery has finally been solved, The Company of Biologists just announced. Biologists have settled the argument and resolved how fleas jump: with their toes, not their knees. (Ah, I could have told them that — ever try jumping with your knees, unless you’re a TM practitioner, that is?)

In 1967, Henry Bennet-Clark discovered that fleas store the energy needed to catapult themselves into the air in an elastic pad made of resilin. But how? To resolve it once and for all, University of Cambridge biologists shot movies with a high-speed camera.

They found that fleas transmit the force from the spring in the thorax through leg segments acting as levers to push down on the taursus (toe), which has gripping claws, and launch themselves at speeds as high as 1.9m/s at up to an amazing acceleration of 150g.

Stapp: Impressive, but no flea.

So how many g’s can humans stand? I looked it up (slow news night): 46.2, in a rocket sled test with Col. John Stapp, the “fastest man on earth.”

What can we learn from fleas? For starters, what about resilin? I looked it up. Turns out it’s the most efficient elastic protein known, and its elasticity can propel a flea up to 150 times their length, which would be a whopping 855 feet for an average-size human male. I also found that scientists at CSIRO in Australia have extracted the resilin gene from fruit flies and cultured it in large quantities in E.coli bacteria, and that they say it could replace similar elastic material in the walls of damaged arteries.

Hmm, what about using it in helmets for soldiers and football players to reduce acceleration trauma? Or maybe a super-athlete could use it (in a new shoe design) to set a new long jump world record? Nike, you listening?

What ideas do this suggest to you?