Natures wonders: how the stinger is fired (Introduction)

by David Turell , Thursday, September 15, 2022, 21:58 (590 days ago) @ David Turell

Jelly fish yield the secret:

https://www.scientificamerican.com/article/how-sea-creatures-pack-a-tiny-propulsive-sting/

"Jellyfish, sea anemones and corals, a group called cnidarians, sting with tiny, pressurized capsules that fire poisonous darts at explosive speeds. Researchers have been unsure of the exact mechanics of this blisteringly fast process, which occurs using special cell organelles called nematocysts. Now a team led by Matt Gibson and Ahmet Karabulut of the Stowers Institute for Medical Research in Kansas City, Mo., has used cutting-edge imaging technology to study nematocyst firing in very fine detail.

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"Using super-resolution fluorescence and electron microscopes, the researchers observed a detailed sequence of events involving a stiff shaft and a flexible, whiplike filament that starts out coiled around it within the nematocyst.

"Cells don't have space to operate a slingshot-type mechanism to propel a stinger, “so they evolved another way,” Karabulut says. Both the shaft and the filament are inside out and neatly folded into the tiny organelle. When the nematocyst fires, the shaft is ejected first and turns right-side out. Then the filament unwinds and moves through the shaft, flipping right-side out as well. This flip turns the tiny, inward-facing barbs on the filament's surface outward to release toxins into unlucky prey.

"Seeing this two-phase discharge process is “such a huge contribution to understanding the mechanics of turning this organelle inside out,” says Cornell University evolutionary biologist Leslie Babonis, who was not involved in the study."

Comment: more irreducible complexity. There is no way this could be built stepwise. It must be built all at once. Only design fits.