Monday, 28 August 2017
Fungi Use Water Cannon to Fire Spores
Fungi are assumed to be among the oldest living organisms, at least according to Darwinian thinking.
But they are definitely not stupid.
Recently, the Journal of the Royal Society Interface published a paper on how fungi use cannons to spread their spores. New Scientist discloses the gist of how these tiny creatures make use of the laws of physics:
“Biologists have long known that the mechanism involved two drops of water interacting with the half-egg shape of spores launched in this way: an elongated drop that forms on its flat side, and a small spherical drop called a Buller’s drop that sits near the rounded base of the spore.
When the drops merge, the loss in surface area releases some of the energy that was maintaining surface tension in the original drops. That is converted into the kinetic energy required to launch the spore away from its parent fungus.”
Chuan-Hua Chen at Duke University in North Carolina, who wrote the paper with his colleagues, says the fungi use a cannon-like device to fire a cannonball, but it’s a bit more complicated than that:
“The Buller’s drop is like the ammunition, and the shared flat surface of the other drop and the spore is like the cannon bore that decides which direction it will go,” he says.
New Scientist explains what then happens:
“The merger of the two drops imparts momentum that can have the spore moving at up to 1 metre per second, although air drag quickly slows it down.
Travelling just a centimetre horizontally is enough to allow it to be carried away by the breeze, instead of dropping back down close by.”
This doesn’t sound very Darwinian.
The research also involves a biomimicry dimension:
“Controlling the spore-launching process is also key to applying it in other areas, like self-cleaning surfaces where water droplets latch on to dirt and fling it into the air.”
Many other creatures, such as the bombardier beetle and the spider man snail, also use sophisticated physics.
And that’s not all. Plankton have an in-built device for catching prey. It operates like a Gatling gun that was used in the American Civil War.
Crane, Leah. 2017. Fungi use water droplet cannons to fling spores into the breeze. New Scientist (26 July).