Dr. Pierre Mariotte
|Posted on March 30, 2015 at 7:25 PM|
(Presented by Cat Adams / BBC Campus)
While some fungi produce their own wind, other fungi produce the stuff of nightmares.
In tropical forests around the world, species of the fungal genus Ophiocordyceps infect carpenter ants, landing on the ant and then burrowing into its brain.
But this is no simple brain-siege. In Thailand, for example, Ophiocordyceps unilateralis first causes the ant to walk erratically, eventually plummeting from its normal home in the canopy to the forest floor below. The fungus then directs the ant to traverse up trees a precise number of centimetres, just less than a metre above the ground, where the temperature and humidity are ideal for fungi to thrive.
The fungus can control not only the height the ant travels to, but also the direction the ant faces, which is usually north-northwest. An uninfected ant would normally not bite a leaf, but infected ants do, clamping down on the underside of a leaf, almost always in the very middle of the leaf, where it is strongest. Like something from an science fiction story, the zombie ant bites down at precisely solar noon.
The ant then dies in this unusual position, stiff with postmortem lockjaw due to muscle atrophy from the fungi rapidly growing in its head. For up to two weeks, the ant corpse remains locked to the leaf while the fungus reproduces, eventually raining spores on unsuspecting healthy ants walking below, carrying food to their nests in the canopy.
And the zombification cycle repeats.
The zombie ant fungus Ophiocordyceps has perfected zombification to a science that has inspired both movies and video games, and was recently the topic of a science crowdfunding campaign to determine which genes are important for the fungus to control its host.
Everybody loves a good zombie story, perhaps the zombie-makers most of all.
Categories: Incredible Nature