The ‘zombie’ fungus infects and germinates inside the host’s body, then hijacks that species’ perception – Photo: STEEMIT
What is a “zombie” mushroom?
That’s the way to call the fungus of the genus CordCordy. There are hundreds of species of fungi in the genus Cordyceps, each infecting a different species of insect, including larvae, butterflies, ants, dragonflies, cockroaches, aphids, bees or beetles.
“Zombie” fungal spores infect and germinate inside the body and hijack the host’s cognition. When the host can no longer control their body, they crawl out of the nest, hang dangerously on the leaf, and wait to die. The mycelium then pierces the host’s body and releases fungal spores into the air.
Of the 600 species of “zombie” fungi in the genus CordCordy, only about 35 are able to control the host’s brain. For example, mushrooms Ophiocordyceps mononisinfecting ants.
The first sign of this fungal infection is that the host will behave erratically and abnormally. Scientists think the parasite gains physical control over its host by growing fungal cells around the brain, hijacking the insect’s nervous system to control its muscles .
Geneticist Ivan Will, a fungal expert at the University of Central Florida (USA), said the ‘zombie’ fungus released a chemical to change the host’s DNA, but it does exactly this. How, in fact, science does not have a clear answer.
But it is a long process. It is clear that this fungus has been parasitic in its host and evolved over time for a very long time, at least 45 million years ago.
Are humans at risk of ‘zombie’ fungal infections?
The answer is “not clear”. Explaining this, João Araújo, an expert on parasitic fungi at the New York Botanical Garden, said: “For this fungus to migrate into any warm-blooded animal would require an evolutionary process. If the fungus really wants to infect mammals, it will need millions of years of genetic modification.”
Each species of ‘zombie’ fungus has evolved to suit a specific insect species, so unique species of fungi will also have little effect on the non-species they evolved to infect. For example, a ‘zombie’ fungus that evolved to infect one species of ant in Thailand cannot infect another species of ant in the US.
If jumping from one species of ant to another is already difficult, jumping from animal to human is even more difficult.
However, according to the scientists, “difficulty does not mean no risk”. Every living thing in this world is evolving every day, and they can also jump species, changing in “quality” when reaching a certain “amount”.
Even without the threat of parasitic ‘zombie’ fungi, there are many other fungi that are more terrifying to humans.
Temperature may be a determining factor in this transmission.
An estimated millions of species of fungi exist in the world, and several hundred are known to be dangerous to humans. One thing that has protected us from serious fungal infections is our own warm bodies. At a temperature of about 37 degrees Celsius, the human body is too hot for most fungi to spread infections.
But one of the reasons we get ringworm is that they can get between the folds of the skin. These are damp, dark places that are cooler than the general body temperature, where fungi can thrive.
As the Earth warms, the change between ambient temperature and body temperature will no longer be so great. That would make it possible for fungi that have evolved to easily tolerate hotter outdoor temperatures that can also survive inside the human body.
There is a fungus capable of infecting humans that scientists think may be caused by warming temperatures, called White ears. This fungus wasn’t even known to science until 2007. But in 2011 and 2012, it was unexpectedly found on three different continents and quickly became of great interest.
When entering the bloodstream, the fungus White ears will exhibit symptoms similar to a bacterial infection. For people with a weak immune system, a series of serious health problems, even death.