Freshly Baked Science
Anticipating a Zombie Apocalypse
21st May 2019
The idea of ‘zombies’ has always fuelled horror stories whether they’ve been brought to life through film and television, through books, or simply through a fun costume one cold Halloween night. The idea provides a source of entertainment and is nothing more than a myth; a bunch of made-up stories used to scare children and backed up by no real science. Though scientific advances almost make the accidental release of a zombie virus believable, I don’t think we’re quite there yet.
However, nature has evolved to grow something that is about as close to a zombie virus as you can get! Truthfully, it’s not a virus – it’s a fungus! Ophiocordyceps uniateralis, also known as the zombie ant fungus, infects ants in tropical forests. Specifically, it infects Campontonus, more commonly known as carpenter ants. You know when an ant has been infected because it’s behavioural patterns change and it usually takes 4 – 10 days to die. On average, male carpenter ants only tend to live for a couple of weeks but females can live for up to 7 years! The exception to this is the queen ant, who can live for over 10 years! Male or female, a 4 – 10 day death sentence isn’t great!
To be honest, the fungus doesn’t really act like the zombies in films. Unlike our friends on TV, our infected hosts aren’t dead. Also, the change in the infected ant’s behaviour doesn’t cause it to hunt down and eat other ants! In fact, it does quite the opposite. Usually, ants live as part of a large group called a colony and wander in smaller groups to bring food back to the nest. An infected ant will leave the safety of the group and take to the forest floor where the temperature and humidity is perfect for the fungus to grow! Once on the forest floor, the ant attaches itself to the underside of a leaf using its mandibles (claw-like extensions near the insect’s mouth). It then stays there until the fungus completely takes over and the ant dies. So really, this is the complete opposite of the zombies described in horror stories. If anything, this fungus sounds more like mind-control! Creepy, huh?
However, mind control isn’t actually the cause of the change in the ant’s behaviour either! In fact, the fungus doesn’t even infect the ant’s brain. Instead, it infects the ant’s entire body forming a 3-D network inside the ant and forcing it to move against its will. Can you imagine having no control over the movement of your own limbs? Now that is the stuff of nightmares! And as if that wasn’t bad enough, the final stage of the infection involves the growth of the fungus out of the ant’s head. This growth then releases spores which can then infect other ants! Gross, right?
Luckily for us, there aren’t any fungi that can take over our bodies in this way. So, the zombie apocalypse predicted for the human race is still a long way off! For now, we’ll stick to hiding under blankets and eating popcorn while we watch The Walking Dead.