I usually live by the 8-leg rule. If an animal has less than 8 legs, it’s fine – it doesn’t freak me out. Starting with spiders, my fear exponentially increases based on the number of legs. I don’t even want to talk about any sort of creature ending in “pede.”

So, going by my rule, ants are usually okay. That is, until you give them giant freaking heads.

Detailed in a study published Friday in the AAAS’ Science journal, scientists have uncovered an ancient genetic trait in a certain genus of ant. This led to the creation of an absolutely terrifying mutant ant with a gargantuan head and jaws.

With the help of Ed Yong from Discover Magazine, here’s how my biologically-challenged brain understands the issue.

The Pheidole are a large genus of ant with over 1,100 species. Some of them have a certain “caste” with large heads, called a solider caste. A tiny fraction of those species (like eight) have been known to produce a supersoldier ant, the ones with the giant heads that we’re talking about here.

Researchers discovered that the ability for ants to produce these freaky supersoldiers is actually not limited to these few species. The ability, on a genetic level, to make these giant-headed ants runs through the whole Pheidole genus. It’s just buried deep inside them somewhere.

The team hit some normal ants with a particular hormone and was able to induce the development of these supersoldier ants.

So that clarifies one important point: the researchers didn’t just create some mutant ant out of thin air. They simply activated an expression that is very rare – but already exists.

Here’s how the study explains it in Science Mag –

Complex worker caste systems have contributed to the evolutionary success of advanced ant societies; however, little is known about the developmental processes underlying their origin and evolution. We combined hormonal manipulation, gene expression, and phylogenetic analyses with field observations to understand how novel worker subcastes evolve. We uncovered an ancestral developmental potential to produce a “supersoldier” subcaste that has been actualized at least two times independently in the hyperdiverse ant genus Pheidole.

This potential has been retained and can be environmentally induced throughout the genus. Therefore, the retention and induction of this potential have facilitated the parallel evolution of supersoldiers through a process known as genetic accommodation. The recurrent induction of ancestral developmental potential may facilitate the adaptive and parallel evolution of phenotypes.

In the wild, the giant heads are used to guard and protect their ant colony from enemy ants.

But I think the point here is that people who are much smarter than I am are able to produce terrifying super ants. Awesome.

[Images from The Daily Mail]