
'Zombie ant' brains left intact by fungal parasite - dnetesn
https://phys.org/news/2017-11-zombie-ant-brains-left-intact.html
======
zaarn
>"Normally in animals, behavior is controlled by the brain sending signals to
the muscles, but our results suggest that the parasite is controlling host
behavior peripherally," Hughes said. "Almost like a puppeteer pulls the
strings to make a marionette move, the fungus controls the ant's muscles to
manipulate the host's legs and mandibles."

Probably the most "And I Must Scream" moment in mother nature. Imagine a human
gets infected by a parasite that controls their body but leaves their brain
intact to observe what their body is doing (and probably drugged to hell as
the article implies).

~~~
TheCoreh
Wouldn't that require the fungus to have a nervous system of its own?

~~~
ajuc
> Although the host brain isn't invaded by fungal cells, previous work has
> shown that the brain may be chemically altered by the parasite, Hughes
> noted.

I think it's much more probably that ants have some high-level chemical
signals that the fungus uses. One to climb, and another to bite maybe?

Ants already use pheromones to communicate.

~~~
arcticfox
That seems more probable and way more intuitive, but I don't really understand
how the mechanics of that mesh with what the researchers are saying happens to
the ant muscles.

------
Grangar
Look at this picture of the final stage, after the 'stalk' sprouts from the
ants head. Pretty haunting.

[https://upload.wikimedia.org/wikipedia/commons/8/85/Ophiocor...](https://upload.wikimedia.org/wikipedia/commons/8/85/Ophiocordyceps_unilateralis.png)

~~~
gabaix
There is a 3-minute video from BBC Planet Earth showing an infected ant and
its demise. [https://youtu.be/XuKjBIBBAL8](https://youtu.be/XuKjBIBBAL8)

It is like watching the Alien scene, except this is real.

~~~
warent
It never occurred to me before... from the perspective of an insect (with a
bit of anthropomorphism), fungus is an invisible, undefeatable faceless enemy
that quickly turns the world into a nightmarish hellscape. It's almost like
the borg. I'm fucking scared.

Imagining A Bug's Life or Antz could have been far less family-friendly if a
couple of these spores made an appearance.

------
shepardrtc
Outside of the horror of a fungus controlling the body, what's really cool is
that they used deep learning to differentiate between ant cells and fungus
cells when doing scans of the organisms.

------
ajuc
One thing I wonder about is - why would it evolve to make the ants go away
from the anthill?

Surely it would be best for spreading the fungus to make them go to the
anthill and die there?

It seems more like a quarantine mechanism from ants POV. The fungus would
spread faster if the ant continued as usual till it died, or stayed in the
anthill.

But it also helps the fungus in a way - if the ants died in the anthill the
whole anthill would soon die and the fungus with it.

So - maybe the ant reaction to the infection is actually a coevolved
compromise between the fungus and the anthill, that lets both survive at the
cost of individual ants?

~~~
openasocket
I believe the other ants recognize that the individual is infected and
forcibly dispel her from the colony, which is a defense mechanism the ants
likely evolved. At least that's what's portrayed in the Planet Earth
documentary, which spends a few minutes focusing on this fungus. The fungus
could have evolved to be more sneaky so the ants wouldn't recognize the
infection until it was too late, but I imagine it's easier to just have the
ant go somewhere high up instead.

It certainly can look like a co-evolved compromise, though it formed through
two competing species. I think what you're getting at is the
[https://en.wikipedia.org/wiki/Red_Queen_hypothesis](https://en.wikipedia.org/wiki/Red_Queen_hypothesis)

~~~
ajuc
Interesting. I meant maybe the "code" to go far from anthill is in all ants,
but only activates (by "design") in sick ones.

    
    
        if (sick)
          goAway();
    

Seems like a pretty sensible behavior to evolve in social insect.

And fungus just make them stop by destroying the correct muscles.

EDIT: and there's also another fungus, that makes the parasitic fungus
sterile, so the fungus want to be spread away.

[https://phys.org/news/2012-05-zombie-ant-fungus-
reveals.html...](https://phys.org/news/2012-05-zombie-ant-fungus-
reveals.html#nRlv)

Damn biology is complicated :)

EDIT2: and they've checked and the fungus can't grow in the anthill for some
reason.

~~~
pvg
_Seems like a pretty sensible behavior to evolve in social insect._

The more reliable mechanism is the one that evolved - other insects decide who
gets to stay and who has to be removed.

------
burntrelish1273
More "zombie" (behavior-altering) parasites:

[https://www.damninteresting.com/nugget/mind-controlling-
wasp...](https://www.damninteresting.com/nugget/mind-controlling-wasps-and-
zombie-spiders/)

[https://www.damninteresting.com/nugget/body-snatching-
barnac...](https://www.damninteresting.com/nugget/body-snatching-barnacles-
and-zombie-crabs/)

[https://en.wikipedia.org/wiki/Behavior-
altering_parasite](https://en.wikipedia.org/wiki/Behavior-altering_parasite)

Also rabies and toxoplasmosis.

~~~
tasty_freeze
Parasite that eats the tongue of a fish than takes up residence in its place:

[http://twistedsifter.com/2009/09/tongue-eating-
parasite/](http://twistedsifter.com/2009/09/tongue-eating-parasite/)

------
ajmarcic
Link to paper:

[http://www.pnas.org/content/early/2017/11/06/1711673114.full](http://www.pnas.org/content/early/2017/11/06/1711673114.full)

------
vwcx
Anand Varma has a really powerful/terrifying photo series on host-parasite
relationships in nature:
[http://ngm.nationalgeographic.com/2014/11/mindsuckers/varma-...](http://ngm.nationalgeographic.com/2014/11/mindsuckers/varma-
photography)

The accompanying article in National Geographic:
[http://ngm.nationalgeographic.com/2014/11/mindsuckers/zimmer...](http://ngm.nationalgeographic.com/2014/11/mindsuckers/zimmer-
text)

~~~
warent
I had no idea so many different wasps were parasitic like this. This made my
eyes water and my stomach churn. Especially the horsehair worm and house
cricket.

------
mlsarecmg
This might sound crazy, i'm already sorry. Though given that the current
theory seems to be that the fungus controls the ant like an exoskeleton
propelling it up a tree without sensory data, maybe not so much, but there's
something you will inevitably encounter when studying the implications of
meditation and the traditions that engaged in it. In that living beings are
supposed to have more than "one brain", in the case of a human being along the
spinal column, several on the sympathetic nervous system and several on the
parasympathetic nervous system.

Headbrain: associates, upper spinal column: movement, coccyx: instinct, solar
plexus/heart: emotion, sexual region: drive. Each is supposed to function
self-sufficiently, contemplates & reacts to the environment, at a certain
velocity. For instance if one accidentally touches a hot-stove, all react
without ones explicit decision or will: instinct -> emotion -> movement ->
thought. The act they once called "mindfulness" or "self-observation" takes
these impulses into account.

------
0xfeba
There are wasps that inject their larvae into caterpillars (and other
animals). The larvae eat the host alive, but are careful to avoid vital
organs. The wasp or larva/pupa inject/secrete something that controls the
caterpillar, and soon the larva burrow out of the host. The caterpillar ends
up spinning silk to nurture the larva after they come out, and defends them
until it starves to death.

[https://www.wired.com/2014/10/absurd-creature-week-
glyptapan...](https://www.wired.com/2014/10/absurd-creature-week-
glyptapanteles-wasp-caterpillar-bodyguard/)

[https://en.wikipedia.org/wiki/Parasitoid_wasp](https://en.wikipedia.org/wiki/Parasitoid_wasp)

[https://www.youtube.com/watch?v=vMG-
LWyNcAs](https://www.youtube.com/watch?v=vMG-LWyNcAs)

------
Sniffnoy
It has to be getting sensory input, though, right? So it must be reading that
out of the brain somehow even if it's not controlling the brain, right? Or no?

Wondering now how ants walk and climb and such -- it would seem easier to go
for the brain if you need to effect complex behaviors like that. But I recall
that with insects' wings, at least, the brain only needs to send one signal
and they'll beat for a long time. So maybe such behaviors are stored down by
the legs or whatever, and that's why it doesn't need to go for the brain?

------
jaequery
How do we 'really' know it was the fungus that controlled the ants? And not
some sort of ants' self-defense mechanism?

------
rossdavidh
Sometimes, when you think something is really creepy, some new knowledge comes
along that makes you think, "ok I thought it ws creepy before, but that was
actually nothing compared to this." I think if I were a researcher in this
topic I would have nightmares.

------
reallymental
Almost like the concept in 'Animorphs'. Even as a child I found that creepy.
This just amplifies that feeling.

[0]
[https://en.wikipedia.org/wiki/Animorphs](https://en.wikipedia.org/wiki/Animorphs)

------
eighthnate
If anyone is interested in "zombies" in nature or parasitism, david
attenborough did a documentary on wasps and their parasitism. There is also
something called hyperparasitism which are parasites that prey on other
parasites.

------
gaius
The excellent novel _The Girl With All The Gifts_ explores this theme

------
antiviral
So what happens if this fungus infects the queen ant?

Does the fungus compel the queen to spread it to the entire hive?

Or does the hive choose to banish the queen, and thereby lose its ability to
reproduce?

------
throwawaycom12
Could further exploration here potentially provide applications for neural
lace technology?

------
nolroz
The flood

~~~
jakebasile
Similar, but the most on the nose example in gaming is The Last Of Us, wherein
this type of fungus leapt from insects to humans.

------
atriches
Man... imagine a human weponize version of that!!!?

~~~
tetraca
Essentially, it would be this:
[https://www.youtube.com/watch?v=xavcTEwk3VQ](https://www.youtube.com/watch?v=xavcTEwk3VQ)

~~~
justrobert
As a fan of stop motion, thank you for this.

I'm glad to see he got funding for ep3 of the series.

