This site is not maintained. Click here for the new website of Richard Dawkins.

← Brainwashed by a parasite

Brainwashed by a parasite - Comments

mordacious1's Avatar Comment 1 by mordacious1

I remember this from, was it two years ago? Of course, still an interesting article.

Tue, 05 Aug 2008 15:19:00 UTC | #213120

Lisa Bauer's Avatar Comment 2 by Lisa Bauer

Is it just me, or did anybody else notice the obvious parallels between this and religious "memes"?

Tue, 05 Aug 2008 16:12:00 UTC | #213148

mandydax's Avatar Comment 3 by mandydax

A similar thing happens with Toxoplasma gondii. The parasite can only carry out its reproductive stage in the guts of felines, and it's been found that rats and mice infected with T. gondii are less afraid of cats and in some cases seek them out, increasing the chances that they will be eaten and thus transmit the parasite to a cat. Extended phenotypes are simply fascinating. I haven't read Richard's book by that title, but he makes reference to it in The Blind Watchmaker:

Replicators that happen to have what it takes to get replicated would come to predominate in the world, no matter how long and indirect the chain of causal links by which they influence their probability of being replicated.

Tue, 05 Aug 2008 16:29:00 UTC | #213159

PristinePanda's Avatar Comment 4 by PristinePanda



The parallels are indeed obvious. Dan Dennett routinely utilizes this particular ant in lectures as an example of malevolent memes. Pretty cool, eh? Reminds me of those perfidious god memes that infect the brains of some of us.

Tue, 05 Aug 2008 16:48:00 UTC | #213163

Mike O'Risal's Avatar Comment 5 by Mike O'Risal

The cordycepioid fungi are among the most interesting organisms on the planet in several ways, IMO. The genus has undergone a lot of revision lately (it turned out to be several genera, some of which have been grouped systematically into entire new families!), but I believe the one mentioned in this article is still among the "true" Cordyceps, which would place it phylogenetically not too far from the genus Claviceps. The best known member of that genus, C. purpurea, is the source of LSD... which may explain a bit about how the Cordyceps sp. alters the behavior of its host.

Another clade that used to be in the genus has been split out into the genus Elaphocordyceps and they offer some intriguing evidence of relatively recent evolution (see Nikoh, N and T Fukatsu. 2000. Interkingdom Host Jumping Underground: Phylogenetic Analysis of Entomoparasitic Fungi of the Genus Cordyceps. Molecular Biology and Evolution. 17:629-638). In brief, at some point in the not-too-distant evolutionary past, several of these fungi were parasites of cicada nymphs, but their descendants made the leap to a sort of truffle that has a similar lifestyle to the insects. Interkingdom host switching is pretty rare, but molecular investigation has backed up Nikoh and Fukatsu's findings.

Lots more on these fascinating critters can be found at mycologist Joey Spatafora's excellent site, An Electronic Monograph of Cordyceps and Related Fungi.

Tue, 05 Aug 2008 17:43:00 UTC | #213171

J Mac's Avatar Comment 6 by J Mac

So the entire clade evolved just to mess with other organisms heads?

And I thought the comparisons between shrinks and fungus were only metaphorical.

Tue, 05 Aug 2008 17:48:00 UTC | #213173

Ascaphus's Avatar Comment 7 by Ascaphus

When it came out in '82 I thought The Extended Phenotype was the best book I'd ever read.

I still do. I usually end up reading that and Toward a New Philosophy of Biology once a year - it just puts all the other reports and papers in perspective.

I never get tired of thinking about things like the ant and the fungus. How much better is that than the fable about the ant and the grasshopper in describing the world through allegory.

Matt

Tue, 05 Aug 2008 21:46:00 UTC | #213181

Vanitas's Avatar Comment 8 by Vanitas

I love fungi. Mindless, yet so cunningly evil.

Wed, 06 Aug 2008 00:59:00 UTC | #213233

neander's Avatar Comment 9 by neander

Yes, Vanitas. Cunningly evil yet lovable. Unlike those damn religious memes which are just cunningly evil.

Wed, 06 Aug 2008 02:04:00 UTC | #213247

J Mac's Avatar Comment 10 by J Mac

Fungus puts mushrooms on our pizza and alcohol in our beer.

All the religious memes got us were some thin tasteless jesus crackers.

Wed, 06 Aug 2008 03:01:00 UTC | #213278

bluebird's Avatar Comment 11 by bluebird

A fungus among us...

Totally fascinating, and what photos!!
Today I'll gaze at the myriad of tiny critter life in our yard, and wonder if any of them will succumb to this scenario.

The hairworm sounds equally fascinating, too.

Wed, 06 Aug 2008 05:46:00 UTC | #213349

Chris Davis's Avatar Comment 12 by Chris Davis

Power to mandydax @3 - but there may be more to the story of Toxoplasmosis.

A massive percentage of humans carry the infection, and although it's generally considered asymptomatic and harmless in people, there were reports some time ago that infected humans are more likely to take risks. I think the data came from the unusually high number of toxo carriers winding up in hospital with trauma from car crashes etc.

Don't know if the supporting data has gone further, but it sounds plausible to me: our neurophysiology can't be all that different from cats' (despite what cats might think), and if the proteins can get through the b/b/ barrier it sounds reasonable that they could affect us, too.

CD

Edit: OK, just LOOK at this stuff. And shit yourself:

http://www.natur.cuni.cz/~flegr/publpar.php

Wed, 06 Aug 2008 05:49:00 UTC | #213352

Shaden's Avatar Comment 13 by Shaden

Very interesting. I'd love to hear how the "theory" of Intelligent Design would explain this.

I think if anyone that takes a good look at nature and then tries to extrapolate a designer from it, they would come to realize that the designer would an insidious character with a penchant for death.

Wed, 06 Aug 2008 05:50:00 UTC | #213354

fizhburn's Avatar Comment 14 by fizhburn

Chris Davis,

Apparently toxoplasmosis does have effects on our behavior, although the exact mechanism and behavior patterns are not yet established, per Jaroslav Flegr (2007) [.pdf].

Wed, 06 Aug 2008 07:34:00 UTC | #213397

Vanitas's Avatar Comment 15 by Vanitas

neander and J Mac: I couldn't agree more.

I apologise if this has already been posted, but I found it fascinating.

http://www.youtube.com/watch?v=XI5frPV58tY

Wed, 06 Aug 2008 08:55:00 UTC | #213446

prettygoodformonkeys's Avatar Comment 16 by prettygoodformonkeys

Isn't Jesus amazing?

He obviously engineered this, since he (as God) is personally responsible for the fate of every single little sparrow.

And ant. And fungus. And Ebola mutation.

In his personal laboratory (earth).

Wed, 06 Aug 2008 09:51:00 UTC | #213503

prettygoodformonkeys's Avatar Comment 17 by prettygoodformonkeys

I read of a similar parasite (Dicrocoelium dendriticum) that lives in the bovine GI system, and when its eggs exit they are picked up by snails, who protect their own GI system by coating the eggs (lancet flukes) with mucus. When they exit the snail, the mucus makes them (little pearls) irresistible to ants, who ingest them. The following day they all head off to work, but in the evening when it gets cooler the infected members don't go back to the colony, but wander off and climb as high as they can get on a blade of grass, and then clamp their mandibles permanently to the top of the grass. They have lost their 'minds' by now and will end their lives in this position.

There they are certain to be eaten by a bovine, and the magic circle of life continues........

Wed, 06 Aug 2008 10:11:00 UTC | #213524

J Mac's Avatar Comment 18 by J Mac

Wait .... Jesus crackers are unleavened bread. That means no yeast...

Does god hate fungi?

Are fungi the antichrist?

Wed, 06 Aug 2008 10:17:00 UTC | #213531

Eshto's Avatar Comment 19 by Eshto

Sweet!

Anybody ever play Resident Evil 4? Anybody?

It's fuckin' awesome. I recommend the Wii version, it's the definitive version.

...

So anyway it's based on this. Except instead of driving an ant up a blade of grass, the "Las Plagas" parasites control humans (known as "Los Ganados" or "cattle") and their goal is world domination.

Oh you guys would love it, Los Ganados takes the form of a religious cult.

...

Yes I'm nearly thirty years old and I still play video games. And proud of it.

Wed, 06 Aug 2008 10:27:00 UTC | #213539

Dr. Strangegod's Avatar Comment 20 by Dr. Strangegod

Eshto - Haven't played it, but I'd like to. Funny you said what you did, because as I was reading the article I had this sudden vision of using parasites to kill mosquitos in Africa to stop malaria, only to then have them infect all the people and turn them into brainless zombies. So, yeah.

And let none of us forget the historical role of fungi in the promotion of religious visions, from ancient Greece to today. That's what I love 'em for.

Wed, 06 Aug 2008 13:55:00 UTC | #213700

Richard Feldmann's Avatar Comment 21 by Richard Feldmann

Yes I'm nearly thirty years old and I still play video games. And proud of it.


There ain't a damn thing wrong with that. :) I'm a gamer myself and I'm 35. In fact, I need to go back and finish RE4. I enjoy that game, but I really hate when the tentacles pop out of someone's head. Just nasty. The infected wolves really freaked me out the first time I fought them.

On topic: Yuck. Parasites are very fascinating to me, but I just hate reading about them, especially when there are pictures. ;)

I once saw some autopsy photos of an elderly Japanese man who had lived nearly all of his life eating sushi. His body was riddled with parasites, and eventually they reached critical mass in his skull and he apparently killed himself to stop the headaches.

I will never, ever, eat raw fish, even if my life depends on it.

Thu, 07 Aug 2008 13:47:00 UTC | #214225

qomak's Avatar Comment 22 by qomak

Very chilling and at the same time fascinating.

Sat, 04 Oct 2008 11:21:00 UTC | #246555

wombat99's Avatar Comment 23 by wombat99

According to this: http://www.theatlantic.com/magazine/archive/2012/03/how-your-cat-is-making-you-crazy/8873/ Jaroslav Flegr's work on parasites' effects on human behaviour was inspired by something he read by Richard Dawkins. What does Dawkins think of his work?

Sun, 18 Mar 2012 03:14:22 UTC | #928194