This hint at such vast diversity and specialization also contains broader implications for assumptions about fungus numbers in general. "We may need to increase fungal diversity estimates by these sorts of factors," Evans notes.
Ancient scourge
The zombifying fungus's vast geographic distribution also hints at the possibility that it has been possessing ants at least since before many of the continents split apart. But these delicate organisms have not been discovered in fossils. Other examples of parasitism have been found preserved in amber dating back 150 million years, and they reveal the parasite and host as a common arrangement—but not any evidence of actual behavior manipulation.
Research published in Biology Letters in 2010 describes a 48-million-year-old fossilized leaf from Germany that bears the distinctive scars of a bite from an ant's mandible on its main vein. The researchers, led by Hughes, describe the find as perhaps "the first example of behavioral manipulation in the fossil record." During that time period the region of Germany would have been similar in climate to the areas of Thailand where contemporary zombie-ant fungus has been documented.
A parasite's parasite
The zombie-ant fungus is not the end of the parasitizing line, however—it meets its own death at the work of yet another parasite.
Andersen and her colleagues have found that a different breed of fungi grow over the ant corpse and the emerging fungus stalk. By covering the original fungus and its stalk, this secondary fungus—or hyperparasite—effectively prevents the zombie-ant fungus from ejecting its spores. "It looks like they completely sterilize it," Andersen says of the second-level parasite.
Even these hyperparasites seem to be specialized for growing on specific parasitizing fungi. "They're not really growing on anything else" in the area, Andersen says. This makes the hyperparasite another obligate parasite, which depends on the zombie-ant fungus, which depends, in turn, on the carpenter ant colony. "Once you're very successful, something else will take advantage of it," she notes. "It's really a little ecosystem in its own [right]."
The zombie-ant fungus's doom, of course, is little consolation for the infected ant. But the castration of the ant-killing fungus means that it will not go on to turn other local ants into zombies. This hobble might, in fact, be one of the reasons the zombie-ant fungus has been so successful over the long term. As a deadly infection, it could severely damage an ant colony. But, if another parasite renders more than half of its mature spores infertile (and more still failing to reproduce due to other interferences), that creates a sort of equilibrium with a colony. According to the research by Andersen and her colleagues (published in May 2012 in PLoS ONE), the actual reproduction rate for each mature zombie-ant fungus organism is a little more than one new mature organism, thus allowing the species and local population to sustain itself as long as there are ants nearby to infect.
In addition to the fungicidal fungi, scientists have also seen small bugs laying their eggs in the infected ant corpse, where their larvae can then eat the growing fungus. These bugs include specialized gall midges (in the Cecidomyiidae family) and a species that appears to be new to science, Hughes says. "It seems their entire nutrition comes from eating the fungus that manipulates ant behavior."
Are such hyper-specialized hyperparasites a freak occurrence? Apparently not: "We have found it all over the world, and most [ant] cadavers have hyperparasites exploiting the zombie-ant fungus at some stage," Hughes notes. And Anderson suspects "the more people study parasites, the more examples we'll find." Even if they are hiding in darker corners.
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19 Comments
Add CommentAnd so it has begun...
Reply | Report Abuse | Link to thisWow. These are some of the coolest parasites in the world. Just...wow.
Reply | Report Abuse | Link to thisRe (p. 2): "The zombie fungus, however, cannot live without the winning ants' continued success. It appears to be an obligate parasite, requiring a specific, local species of ant for it to inhabit, grow and propagate its spores."
Reply | Report Abuse | Link to thisParisitism, especially that which is species specific, is fascinating. What is the evolutionary explanation for how these biological organisms were abel to "team up?"
I wonder if it would be possible for human brains to become infected with any sort of zombie fungus. I know that rabies virus can sort of turns humans into zombies.
Reply | Report Abuse | Link to this"Team up"? No. The fungus had a golden opportunity, took it, and became so reliant upon said opportunity (parasitizing ants) that it lost the ability to survive without it.
Reply | Report Abuse | Link to thisEverything's a continuum in evolutionary biology. There are cases of facultative parasitism and mutualism, parasites that are more specialized than *Ophiocordyceps*, and parasites that are much more generalized. If you continue to advocate creationism on SciAm, I will report you. Furthermore, if you persist, I will start spamming creationist websites and hangouts in the same manner in which you spam SciAm. Just imagine it--me, in that laughable "creation museum", burning bibles and lecturing about how they are literally full of lies and communism. Of course, I probably would wait on a step like that until someone like Toad Akron the Magic Vagina Guy actually got elected, but the image of me doing something so drastic (but protected by the First Amendment) ought to keep you away. Go mess with Richard Dawkins.
Evolution is the successful outcome of random events. The passionate curiosity of our minds can lead us to create answers to alleviate the angst of uncertainty.
Reply | Report Abuse | Link to this"""What is the source of the opportunity?"""
Reply | Report Abuse | Link to thisReally? Are you suffering from mental retardation? Read my comment; I explained it to you.
"""Re: "If you continue to advocate creationism on SciAm, I will report you."
This has really gotten old. You've already reported me by virtue of the fact that the author of this web page has the authority to block my comments as has been done on four other web pages."""
Then why haven't you taken the hint? If you've been banned four times, you're clearly doing something wrong.
"""Re" ...protected by the First Amendment..."
Are you the only citizen of this nation who is protected by the First Amendment?"""
Nope. Anyone in the country has the right to say the stupidest things that he or she can imagine. You seem to exercise this right at every opportunity, BTW.
Technically, you are allowed to be a creationist on SciAm, but that means that I can say that your bible is a pack of lies as often as I like whenever and wherever I like, including on creationist sites. Don't try to use my arguments against me; I am known for my ability to tear apart the arguments of people who do so.
Furthermore, you are allowed to burn any books or flags that you like, as long as said books or flags belong to you. You are not, however, allowed to attempt to pass off your ridiculous views as science. The Supreme Court has made several decisions to that effect.
Bird/tree/dinosaur/etc. geek,
Reply | Report Abuse | Link to thisRe: "Read my comment..."
Better yet, here it is reproduced: "Team up"? No. The fungus had a golden opportunity, took it, and became so reliant upon said opportunity (parasitizing ants) that it lost the ability to survive without it.
That is not an explanation, it's an assertion. An explanation should require evidence.
Re: "...I can say that your bible is a pack of lies..."
At the risk of having you tear me apart:
THE BOOK OF PSALMS
49:1. A psalm for Asaph. The God of gods, the Lord hath
spoken: and he hath called the earth. From the rising of
the sun, to the going down thereof:
[Catholic Bible. (c) 2000. Douay Rheims translation. Murray, KY: A production of Catholic Software]
http://www.youtube.com/watch?v=Cw_JfsU0OWY
http://www.youtube.com/watch?v=8tyNaJxZ76A
First comment: I'm not here to do your homework for you. If you were willing to make the effort to understand evolution, you would.
Reply | Report Abuse | Link to thisSecond: Sorry, but the bible is a pack of lies. Religion is hookum. Your quote is taken from the bible, and therefore is not acceptable evidence.
Has anyone told the Umbrella Corp. about these fungi?
Reply | Report Abuse | Link to this8^)
Bird/tree/dinosaur/etc. geek,
Reply | Report Abuse | Link to thisYou were not asked to do my homework, only your own.
As regards the Bible, your claim will only be credible to the extent that you provide evidence for it.
There is never going to be direct evidence of the first parasitic infection, these things happen far to long ago and to such delicate structures it's not going to have survived. As to how, here's a situation, ant/ant relative bug gets stepped on, fungus spore lands on spilled guts, eats thrives releases spores near ant colony. More ants from colony get stepped on spilling more guts, feeding more fungus, ad infinitum. With each subsequent spore getting every so slightly more dependent on the ant guts.
Reply | Report Abuse | Link to thisZexks,
Reply | Report Abuse | Link to thisRe: "There is never going to be direct evidence..."
The late Prof. Stephen Jay Gould seem to have made a similar admission over 3 decades ago:
"As a paleontologist and evolutionary biologist, my trade is the reconstruction of history....Scientists who study history, particularly an ancient and unobservable history not recorded in human or geological chronicles, must use the inferential rather than experimental methods."
[1978. Senseless Signs of History. NATURAL HISTORY, October, p. 22]
Inference, bereft of evidence, then, would seem to be the stock-in-trade of evolutionists.
Bird/tree/dinosaur/etc. geek,
Reply | Report Abuse | Link to thisRe: "...[G]et off of this thread. We all hate you, so please go away."
Ok.
THE HOLY GOSPEL OF JESUS CHRIST ACCORDING TO SAINT MATTHEW
5:44. But I say to you, Love your enemies: do good to them that hate you: and pray for them that persecute and calumniate you...
[Catholic Bible. (c) 2000. Douay Rheims translation. Murray, KY: A production of Catholic Software]
Now that is a good question. If the parasitic fungi actually represent potentially hundreds of different species respective to their ant hosts' species, then that would seem to indicate a high degree of ability to change. The Walking Dead a little closer to reality.. :-)
Reply | Report Abuse | Link to this[quote]
Reply | Report Abuse | Link to thisThe late Prof. Stephen Jay Gould seem to have made a similar admission over 3 decades ago:
"As a paleontologist and evolutionary biologist, my trade is the reconstruction of history....Scientists who study history, particularly an ancient and unobservable history not recorded in human or geological chronicles, must use the inferential rather than experimental methods."
[1978. Senseless Signs of History. NATURAL HISTORY, October, p. 22]
Inference, bereft of evidence, then, would seem to be the stock-in-trade of evolutionists.
[/quote]
On the chance that this might be a useful discussion to some reders, I'll respond.
Your conclusion is wrong because it make the overt assumption that inferential logic is "bereft of evidence". Inference requires evidence. Consider any detective novel. The difference is how direct is the evidence. If this was a discussion about a murder mystery, it is clear we cannot use experimental methods to recreate the murder (that would involve reversing time or at least resurrecting the victim). We have to use inferential methods in this case (e.g. bloody fingerprints or the weapon or other clues).
Using either method, you have to build a case for the conclusion. I'm a Bible believer, but I do not see it as a science textbook. The case for evolution seems very strong. At leaast a few orders of magnitude stronger than the case for literal interpretation of all of the Bible. Since you quoted the Douay Rheims (Catholic) translation, I'll mention that even the Catholic Church does not take a literal approach and accepts evolution. I actually find it interesting that evolutionary evidence suggests all modern humans decended from a single female (based on mitochondrial DNA). Difference is the literal interpretation puts Eve a few thousand years ago while science puts it back a million or so years ago.
So your quote about inference is right, but your conclusion derived from it is very wrong.
Toxoplasmosis (caused by an accidental protist infection) can alter behavior patterns, so it's not that much of a leap.
Reply | Report Abuse | Link to thisCould this fungus be infecting Democrats?
Reply | Report Abuse | Link to thisHmmm, probably not. In this case, The fungus kills the host. Liberalism, the disease affecting democrats, just leaves them damaged and with a desire to kill the rest of us (economically and sometimes literally). After we die, of course, then there's nothing left to feed on, so then they die. They are more of an excellent example of kleptoparasitism :-)
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