David Chen
10 March 2014
Penn State
Published: 13 September 2013
Summary:
Today, many people write fiction about zombies. They have fictitious movies and TV shows. Emphasis on the word "fiction". But zombies are real, and they have existed for at least 50 million years. Ophiocordyceps unilateralis is a species of fungus that spends it's life cycle infecting a single species of ants. David Hughes, a behavioral ecologist at Penn State, describes it like this: "Once a disciplined member of a rigidly structured society, the affected ant stumbles out of its colony like the town drunkard, guided by a pathogen that has pickled its brain with a cocktail of chemicals." As the fungus infects the ant, it releases chemicals into the ant's brain, giving the fungus control over the ant's body. Then, the ant heads to a precise place in the forest. Once it dies, jaws clenched onto a leaf, a huge fruiting stalk erupts from its head to rain spores onto the rest of the ants below. But being around for 50 million years, the ants and fungus have co-evolved in a way, a host-parasite evolution. The ants can detect when a member has been infected, and responds by carrying it far away from the colony. However, an even stranger occurrence in this million year co-evolution is the appearance of hyper-parasites. This fungus invades the already infected ant and covers the fruiting stalk, making it so the spores cannot be released. This fungus is also dependent on one species of the other fungus.
Connection:
This article connects with the Fungus unit that we learned. This shows how fungi are not only decomposers, but can also be active members in parasitic relationships. Also, it shows the reproduction process of fungi, with the fruiting body of the fungi erupting through the head of the ant and showering spores. This article also connects with a past unit on evolution. The fungi and the counter-fungi fungi are so specific to each other through years of evolution that it can count as a type of co-evolution. Most co-evolution we have learned has been mutualist based, however, this case shows how host-parasite relationships can produce co-evolution.
Are parasitic co-evolution common in an environment? If so, could you list other possible relationships?
ReplyDeleteDoes this fungus infect other insect species?
ReplyDeleteIt depends on what you are asking. The specific species of fungus here infects only one species of ant. However, may different ant species have their own species of fungi to infect them. I cannot pull any information about insects other than ants, which may have to do with the fact that the fungi is designed for attacking large amount of victims, and the ants are very social and live in large colonies.
DeleteIf this type of fungus were to be able to infect humans, what do you think will happen to society?
ReplyDeleteI think somewhat of a zombie scenario would happen. In fact, "The Last of Us" is based on a fungus that attacks humans. However, this fungus spreads its spores by mass-releasing them into the air. This would mean traditional methods with dealing with zombies would not work, and instead widespread treatment would be needed. However, if we could introduce a counter-fungus-fungus.....
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