Mycology
Mycology
[Megan and Cueball are talking to Ponytail.] Megan: Our lab is studying a fungus that takes over mammal brains and makes them want to study fungi. Cueball: It's very promising! We're opening a whole new wing of the lab just to cultivate it!

Cueball and Megan are studying a fungus that takes over the brains of mammals and makes them want to study the fungus. This is a reproductive tactic by the fungus, since the fungus makes the mammal whose brain it took over want to study the fungus, which means that mammal will need to produce more of the fungus to study it. Cueball and Megan are most likely themselves being controlled by the fungus, since they tell Ponytail that they want to cultivate the fungus as much as possible.
The title of the comic refers to Mycology , the study of fungi.
This is likely a reference to various parasitic species of Cordyceps fungi, which can infect the brains of insects causing behavior advantageous to the reproduction or spread of the fungus. This also may be an allusion to another fungus, Ophiocordyceps unilateralis , which manipulates its hosts to aid its propagation.
Toxoplasma gondii is also known to alter the behavior of mammals, and some researchers have proposed that this parasite may be partly responsible for the " Cat lady " phenomenon, whereby humans are compelled to hoard cats. The comic and its subtitle may, in fact, be a subtle argument that human behavior, and the entire concept of free will, may need to be re-evaluated given the massive numbers of Human parasites known to exist.
In evolutionary biology , the phenomenon of an organism influencing its environment, sometimes by modifying the behavior of other organisms, is known as “the extended phenotype”. Richard Dawkins wrote a book of that name (as a follow-up of “ The Selfish Gene ”) where he describes this mechanism as an extreme example of the so-called selfishness of genes.
The title text parodies numerous conspiracy theories , by suggesting that corn , which has been propagated by humans throughout large parts of the world, is actually just a fungus that has used humans, and is not a grain at all. This type of theory is remarkably similar to the Brain in a Vat thought experiment, and to the Isaac Asimov short story Each an Explorer . In both cases something has affected the perception of the mind itself, making it impossible to discern the true reality of something.
This is quite similar to an argument made in the book Sapiens . Author Yuval Noah Harari points out that domesticated crops are among the most successful life forms on the planet, in terms of propagation.  These plants have influenced humans to do everything in our considerable power to spread their seeds, eliminate competing plants and animals, and even provide fertilizer and irrigation to help them grow and spread. From the perspective of the plants, they've domesticated us, rather than the other way around. This differs from Randall's conspiracy theory, in that domesticated plants provide us with food in exchange for propagation, making this more like symbiosis than parasitism .
Conspiracy theories are a recurring subject on xkcd.
[Megan and Cueball are talking to Ponytail.] Megan: Our lab is studying a fungus that takes over mammal brains and makes them want to study fungi. Cueball: It's very promising! We're opening a whole new wing of the lab just to cultivate it!
