# From Mushrooms To Menshrooms

Alternate question title: From Fungi to a Fun Guy

So, I asked a previous question about which non-animal would be the likeliest to evolve sentience. The answer turned out to be fungus, since mycelial networks closely resemble neurons.

My question is dual pronged, because I think it would be difficult to separate. How would a fungus evolve into a sentient creature, capable of animal-like levels of movement and perceiving their surroundings, and of human level intelligence? What kind of environment would foster these developments?

• Fungi is a totally different kingdom from plants. They're as different from plants as animals are. – Samuel Dec 22 '16 at 20:29
• @Samuel More different, actually. Fungi are more closely related to animals than plants. Obligatory XKCD: xkcd.com/1749 – ApproachingDarknessFish Dec 22 '16 at 20:34
• @ApproachingDarknessFish Right, fungi being "as different from plants as animals are" doesn't mean they're the same difference away from animals as plants. Savy? – Samuel Dec 22 '16 at 20:40
• @Samuel Ah you're right. – ApproachingDarknessFish Dec 22 '16 at 20:42
• Plants also have been shown to be capable of animal reasoning. – Thom Blair III Dec 22 '16 at 21:22

Before we start, it's worth noting that fungi really aren't more likely to develop intelligence than plants. Sure, there may be "intelligent" fungi, but there are plants that do the same things that are significantly safer than fungi, and that can inhabit a wider range of habitats. Making decisions about routing nutrients is not uncommon - and it's in no way closer to intelligent thought than, for instance, the reflexes of a carnivorous plant.

I still advise choosing plants instead, but that doesn't mean fungi cannot make it work.

Yeasts are usually single-celled fungi. Some have been observed to produce longer chains - an excellent start to build some larger tissues. Similarly to how life is thought to have evolved from single-celled organisms long ago, you could provide the evolutionary pressures to develop yeasts extensively into larger animals.

A good starting pressure could be the need to compete for food (sugars in this case) due to scarcity in an environment. This would produce complex locomotion and sensory methods generations later, and perhaps small, multi-celled animals would evolve given enough time. They would no longer rely on parasitism or decomposition to procure sugars; an herbivorous lifestyle could develop. From there, the same basic evolutionary steps that produced humans can be followed.

## Option #2: Require active response for survival

Your previous question has answers that can be adapted for this one. @ChefCyanide said the following when describing how a plant would evolve intelligence:

As for evolution, this complex would require a rather unique environment, in which traditional methods of mating (pollination) and/or obtaining resources (photosynthesis) are possible and yet not ideal for survival and continuation of the species. An example of this could be an area frequently shrouded by large, dense, slow-moving clouds, or where there is virtually no wind or pollinating insects present.

While we are not dealing with plants, the same ideas apply: your organism must actively respond to stimuli relatively quickly. If you want to adapt a mycelial network (like that described in the top answer to the previous question) to become conscious, for example, you must make resources hard to get - and have it actively work for them.

Maybe food is scarce, or the soil is barren, so the fungus has to actively grow onto a nearby tree to sustain itself. Or perhaps it must divert energy into making a sweet-smelling chemical to attract insects, or change colors depending on the predator nearby. All of these processes could develop through mutation, specialization, and natural selection.

Eventually, it is possible for consciousness to develop in such an organism in order to respond more efficiently to the world around it. It may be a drastically different consciousness to our own, and it may not have the potential to develop communication or locomotion, but it will be able to think.

## Option #3: Endosymbiosis

The cordyceps fungus has been observed infecting hundreds of species of insects. In some cases, it "hijacks" the brains of its hosts, compelling them to do specific actions - such as climbing trees, so that it can release its spores into the wind.

In a process called endosymbiosis, it may be possible for a similar fungus to coexist with its hosts. Perhaps it evolves the ability to release multiple rounds of spores. To spread them over a larger area, the host must be kept alive long enough to move around significantly. The fungus coexists with the hosts, and spreads to their offspring, until they're united as one "species". This favors the hosts, which are more likely to survive than other infected parts of the population - and may become immune to other invasive fungi if the space is already taken. It also favors the fungi, which now require less work to reproduce; they have the guarantee of the entire infected population.

The fungi may continue to produce chemicals that impact the hosts' brains. They may become more complex, and beneficial, over generations - allowing the fungus to "think" indirectly.

• I like your answer, you covered the most likely possibilities and situations, and all around did a good job. The main reason I didn't end up going for plants was the roots. I figured fungi would be more flexible in developing movement than plants, since plants need nutrients from the soil, whereas fungus isn't necessarily so. – Xandar The Zenon Dec 22 '16 at 22:48
• @XandarTheZenon Thanks. While roots may be a problem for a problem, there are plants without deep roots - and fungi with deep mycelium instead; it really depends on the species. – Zxyrra Dec 22 '16 at 22:49

From the 80's and 90's video game Star Control, consider Mycon. Mycon was a genetically engineered artificial species, designed to perform labor in terra-forming. They absorb ambient energy and can intentionally select which genes to pass on to the next generation.

Borrowing from this, as many fungi reproduce asexually, one develops the ability to select which genetic characteristics to pass on to the next generation. First, they will improve the ability to select genes. A by-product of this is enhancing intelligence to improve decision making. Over time, they gain sentience.

Then, massive death starts in their community. They first select genes to allow sensing of their surroundings, and then a means to share information. They learn that they are being consumed by humans, using machines.

The fungi first try poison - and learn that the humans can destroy them very rapidly. They then develop a means to escape by wind, then eventually develop muscles. They find that muscles require a ton of energy, so they find a way absorb electricity directly. They then spread via the electrical infrastructure, and learn to control computers and machines, then how to consume humans.

From hear, of course they learn how to leave the planet to spread through the universe.

• This is creative but I feel like genetically engineering them does not fit the authors ideas of evolving life forms. – Zxyrra Dec 22 '16 at 23:48
• @Zxyrra Self Genetic Engineering isn't that exotic. We mammals do it; mate selection is a huge and interesting area. Perhaps the species in question does it unawares. – axsvl77 Dec 23 '16 at 1:58
• That's quite different from the ability to select which genetic characteristics to pass on - nitpicking individual genes to make themselves intelligent, which also requires intelligence .. already – Zxyrra Dec 23 '16 at 2:09
• The big difference is that the selection would be asexual; but it isn't that far fetched. – axsvl77 Dec 23 '16 at 2:49

First, it would have to be conducive to mushroom life, nearly planet-wide, then there would have to be environmental pressures making life difficult and pushing adaptation.

For plant life not to be dominant there needs to be little or no sunlight in the environment, or places where sunlight is blocked by plantlife.

There would have to be a reason to develop a brain and everything else (like hands). I can see it being a colony with one or two "caretakers" shaping the environment. Since those colonies with caretakers would thrive, more would be made.

That's my take on it anyway!

• Not all mushrooms grow only in the dark. Some grow in full sunlight. Also, there are even mushrooms that grow in the desert. However, they are rare. – Thom Blair III Dec 22 '16 at 20:54
• @ThomBlairIII Mushrooms in full sunlight are likely to be out competed by plants before they can reach sapience. – Bellerophon Dec 22 '16 at 21:48
• But what kind of pressures? What might it end up looking like? – Xandar The Zenon Dec 22 '16 at 22:05
• @XandarTheZenon The usual--lack of resources and looking for a new way to get it--or competition. So if there's more sunlight than there used to be=more plants, which takes more resources. If they are hunted, if there's competition for resources, if they have to be more clever to get what they need--all those pressures lead to changes. – Erin Thursby Dec 22 '16 at 22:22
• @ThomBlairIII What Bellerophon said, basically. "For plant life not to be dominant..." is the key phrase. Aware that mushrooms can exist in a number of environs, just think it would be helpful to have places with less sunlight (at least early in the evolution) to give mushrooms an edge. – Erin Thursby Dec 22 '16 at 22:25