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So, about one mushroom species in five is poisonous. Why is the ratio so low, why are there lots of edible ones? Without hard-shelled seeds to spread, why be ea

So, about one mushroom species in five is poisonous. Why is the ratio so low, why are there lots of edible ones? Without hard-shelled seeds to spread, why be eaten? And the poisonous ones apparently don't use color as a warning signal, and don't smell all that bad, and some of the poisons have really mild effects, like "gives only some people diarrhea" or "makes a hangover worse". Meanwhile three of the deadliest species seemed to need their toxin (amanitin) so much that they picked it up through horizontal gene transfer. Why did just those ones need to be deadly? In addition to which we have these species that don't even make you sick, just make you trip out, a function which looks to have evolved three times over in different ways. What kind of half-assed evolutionary strategies are these? What do mushrooms want?

tirant 10mo ago
That’s also my thought. The seem to be inside some type of evolutionary gray area or dead-end, where mutations in the edibility axis do not seem to matter much for the survival of the specifies. So we end up getting species of all extremes: extremely poisonous, highly valuable for coursing, trippy, non-trippy, mildly poisonous, etc.
- yieldcrv 10mo ago
  Metastatic cancer where our organs and cells grow every direction forever until resources expire is extremely counterproductive and doesn’t matter for the survival of our species because it usually occurs after reproductive age and the reproduction happened. Perpetuating the flawed genes in the next generation. Its the same with mushrooms, the difference being that not only do the spores exist in high numbers, a mushroom getting eaten does nothing to the mycelium that spawns the mushroom
choilive 10mo ago
Its the same evolutionary patterns that plants went through. Most mushrooms are edible because their spores can pass through the digestive system of most animals, thus allowing them to spread. Other mushrooms developed toxins to protect their fruiting bodies - often the biggest threat isn't larger animals, but insects. Toxins that are neurotoxic to insect nervous systems, happen to cause mostly "harmless" psychedelic trips to our brains. Other toxin mechanisms happen to be deadly to both insects and humans. As proof of this evolutionary arms race, there are fruit flies that have developed resistance to amatoxins.
- ajb 10mo ago
  It may be worth mentioning, for anyone who didn't know this already; that the fruiting body, which is what your normally see, isn't most of the mushroom. The rest of it is in the ground, or in something else like a dead log or live tree. So the organism can afford the fruiting body to be eaten, if it serves the purpose of spreading spores.
  - uplifter 10mo ago
    This relates to why you will often see multiple mushrooms of the same type blooming at the same time in a ring pattern: the edge of the ring is the periphery of the linearly, radially expanding mat of subterranean fungal fiber weave, which produces fruiting bodies at its edges.
    - robocat 10mo ago
      Incorrect. The inside of a fairy ring dies off as it uses up nutrients. The leading edge of the circle remains alive so that is why the fruiting bodies (mushrooms) are there. The fungus produces nitrogen which leads to the growth of a greener ring of grass. The ring’s steady expansion is driven by growth of the underground mycelium (not spores).
- seizethecheese 10mo ago
  > Toxins that are neurotoxic to insect nervous systems, happen to cause mostly "harmless" psychedelic trips to our brains. True for coffee as well (if you substitute psychedelic with a more appropriate word).
  - choilive 10mo ago
    Yep, thats a good one. Caffeine is deadly to insects, but a mostly safe stimulant for us. Nicotine also comes to mind. Plants have developed tons of defense mechanisms that are deadly to one class of animals, but useful or only mildly deterrent to others. Avians are immune to capsaicin, but an irritant for mammals.. except for some hairless primates.
observationist 10mo ago
They want the same thing as every other organism wants - maximal exploitation of a niche by a lineage. Each adaptation that survives overwhelmingly tends toward advantage in the exploitation of a niche - fending off predation, establishing control over resources, symbiotic support, parasitic drain, and a myriad other capabilities that are highly environment dependent. Just look at antelope in north america - they evolved incredible speed and agility in order to outrun and evade megafauna predators, but there's nothing left nearly fast enough to be a threat to them. Environments can change, and leave an organism with features that are no longer necessary or even beneficial in terms of overall quality of life and energy efficiency. The slightest noise can disturb a herd of antelope into bolting as if there were prairie lions or sabertooth tigers on the prowl. They don't need to be hypervigilant in the same way, and it burns a lot of calories to move the way they do, so whitetail deer and other slower species that aren't quite as reactive or fast are better at exploiting the ecosystem as it is. With mushrooms that have mysterious chemistry, there will be a lot of those sorts of vestigial features. Extinct species of insects and animals and plants will have been the target of specific features, or they might end up in novel environments where other features are particularly suitable, but some become completely counterproductive in practice. As far as psilocybe mushrooms go, in lower quantities, they actually provide a cognitive advantage sufficient to make a symbiotic relationship plausible between mammals and the mushrooms, albeit indirect. Animals under low levels of psilocybin influence have better spatial perception, can better spot movement in low light conditions, and there's a slight reduction in the neural influence of trauma inspired networks. Large quantities can be beneficial in a number of abstract ways. Any animal that sought those mushrooms out could thereby gain adaptive advantage over competitors that didn't partake. Having an extremely toxic substance might be useful for killing large organisms and their decomposition either feeding the fungi directly, or feeding the organisms beneficial to the fungi. This can be plants, other fungi, or the feces of scavengers. Horizontal transfer might occur if there's an initial beneficial relationship, animals like the smell and taste of a thing, and then the fungi picks up the killing poison, and the consequences are sufficiently beneficial to outbreed the safe ones. If too many become deadly, animals get killed off, and the non-deadly ones tend to gain the upper ground, since they aren't spending any resources on producing any poisons. Where there's a balance of intermittent similar but poisonous mushrooms, they take down enough animals to optimize their niche. There are dozens of such indirect webs of influences and consequences that spread from seemingly simple adaptations, and it's amazing that things seem so balanced and stable as they do. It's a constant arms race of attacks and temptations and strategies.
fooqux 10mo ago
Two things: 0) Humans (and even our recent ancestors) eating you are a very recent thing to be concerned about, numbers-wise. By the time our numbers were enough to provide evolutionary pressure, we started farming what we wanted, which kinda breaks the process. Also. most poisons don't effect everything equally, so what might prevent a horse from eating you might taste delicious to us (like the nightshade family) or even be sought after for other reasons, like capsaicin. 1) You're succumbing to the usual evolution fallacy. Evolution doesn't want anything more than 1 and 1 want to be 2. It's just a process, and sometimes (hell maybe even often) it doesn't work in a linear fashion. Lots of "X steps back, Y steps forward", and oftentimes each of those steps can take anything from decades to centuries or more to make, and by the time it happens what was pressuring that change is gone. So many people, even when they obviously know better, like to think of evolution as intelligent. It's obviously not. But every time someone says stuff like this, it reinforces the fallacy and then we get people saying things like "if evolution is real, why come $insane_argument_against_evolution?"
- malux85 10mo ago
  Also way too biased to humans, the fact that they poison us could just be a biochemistry coincidence, the author is operating from a very human-centric POV (like you say in (0))
- VanshPatel99 10mo ago
  I would expect this way of thinking about evolution would be common but unfortunately it isn't. I feel the way we say "X animal evolved to do Y" sets the ton as if it was a active, thought out decision. Instead, it was just 1000s of mutation happened and maybe a certain kind was able to survive while other wasn't. It is more of a mathematical concept than conscious one.
  - uh_uh 10mo ago
    I find it hard to believe that evolution is completely blind. The search space that it can explore via mutations is astronomically large. Considering that the experiment is run at planet-scale over billions of years doesn't really save the argument as it takes some specimen years to develop and get feedback on their fitness. It's hard to believe that it's truly just random "bit-flips". I'm not trying to suggest woo here, but there has to be some mechanisms to constrain the search space somewhat.
kgwxd 10mo ago
Some are saying: "Don't come anywhere near me". Others are are saying: "Take a little, I'll show you a good time. Take too much... I will make you end your own life."
- bdangubic 10mo ago
  what others are saying works for hotdogs too :)
RajT88 10mo ago
> And the poisonous ones apparently don't use color as a warning signal, and don't smell all that bad, and some of the poisons have really mild effects, like "gives only some people diarrhea" or "makes a hangover worse". Some of the poisonous ones even taste really good, and don't start making you sick for a day or two (and then you die horribly). You hear about it from time to time, where people have the best dinner of their life and then are dead.
- decimalenough 10mo ago
  You're likely referring to the death cap (Amanita phalloides), which is reportedly quite tasty. But there's also a mushroom that's both deadly poisonous and a sought-after, commercially sold delicacy, the only difference being the method of preparation: https://en.wikipedia.org/wiki/Gyromitra_esculenta https://en.wikipedia.org/wiki/Gyromitra_esculenta Although recent research suggests that some poison remains even after careful preparation, and that consumption may even be linked to ALS (Lou Gehrig's disease).
  - RajT88 10mo ago
    Partly I am sure. I have read stories similar to what I wrote from China as well. I think Europe too, but I would not swear on it.
sans_souse 10mo ago
I dig your style, you sound like my inner monologue :D
ACCount37 10mo ago
Natural selection cuts both ways. Sure, many things evolved to be less edible. But humans themselves are hunter-gatherer omnivores - who evolved to be very good at eating a lot of very different things. There are adaptations in play on both ends. There are, in fact, many countermeasures that would deter other animals, but fail to deter humans. In part due to some liver adaptations, in part due to sheer body mass, and in part due to human-specific tricks like using heat to cook food. If your countermeasures just so happen to get denaturated by being heated to 75C, good luck getting humans with them. It's why a lot of grains or legumes are edible once cooked but inedible raw. The same is true for many "mildly poisonous" mushrooms - they lose their toxicity if cooked properly. Those countermeasures don't have to be lethal to deter consumption! If something causes pain, diarrhea or indigestion, or some weirder effects, or just can't be spotted or reached easily, that can work well enough. So the evolutionary pressure to always go for highly lethal defenses isn't there. It's just one pathway to take, out of many, and evolution will roll with whatever happens to work best at the moment. Human takeover of the biosphere is a recent event too, and humans are still an out-of-distribution threat to a lot of things. So you get all of those weird situations - where sometimes, humans just blast through natural defenses without even realizing they're there, and sometimes, the defenses work but don't work very well because they evolved to counter something that's not a human, and sometimes, the defenses don't exist at all because the plant's environment never pressured it to deter consumption by large mammals at all. And with the level of control humans attained over nature now? The ongoing selection pressure is often shaped less like "how to deter humans" and more like "how to attract humans", because humans will go out of their way to preserve and spread things they happen to like.
username135 10mo ago
I appreciate your thirst for knowledge
bluerooibos 10mo ago
Amanita Muscaria seems like it does use colour as a warning signal - it's bright red.
- godelski 10mo ago
  Not exactly. You can eat that mushroom but you'll have indigestion problems. Squirrels around me love it though. You can also parboil it and you'll be fine, which it is actually quite tasty. That mushroom (Amanita muscaria) is also related to the death cap (Amanita phalloides). Though the toxins are different in the death cap and will not be converted/removed by parboiling. Worse than that, you won't show symptoms for over a day. The death cap is white or yellow, looking quite mundane. Especially compared to Muscaria.
- vintermann 10mo ago
  There are other bright red mushrooms (especially russulas) which are quite tasty. Russulas also can have many other bright colors. Conversely, many of the deadliest mushrooms where I live are plain and unassuming, at least in the color spectrum I can see.
jerf 10mo ago
Many good answers, but I'll add another angle I don't see any replies covering, which is that being poisonous/toxic is expensive. We humans lead charmed lives by the standards of the biosphere, where we get obese, and even before we got obese, many of us had unbelievable access to nutrients and energy. The steady state of the ecosystem is a war where every calorie must be spent carefully. This is particularly clear in the bacterial world but it progresses up to macroscopic plant life as well. Producing poisons is energy you could be using to grow or reproduce. Some poisons require additional care because they're still poisonous to the producer, it's just that the producer spends additional resources on containing the poison so it doesn't affect them. There is a constant, low-level evolutionary impetus to stop spending any calorie that doesn't need to be spent, which would generally include the production of poisons of any kind. This low-level impetus is clearly something that can be overcome in many situations, but it is nevertheless always there, always the "temptation" to stop spending so much on poisons and redirect it to growth or reproduction. Over time it's a winning play quite often.
heavyset_go 10mo ago
Fruit bodies are reproductive organs, spores can survive digestion, and there are plenty of species that use animal waste as a substrate. The same logic of hard seeds applies to spores.
estimator7292 10mo ago
It's really fucking suspicious that mushrooms evolved mechanisms to produce serotonin. But it helps when you remember that a mushroom is the fruit of a (usually) much larger organism. Then you can start applying normal fruit rules. Some want to be eaten, or picked up and moved around. Some want to keep insects from infesting the fruit. Others don't give a damn and release spores into the wind or water. Also remember that nicotine is an insecticide. Insects that nibble on tobacco die, which prevents infestation at scale. (Un?)fortunately it's also neuroactive in apes, so we farm incredible quantities of tobacco to extract its poisons. There is no logic in evolution at large scales. Things happen, sometimes there's fourth order effects like some oddball internal hormone causing wild hallucinations in apes. It's all random optimization for small scale problems that ripple out to unintended large scale consequences.
- Sam6late 10mo ago
  BTW, Caffeine is also a naturally occurring insecticide, yet humans tend to repurpose and hack things.
  - barbacoa 10mo ago
    Some argue that THC in cannabis actually works similarly because when herbivores regularly ingest it, they become lethargic and lazy, causing them struggle to survive in the world. Kinda like my roommate.
    - spike021 10mo ago
      your last sentence reminds me of my dorm roommate in college. very standard stoner who was constantly blazing and years later i've never known a lazier dude.
    - shaneofalltrad 10mo ago
      But cannabis the needs heat to convert, it’s more likely it evolved with Human influence considering the years of overlapping land races tied to our trade routes
DoctorOetker 10mo ago
A mushroom doesn't produce seeds, it produces spores. If you pick a mushroom the spores use you, your clothes, your pets, your horses as vectors for spreading.
homerowilson 10mo ago
"one mushroom species in five is poisonous"? 20% ??? That seems like a crazy high estimate to me, at least if you mean deadly poisonous to humans. In the USA there are only a few species of amanita, galerina, a few of the hundreds of species of cortinarius, maybe some gyromitra and a handful of others I can think of that will kill you. Among the many thousands of mushroom species in the USA, there are only a few dozen known deadly poisonous ones. It's a really tiny percentage. Of course that doesn't mean that the others are edible, just not gonna kill you...
- zjuventus14 10mo ago
  Seems clear to me that poisonous != deadly poisonous by GPs - as they stated, many of the poisonous mushrooms have mild side effects, like “makes a hangover worse.” So 20% is definitely high for deadly poisonous, but not for inedible/mildly poisonous.
hristov 10mo ago
The fly agaric, is very poisonous and has a very distinctive red with white dots pattern to warn about its poison. Unfortunately, that pattern looks so pretty that disney and ninetendo decided to use it as their generic mushroom coloring. So, if you are hiking with your kids, and they see a pretty mushroom just like in cartoons, don't let them touch it. If there are enough poisonous mushrooms, it is possible that most animals decide to leave mushrooms alone regardless of distinctive coloring. That seems to be the case because mushrooms tend not to be bitten by large animals, at least when i go mushrooming. If that happens, it is possible that other mushrooms do not develop poison but rather freeload on the poison of other mushrooms. Thus, one may guess, that first distinctive poisonous mushrooms like the fly agaric developed, then most animals large enough to eat them developed an instinct to avoid all mushrooms, and then the non-poisonous freeloading mushrooms developed. There are some psychedelic mushrooms in the amazon that use their psychedelic effect to zombify ants and force them to spread the mushrooms spores. That is really disturbing, find a youtube video of it if you feel like having some nightmares. Furthermore it should be noted that the poison or the psychedelic effect may not even be relevant for evolution. The poisonous or psychedelic compound may be produced for completely different purpose or as a byproduct of the production of another useful compound.
- vintermann 10mo ago
  There are plenty of poisonous plants that large animals e.g. farm animals will happily eat and die. Yew, water hemlock etc. are notorious livestock killers. According to a farmer friend of mine, sheep are also absolutely crazy about hedgehog mushrooms (hydnum repandum), which is not poisonous, but it suggests that they don't shun mushrooms.
- uplifter 10mo ago
  >Thus, one may guess, that first distinctive poisonous mushrooms like the fly agaric developed, then most animals large enough to eat them developed an instinct to avoid all mushrooms, and then the non-poisonous freeloading mushrooms developed. Just wanted to note that these phenomena are important enough in the study of mimicry in biology to have earned their own names: Müllerian mimicry is when two species who are similarly well defended (foul tasting, toxic or otherwise noxious to eat) converge in appearance to mimic each other's honest warning signals. Batesian mimicry is when a harmless or palatable species evolves to mimic a harmful, toxic, or otherwise defended species.
r00f 10mo ago
I've watched a documentary on mushrooms. Their posion is not a defense mechanism in most (all? don't remember) cases. It is just a consequence of the fact that mushrooms need to dump the excess Nitrogen somewhere, and that is related to the fact that most posionous mushrooms are those who thrive in Nitrogen-rich environments, like a leaf forest floor. And unfortunately for us, Nitrogen is a component for many creative biologically active substances. FWIW, human is the best mushroom's friend, when you cut it and carry around you seed tons of spores, so as a sibling comment said, mushrooms would not need to develop anti-human defenses. It's just that some of them got (un)lucky when played the chemical roulette while trying to figure out how to get rid of Nitrogen waste.
m463 10mo ago
I think of those "genetic algorithm car thing" simulations that run in a browser. weird stuff survives. and good stuff crashes and burns sometimes.
HaukeHi 10mo ago
Plants want to be eaten only by big animals that take them on long and random walks and then die far away from where they are picked up to fertilize the seed.
- DonHopkins 10mo ago
  Which also explains the talking Ameglian Major Cow on the menu at Milliways, in Douglas Adams' The Restaurant at the End of the Universe: when you confuse evolutionary outcomes with intent, you end up with livestock enthusiastically volunteering for dinner. https://www.youtube.com/watch?v=bAF35dekiAY https://www.youtube.com/watch?v=bAF35dekiAY
scotty79 10mo ago
> What do mushrooms want? I think it's a way of mushrooms saying "We don't think of you at all."
mapmeld 10mo ago
Horizontal gene transfer is looking a lot more common than we learned in biology class. Fungi have a class of proteins (Starships) which transfer hundreds of genes, beetles picked up cellulose-digesting proteins from bacteria in their digestive tract and embryos. https://en.wikipedia.org/wiki/Starship_(genetics) https://en.wikipedia.org/wiki/Starship_(genetics)
hammock 10mo ago
A corpse keeps other grazers away for the rest of the season.

tirant 10mo ago

That’s also my thought. The seem to be inside some type of evolutionary gray area or dead-end, where mutations in the edibility axis do not seem to matter much for the survival of the specifies. So we end up getting species of all extremes: extremely poisonous, highly valuable for coursing, trippy, non-trippy, mildly poisonous, etc.

yieldcrv 10mo ago
Metastatic cancer where our organs and cells grow every direction forever until resources expire is extremely counterproductive and doesn’t matter for the survival of our species because it usually occurs after reproductive age and the reproduction happened. Perpetuating the flawed genes in the next generation. Its the same with mushrooms, the difference being that not only do the spores exist in high numbers, a mushroom getting eaten does nothing to the mycelium that spawns the mushroom

choilive 10mo ago

Its the same evolutionary patterns that plants went through. Most mushrooms are edible because their spores can pass through the digestive system of most animals, thus allowing them to spread. Other mushrooms developed toxins to protect their fruiting bodies - often the biggest threat isn't larger animals, but insects. Toxins that are neurotoxic to insect nervous systems, happen to cause mostly "harmless" psychedelic trips to our brains. Other toxin mechanisms happen to be deadly to both insects and humans. As proof of this evolutionary arms race, there are fruit flies that have developed resistance to amatoxins.

ajb 10mo ago
It may be worth mentioning, for anyone who didn't know this already; that the fruiting body, which is what your normally see, isn't most of the mushroom. The rest of it is in the ground, or in something else like a dead log or live tree. So the organism can afford the fruiting body to be eaten, if it serves the purpose of spreading spores.
- uplifter 10mo ago
  This relates to why you will often see multiple mushrooms of the same type blooming at the same time in a ring pattern: the edge of the ring is the periphery of the linearly, radially expanding mat of subterranean fungal fiber weave, which produces fruiting bodies at its edges.
  - robocat 10mo ago
    Incorrect. The inside of a fairy ring dies off as it uses up nutrients. The leading edge of the circle remains alive so that is why the fruiting bodies (mushrooms) are there. The fungus produces nitrogen which leads to the growth of a greener ring of grass. The ring’s steady expansion is driven by growth of the underground mycelium (not spores).
seizethecheese 10mo ago
> Toxins that are neurotoxic to insect nervous systems, happen to cause mostly "harmless" psychedelic trips to our brains. True for coffee as well (if you substitute psychedelic with a more appropriate word).
- choilive 10mo ago
  Yep, thats a good one. Caffeine is deadly to insects, but a mostly safe stimulant for us. Nicotine also comes to mind. Plants have developed tons of defense mechanisms that are deadly to one class of animals, but useful or only mildly deterrent to others. Avians are immune to capsaicin, but an irritant for mammals.. except for some hairless primates.

observationist 10mo ago

They want the same thing as every other organism wants - maximal exploitation of a niche by a lineage. Each adaptation that survives overwhelmingly tends toward advantage in the exploitation of a niche - fending off predation, establishing control over resources, symbiotic support, parasitic drain, and a myriad other capabilities that are highly environment dependent. Just look at antelope in north america - they evolved incredible speed and agility in order to outrun and evade megafauna predators, but there's nothing left nearly fast enough to be a threat to them. Environments can change, and leave an organism with features that are no longer necessary or even beneficial in terms of overall quality of life and energy efficiency. The slightest noise can disturb a herd of antelope into bolting as if there were prairie lions or sabertooth tigers on the prowl. They don't need to be hypervigilant in the same way, and it burns a lot of calories to move the way they do, so whitetail deer and other slower species that aren't quite as reactive or fast are better at exploiting the ecosystem as it is. With mushrooms that have mysterious chemistry, there will be a lot of those sorts of vestigial features. Extinct species of insects and animals and plants will have been the target of specific features, or they might end up in novel environments where other features are particularly suitable, but some become completely counterproductive in practice. As far as psilocybe mushrooms go, in lower quantities, they actually provide a cognitive advantage sufficient to make a symbiotic relationship plausible between mammals and the mushrooms, albeit indirect. Animals under low levels of psilocybin influence have better spatial perception, can better spot movement in low light conditions, and there's a slight reduction in the neural influence of trauma inspired networks. Large quantities can be beneficial in a number of abstract ways. Any animal that sought those mushrooms out could thereby gain adaptive advantage over competitors that didn't partake. Having an extremely toxic substance might be useful for killing large organisms and their decomposition either feeding the fungi directly, or feeding the organisms beneficial to the fungi. This can be plants, other fungi, or the feces of scavengers. Horizontal transfer might occur if there's an initial beneficial relationship, animals like the smell and taste of a thing, and then the fungi picks up the killing poison, and the consequences are sufficiently beneficial to outbreed the safe ones. If too many become deadly, animals get killed off, and the non-deadly ones tend to gain the upper ground, since they aren't spending any resources on producing any poisons. Where there's a balance of intermittent similar but poisonous mushrooms, they take down enough animals to optimize their niche. There are dozens of such indirect webs of influences and consequences that spread from seemingly simple adaptations, and it's amazing that things seem so balanced and stable as they do. It's a constant arms race of attacks and temptations and strategies.

fooqux 10mo ago

Two things: 0) Humans (and even our recent ancestors) eating you are a very recent thing to be concerned about, numbers-wise. By the time our numbers were enough to provide evolutionary pressure, we started farming what we wanted, which kinda breaks the process. Also. most poisons don't effect everything equally, so what might prevent a horse from eating you might taste delicious to us (like the nightshade family) or even be sought after for other reasons, like capsaicin. 1) You're succumbing to the usual evolution fallacy. Evolution doesn't want anything more than 1 and 1 want to be 2. It's just a process, and sometimes (hell maybe even often) it doesn't work in a linear fashion. Lots of "X steps back, Y steps forward", and oftentimes each of those steps can take anything from decades to centuries or more to make, and by the time it happens what was pressuring that change is gone. So many people, even when they obviously know better, like to think of evolution as intelligent. It's obviously not. But every time someone says stuff like this, it reinforces the fallacy and then we get people saying things like "if evolution is real, why come $insane_argument_against_evolution?"

malux85 10mo ago
Also way too biased to humans, the fact that they poison us could just be a biochemistry coincidence, the author is operating from a very human-centric POV (like you say in (0))
VanshPatel99 10mo ago
I would expect this way of thinking about evolution would be common but unfortunately it isn't. I feel the way we say "X animal evolved to do Y" sets the ton as if it was a active, thought out decision. Instead, it was just 1000s of mutation happened and maybe a certain kind was able to survive while other wasn't. It is more of a mathematical concept than conscious one.
- uh_uh 10mo ago
  I find it hard to believe that evolution is completely blind. The search space that it can explore via mutations is astronomically large. Considering that the experiment is run at planet-scale over billions of years doesn't really save the argument as it takes some specimen years to develop and get feedback on their fitness. It's hard to believe that it's truly just random "bit-flips". I'm not trying to suggest woo here, but there has to be some mechanisms to constrain the search space somewhat.

kgwxd 10mo ago

Some are saying: "Don't come anywhere near me". Others are are saying: "Take a little, I'll show you a good time. Take too much... I will make you end your own life."

bdangubic 10mo ago
what others are saying works for hotdogs too :)

RajT88 10mo ago

> And the poisonous ones apparently don't use color as a warning signal, and don't smell all that bad, and some of the poisons have really mild effects, like "gives only some people diarrhea" or "makes a hangover worse". Some of the poisonous ones even taste really good, and don't start making you sick for a day or two (and then you die horribly). You hear about it from time to time, where people have the best dinner of their life and then are dead.

decimalenough 10mo ago
You're likely referring to the death cap (Amanita phalloides), which is reportedly quite tasty. But there's also a mushroom that's both deadly poisonous and a sought-after, commercially sold delicacy, the only difference being the method of preparation: https://en.wikipedia.org/wiki/Gyromitra_esculenta https://en.wikipedia.org/wiki/Gyromitra_esculenta Although recent research suggests that some poison remains even after careful preparation, and that consumption may even be linked to ALS (Lou Gehrig's disease).
- RajT88 10mo ago
  Partly I am sure. I have read stories similar to what I wrote from China as well. I think Europe too, but I would not swear on it.

sans_souse 10mo ago

I dig your style, you sound like my inner monologue :D

ACCount37 10mo ago

Natural selection cuts both ways. Sure, many things evolved to be less edible. But humans themselves are hunter-gatherer omnivores - who evolved to be very good at eating a lot of very different things. There are adaptations in play on both ends. There are, in fact, many countermeasures that would deter other animals, but fail to deter humans. In part due to some liver adaptations, in part due to sheer body mass, and in part due to human-specific tricks like using heat to cook food. If your countermeasures just so happen to get denaturated by being heated to 75C, good luck getting humans with them. It's why a lot of grains or legumes are edible once cooked but inedible raw. The same is true for many "mildly poisonous" mushrooms - they lose their toxicity if cooked properly. Those countermeasures don't have to be lethal to deter consumption! If something causes pain, diarrhea or indigestion, or some weirder effects, or just can't be spotted or reached easily, that can work well enough. So the evolutionary pressure to always go for highly lethal defenses isn't there. It's just one pathway to take, out of many, and evolution will roll with whatever happens to work best at the moment. Human takeover of the biosphere is a recent event too, and humans are still an out-of-distribution threat to a lot of things. So you get all of those weird situations - where sometimes, humans just blast through natural defenses without even realizing they're there, and sometimes, the defenses work but don't work very well because they evolved to counter something that's not a human, and sometimes, the defenses don't exist at all because the plant's environment never pressured it to deter consumption by large mammals at all. And with the level of control humans attained over nature now? The ongoing selection pressure is often shaped less like "how to deter humans" and more like "how to attract humans", because humans will go out of their way to preserve and spread things they happen to like.

username135 10mo ago

I appreciate your thirst for knowledge

bluerooibos 10mo ago

Amanita Muscaria seems like it does use colour as a warning signal - it's bright red.

godelski 10mo ago
Not exactly. You can eat that mushroom but you'll have indigestion problems. Squirrels around me love it though. You can also parboil it and you'll be fine, which it is actually quite tasty. That mushroom (Amanita muscaria) is also related to the death cap (Amanita phalloides). Though the toxins are different in the death cap and will not be converted/removed by parboiling. Worse than that, you won't show symptoms for over a day. The death cap is white or yellow, looking quite mundane. Especially compared to Muscaria.
vintermann 10mo ago
There are other bright red mushrooms (especially russulas) which are quite tasty. Russulas also can have many other bright colors. Conversely, many of the deadliest mushrooms where I live are plain and unassuming, at least in the color spectrum I can see.

jerf 10mo ago

Many good answers, but I'll add another angle I don't see any replies covering, which is that being poisonous/toxic is expensive. We humans lead charmed lives by the standards of the biosphere, where we get obese, and even before we got obese, many of us had unbelievable access to nutrients and energy. The steady state of the ecosystem is a war where every calorie must be spent carefully. This is particularly clear in the bacterial world but it progresses up to macroscopic plant life as well. Producing poisons is energy you could be using to grow or reproduce. Some poisons require additional care because they're still poisonous to the producer, it's just that the producer spends additional resources on containing the poison so it doesn't affect them. There is a constant, low-level evolutionary impetus to stop spending any calorie that doesn't need to be spent, which would generally include the production of poisons of any kind. This low-level impetus is clearly something that can be overcome in many situations, but it is nevertheless always there, always the "temptation" to stop spending so much on poisons and redirect it to growth or reproduction. Over time it's a winning play quite often.

heavyset_go 10mo ago

Fruit bodies are reproductive organs, spores can survive digestion, and there are plenty of species that use animal waste as a substrate. The same logic of hard seeds applies to spores.

estimator7292 10mo ago

It's really fucking suspicious that mushrooms evolved mechanisms to produce serotonin. But it helps when you remember that a mushroom is the fruit of a (usually) much larger organism. Then you can start applying normal fruit rules. Some want to be eaten, or picked up and moved around. Some want to keep insects from infesting the fruit. Others don't give a damn and release spores into the wind or water. Also remember that nicotine is an insecticide. Insects that nibble on tobacco die, which prevents infestation at scale. (Un?)fortunately it's also neuroactive in apes, so we farm incredible quantities of tobacco to extract its poisons. There is no logic in evolution at large scales. Things happen, sometimes there's fourth order effects like some oddball internal hormone causing wild hallucinations in apes. It's all random optimization for small scale problems that ripple out to unintended large scale consequences.

Sam6late 10mo ago
BTW, Caffeine is also a naturally occurring insecticide, yet humans tend to repurpose and hack things.
- barbacoa 10mo ago
  Some argue that THC in cannabis actually works similarly because when herbivores regularly ingest it, they become lethargic and lazy, causing them struggle to survive in the world. Kinda like my roommate.
  - spike021 10mo ago
    your last sentence reminds me of my dorm roommate in college. very standard stoner who was constantly blazing and years later i've never known a lazier dude.
  - shaneofalltrad 10mo ago
    But cannabis the needs heat to convert, it’s more likely it evolved with Human influence considering the years of overlapping land races tied to our trade routes

DoctorOetker 10mo ago

A mushroom doesn't produce seeds, it produces spores. If you pick a mushroom the spores use you, your clothes, your pets, your horses as vectors for spreading.

homerowilson 10mo ago

"one mushroom species in five is poisonous"? 20% ??? That seems like a crazy high estimate to me, at least if you mean deadly poisonous to humans. In the USA there are only a few species of amanita, galerina, a few of the hundreds of species of cortinarius, maybe some gyromitra and a handful of others I can think of that will kill you. Among the many thousands of mushroom species in the USA, there are only a few dozen known deadly poisonous ones. It's a really tiny percentage. Of course that doesn't mean that the others are edible, just not gonna kill you...

zjuventus14 10mo ago
Seems clear to me that poisonous != deadly poisonous by GPs - as they stated, many of the poisonous mushrooms have mild side effects, like “makes a hangover worse.” So 20% is definitely high for deadly poisonous, but not for inedible/mildly poisonous.

hristov 10mo ago

The fly agaric, is very poisonous and has a very distinctive red with white dots pattern to warn about its poison. Unfortunately, that pattern looks so pretty that disney and ninetendo decided to use it as their generic mushroom coloring. So, if you are hiking with your kids, and they see a pretty mushroom just like in cartoons, don't let them touch it. If there are enough poisonous mushrooms, it is possible that most animals decide to leave mushrooms alone regardless of distinctive coloring. That seems to be the case because mushrooms tend not to be bitten by large animals, at least when i go mushrooming. If that happens, it is possible that other mushrooms do not develop poison but rather freeload on the poison of other mushrooms. Thus, one may guess, that first distinctive poisonous mushrooms like the fly agaric developed, then most animals large enough to eat them developed an instinct to avoid all mushrooms, and then the non-poisonous freeloading mushrooms developed. There are some psychedelic mushrooms in the amazon that use their psychedelic effect to zombify ants and force them to spread the mushrooms spores. That is really disturbing, find a youtube video of it if you feel like having some nightmares. Furthermore it should be noted that the poison or the psychedelic effect may not even be relevant for evolution. The poisonous or psychedelic compound may be produced for completely different purpose or as a byproduct of the production of another useful compound.

vintermann 10mo ago
There are plenty of poisonous plants that large animals e.g. farm animals will happily eat and die. Yew, water hemlock etc. are notorious livestock killers. According to a farmer friend of mine, sheep are also absolutely crazy about hedgehog mushrooms (hydnum repandum), which is not poisonous, but it suggests that they don't shun mushrooms.
uplifter 10mo ago
>Thus, one may guess, that first distinctive poisonous mushrooms like the fly agaric developed, then most animals large enough to eat them developed an instinct to avoid all mushrooms, and then the non-poisonous freeloading mushrooms developed. Just wanted to note that these phenomena are important enough in the study of mimicry in biology to have earned their own names: Müllerian mimicry is when two species who are similarly well defended (foul tasting, toxic or otherwise noxious to eat) converge in appearance to mimic each other's honest warning signals. Batesian mimicry is when a harmless or palatable species evolves to mimic a harmful, toxic, or otherwise defended species.

r00f 10mo ago

I've watched a documentary on mushrooms. Their posion is not a defense mechanism in most (all? don't remember) cases. It is just a consequence of the fact that mushrooms need to dump the excess Nitrogen somewhere, and that is related to the fact that most posionous mushrooms are those who thrive in Nitrogen-rich environments, like a leaf forest floor. And unfortunately for us, Nitrogen is a component for many creative biologically active substances. FWIW, human is the best mushroom's friend, when you cut it and carry around you seed tons of spores, so as a sibling comment said, mushrooms would not need to develop anti-human defenses. It's just that some of them got (un)lucky when played the chemical roulette while trying to figure out how to get rid of Nitrogen waste.

m463 10mo ago

I think of those "genetic algorithm car thing" simulations that run in a browser. weird stuff survives. and good stuff crashes and burns sometimes.

HaukeHi 10mo ago

Plants want to be eaten only by big animals that take them on long and random walks and then die far away from where they are picked up to fertilize the seed.

DonHopkins 10mo ago
Which also explains the talking Ameglian Major Cow on the menu at Milliways, in Douglas Adams' The Restaurant at the End of the Universe: when you confuse evolutionary outcomes with intent, you end up with livestock enthusiastically volunteering for dinner. https://www.youtube.com/watch?v=bAF35dekiAY https://www.youtube.com/watch?v=bAF35dekiAY

scotty79 10mo ago

> What do mushrooms want? I think it's a way of mushrooms saying "We don't think of you at all."

mapmeld 10mo ago

Horizontal gene transfer is looking a lot more common than we learned in biology class. Fungi have a class of proteins (Starships) which transfer hundreds of genes, beetles picked up cellulose-digesting proteins from bacteria in their digestive tract and embryos. https://en.wikipedia.org/wiki/Starship_(genetics) https://en.wikipedia.org/wiki/Starship_(genetics)

hammock 10mo ago

A corpse keeps other grazers away for the rest of the season.