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[pisskop]

Given how its relatively easy to shift colors through some genetic drift, I imagine that theyre specifically trying to blend in.  Or the benefits of coloration just arent a requirement.

Besides the mushroom caps and stalks arent the mushroom, theyre a fruiting body; more like the flowers on the tree.  You pluck the cap, it grows from the roots

[martinuzz]

Indeed. If you see a ring of mushrooms growing around a tree, it's likely that they are all one single organism / mycelium network.

[JoshuaFH]

For the most part, only humans depend on their eyes to the extent we do. Most other things depend on their noses to inhabit the world of smells that surround them. That, or that the poisonous things in question are much more concerned with other types of predators that don't have eyes at all: ants, microorganisms, fungi, things like that.

[martinuzz]

So the evolutionary arms race of poisonous things and things that eat them has always intrigued me. Producing poisons serves no inherent benefit to an animal, and if it is eaten and its predator dies, the animal is still dead. Only in aggregate does the animal benefit, and only if predators have some capacity to learn, identify and remember what prey are poisonous. Most poisonous things subsequently face the selection pressure to evolve bright warning colours in much the same way that nuclear deterrence doesn't work if no one knows you have nuclear weapons. But then what's the deal with all those plants that have no warning colours yet are toxic as hell? Deathcap mushrooms look like any other mushroom, hemlocks and wild carrots are relatives. Like there are all these plants and fungi that are just well-hidden landmines, and that doesn't seem to their benefit either?

Evolution is a slow process. The poisonous animal does not need it's predator to be able to learn it's poisonous at all for it's poison to do it's job. The animal that got eaten might be dead, but the predator that dies will not eat it's brothers and sisters, and it will not reproduce, so the poisonous speciess survives and thrives by the sacrifice of some.
Same for plants. If animals that eat you die, they will not make offspring or eat more plants.

Example: a predator eats 1 frog per day. The predator lives for 3 years. It will eat 1095 frogs in it's lifetime. Now imagine it eats 1 poisonous frog when it is 1 year old. The death of that single poisonous frog will have saved 730 fellow frog lives.

[Great Order]

For the most part, only humans depend on their eyes to the extent we do. Most other things depend on their noses to inhabit the world of smells that surround them. That, or that the poisonous things in question are much more concerned with other types of predators that don't have eyes at all: ants, microorganisms, fungi, things like that.

This is important to note. Humans are derived from brachiators that needed to be able to see well in order to get through the trees without missing a branch and falling. As a result, we developed a high dependence on our sight at the cost of senses like smell. Other animals likely have other ways of identifying that something will make their liver turn inside-out, while we have to rely on visual cues and our obscene level of intelligence (To the extent there's the question of just why we evolved such intelligence given being dumb seems to work just as well and is less resource intensive. My favourite theory is that intelligence was a sexually selected trait) to ensure we don't eat something dangerous.

I mean, we straight up lack a Jacobson's organ. Most non-primate terrestrial vertebrates have those and they're great for picking up chemicals that you can't smell or taste.

[Egan_BW]

Given how its relatively easy to shift colors through some genetic drift, I imagine that theyre specifically trying to blend in.  Or the benefits of coloration just arent a requirement.

Besides the mushroom caps and stalks arent the mushroom, theyre a fruiting body; more like the flowers on the tree.  You pluck the cap, it grows from the roots

I guess in that way, for a fungus having a fast acting poison in its mushrooms can be a source of food. Critter eats the mushroom, falls dead right on the ground where the mycelium is.

[martinuzz]

Most if not all mushroom poisons are slow poisons.

Not all toxiciy evolves as a means of defense. There's also situations where an organism's metabolic products just happen to be toxic to others (or to itself. Yeast dies of it's own alcohol production when it exceeds a certain percentage for example).

[Great Order]

Yeah but toxin production's costly (Hence why a lot of venomous animals will dry-bite) and given animals will mostly avoid them I can't see much benefit to that.

When you get stupidly toxic stuff it's usually the result of an evolutionary arms race. A becomes toxic, B counteracts it. A becomes more toxic, B counteracts it. A becomes even more toxic...

And you wind up with one organism with strong enough toxins to kill fifty elephants, and another with a (often specific) toxin resistance that's just absurd.

EDIT: And Ninja'd. Yes, most mushrooms kill you over the course of hours or days too, if only because they need digesting. Fast-acting toxins are usually venoms because they're injected straight into the blood and often specifically used for hunting, where quickly killing the prey is advantageous.

[martinuzz]

I guess in that way, for a fungus having a fast acting poison in its mushrooms can be a source of food. Critter eats the mushroom, falls dead right on the ground where the mycelium is.

Interestingly, brambles, and other thorny vines are speculated to do just that with their thorns. Entangle sheep, sheep dies, sheep rots at the spot and it's nutrient's enrich the soil. It's just a theory though.

[Great Order]

It sounds more incidental to me, brambles are bastards though. They flail about over the course of a day and slice open any nearby plants with those thorns.

[Egan_BW]

Evolution doesn't really have such a thing as intent, so even if murdering animals to use as fertilizer isn't the biggest utility that the brambles get from having thorns, it is of benefit to the plant occasionally, which counts.

[Great Order]

Eh, saying "X evolved for Y" isn't completely accurate but it's a good enough approximation for lay conversation.

[Eric Blank]

It's technically all incidental. Poisons, brambles and all. It's noteworthy to mention that just because something happened to develop a gene to produce poison doesn't mean it's going to develop a gene to become colorful; they're both coincidental, and the first makes the second suddenly useful instead of detrimental, but doesn't cause it to happen. For poisonous plants, though, it's possible they don't favor bright pigments more often to display their toxicity explicitly because it might interfere with light absorption (even though the pigmentation isnt necessarily in the chloroplasts). So chemical indicators like smells affect their metabolic needs less. They don't have camouflage for the most part either; they can't run from predators, and they can't hide from predators because they explicitly have to be out in the open to survive. So their survival isnt really dependent on pigmentation outside of producing sugars, which they need the pigments in their chloroplasts for, and for flowers to attract pollinators. There's no reason then that going out of their way to subvert the camouflage game and brightly display themselves benefits them. For animals, it's a clear "don't fuck with this guy even though you can clearly see him" but the plant never had the opportunity to hide; it has always been plainly obvious and in the open.

[JoshuaFH]

(To the extent there's the question of just why we evolved such intelligence given being dumb seems to work just as well and is less resource intensive. My favourite theory is that intelligence was a sexually selected trait)

I mean, how else would it have been selected for and developed? The 3 F's of Evolution: Fighting, Fucking, and Finding Food are all infinitely enhanced with greater intelligence. There's also something of an Unvirtuous Cycle which compels them all to compliment eachother: If you want food and sex and safety you probably need to kill for all of them. The evolution of warfare compels tribes and societies to advance and grow to support armies. The growth of tribes and societies compels the nomads to become farmers. The additional scarcity of precious food and resources for their favorite tribe compels the armies to increase in size, use increasingly better weapons, using increasingly better tactics. Which forces larger and more complex societies. Which have more intense logistical challenges to sustain themselves... The point being that the increase in size and complexity of all of these things poses new challenges that can only be overcome with increasingly greater intelligence, which inevitably means that the less intelligent apes that couldn't rise up to these challenges got weeded out.

Honestly, the more I think about it, the more surprised I am to not see more highly intelligent creatures on par with ourselves. Intelligence seems evolutionarily inevitable. I'd probably have to say the only reason we don't see more intelligent creatures like us is because we killed them all during our rapid conquest of the planet.

[Loud Whispers]

For the most part, only humans depend on their eyes to the extent we do. Most other things depend on their noses to inhabit the world of smells that surround them. That, or that the poisonous things in question are much more concerned with other types of predators that don't have eyes at all: ants, microorganisms, fungi, things like that.

One of my favourite evolutionary theories is one speculating that predominant phobias of things like the uncanny valley stem from fear of diseased humans, common phobias like arachnids and centipedes because hey, venomous critter, and our visual system is snake-detected based all the way down

Evolution is a slow process. The poisonous animal does not need it's predator to be able to learn it's poisonous at all for it's poison to do it's job. The animal that got eaten might be dead, but the predator that dies will not eat it's brothers and sisters, and it will not reproduce, so the poisonous speciess survives and thrives by the sacrifice of some.
Same for plants. If animals that eat you die, they will not make offspring or eat more plants.

Yeah I get that, but when you have two poisonous creatures, and one looks like a delicious edible morsel whilst the other one looks like a rainbow circus, the former is going to get eaten a lot more than the latter. Over time the latter should outcompete the former. My quandary is not why poisonous critters stick around, but why is it poisonous animals tend to advertise their poison, but there are an abundance of plants (and to a lesser extent fungi) that are very dangerous but do not advertise they are dangerous. You have ones like stinging nettles that just don't give a fuck, look like a normal plant but will fuck you up, & the previous example of neurotoxic hemlock, irritant toxic hogweed, looking like wild carrot e.t.c.

Most if not all mushroom poisons are slow poisons.

Not all toxiciy evolves as a means of defense. There's also situations where an organism's metabolic products just happen to be toxic to others (or to itself. Yeast dies of it's own alcohol production when it exceeds a certain percentage for example).

This is a pretty good explanation, but you would still think that within the same species of toxic plant/fungus, a species that is poisonous and signals its toxicity would proliferate better than one that does not. E.g. compare fly agaric mushrooms which are super toxic, bright red and white spots. Maybe fungi are bad examples, but what I'm getting at is there are a lot of toxic plants - but there aren't any toxic plants I can think of that advertise they are inedible, and there are many which even look like edible plants. So you'd think selection pressure would create a niche for a plant all herbivores would know to avoid by sight or smell

Maybe:
1. The downsides of investing resources into warning colouration are more serious for a plant than for an animal
2. Selection pressures caused it to evolve warning signs that are obvious to other species, but not us (upon looking it up, all parts of the wild carrot plant smell like carrots, but hemlock does not as an example). Also lol looking at all the plants that evolved signals like coloration for pollinators and scent that are now extinct this one seems just as likely for the reverse; it did evolve warning signals, but for herbivores/omnivores that are now long gone
3. Selection pressures do incentivise a poisonous plant to look distinct, but also incentivises edible plants to look like distinct poisonous plants, making them both indistinct over the course of evolution