The impossible predicament of the death newts | Hacker News Reader

The impossible predicament of the death newts

crookedtimber.org

578 pointsbdr183 comments

> Meanwhile, evolving resistance also comes at a cost. We don’t know that directly, but we can infer it pretty well. If resistance to tetrodotoxin were cheap and easy, everything would evolve it. [..] We don’t know, but we’re pretty sure there must be something. We know that garter snakes outside of the Pacific Northwest are much less resistant to tetrodotoxin. They’ll drop dead from doses that their Oregon cousins simply ignore. So evolving the resistance must have some cost or drawback.

I'm not so sure that's really the case; it's more that for many animals there simply isn't any pressure to evolve (or retain) this trait.

It's not like the natural selection process has a feature list it can tick off. It operates with zero foresight and an incredibly dumb principle: whatever helps procreation.

Cows are not dying due to tetrodotoxin poisoning in significant numbers, as far as I know, so there is no reason for them to evolve resistance to it. The same applies to most animals, including the snakes outside that area.

Your dog can synthesise their own vitamin C and will never develop scurvy. Most animals can do this – humans and some other primates are the exception. An ancestor lost the trait for vitamin C synthesis by chance, and because these primates were living in trees eating lots of fruit with vitamin C, evolution simply didn't notice. There is no disadvantage to being able to synthesise vitamin C, and no advantage in dropping the trait. It didn't affect procreation (at the time). Now we're all stuck with it.

Now, maybe all of this does have a cost for the snakes. But it's far from a given that there is one.

I think it might be more useful to look at the author's claim from the other side of the lense. We do carry around barely useful traits, like resistance to toxins that we seldom come in contact with. We can assume that carrying such traits is cheap. If resistance to tetrodotoxin was one such cheap trait, it might have been more prevalent, but it's not so, it could be inferred that it's expensive. Or at least, not cheap.

This is another case of a huge fallacy humans seem endlessly afflicted with: The Root Cause Fallacy.

You are assuming there is but one cause for development and/or loss of resistance.

There may not be much pressure to develop resistance to tetrodotoxin for most species. Simultaneously there might be a higher metabolic cost to retaining it for some species but not for others. It is also possible that resistance with low cost is very rarely lost which is why we carry resistance to toxins we don't often see but population bottlenecks in ancestral lines can cause loss of a trait to propagate - even by accident. And much like Vitamin C loss if it doesn't matter the loss sticks. We should not forget that there are multiple resistance mechanisms as well: an immune system generally primed to fight certain common causes of mortality can, entirely by accident, also be primed to recognize and destroy certain proteins conferring resistance to some toxins and not others.

I have barely scratched the surface above. The random walk of evolution and its constant hoarding tendencies should make everyone skeptical simplistic mechanisms of action as well as "just so" explanations of evolutionary history.

FWIW most things are multi-causal. I previously made the same argument about house prices. People who claim it is caused by foreign money, low interest rates, restrictive zoning, etc all want their pet theory to be The One True Reason. In reality the market is complex and many of the proposed causes are merely contributing factors.

> You are assuming...

I made no assumptions. As I pointed out to another commenter, you might be in too much of a haste to play at being a contrarian. It might be more useful to pay closer attention to what you're objecting to.

Evolutionary game theory demonstrates that evolution is a matter of fitness payoffs. If cost of a trait increases, fitness is reduced. The prevalence of a trait in a fit population is indicative that, at best, the trait increases fitness, at worst, it doesn't hinder it. In both cases, the genes tend to be passed on and the game is allowed to continue. When carrying the trait becomes costly, there's pressure to get rid of it (through the usual evolutionary means).

The above model encompasses all the unnecessary specificity you tried to bring into the matter. If you object to it, address your concerns to the scientists that are leading us all astray.

For now, let's circle right back to the author's original argument. Absence of an actually useful trait to increase fitness (i.e. protecting ones from certain food sources and others from predators) might be indicative of a hefty tax to pay for carrying it.

As a biologist, reading your comments is deeply distressing :(

Isn’t evolutionary game theory a behavioural model from the 1970s? Not that it’s not interesting; I don’t see the relevance here. Maybe it’s just your condescending tone.

(No offense, I hope you don’t realize how you are coming across, or that if you do this comment will trigger some introspection)

You need to accept that you don't know what you're talking about.

Jesus man, your hubris is astounding. 'I made no assumptions'? Ridiculous lol

Behave yourself

That resistance to toxins we don't encounter often enough to constitute selective pressure, we carry around only if it's the accidental byproduct of another selected-for trait. Otherwise entropy would take care of it, sooner or later. Parent is right, evolution doesn't pay an annual subscription fee for some service which was useful in the past and might come in handy in the future.

You may just be trying to disagree with the author for sport.

> we carry around only...

Not true. We can carry resistance to some ancestral pressure which isn't part of the current environment.

> sooner or later...

Yes, sooner when it's costly, later when it's less so, through normal evolutionary pressure (entropy and all).

The point is, most species at time T do carry traits that aren't that useful to them anymore. The costlier ones yield enough negative fitness points in evolutionary game theory to rid the gene pool of them quicker. It brings us right back to the author's original argument.

It would be interesting to see how toxic these newts would remain if the garter snakes were eradicated. If this was indeed a costly trait, we should see a drop in toxicity over a long period of time (possibly evolutionary time). To rule out coincidence, you could follow multiple lineages as they speciated.

In fact, looking at related newts whose ancestors were toxic (assuming the trait is not novel in these ones) would give us some idea as well.

In the context of TFA, are you sure it's not GP who's arguing for sport? Maybe this clarifies the issue: one way to reword the root (critical) comment is "of course there is a cost, since entropy is always exacting a price". There's constant upkeep necessary for any trait if it is to be preserved. It points out a glaring blind-spot in the article.

(I agree with you)

It’s funny how often this sort of thing comes up. I’ve always felt that “biology” as a field was unique in the way that it is often taught. Bio 101, etc. - most of undergraduate biology - is often taught with this sort of sweeping worship of the process of evolution in a way that leads to it transcending rational thought. Natural selection is very real, and it’s also such a sorry excuse for an evolutionary algorithm :D

It’s been a long time since my first bio classes so I can’t remember the way I was first taught it, but I do remember all more advanced bio literally being told to unlearn what we had already been taught.

You really seem to lack any understanding of how evolution or biology work :(

It’s not some binary thing but degrees of adaptation.

People can handle significantly more of a wide range of plant toxins like theobromine and caffeine (both found in chocolate) which harm more pure predators like dogs in very low doses, but where rare for out imitate ancestors.

Cattle, deer etc however can handle many of those at much higher doses.

> like resistance to toxins that we seldom come in contact with.

Is that because resistance to those toxins was strongly selected for in humans, or because the source of those toxins did not strongly select for effectiveness in humans?

You wildly misunderstood the topic being discussed and user above you is correct.

Not wrong, but one could frame that as a "cost" that you pay in the space of genealogical problem solving. Having one less constraint makes it easier to adapt to other evolutionary pressures

Agreed, it's just shorthand/abstraction. Just like my for-loop in python doesn't actually mean my computer speaks Python

I omitted some bits from the quote for brevity and HN's faux-quoting sucks, but that's not really the type of "cost" the article is talking about: "maybe they’re suffering from much more subtle neurological effects, like being prone to insomnia or hallucinations or sexual dysfunction. Or maybe they’re just a bit dim."

That claim jumped out to me as well. Evolution is supply and demand, cost and benefit, capacity and constraints, none of it balanced by anything apart from luck.

This is categorically false, we know evolving bigger brains required us to reduce our muscle mass compared to other primates, for the energy budget required to create such brains.

And those adorable koalas made the opposite bet, shrinking brain size in order to conserve energy so as to be able to carve a niche no other mammal cared for: https://youtu.be/dXUp_JMQjvg

Do we know that? I thought that the evidence suggested that early hominids lost muscle mass, especially in our arms, as they came down from the trees. We also switched from stronger muscle fibres to high endurance muscles.

You’re right that there was an energy trade-off, but it was being able to run faster and longer that was more important than strength for our ancestors, who still had quite small brains (the brain of an Australopithecus is only 35% the size of a human).

Brain size developed later, probably in a feedback loop with our diet - as we began to eat more meat our brains got bigger, which made us better hunters. And hominids actually got bigger and stronger as their brains grew.

The diminished muscles in our jaws are one of the direct causes we have bigger brains, source: https://www.newscientist.com/article/dn4817-early-humans-swa...

Humans evolved Wesker muscles to gain brain mass, source: https://www.nationalgeographic.com/culture/article/140527-br...

From the first article:

> Humans owe their big brains and sophisticated culture to a single genetic mutation that weakened our jaw muscles about 2.4 million years ago, a new study suggests.

_A new study suggests_

I don’t think you can treat these claims as categorically true. It’s plausible and probably warrants further study, like most things in biology.

Edit: I could not read the second article you linked as it was behind a paywall, but I found the full text of the original paper[1]. The paper appears to make a much weaker claim: that a weakening of jaw muscles in humans coincided with acceleration in brain size. This is certainly intriguing, but correlation does not imply causation.

[1]: https://pmc.ncbi.nlm.nih.gov/articles/PMC4035273/

So we are to believe evolutionary paths are free? A stronger homosapiens could have done much more in their lifetime than an equal specimen with the same brain matter but less muscles, even with all the niceties of common era I very frequently find myself in scenarios where being stronger would have helped, I had to move to a building without an elevator and had to carry the freezer, the washing machine and other stuff to the fifth floor, having more muscles certainly would have helped, more recently I found a screw I couldn't unscrew just because I lacked enough force (not because it was a stripped screw), just imagine the amount of scenarios I would find myself if we didn't had all this technology and kitchen appliances that we have this days? You think our manual farming ancestors didn't need all the extra help they could get? To me it's almost preposterous to suggest we gave up our muscles just because we didn't use them because we lacked reasons to use them.

> So we are to believe evolutionary paths are free?

Huh? Where did I say that?

I was just pointing out you presented two claims as facts and the sources do not support your claims. Maybe there are other sources that do, but the two studies you cited make much weaker claims.

The news article titles misrepresent the findings in the typical way that news articles sensationalize and misrepresent science etc etc.

That cost and benefit trade-off emerged as an opportunity only through luck and it survived only through luck, even if the odds were in its favor.

That's a very broad definition of the word luck, like saying I landed a job by having luck that some company was offering that role, therefore everything is luck, and communication wise would make the word almost useless.

You’re comparing the intelligent design of your job search to evolution.

Luck is defined as something happening that was unlikely to happen, so having that in mind that evolution kept happening that is no luck, happens on every living organism (last specimens before extension being the exceptions), that the smarter apes got to reproduce is not luck, it is predictable, that they had to use less muscles if they are smarter is also predictable, that muscles are something primates can give up easier than e.g. liver function it is fairly predictable, that you would prefer to take better care of your smarter offspring is also fairly predictable (not saying it's morally justifiable), and so there are so many aligned factors and feedback loops at play that calling it luck would be a disservice, yes evolution has a slight "brute-force" approach to it that arguably involves "luck" but that it's just a small part of it

There’s a practically infinite space of possible innovations. The fact that any part of it has ever been explored is just down to luck—and that’s ignoring the fact that once evolution discovers an innovation, survival of the fittest is still itself not a rule but rather a likelihood. Maybe there was a fish who could communicate telepathically and fly at the same time there was a fish with feet, but the latter ended up devouring the former in the nursery.

Once you reach a particular point, things might tend to play out in ways that look more deterministic in specific places, but fate is still hard to predict. Consider the Vaquita. A species that has thrived for ages has been nearly wiped out of existence because a random primate species evolved to invent plastic fishing nets, and now that same primate species might altruistically manage to govern itself out of destroying the Vaquita. Really, nothing in that story was guaranteed to happen based on the frontier of the search process 1,000,000 years ago, it was just how the dice landed.

The Vaquita’s survival or loss is playing out in some ways as an international diplomacy story, where the first Trump administration saw declines in Vaquita numbers and the Biden administration took steps to improve their chances, and then Trump was re-elected, with some people believing that came down to Biden—a single human man who does not live in Mexico—experiencing age-related declines, and with others believing oligarchs bought the election to support causes like Russia’s pursuit of Ukraine. Really, this is about as random and as divorced from survival of the fittest as it gets. But it is no more random than the fact that the person who might have ushered in 1,000,000-year era of world piece and cured all suffering in all species would be just as likely to die as a child in a car accident as anyone else.

In ML, evolutionary algorithms are classified under randomized optimization, due to the way that they take random steps to forge random paths into vast combinatorial spaces that could never be completely understood or completely explored.

Biased random walk and luck are related but not the same thing. It is not necessarily correct to term the outcome of a stochastic process as luck.

> An ancestor lost the trait for vitamin C synthesis by chance, and because these primates were living in trees eating lots of fruit with vitamin C, evolution simply didn't notice. There is no disadvantage to being able to synthesise vitamin C, and no advantage in dropping the trait.

The fact that guinea pigs, fruit bats, and passerines (almost half of all bird species!) also have a mutated GULO gene suggests that there is in fact some pressure to get rid of it as soon as it is bioavailable from diet.

Eh, enzyme mutations leading to inactivity aren't uncommon. It could just be drift when enough vitamin C is available.

> There is no disadvantage to being able to synthesise vitamin C, and no advantage in dropping the trait.

So why did the trait of that mutant primate spread throughout the entire population? There should instead be a mixture of those who can and those who can’t synthesize vitamin C.

(Indeed, one should perhaps not so blithely assume that there was sufficient fruit for everyone and so C didn’t matter… for it is precisely the ability to survive in times of drought and scarcity that drive evolution, and there id no reason to suspect a population that could synthesize their own vitamin C was less fit than a population that couldn’t. The issue of vitamin C is far from simple…)

There is no reason for it to spread, but also no reason for it not to. Presumably there was another (completely unrelated) trait, and it happened to spread because of that.

> There should instead be a mixture of those who can and those who can’t synthesize vitamin C.

Probably was for a long time. All of this happened about 60 millions years ago. It's been a while.

It's more likely that a mutation in the gene/pathway arose multiple times independently, instead of one spreading through the population.

> There is no disadvantage to being able to synthesise vitamin C,

Synthesizing vitamin C takes energy, energy that could be used for other biological processes. It's also possible excess vitamin C has some minor deleterious effect. For example, it's an antioxidant, and these render immune cells somewhat less effective against certain threats (which they use oxidizing chemicals to destroy). It's been found larger doses of the ACE vitamins causes increased growth of lung cancer, probably due to reduced immune attack.

Some have argued against this idea, though, although I'm not convinced by the argument (see if you can spot the problem.)

https://pmc.ncbi.nlm.nih.gov/articles/PMC3145266/

Survivorship bias, you perceive it doesn't come with a cost, but perhaps some species that were exposed to it died from it because they failed to adapt because it does come with a cost they couldn't pay, so they went extinct, like it's wildly common.

Reptilian Predation squeezed mamalian reproduction into the fast and the furious . Meanwhile birds and turtles reproduce hapoy at methusalem ages. No creator, no design, just merciless pressure that stupidly rewards successful maiming to adapt.

But a nonzero number of animals and people die of tetrodoxin poisoning, so there is some pressure. Therefore if it were cheap and easy enough, it’s likely we all would have evolved it. That cheapness threshold might just be incredibly high.

If it is rare enough it probably doesn't exert much selection pressure.

Has anybody modeled what percent of a population has to die from something for the protective gene to become widespread?

If you're willing to abstract a bit from populations of animals to populations of bacteria, there is the minimum selective concentration (MSC), which is the smallest amount of antibiotic you can add to the growth medium and detect antibiotic resistant bacteria competing out non-antibiotic-resistant bacteria:

https://revive.gardp.org/resource/minimal-selective-concentr...

> Has anybody modeled what percent of a population has to die from something for the protective gene to become widespread?

The question is incoherent. The gene spreads if the organisms carrying it average more children. It unspreads if they average less. All of them could be dying of the same thing, and it wouldn't matter.

The rate of spread is given by the https://en.wikipedia.org/wiki/Selection_coefficient , but cause of death isn't relevant.

Yes! Thank you! I’m barely knowledgable when it comes to biology and I still get annoyed when evolution is framed as cause-and-effect.

Well, there is some "cause-and-effect" in evolution.

Whenever a species winds up isolated in a cave, it loses eyesight really quickly in evolutionary terms because making and maintaining an eye is so metabolically expensive. So, while the mutations are random, any of them that can save the energy of developing vision get selected for very quickly.

So, even though the mutations are random, it really looks like "cause-and-effect" from the outside: get isolated in cave->lose vision; get exposed to outside light again->regain vision.

By the same token, changes that aren't very expensive metabolically will have very weak "cause-and-effect" because there is no particular pressure to carry the mutations forward or clean them up.

No need to be annoyed. I think if you look deeper, you might find that, in fact, all occurrences of what we call cause and effect are of a similar nature.

I recently learned, there is a dangerous plant in many gardens around the US. If you stand under it for more than 10minutes, you're pretty much dead.

Turns out, it's the water-lily.

Water lillies not only are not dangerous, they’re partially edible and have also been used in medicines. Do you mean peace lilly or calla lilly? Neither is deadly, but they can make you ill. Water hemlock is deadly and has white flowers?

The joke here is that: If you stand under a water lily for 10 minutes, you are underwater for 10 minutes

Well you see, I’m not smart

I recently learned that (Wikipedia) "Vascular cambia are found in all seed plants except for five angiosperm lineages which have independently lost it; Nymphaeales, Ceratophyllum, Nelumbo, Podostemaceae, and monocots.[1]" Four of these lineages are aquatic plants (including water lilies) and some scientists theorize monocots may have also evolved in the water. I seem to recall reading that aquatic plants don't "need" woody growth for structural stability, but can't find a source right now.

Though now I kinda want a horror short where someone slowly realizes the water-lilies are the real apex predators

The linked article about toxic blue-ringed octopus is even more interesting.

https://crookedtimber.org/2025/03/14/occasional-paper-the-in...

The author points out something I've thought about a few times; we are just giant robots that bacteria use to live in and move around rapidly.

Nature is not kind.

Interestingly written article. Raises some questions:

>Newts with weaker poison? They get eaten. Snakes with less resistance? Have trouble finding newts they can choke down, and don’t get to steal their poison. So the arms race continues.

How does a snake know that the Newt has weaker/strong poison? Is it leaving some Newts along and eating others, or is it eating any Newt it runs across? Does a strong-poison newt survive snake consumption attempts?

it was mentioned elsewhere on the article that the snake may spit out the newt of it's too strong, kinda like a human with chili peppers, I suppose.

Maybe a better way to frame it is over time, there's some genetic sequence that gave the snake a preference for eating this newt in particular out of all potential prey and some other genetic sequence that gives them a bit of resistance so they can store the poison inside them. Those snakes that eat more of them with that genetic makeup, up to a point, are better able to reproduce. Run a few thousand years of iterations over this process, where the snake and newt are in a red queen situation, both running faster and faster just to keep up. It is possible to look at this as situation where neither the snake or newt is conscious of the choices or there is no ability to make decision, there is only following the built in behavior.

I think the preceding sentence in that paragraph answers it. Important context here is that garter snakes tend to swallow prey whole. tldr: a strongly poisoned newt survives consumption attempts.

> And it explains why the newts keep evolving to be more toxic: the snake may want to eat newts generally, but if an individual newt packs enough of a wallop, the snake may just retch it up and go after a different one. Newts with weaker poison? They get eaten. Snakes with less resistance? Have trouble finding newts they can choke down, and don’t get to steal their poison. So the arms race continues.

> Snakes with less resistance? Have trouble finding newts they can choke down, and don’t get to steal their poison.

That's got to be an extremely weak effect. No snake gets an individual benefit from eating the newts. They get a collective benefit, that predators recognize the species as poisonous, in which all snakes, poisonous and delicious alike, share equally.

The problem is large enough that actually-poisonous animals routinely have delicious mimics of entirely different species who free-ride off of the work the originals do to be poisonous.

You can't explain why snakes apparently need to avoid sending a dishonest signal with a theory that predicts that mimics don't exist.

Yeah that particular aspect of his claim feels like the weakest.

Here is a slightly more in-depth piece where a wildlife biologist mentions other possible forcing functions that cause the snakes to eat the newts: https://baynature.org/2022/04/06/the-bay-area-is-the-center-...

From the article:

> “When garter snakes are born in the late summer, they often live under mats of drying pond vegetation … That happens to be where the newly metamorphosed newts come out in the fall, and we suspect there could be a lot of interaction between predator and prey just because of this overlap in microenvironment. That could have led to strong selection in the past that resulted in such high levels of resistance.”

Interesting.

Let me see if I follow: once the snake population has the warning coloration, and predators know not to eat them, then individual snakes being successful at eating poisonous newts is unrelated to the snakes living long enough to pass their genes (i. e. being successful in terms of natural selection). So a snake which has the right colors will be successful, regardless of its diet.

I wonder, is there a point where mimicry can fail? Can predators at some point start to eat the mimics?

> Let me see if I follow: once the snake population has the warning coloration, and predators know not to eat them, then individual snakes being successful at eating poisonous newts is unrelated to the snakes living long enough to pass their genes (i. e. being successful in terms of natural selection). So a snake which has the right colors will be successful, regardless of its diet.

Sort of. Whether the snake is poisonous is unrelated to its success, because it dies upon being eaten whether there are consequences to its predator or not. (The article takes some pains to show that this is untrue of the newts, but not the snakes.)

However,

> the snakes living long enough to pass their genes (i. e. being successful in terms of natural selection)

This does not reflect a good understanding. Success means having more children, not having any children.

> This does not reflect a good understanding. Success means having more children, not having any children.

I never said "any children", so your remark doesn't reflect a good understanding of what I wrote.

Try not being pedantic for pedantry's sake, and engage with a question asked in good faith without playing games of one-upmanship.

You said that living long enough to reproduce constituted Darwinian success. That idea is (1) extremely common, and (2) dead wrong.

It's extremely tiring to have to write informal comments while couching them in all kinds of caveats and clarifications to make them iron-clad and beyond reproach by even the most persistent of nitpickers. It makes pleasant conversation impossible.

And for what? Instead of focusing on the question I actually asked, you decided to correct me on something tangential for meaningless internet cred.

Congrats, you won 1000 megacredits.

> Instead of focusing on the question I actually asked, you decided to correct me on something tangential for meaningless internet cred.

Instead? The response to that question heads my comment.

> I wonder, is there a point where mimicry can fail? Can predators at some point start to eat the mimics?

The same sources of variation which provide the variety for evolution to work on to evolve avoid eating things with this appearance behavior will also provide variation that evolution can work on to evolve back to do eat things with this appearance behavior; the frequency with which eating causes death vs. the degree to which not-eating results in insufficient nutrition will decide which wins.

That's all true, but I should point out that there are finer grains of behavior, and some of them asymmetrically make it easier to learn that "actually it's OK to eat those". Predators could evolve the ability to tell the difference between mimics and originals (which is generally rare but extant; consider how human children are taught to tell the difference between coral snakes and king snakes, or how certain birds can reject eggs that they didn't personally lay, but most can't), or they could evolve the behavior of "don't eat things that look poisonous, unless you're really hungry" (which is not rare, and which doesn't work well in a low-mimic environment, but does work very well in a high-mimic environment).

As you note, the behavior you end up with is determined by how much stress the mimics place on you.

I suspect that as the number of mimics increases (either an individual species or convergent evolution of mimicry, like we see with the number of insects with bee or wasp-like coloration), the relative risk of consuming things that look poisonous drops to a level where it’s sustainable for a population of predators.

To your point I wonder if eventually some truly toxic species can become a victim of their own success

> The problem is large enough that actually-poisonous animals routinely have delicious mimics of entirely different species who free-ride off of the work the originals do to be poisonous.

When cargo culting goes right.

Yes, if supply planes couldn't tell the difference between military runways and cult runways, cargo cultists could lure them in and... depending on their defenses... overpower the pilot and take all the stuff.

I found this on Wikipedia, but tldr they taste test it.

> Successful predation of the rough-skinned newt by the common garter snake is made possible by the ability of individuals in a common garter snake population to gauge whether the newt's level of toxin is too high to feed on. T. sirtalis assays toxin levels of the rough-skinned newt and decides whether or not the levels are manageable by partially swallowing the newt, and either swallowing or releasing the newt.

> Turns out there is an answer: the garter snakes sequester the tetrodotoxin, storing it in their livers. This makes them toxic to their own predators.

Second-order effects are so cool

Love the title, and great article.

This might be a total tangent, but every time I see “newts”, I think about how Karel Capek actually coined the word robot in his 1920 play R.U.R., and then later gave us War with the Newts...really smart amphibians. Thanks for sharing.

As a French person, it's the first time I see this word. My brain can't help but parse the title as "death news".

I can understand why. You rarely see newts mentioned, even though they’re biologically fascinating. Maybe it’s just because people mistake them for another kind of lizard.

The War with the Newts is fascinating. An indictment of mankind told with dark humor...

Apparently the snakes' immunity pales in comparison to the local caddisflies.

[0]https://www.discovermagazine.com/planet-earth/a-beautiful-we...

Newt poisoning of humans must be rare, I’ve lived in this region my whole life and I don’t think I’ve ever heard of this!

I did several semesters' worth of biology fieldwork in college that involved handling many of these guys, under the guidance of a professor who was obsessed with them. Their toxicity was discussed more as a point of interest rather than an immediate danger. We always wore gloves when handling them, but the rationale was more for the newts' protection rather than our own. I never heard of there being a newt poisoning incident during the past decades of this professor overseeing similar fieldwork. Of course, eating them was out of the question.

Yes, I must have played with these newts at least a couple dozen times as a child, they were under every leaf and log in the forest and near streams where I grew up.

I live in the PNW and I see hundreds of garter snakes, some newts, but never a Rough-Skinned Newt. I had no idea such a creature was around here.

I think the article is exaggerating quite a lot

> It’s so toxic that the poison from a single newt can easily kill several adult humans. You could literally die from licking this newt, just once.

TBF there is one death reported in Oregon from someone eating an entire newt in 1979, but they aren’t as bad as the article would have you believe. Many of us have handled these newts. There would be a lot more dead people if licking is all it took.

> A 29-year-old man drank approximately 150 mL of whiskey at about 11 AM July 9, 1979. At 6 PM he swallowed a 20-cm newt on a dare. Within ten minutes he complained of tingling of the lips. During the next two hours he began complaining of numbness and weakness and stated that he thought he was going to die. He refused to be transported to a hospital and was left alone for 15 minutes and then experienced cardiopulmonary arrest

Oooooh! I saw “I’ll have to teal deer it” and thought it must be some strange idiom. Had to go to Urban Dictionary to find out “teal dear = tl;dr”, and now I feel as dim as a garter snake that’s evolved resistance to large amounts of tetrodotoxin.

I didn't get it either, but now I'm just sad that it's come to this, where we have to replace 5 characters with 9 just to seem "cool". Sure, it's 2 syllables instead of 4, but then we REALLY should have avoided using www as the prefix for the web. It's not like we talk about surfing "the WWW" - and even saying the 3 letters is WAY longer than saying "World Wide Web".

It's great in german - 3 syllables for 3 letters, but english/french, it's NINE syllables for 3 letters. I always thought it should have been web.domain.org.

> It's great in german - 3 syllables for 3 letters, but english/french, it's NINE syllables for 3 letters.

Kind of absurd to use multiple syllables for a single letter if you think about it.

> I always thought it should have been web.domain.org.

It should have just been "domain.org" - the web part is already specified in the protocol. And if you are concerned about domains only having a single IP that could have been (and for many protocols has been) solved with SRV records.

Thanks to YOU for the teal dear.

That just means you're adapting to survive the modern web

I was thinking it must be a play on "steel-man" but nope.

Thanks for the taking the time to find out for the rest of us.

They're cute. They're pretty much harmless in my experience.

They swarm all over the PNW, in season. Don't step on them if you can help it. They're not death newts. I'd be a dead commenter if they were death newts.

They swarm all over the trails in spring, and then they're gone for the rest of the season. That's my recollection of it.

I don't live there anymore, maybe they have evolved into these dangerous death newts. One can hope.

> Turns out there is an answer: the garter snakes sequester the tetrodotoxin, storing it in their livers. This makes them toxic to their own predators.

But this doesn't seem as immediate as the newt's defense where it's on the skin and thus causes potential predators to spit them out or even to seize up - meaning that at least some attacked newts survive the encounter. Eating the liver means the snake is dead. And since it's going to be impossible to tell if a particular snake is immune (and is thus potentially toxic) how would this deter predators? (Especially given the limited range of snakes with this immunity and the probability that there are predators of the snakes that don't necessarily have this same limited range - ravens, raptors, etc.)

If the predator species have heritable differences in prey selection, no matter how slight, natural selection can work with that.

Eating a snake might not kill a predator outright.

And higher predators (like mammals) also have food preferences. They don't always eat stuff indiscriminately, so predators that don't _like_ snakes will preferentially survive. Eventually, this can get established as a genetic trait.

Or as a behavioral one, if parents don't teach cubs to hunt snakes.

> how would this deter predators?

Maybe the predator's carcass next to a half eaten garter snake is meant to serve as a lesson to other potential predators.

Or perhaps the aim is not to deter but to simply take one natural predator down with them for the good of their species.

Christ, I handled these as a kid quite a bit. Add that to the list of reasons I will wonder how I survived past age 10.

I used to keep native snakes and lizards (and inadvertently breed them!), and couldn’t keep newts because I wasn’t sophisticated enough to create the right environments for them. This is one species I kept (and killed, unfortunately). I’ve learned to do it far better since then, but haven’t tried keeping newts again. They’re beautiful little creatures.

I also handled these all the time as a kid in northern Oregon, literally hundreds in a day because they would hang out in a series of lakes nearby. Is there a non-poisonous rough-skinned newt variant? I find it impossible to believe that as a young kid I wouldn’t have licked my fingers after years of doing this.

few more generations of handling these lil friends and maybe we can get aposematic coloring in humans

Maybe we’re already in the afterlife. How would we know any different, really? Bested by newts

I'm not aware of other newt species in their range that look similar.

I do think the article plays up their toxicity some. There's only one reported human fatality I could find, from some dipshit who ate one on a dare. If you handle them gently and don't stuff your entire hand in your mouth immediately after, I suspect you're fine.

Same here. I had no idea they were this toxic, I feel like someone should have told us this as children!

What a fun read! One side note: the coloration of that garter snake is very strange to my midwestern eyes. Our garter snakes aren't nearly as vibrant.

Could being a toxic or venemous creature be bad for survivability of a species in the long term if smarter creatures discover you’re lethal and thus become determined to kill your kind on sight?

I'm curious about the broader concept of species intentionally killing other species for reasons other than food.

Intraguild killing (such as lions killing leopards or cheetahs) has been described in multiple species.

Perhaps interesting; https://pubmed.ncbi.nlm.nih.gov/34816428/ (Still need to read it)

Territorial animals will kill to protect their turf. A successful species could conceivably kill off a less successful one by conquering all its territory.

Cats kill things for I guess what you'd call fun, although it is food related as they hone their skills for when they may need them.

What would be the advantage of that? Killing the animal comes with the risk of being poisoned, and no reward. It's best to just ignore them.

In theory, you're killing a species that competes with your preferred prey species for habitat or food, which could mean more abundant food for you and your kin in the future.

I am not aware of any species besides humans that do this, though.

Most people who get bitten by venomous snakes were fucking with the snake. It's a bad strategy, much better is to leave the snake alone.

Wolves and other predators were hunted to near extinction in North America on this rationale. My mother in law kills all spiders and snakes she can on sight.

Guess she doesn't know what snakes eat. Usually if there are snakes around it's because you have rodents. If you're smart you leave the snakes to their business and try to address the rodent problem instead.

Same deal with spiders, they're obligate carnivores. If there are spiders around, that's because there are other bugs about.

Honestly I understand wolf culls a lot more. I don't agree with them, but I understand the rational motive of people who have livestock, pets, or even children.

How even when we think we've figured it out the system throws in a curveball. Nature's like, "Oh, you thought this was simple? Cute."

Fascinating article and really enjoyably written.

Though I remain a tiny bit disappointed that it wasn’t about some arcane royalty arrangement for the band “The Death Newts”.

Or Axolotl and the Hellbenders!

Mirror snapshot: https://archive.ph/hJHNM

I learned a new word: "aposematic"

I can already think of uses of this word jokingly in a people context

Fascinating and well written article!

I'm pretty sure my degoogled Murena /e/ OS pixel 5 won't have this problem.

Wrong thread -> https://news.ycombinator.com/item?id=44193198

Indeed

Don't snakes find their victims more by smell than sight? Do they even see in color? It seems that "don't eat me" coloration might work for the newts.

What a fasinating read. Thoroughly enjoyable writing. Thank you.

intersting

I once took a group of young people foraging for mushrooms in the Willamette valley on a farm that had loads of these newts. I warned every body not to touch them.

After preparing dinner, one girl got very ill, as did I, while other people who ate the dinner were fine. I was so worried I'd mis-identified some mushrooms.

But turns out she had handled one of these newts and the bacteria had transferred to the mushrooms she picked. I contacted it from washing the mushrooms. I threw up several times that night.

In hindsight, had we not washed the mushrooms as thoroughly as we did, things could have gone much worse.

Eating wild mushrooms has got to have the worst cost/benefit ratio outside of wingsuiting or recreational bear wrestling. In exchange for hours of study and a significant risk of death you get fifty to a hundred calories of food. Probably made sense in the tenth century when the average person was one bad harvest away from starvation, but it seems harder to justify today.

Where I live mushrooms are by far the most abundant wild food. It's good exercise, very enjoyable "work", and they taste really really good with a huge variety of flavors.

Leafy greens also have very low calories per pound. We eat them for the nutrients not for the calories. Because of mushrooms and wild greens, I buy very little vegetables, all I need is relatively cheap (per calorie) foods to go with the wild stuff.

There is also risk of food poisoning with food from restaurants or the store.. not to mention the chronic poisoning of eating food grown with excessive pesticides etc.

For the most part the abundant edible mushrooms look very different from the dangerous ones. But yes you do need to know ID thoroughly if you go for certain species.

That said not everyone lives where edible mushrooms are abundant, I'm not trying to suggest everyone should do it.

Where is this, if you don't mind my asking?

Not even that much. A couple of cups of mushrooms -- a generous helping as a side dish -- has around 30 calories.

All the significant calories comes from the oil or butter they're cooked in.

I'm not sure it was ever about avoiding starvation, but rather just a different flavor to eat sometimes. When you're always eating the same local ingredients, food can get boring pretty quick. It's the same appeal of spices -- you got a new flavor!

Mushrooms add to the umami flavour, before salt was easily accessible this was probably your best bet for easy flavour enhansement

Salt is more fundamental for the body than just flavoring. I'd hesitate even to call it a spice. That said, umami ingredients like mushrooms and seaweed are certainly used together with salt.

Salt has always been freely available from the ocean, which I believe most people lived pretty close to.

MSG is like $0.30/kg.

I don't think they had MSG before salt

There's a long history of glutamate containing food and food products being used in place of salt across the world, before it was first chemically isolated.

Who cares? We don't live "before salt". Human use of salt _predates writing_ by about 3000 years.

You wouldn't choose to do manual typesetting (or copying books by hand!!!) today either versus alternatives.

If you're _just_ looking to add umami flavor to a dish today, you'd be crazy to pick foraging for wild mushrooms over Aji no Moto.

Well you were replying to a comment about why we foraged for them before salt broski. Doesn't really make sense to bring up the price of something that wasn't isolated then.

I'm skeptical of any food that humans only started eating since the industrial revolution, including those that are derivatives of or isolated compounds of real food. Mostly the effects on our bodies are not well studied. I haven't specifically read studies on msg though.

I mean, foods like soy sauce and yogurt and sauerkraut predate industrialization, but are very processed. I wouldn't worry too much about MSG in particular, since it is also mostly made by fermentation:

https://en.m.wikipedia.org/wiki/Monosodium_glutamate

How much studying of food do you think was happening before the industrial revolution?

> Human use of salt _predates writing_ by about 3000 years.

That looks like... an intensely conservative estimate. Deer use salt.

> It's the same appeal of spices -- you got a new flavor!

That's not the appeal of spices. People don't stop using the spices they like in quest of newer, worse-tasting ones. By far the most common case when a person is eating spices is that there's nothing new about the flavor.

Could also be used to mask stale or spoiled foods that if cooked enough, wont kil you and still contains nutrition. Nothing goes to waste. Another could be preservation as is the case for salt.

Salt is much simpler than that. It's a vital nutrient and if you don't eat enough of it, you'll die. It's useful for preservation, sure, but you're not eating it because you couldn't find fresh food. You're eating it because it's salt.

Many spices, as well as actual oil extracted from actual snakes by actual healers, and mushrooms as well, gained reputations in antiquity as medicinal and/or beneficial to health in some way.

And this often fueled increased trade and increased cultivation volumes and increased prices and tariffs and wars and cruel laws. In antiquity.

And often, the actual medicinal benefits became overhyped, and crept from their scope, and each nation's crown jewel of a spice became a miracle cure-all, and cue the trade wars and sword-wielding knights defending their spice.

Basically the "Snake Oil Salesmen" of the Wild West were white hucksters who diluted the actual snake oil down so much, or didn't bother adding any in the first place, then sold the elixirs on Main Street between the saloon and the whorehouse. So the Native Americans were nonplussed that their shamanistic remedies had been subverted as a trope of quacks and hoaxers.

Most of all, these spices and mushrooms have been gradually enshittified, perhaps literally, and many of them are a shadow of their former selves, bred for mass-production. And Americans sit there and dust our burger and fries with gray sand that doesn't even taste like black pepper anymore. Not to mention the salt that's been refined until there's nothing but sodium in it.

Perhaps mushrooms are the least likely food to be enshittified or deliberately commercialized, except for about 4 types in the grocery stores. From what I've learned about mushroom foraging, it's never worth it; just go buy mushrooms in the store, I mean for crying out loud. The risk is too great, and aficionados can claim "easy identification" all they want, but "easy" is relative and not for you to judge, because there's a fine line between tasty and fatal.

Oh come on - Making cost benefit analysis of foraging and eating wild mushrooms into a matter of calories is wild.

The calorific value of a meal is one of the least important aspects - you might as well complain that the mushrooms don’t come in sufficiently varied colours to make it worthwhile.

It’s not about the calories. It’s about the experience - the taste, the texture, the satisfaction of knowing you did it yourself.

Yeah, when I read the comment about calories I thought "This is a prime example when engineers only think about numbers and completely miss the forest for the trees (err, mushrooms)"

Also, for many mushrooms, the risk of consuming a toxic variety is extremely low if you know what you're doing. People love to bring up examples of "But the head of the Mycological Society of XYZ died of misidentified mushrooms!!", but a while back I dug into those examples and found 0 evidence for any of them - they're just popular Internet old wives' tales that people love to regurgitate.

A high percentage of fatal poisonings in the US have been Southeast Asian immigrants because, in the button stage, the North American death cap looks nearly identical to the paddy straw mushroom they know from home.

Acccording to America's poisen center these are the numbers:

Calls to poisen control concerning mushrooms: 8,294 Of those calls, 4862 were of unknown origin, only like 3-400 are confirmed dangerous wild grown mushrooms, 2k+ are psylocibin. 3-400 is probably <1% of the amount of people who forage, so its a lot safer than driving a car I'm guessing.

(This was a quick scan)

https://piper.filecamp.com/uniq/dPhtQdu6eCQnIQ5R.pdf [page 174-175]

Meanwhile 48 million Americans get some kind of food poisoning each year. Eating food is dangerous!

I've eaten many hundreds of pounds of wild mushrooms in the last eight years and have not had any food poisoning at all.

To be honest, I will probably still pass. Mushrooms kinda freak me out on a biological level anyways. What is crazy to me is how people find certain things scary or risky but they'll literally strap themselves inside a metal box on wheels that has uses a controlled explosion produced with highly carcinogenic toxic chemicals, that has hundreds of parts that can fail, it can slam into the other contraption next you tear you in half, all so they don't have to ride a bike or walk for an extra twenty minutes..

I can't remember who said it originally, but it amuses me to no end that the only reason our society works as well as it does is a mutual agreement to follow some lines and not play bumper cars

Honestly it's not hours of study. You identify the one mushroom that you're going foraging for, and then you need to know the ones that look like it so that you don't get those by mistake. It's pretty simple if you know what you're doing. Ie: Chantrelles have a symbiotic relationship with Douglas Fir trees, so you're only going to find them around Douglas firs.

> Chantrelles have a symbiotic relationship with Douglas Fir trees, so you're only going to find them around Douglas firs

I'm not sure that's true, I know that we had Cantharellus cibarius ("golden chanterelle") growing up everywhere in the woods, but I don't think the Douglas fir even exists there, never heard that name before. The forest was mostly oak I think.

You can say that to any mildly dangerous hobby

How many people in the US do you think actually forage wild plants and fungi?

The number of hospitalizations is somewhere around 10k a year. For ~1500 of those it's at least life threatening. ~100ish end up with organ failure or permanent neurological problems. ~10 of them die. That's every year.

That might be mildly dangerous compared to other hobbies, but if you isolate for actual practitioners of the hobby, suddenly those numbers look extremely dangerous.

Where are you getting your data? Is this a specific country/worldwide/what? If you're just talking about the US, a quick Google search shows your numbers are off by a few orders of magnitude. This article from the CDC estimated 100 hospitalizations for mushrooms in the US in 2016: https://www.cdc.gov/mmwr/volumes/70/wr/mm7010a1.htm

Foraging for mushrooms is not dangerous if you know what you're doing and stick to easily identified mushrooms that aren't easily confused with poisonous varieties.

AAPCC annual reports, linked to from an actual mushroom foraging guide.

Also I said plants and mushrooms. Not specifically mushrooms. AAPCC doesn't track mushrooms separately and I would consider the CDC to not be the authority on poisoning -- their specialty is diseases.

Here's the relevant section from the 2023 National Poison Data System:

https://i.imgur.com/vIXenG8.png

8294 case mentions, 3039 hospitalizations.

for outcomes check the table.

Huh, that is quite interesting, thank you.

Looks like that includes the hallucinogenic mushrooms, which leads to 2139 case mentions and 1146 hospitalizations a year.

Eating plants at random must be more dangerous than eating mushrooms. I have heard that there are far more poisonous plants than fungi, and greens have almost no calories.

Hopefully nobody is eating plants or mushrooms at random!

do you only eat the food with the highest calories:risk ratio?

Risk of death is a huge cost/downside. I've known several people poor enough to optimize all of their eating around cost per calorie. 30-50 calories is basically only worth your consideration if it's free at that point. If that came with a high risk of illness/death it's not even worth considering.

Ironically, optimizing around cost per calorie is, at least in most places in the US, a great way to have horrible health and die an early death.

A lot of the cost per calorie is in preparation; if you can cook your own meals, you can reduce your cost per calorie signficantly. The problem is a lot of people don't have the time (or maybe will-power) to cook every meal; a few of my previous jobs made it very difficult to cook my own meals, so I ate fast-food alot, and gained a lot of weight.

When your boss starts pushing Return To Office, ask if the company has a worthwhile kitchen in the office; at least a burner and plenty of room in the refrigerator for ingredients; it should be feasible to cook breakfast and lunch, but also dinner, in case you need to work late.

No its not. This is such a weird talking point completely divorced from reality. It's the complete opposite.

That's what I was thinking. Rice and beans are cheap cheap cheap.

Starve now or die later is not a difficult choice for most people.

"Starve now"? If you're talking about the US, get real.

Essentially nobody is starving in the US for lack of calories (unless it's a case of mental illness or something similar). In fact, in the US, usually the opposite is true. From the Wikipedia page on food insecurity in the US:

> Reliance on food banks has led to a rise in obesity and diabetes within the food insecure community. Many foods in food banks are highly processed and low in nutritional value leading to further health effects. One study showed 33% of American households visiting food pantries had diabetes.

What food and $/calorie do you get to determine that?

Meh, there are a couple of mushrooms that are super easy to identify with no risk of confusing them with anaything dangerous (at least where I live). Stick to those and you're fine. Also, they are super tasty ;)

They’re also an acquired taste, which makes it even more absurd.

Well then, what do you think about eating fugu?

With foraged mushrooms and bear that you have fought as a side dish.

fugutaboutit?

Sorry but skill issue.

I'm honestly amazed I didn't get tetrodotoxin poisoning when I was a kid. We used to play with these rough skinned newts all the time, they were everywhere, and nobody was especially diligent about washing their hands.

Same! I even kept a couple of them in a terrarium. And, my dad was a PhD in zoology, so it wasn't like I lacked access to expert advice. It was a "they have toxins on their skin, so... Eh, maybe wash your hands a bit", not "wash your hands or the whole family dies" level of concern.

Makes me wonder if a) these toxicity stories are exaggerated, b) it's really regionally specific, c) toxicity has radically increased in the past ~40 years since I was playing with newts, or d) we got dumb lucky.

I loved this article. I didn't know anything about the newt / snake interaction; I wonder if my dad did.

I think B is the case - it seems to be very regionally specific.

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