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Comment by svara | Hacker News Reader

Informative here meaning that you can deduce something about a plant's condition from faint sounds emitted by it. It's not implying that the plants use those sounds for the purpose of transmitting information. From the article:

"These results demonstrate the potential in studying plant bioacoustics, suggest that plant acoustic emissions may play an important role in ecology and evolution, and may have direct implications for plant monitoring in agriculture"

To me even the "suggests..." part is wild overselling. IMO this should have been in such a high impact journal only if they had actually succeeded in demonstrating the ecological relevance, by showing that the sounds are detected and acted upon by other organisms.

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If the signal is being sent, you can be pretty sure that due to the intrinsic efficiency-maximization that biological systems perform then most likely the mechanism for detecting and acting upon it has been evolved by other organisms, especially for something as fitness-critical as stress.

It's a nice thought. But many humans aren't able to do that with each other, so it seems like a high bar for a potato.

> many humans aren't able to do that with each other

Many doesn’t disprove that some do. And it need not be plants; if symbiotic insects pick up on the cue, that’s still interesting.

potatos have more genes that you

This just means that the potato dna-source-code devs were being evaluated by management against a "kLOC" metric.

You reminded me one of my favourite quotes:

"There is considerable overlap between the intelligence of the smartest bears and the dumbest tourists"

~ Quote by a forest ranger at Yosemite National Park, on why it is hard to design the perfect garbage bin to keep bears from breaking into it.

I'm not sure why you can assume that without any direct evidence.

Life is an infinite unfolding of undefinably rich and interconnected phenomena, and we only have labels for a small subset of phenomena.

As a thought experiment, reverse the question: how could we assume that there aren’t interconnected phenomena after discovering evidence that this phenomena exists?

Even if we never discover what those interconnections are or establish labels for them, interconnection/interdependence is the continuing unfolding of everything, and so I tend to think a more helpful default is to wonder what those interactions are instead of if they exist.

At a minimum, Newton’s 3rd law applies, and however subtle the effects, they are almost certainly there. Where or not they’re particularly interesting to us or “useful” to human inquiry is another question entirely.

> As a thought experiment, reverse the question: how could we assume that there aren’t interconnected phenomena after discovering evidence that this phenomena exists?

The opposite of assuming a thing without direct evidence isn't to assume the negation of that thing without direct evidence. They're two examples of the same mistake.

That’s not quite what I’m getting at here. I’m not claiming that something specific exists without evidence, or making any claims about some particular phenomena that I believe exists and must do <x>.

Rather I’m pointing out that the existence of this phenomena is a form of evidence that opens the door to interrelated phenomena. And based on our understanding of the laws of nature, we can be certain that there is at minimum, some interrelation. Whether that interrelation is interesting or worth labeling as some unique phenomena to humans is what cannot be determined without further discovery/evidence.

I’d agree with your comment if the described phenomena itself was just speculation, but that’s not the case here.

It's known that plants respond to chemical cues sent by another plant that has just been eaten or lawnmowed.

From this article:

> Recently, plants were also demonstrated to respond to sounds,13,28,29,30 e.g., by changing the expression of specific genes,29,30 or by increasing sugar concentration in their nectar.31

So there is enough indirect evidence for hypothesis formation.

The sound emission frequencies are also within the hearing ranges of various animals, some of which are herbivores, and some of which eat herbivores. It would be to their benefit to decode the meaning of plant sounds.

Like the xkcd about emacs control key spiking cpu[0], I think its a generally safe assumption that if a behavior exists consistently, then somebody likely depends on it for their workflow

[0] https://xkcd.com/1172/

is argument ad xkcd an official logical fallacy yet?

The sun doesn't shine so that we can see it. It just shines. And now we can see.

Not entirely. Efficiency maximization can also result in a state where a feature is interesting to us but neutral, or just not harmful enough to be worth the energy to change. Remember that the watchmaker is completely blind.

I like that line of thinking. But I still fail at giving a good explanation of that concept. Maybe it's intuitive for me due to having learned about cellular automata during my youth. I know I'm entering esoteric and new age territory but something tells me this can even be applied to phenomena like quantum entanglement. My idea is that if there is an information receivable and possibly even emittable by a biological system then that system will through evolutionary pressure begin to incorporate this transmission in a way that improves fitness. Telepathy maybe even. That's also why I don't "believe" anymore in this compartmentalization of the human body into separate organs. Tissue can isolate an organ to some extent but even then there will be hormonal or mechanic exchange. Example would be relevance of belly breathing for intestinal function. At the extreme we reach this sense of connectedness between all or most or some living beings. It just appears to me that this would make sense.

The rule of thumb in evolutionary biology is if it has a cost and lasts through evolutionary time, it is beneficial. Because otherwise a similar organism that doesn't waste that time/energy on the useless thing/behavior will outcompete. Here's some odd and obvious examples.

Religion has a cost (lots of resources and time are spent on them) and they have lasted through time, therefore it is evolutionarily beneficial.

A small percentage of the population is psychopaths, this has an obvious cost to communities, but the pattern has lasted through time, therefore has a benefit. Likely it's for war/fighting/hunting.

Growing light sensitive cells has a cost in energy and materials, and has lasted through time, therefore it must have a benefit (sight).

This strongly suggests that SOMETHING is listening to that plant make noise and it either directly or indirectly benefits the plant.

Only applies to genetic traits though. If psychopathy, for example, turned out to be epigenetic, environmental, or entirely psychological, it would potentially defy that pattern.

It doesn't only apply to genetic traits, it also applies to memes which also evolve and would cover your concerns.

By a trait being "beneficial" you mean that it prolongs the existence of some gene specifically, right? My understanding of evolution is that traits aren't necessarily beneficial to those who posses it in the colloquial sense. For example, animals that perish due to reproduction.

Also, isn't saying a trait exists so it must be beneficial a bit of an over simplification? Couldn't a relatively useless trait hypothetically exist due to genes that are also related to some other relatively useful trait? It seems like a stretch to say any lasting trait must be beneficial, unless you can isolate it from other traits on the genetic level or otherwise through analysis. Traits can also cease being beneficial as we can see from the countless species that have gone extinct.

Sorry if this seems like I'm ranting, but I just need more convincing that this rule of thumb makes sense, and would appreciate being pointed in the right direction if I'm off-base.

Yes, beneficial refers to those genes continuing on into the future.

The operative descriptive word describing those "useless traits" is cost. If nothing else, they have a cost of the energy and resources required to produce the relevant cells or whatever. Another organism that does not waste that energy and resources will out-compete the one building the useless trait. Natural selection will make it go away.

Though that might just be the case for most things, I don't think it would be fair to say that for all things. Two traits could develop in conjunction with another, and trait 1 gives an advantage, while trait 2 is a disadvantage. The most in-your-face example I think is the stereotype of nerds and glasses. In short, a good enough trait could get you laid and fed even though you have a crappy trait that came with it.

edit: alternatively, a bad enough trait could completely derail the development of a good train. Maybe dolphins born with 200iq brains develop some other kind of bad trait as a result of the same mutation that doesn't allow for the 200iq trait to permeate.

The characteristic one for this in humans is sickle cell anemia. It really sucks for the people who have it but it sucks less than malaria, so it’s persisted in the gene pool… in regions with endemic malaria.

The poor eyesight you're referring to comes with age, generally after the primary ages of procreation. That's why, on an evolutionary timescale, there wasn't much benefit to weeding out the need for glasses. Maybe into the future we will see that. Conditions which cause poor eyesight from birth get weeded out.

That assumes that natural selection is a perfect process, and that we are at some "end" of it. In truth, the cost of generating useless noise could be small enough that it just doesn't matter and it hangs around. Maybe it will disappear in a few more billion years.

Any organism we see today may very well have unnecessary traits that evolution is in the process of removing.

You put that assumption in, not me.

Unempathic people can make hard decisions; Such as choosing between spending a hospital budget on fuel for the generators, building upkeep, restocking, and employee wages –v.s. the life of one child. A lot of people can't make such a decision.

I wouldn't want such people unchecked though.

there's a line of thinking that it's strange how many of our leaders are psychopaths. But for all we know, it's strange how few of our leaders are psychopaths relative to other cultures throughout history.

> A small percentage of the population is psychopaths, this has an obvious cost to communities, but the pattern has lasted through time, therefore has a benefit.

It has a benefit to individuals. A benefit to the community is not necessary.

> Likely it's for war/fighting/hunting.

This is a non sequitur.

Nothing is all cost and no benefit, and nothing is all benefit and no cost either. You don't see people arguing that vulnerability to cuckoos is beneficial to the birds they parasitize. The benefit is real (you don't need to bother recognizing your offspring, because recognizing your nest is sufficient) but the cost is so much larger (your children all die) that it's obvious the birds would be better off with the ability to recognize their own young (and/or eggs). They don't have that ability... yet.

I mostly agree with your point however IMO the psychopath thing is not a great example because it could be explained as the incomplete or nonexistent development of something that is complex that is beneficial. I think the error is that we can’t necessarily know what the cost was. And the benefit doesnt necessarily have to be that big relative to the cost. I mean I’m replying to you and that me costs something, and what’s the benefit?

While the sounds don’t make themselves, they could be a side effect of something else… instabilities in the structural tissue, the plant straining to increase the movement internal fluids… who knows?

That said, I personally think there is communication between plants, or that at the very least it’s something like trying to mimic predator insect sounds. But could be that the vibrations themselves help move fluids around (as opposed to being a byproduct of something else that does)

This isn't "my point," this is how the field of evolutionary biologists look at traits. If what I said was false it would mean there's no such thing as natural selection. We may not understand how a trait is beneficial, and we may be incorrect about why a trait is beneficial, but if it has a cost and lasts through evolutionary time then by definition it has a benefit.

>it could be explained as the incomplete or nonexistent development of something that is complex that is beneficial.

If it has a cost but doesn't have a benefit right now, it's going to get weeded out via natural selection in favor of variants of the organism that are not wasting the time and resources on that trait.

The argument is flawed. You defend. "if it has a cost and lasts through evolutionary time, it is beneficial."

But to conclude your conclusion, you must also show that:

- emitting noise has cost (fairly believable)

- and that something listening to it is the only way to make it beneficial, which is far from obvious. (Could just be a way to dissipate energy, or to send signal within the plant, or to get rid of some chemicals, or many other beneficial things that doesn't involve something listening)

>has been evolved by other organisms

Like, a human?

By now, there is at least one other organism that can detect and act upon the signal. If farmers applies knowledge about this signal to improve their yields, plants may be selected for their ability to emit sounds under stress.

There is some reserach that trees already communicate indirectly via a network of fungi around their roots using sugars so it's not that far fetched

https://www.smithsonianmag.com/science-nature/the-whispering...

add to that https://www.scientificamerican.com/article/do-trees-support-... 'Do Trees Really Support Each Other through a Network of Fungi'

Interesting. Seems like the authors main contention is with the popularization of the concept that trees might be cooperating with each other instead of hyper competing as we historicallly assume via just natural selection pressures.

I’m sympathetic to their argument that we need to be careful how far we take the cooperation argument but I think they’re also throwing out the baby with the bath water. These authors are highly focused on showing the validity of the opposite point of view and so have conducted a meta analysis of the literature that is very, I would say, biased towards the exclusion of studies that show communication and transfers of chemicals between trees using mycorrhizal networks. I still find their meta analysis interesting but would caution people to also take their cutting down of the idea of transfers between plants using mycorrhizal networks with large grains of salt. They, as researchers, are also incentivized to kind of go a bit too far the other way from what they were arguing against (transfers between plants using mycorrhizal networks)

Sometimes signal is just there regardless.

If you hit your tissue hard enough, it becomes blueish for a while (a bruise, a hemorrhage). It may benefit something by accident, but a bruise just can’t stay as pink as the rest of you, due to the physics of the process.

(From tfa) Plants exposed to drought stress have been shown to experience cavitation – a process where air bubbles form, expand and collapse in the xylem, causing vibrations

In other words, dry wood cracks.

> In other words, dry wood cracks.

How dare you translate academic technobabble to common tongue?

The person you’re responding to is talking about other organisms (ie not the tree), which seems compatible with your observation here.

Trees might be screaming/bubble-popping into the abyss for simple physical reasons, but if cavitation is very important to some creature, there’s a decent chance that creature has evolved to sense these vibrations.

Random guess: woodpeckers might, as for them this may be a way to detect which trees offer most food for least effort.

Ironically, something I didn't realize until now, and what also confirms the original point: apparently[0] the drumming itself turned into form of communication for woodpeckers.

[0] - https://en.wikipedia.org/wiki/Woodpecker#Drumming

Maybe this bruise evolved with our social behaviour : most animals skin don't show this, or for higher stress. The bruise is very important in a social envirronment and is a good optimisation for mutual Care.

>> (From tfa) Plants exposed to drought stress have been shown to experience cavitation – a process where air bubbles form, expand and collapse in the xylem, causing vibrations

> In other words, dry wood cracks.

I don't think it's saying that at all

Conversely, perhaps humans evolved to not hear plants.

They're saying it's in the realm of possibilities, plants *may* be communicating via sound, and this is in the context of a study that shows plants are making noises that can be used to convey information.

They're saying it merits further investigation, not presenting it as a hard fact. To claim that's "wild overselling" and that it doesn't belong in a "high impact" journal is wildly underselling the study. They make sure to use the word "may" in everything they suggest that's not directly backed up by the study.

Imagine how will it be if deaf aliens, 50 metres high, were to encounter a human being. Our expressions would mean nothing to them, nor our screams. They could break us into pieces, or munch on us, never wondering what “these little things” are doing.

If you break a branch, the sound of it breaking informs you that you have broken a branch.

It also informs other animals that a large creature may be passing by.

Like breaking bones and speech are both informative sounds emitted by a human from which you can learn something about that human condition. The difference between those sounds is more subtle than might appear at first

If a branch falls in the forest and there is no-one there to hear it, does it make a sound?

https://en.wikipedia.org/wiki/If_a_tree_falls_in_a_forest#:~....

"... majority view of the quantum mechanics community then and arguably to this day is that existence in the absence of an observer is at best a conjecture"

"Observer" is the most unfortunate word physicists could have chosen, though. It gets people all confused about observation mistakenly having something to do with thinking or perception. "Interacter" would have been a more accurate term, but it doesn't sound as sexy.

To wit, yes, the tree makes a sound because the tree is there to hear it.

Well yes IF it is true that trees can hear, which is what these new experiments give some credence to but don't prove conclusively

If a tree falls in the forest, all the other trees are there to hear it.

But you could use ultrasound sensors to monitor plants in agricolture... maybe this is why it got published in such a high impact factor journal.

From the introduction:

> Recently, plants were also demonstrated to respond to sounds,13,28,29,30 e.g., by changing the expression of specific genes,29,30 or by increasing sugar concentration in their nectar.31 Thus, if plants emit airborne sounds, these sounds can potentially trigger a rapid response in nearby organisms, including both animals and plants.

The sounds emitted by the plants are between 20 and 80 kHz, which is within the auditory range of some mammal, such as mice. Although the normal range of hearing in humans is said to be 100 Hz to 20 kHz, when I was a grad student in my early 20s I could detect sounds up to 28 kHz in the sound booth.

I wonder whether there are people who can hear these sounds, even faintly.

> Informative here meaning that you can deduce something about a plant's condition from faint sounds emitted by it. It's not implying that the plants use those sounds for the purpose of transmitting information.

We already know that plants transmit information to each other through the air by emitting chemicals. It doesn't seem hugely significant whether or not they also do it by emitting sounds.

In algculture setting, it is far easier to record sound than testing for chemical.

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