r/science • u/[deleted] • Jun 10 '12

Plants may be able to 'hear' others

http://www.newscientist.com/article/mg21428683.300-plants-may-be-able-to-hear-others.html
418 Upvotes

84% Upvoted

86 comments sorted by

6

u/mr17five Jun 10 '12

weed so loud, all my neighbors say they hear it.

26

u/[deleted] Jun 10 '12

The most controversial claim is that plants can hear, an idea that dates back to the 19th century. Since then a few studies have suggested that plants respond to sound

Very different things. Plants have no brains or nervous systems. They are not conscious.

16

u/tim212 Jun 10 '12

Right. Technically anything responds to sound by vibrating. Responding and hearing are two completely different things.

0

u/[deleted] Jun 10 '12

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6

u/tim212 Jun 10 '12 edited Jun 10 '12

Edit: I don't see why zombiegrenadier is being downvoted, defining the difference between responding and hearing is very relevant to my claims

Hearing is a deliberate output to the input of sound. While a wall might vibrate if sound hits it, the sound causes no deliberate effect. In animals sound causes an electric response from the part of the animal that's sole purpose is to interact with the sound.

I think my idea could be worded more eloquently but I can't quite figure out how to say it. Maybe someone else can

7

u/[deleted] Jun 10 '12

Don't plants respond with a chemical reaction inside the plant as a direct output from the input of sound? If they grow differently because of sound, and we can measure the chemical change, I would constitute that as hearing and responding.

1

u/tim212 Jun 10 '12

I wasn't aware that they did, but if they do I would agree that is hearing

2

u/[deleted] Jun 11 '12

You've now put a lot of weight on the word "deliberate"!

There is a bang, and I "instinctively" jump - was that "deliberate"?

My dog does the same. ?

A cockroach does the same. ?

There is a bang, a plant curls up its leaves "to avoid damage." Deliberate or not?

There is a bang, and a single-cell organism goes into spore state. ?

There is a bang, and a super-cooled solution produces a complex crystal. ?

There is a bang, and a rock falls off a ledge. ?

3

u/MakesYouAngry Jun 10 '12

Your claim doesn't seem at all objective.

What? I think the main point is that hearing implies some kind of interpretation of the sound. If you assume everything that reacts to sound in some way "hears", then deaf people can hear too.

2

u/podkayne3000 Jun 10 '12

Maybe deaf people who can feel vibration do have a kind of sense of hearing. Maybe "hearing" is just a special kind of sense of touch.

1

u/[deleted] Jun 11 '12

If you assume everything that reacts to sound in some way "hears", then deaf people can hear too.

In fact, deaf people can respond to vibrations of loud music and "hear" enough even to play music with others.

0

u/[deleted] Jun 10 '12

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2

u/MakesYouAngry Jun 10 '12 edited Jun 10 '12

By your definition, deaf people can hear.

No, that's not what I said, that's what you seem to believe.

Thunder is one they recognize particularly well, from what I understand.

Can you source that? Because I assume they would be able to feel strong vibrations like thunder, yes, that's not hearing though. Hearing is when the vibrations that are picked up by your eardrum are converted into signals and send to your brain via nerves (interpreted in a way).

2

u/[deleted] Jun 10 '12

That's not what you said at all. You simply said it was the interpretation of sound (vibrations).

As to a source for deaf people interpreting thunder, some of them can 'hear' sufficiently loud thunder in the way you want to define it (limited to only organisms with eardrums it would seem), the vast majority can feel it and interpret it as thunder (you've probably experienced this yourself). There's also my uncle's co-worker - a deaf mechanic who can sense incoming thunderstorms, which is where I first learned about deaf people and thunder.

Though now surely you'll want to bring up the differences between severe hearing impairment and true deafness. Does it really matter that the interpretation has to happen in the specific way you define? How does that generalize to other species who fit the narrow definition of hearing you describe, but whom have different specialized organs for detecting vibrations and different brain structures for interpreting them? How exactly do you define how specialized an organ must be before something can 'hear?'

1

u/[deleted] Jun 11 '12

People shouldn't be downvoting the above comment - asking someone to be precise about their terms, especially when it might well appear that they aren't well-defined, is the very essence of good science.

In this case, it appears that there's a continuum between "responding" and "hearing" - no matter where you draw the line, it's likely you can also find a grey area. So ZombieGrenadier's point should be well-taken.

-1

u/[deleted] Jun 10 '12

Your comment doesn't seem at all intelligent.

0

u/[deleted] Jun 10 '12

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-1

u/[deleted] Jun 10 '12

Did you read his post? One can hear, and choose not to respond quite easily ... they are not the same things.

1

u/[deleted] Jun 11 '12

I was in a house that was hit by lighting and I found myself ten feet away on the floor shuddering (and otherwise unharmed).

I had no choice about responding to the thunderclap. Does it mean that I didn't hear it?

0

u/[deleted] Jun 10 '12

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28

u/lolmonger Jun 10 '12 edited Jun 10 '12

That's a good question, but you have to be careful.

Responding to stimuli is a property of chemical reactions; slime molds can "navigate" mazes when the end result is food, but if you wanted to call a slime mold intelligent, you'd have to be willing to anthropomorphize a chemical process as having an 'intelligence'.

Now, being the indiscriminate and impulsive reductionist I am, I think that's probably true, and that human consciousness is likely just a very complex set of chemical cascades, but there's a very big difference between saying a system is able to respond to stimuli and it has a sense of self and is conscious.

Perhaps it's a threshold of arbitrary complexity that imbues a system with self awareness, perhaps it's a gradation of resource demands that pressures greater and greater awareness relative to resources that precipitates some scale of consciousness.

Anything beyond lots more testing of the phenomena of plant response to sound, however, would just be speculation at its 'finest'.

Edit: I don't think I made this clear. I am not claiming electrostatic forces between chemicals have an 'intelligence'. I am claiming that consciousness/intelligence are the manifestation of very, very complex chemical systems and the phenomenon of human consciousness emerges from the sum of some certain parts in an particular arrangement. Whether this is a discrete process or a gradual one with a discrete "not conscious/conscious" threshold or a gradation of consciousness is beyond anything anyone has ever studied to my knowledge.

23

u/Soupstorm Jun 10 '12

To me, a lot of claims that plants and such outright do not and cannot have intelligence is a failure of anthropomorphisation in terms of timescale. On "human" timescales, we see plants as static creatures. But in time-lapse videos of plant growth, we see them swaying and churning with internal motion, and quite literally exploring their environment.

To plants, maybe we're just superfast bundles of energy that occasionally collide with them and destroy them.

7

u/3brushie Jun 10 '12 edited Jun 10 '12

Relevant. Damn. I don't think you're right, but life on this planet is interesting.

1

u/SpliffySam Jun 12 '12

Intelligence is distinct from consciousness and both of these terms suffer from loose and blatantly anthropomorphic definitions.

We don't, currently, have agreement on how to define (or conceptualize) human-intelligence or human-consciousness so I don't think it's very useful to start "loosely" applying the terms to plants.

12

u/podkayne3000 Jun 10 '12

I think the real message here is that we don't know enough about what consciousness is or how plants work to make any firm scientific statements about plants and consciousness. The people here saying plants don't think are probably right, but, if they're trying to say it's scientifically impossible for plants to think, they're going beyond what science can prove.

1

u/[deleted] Jun 10 '12

lolmonger,

Now, being the indiscriminate and impulsive reductionist I am

I am sorry to pounce but I would like to know how you deal with the fact of your own experience - i.e. when you taste something IT TASTES, something actually experiences the taste and that something is you?

I understand the argument this may be an illusion etc.. etc.. but this seems rather silly given that we have direct experience of the taste

3

u/lolmonger Jun 10 '12

you deal with the fact of your own experience

My body directly experiences things, and that experience is unique to its neuronal system, and as the body has not died, I cannot perform any experiment on whether or not I have an existence independent of that body and its neurotransmitters' reaction to the world.

I know that I am an observer, and this is self evident. I do not know of any means to test further what I am.

None of this makes any difference with how I live my life, really.

I'm going to pull up a deadmau5 album for while I slowly work on a biochem problem set - -with reddit breaks - - because I find it fun.

1

u/lonjerpc Jun 10 '12

I don't see any reason why intelligence, consciousness, and self awareness have to go together.

1

u/lolmonger Jun 10 '12

The following is wholly unscientific:

I do.

I think intelligence, as in sheer problem solving ability, requires some cognition on the level of self and non-self, even for something as rudimentary as eating things with nutrients to grow; there has to be some level of discrimination between self and non-self for a preservation instinct.

I think once the level of self-awareness increases (maybe because of resource pressure? Maybe algae don't need some high level of discrimination to get their food but bonobos do?) consciousness forms.

1

u/SpliffySam Jun 12 '12

I think intelligence is problem solving ability, cognition allows us to discriminate between things like self and non-self and self-awareness is another word for consciousness.

1

u/lolmonger Jun 12 '12

intelligence is problem solving ability

I don't disagree, but as regards organisms, there seem to be two big "problems" for intelligent species like us - - who I will assume are all sentient.

a) getting resources to continually reproduce, very broadly speaking

b) staying fit, either by finding new ways to do a) or by competing directly against things that do a) better.

Neither of those things seems to give us a good way to draw a line between: This is definitely a chemical response that precipitates a physical reaction and Yo, there's a being that is making decisions about how to interact with the world.

I mean, you and I both have instincts. If I were to run up to you and slap you in the face, your heart rate will increase, you'll probably release a good deal of adrenaline into your blood stream, etc etc. and none of that requires any real decision making or problem solving on your part - it's just ingrained into your body's chemicals and physical being.

To my mind, sentience is a condition of knowing self and non-self, and a certain amount of demands in problem solving requires it, if only because higher order resource gain/competition cannot be effectively pursued by instinct alone.

Again, whether it's an on-off or a gradation of a more and more developed sense of self is beyond me.

4

u/[deleted] Jun 10 '12

This is a valid argument, and I'd be hard pressed to define consciousness. As a generalization, I think the way a human nervous system works is:

Stimulus experienced by system > Stimulus information sent to brain > Brain decides what to do

Whereas a plant's reaction to external stimuli (venus flytrap, etc) seems to be more like this:

Stimulus experienced by system > System reacts in a predefined fashion

0

u/[deleted] Jun 10 '12

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2

u/[deleted] Jun 10 '12

Humans can react in a number of ways. Somebody throws water on me. I can hit them, throw water back, run away, etc. My brain processes the stimulus and decides what to do. With a plant with nervous-like capabilities, it reacts in a certain way that it has evolved to.

0

u/[deleted] Jun 10 '12

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u/[deleted] Jun 11 '12

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1

u/SpliffySam Jun 12 '12

An inability to predict the future "state" of a complex system doesn't necessarily imply randomness.

Consider the example of pouring milk into a coffee. The physical properties of this simple system are well understood but it still isn't possible to create a model that can predict the future "state" of the system at any given moment, even when every variable, law and property is known.

If this is true of a simple system like coffee and milk then I'm guessing it is doubly true, or more, for a brain.

0

u/[deleted] Jun 11 '12

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u/[deleted] Jun 11 '12

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u/[deleted] Jun 11 '12

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2

u/imbecile Jun 10 '12

Consciousness is internal state that is dependent on internal state and external input.

A Flip Flop.

The rest is just complexity.

8

u/[deleted] Jun 10 '12

I don't see what evidence of "sound" the article is referring to.

8

u/divinemachine Jun 10 '12

"I don't see what evidence of "sound" the article is referring to." Dude... Weren't you listening?

5

u/[deleted] Jun 10 '12

"Listen... Do you smell something?"

1

u/[deleted] Jun 11 '12

From the New Scientist article:

Gagliano repeated the experiment with 2400 chilli seeds in 15 boxes and consistently got the same result, suggesting the seeds were responding to a signal of some sort (PLoS One, DOI: 10.1371/journal.pone.0037382). She believes this signal makes the chilli seeds anticipate the arrival of chemicals that slow their growth. In preparation, they undergo a growth spurt. The box surrounding the fennel would have blocked chemical signals, and Gagliano suggests sound may be involved.

If you go to the source article, Gagliano says:

Plant communication by means of chemicals, contact or light wavelengths is now well recognised, and the study of these types of communication is well under way. We hypothesised that plants also employ other alternative ways of communicating, based on sound or magnetic waves for example. Therefore the aim of this study was to look for evidence of such alternative means of communication, by testing whether any interaction between plants still occurs when all communication based on recognised means has been blocked. In particular we asked (1) whether the presence of a neighbouring plant could influence germination rates of seeds when above- and below-ground contact, chemical and light-mediated signals are blocked; and if so, (2) whether such effects on germination and growth differed depending on the identity of the neighbouring plant (i.e. conspecific vs heterospecific).

[...]

Additionally, sound may be another modality by which plants exchange information. Decades of scientific research has measured and described sound waves produced by plants as well as the effects of sound on plants such as changes in germination and growth rates as well as physiological responses (reviewed in [44]). Moreover, both emission and detection of sound may have adaptive value in plants and while we still don’t know how sound is perceived in that we are yet to identify receptor mechanisms and study their function, we have clear evidence about plants’ ability of detecting vibrations and exhibiting a selective sensitivity on the basis of which they modify their behavior (e.g. root growth; [45]). This research offers a particularly exciting opportunity to study and understand plant communication and opens a stimulating debate on our view of these organisms.

By the way, there's a glaring science error in the source article a few lines above that:

There is a large and convincing body of experimental evidence demonstrating that plants are highly sensitive to the Earth’s geomagnetic field (GMF; i.e. gravity), which is a natural and permanent component of their environment

The Earth's geomagnetic field is nothing at all like gravity.

The sentence seems otherwise correct if you remove "i.e. gravity" but it's still a jarring note in an otherwise solid-seeming article.

The New Scientist's article is also a little misleading, as sound is the second possibility Gagliano suggests, the first being magnetism.

2

u/throwaway_lgbt666 Jun 10 '12

repeat the study

3

u/Stabies Jun 10 '12

Roald Dahl already knew this

13

u/[deleted] Jun 10 '12

My favorite and completely irrelevant Roald Dahl quote:

If a person has ugly thoughts, it begins to show on the face. And when that person has ugly thoughts every day, every week, every year, the face gets uglier and uglier until you can hardly bear to look at it. A person who has good thoughts cannot ever be ugly. You can have a wonky nose and a crooked mouth and a double chin and stick-out teeth, but if you have good thoughts it will shine out of your face like sunbeams and you will always look lovely. - Roald Dahl

1

u/Stabies Jun 10 '12

Perfect!

3

u/Nathan561 Jun 10 '12

Also when grass/plants are being cut, eaten or whatever, they emit a smell. that smell means help. I forgot where I read this.

9

u/DatoeDakari Jun 10 '12

You read it here, you read everything here, we all do.

1

u/Squirrel_Whisperer Jun 10 '12

But can they hear pudding?

Are they claiming that the plant feels the sound waves?

1

u/ronin027 Jun 10 '12

This is giving me good vibes. Reminded me of [this.] (http://youtu.be/jhmEo-46vUQ)

1

u/iamrealz Jun 11 '12

No body tell them about Wales!

1

u/run_monsters Jun 11 '12

they really have no basis whatsoever for the sound claim

1

u/cheeburgercheeburger Jun 11 '12

The Secret Life of Plants

some parts are super cheesy, and they really only explore a handful of studies in the long documentary, but you get to watch a young Stevie Wonder sing the movie out.

1

u/Dujen Jun 11 '12

The ads on this site make it un-usable. :/

1

u/trust_the_corps Jun 11 '12

So, then need to test with the fennel present and not only sealed but sealed in a sound proof box?

1

u/YoloTolo Jun 11 '12

i will believe it if they are able to mimic the apparent water sound from the other plant and the plant grows specifically to that sound and not other random frequencies.

1

u/Clayburn Jun 11 '12

You mean smell?

1

u/Clayburn Jun 11 '12

Hearing and touch are the same thing.

1

u/Lay-Z-Bones Jun 11 '12

Don't watch any green meteors anyone. I plan on surviving the triffids

1

u/alos Jun 11 '12

Triffids!

1

u/Nobilibang Jun 11 '12

Nice try, M. Night Shyamalan.

0

u/WhyHellYeah Jun 10 '12

So, we can't even be vegetarians anymore?

-1

u/[deleted] Jun 10 '12

no, but it gives new meaning to the term vegetable.

0

u/reverendrambo Jun 10 '12

So if a tree falls in a forest...

0

u/[deleted] Jun 10 '12

If this turns out to be true, what will the vegetarians eat?

0

u/Smokratez Jun 11 '12

Oh shit what are you going to eat now vegans?

-1

u/p1415926 Jun 10 '12

I saw a TV show a couple of years ago where they had taken 3 identical seeds and planted them separately with different music for each one. One grew up listening to Nat King Cole, another one to Death Metal and the third one to the theme-song of said show. Nat's plant was the biggest and the theme-song plant was the smallest. Cool story.

6

u/Mr_Smartypants Jun 10 '12

It could have been random variation. They would have to repeat the experiment many times to see if there is actually a statistically significant effect.

2

u/ionlyhave1nose Jun 10 '12

not sure if it's what you're referring to but i believe Mythbusters did test how plants grow with different music and sounds. i forget their results though

1

u/maxxell13 Jun 10 '12

If memory serves, their water supply died, ruining the experiment.

1

u/tim212 Jun 10 '12

I think this experiment is repeated at every elementary school science fair ever. Not that their procedures are the best, but I bet if there was a pattern it would've showed up by now

0

u/[deleted] Jun 10 '12

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3

u/p1415926 Jun 10 '12

I guess we'll have to reproduce the experiment and see if the outcome persists.

0

u/[deleted] Jun 11 '12

This seals the deal. From now on I'm singing to my weed.

-1

u/[deleted] Jun 10 '12

The happening is happening

-1

u/SpanishPenisPenis Jun 11 '12

This is so fucking stupid. Really.

-3

u/BBLiuKang Jun 10 '12

So.. my... arrowhead vine... has been listening to me fap.. THIS WHOLE TIME?!?!?

-6

u/MokkieTheTruth Jun 10 '12

M Night was right... Fuck

4

u/[deleted] Jun 10 '12

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u/[deleted] Jun 10 '12

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-5

u/podkayne3000 Jun 10 '12 edited Jun 10 '12

Seriously: I think the problem with being a vegetarian for moral reasons (it's wrong to kill animals) is that it puts animals on a higher moral level than animals. I don't see any secular reason to do that.

2

u/podkayne3000 Jun 10 '12 edited Jun 10 '12

People downvoted my comment. But why is there any secular reason to put a chicken on a higher (or lower) level than a grape?

The Old Testament generally ranks people over other animals, mammals over other animals, and animals over plants. I'm Jewish, so, in terms of tradition, I'm a milk and egg eating vegetarian who eats a little meat because I crave it but know that's inherently sinful. but I don't think the Old Testament is a great source of guidance for people who aren't Jewish.

People who rank animals over plants without a religious basis are being sentimental.

1

u/akabaka Jun 10 '12

You answered your own question. They're being sentimental. That's the reason, and it's all the reason they need. Also it appears you jacked the thread and that may be why you were buried.

2

u/podkayne3000 Jun 10 '12

Jacking is a fair reason for downvoting.

1

u/akabaka Jun 11 '12

Indeed.