Repurposing flowers
January 11, 2019 9:48 AM   Subscribe

Plants Can Hear Animals Using Their Flowers "In both lab experiments and outdoor trials, they found that the plants would react to recordings of a bee’s wingbeats by increasing the concentration of sugar in their nectar by about 20 percent. They did so in response only to the wingbeats and low frequency, pollinator-like sounds, not to those of higher pitch. And they reacted very quickly, sweetening their nectar in less than three minutes." [EdYongFilter]
posted by dhruva (35 comments total) 57 users marked this as a favorite
A quick thought here (although plants are really not my area of science): it looks like both the papers the Atlantic piece points to are only on biorxiv, and haven't been peer reviewed yet. I'm (somewhat) encouraged to see that the author of the piece did seek out researchers in this area to comment on them in the course of writing the piece, but that's not a substitute for peer review.

That doesn't mean these results aren't real, I'd just suggest a larger grain of salt than usual.
posted by Making You Bored For Science at 10:12 AM on January 11 [5 favorites]

I also noticed that, and I think this is probably the first science communication article that takes the effort to contextualise preprint data. Ed Yong basically acted as an editorial board member and commissioned his own peer reviews!
posted by dhruva at 10:23 AM on January 11 [1 favorite]

That doesn't mean these results aren't real, I'd just suggest a larger grain of salt than usual.
posted by Making You Bored For Science at 1:12 PM on January 11

A larger grain of sugar?
posted by ZaphodB at 10:30 AM on January 11 [5 favorites]

Love this stuff. As to "where are their ears?", you don't need ears to feel the vibrations of sounds such as a bee buzzing. I know, I can feel them when I'm beekeeping. Through leather gloves. If a flower can increase nectar sweetness based on bees buzzing that is incredible. Can't wait for more results!
posted by Sophie1 at 10:49 AM on January 11 [8 favorites]

Ed Yong is one of my favorite science writers. I've been reading his articles for over ten years.
posted by Agave at 10:53 AM on January 11 [1 favorite]

The use of the verb "hear" is ridiculously anthropomorphic and misleading.
posted by stonepharisee at 11:03 AM on January 11 [2 favorites]

stonepharisee: The use of the verb "hear" is ridiculously anthropomorphic and misleading.

I hear what you're saying, but "anthropomorphic" seems like the wrong word, since many animals other than humans can also hear. Something like "zoomorphic" would be closer, though it looks like that one is already taken for something else.

If "hear" isn't good, then it would also be nice to have another word for what plants are doing when they respond to sound.
posted by clawsoon at 11:10 AM on January 11 [4 favorites]

Whoops, nevermind, "zoomorphism" is the correct word.
posted by clawsoon at 11:11 AM on January 11 [2 favorites]

Why is “hear” wrong? What would you call a sensory capability allowing an organism to detect and respond to sound waves?
posted by killdevil at 11:13 AM on January 11 [24 favorites]

Zoomorphic is good, though there are plenty of examples of animals who are sensitive to vibrations of all sorts where the term "hearing" is a stretch. We label the world from a human perspective, and that comes with ears and all sorts of good, but very specific and human-morphology-based, stuff. "Hearing" necessarily brings phenomenological associations: a what-it-is-like-ness to our understanding.

If you think about it, what we call sound is vibration which our bodies are sensitive to, so sound, is in part defined by the acuities of the human auditory system. Vibration outside of about 20 Hz to 20,000 Hz is just vibration.
posted by stonepharisee at 11:32 AM on January 11 [2 favorites]

Or, they're sounds only other species can hear. Are you saying my cat detecting "vibrations" at 60,000 Hz with their ears and processing them just like they do vibrations at 10,000 Hz aren't hearing those vibrations as sound?

Antropocentrism is also a fallacy.
posted by thoroughburro at 11:38 AM on January 11 [4 favorites]

clawson -

If "hear" isn't good, then it would also be nice to have another word for what plants are doing when they respond to sound.

how about floral aurality? floral aural? auraflora?

re antropocentrism - ascribing any kind of intelligence to non-human life is a slippery slope, it might lead to veganism or actually caring for Earth. We are such an arrogant specie.

Often I discover or see the most extraordinary things where plants and animals do things that don't seem 'reasonable' or instinctive not being the dumb nature humans seem to need,
posted by unearthed at 12:23 PM on January 11 [4 favorites]

My dad discovered that certain tunicates could detect and respond to vibrations using an unusual "capsular organ" and he always referred to this as them having "hearing" though of course he fancied it up for publication.

(He discovered this by the time-honoured Scientific! Method! means of noting that when someone slammed his lab door then the tunicates responded, and taking it from there)
posted by Rumple at 12:25 PM on January 11 [14 favorites]

That's pretty amazing, if confirmed. I seem to recall that there has been some previous evidence that plants can 'hear', in that someone had research indicating that roots grew faster in the direction of the sound of moving water, but don't know if it got backed up by further studies.
posted by tavella at 12:30 PM on January 11

If you think about it, what we call sound is vibration which our bodies are sensitive to, so sound, is in part defined by the acuities of the human auditory system. Vibration outside of about 20 Hz to 20,000 Hz is just vibration.

This also reminds me of one of the peacock studies I was digging through the other day, in which peacocks aren't technically hearing the air vibrations that result from peacock tail and feather displays... but rather feeling them through mechanosensors in the peafowls' crests. It's hard to know what to call this when you have two totally separate sensory mechanisms for detecting vibration at different frequencies in the same damn bird, let alone when you look at similar cases in plants.

Personally, I am happy enough to refer to it as hearing because acoustic perception organs in different animals are so very wildly different--a cricket ear and a human ear are independently evolved structures that work in different ways, with no shared evolutionary history between them, and yet we call that hearing in crickets, too.

Here, too, it doesn't really sound like the flower is acting like a human pinna--the fleshy outside of the ear that funnels sounds in--because the flower itself seems to need to be actively vibrating to convey the effect. Rather, it sounds to me like the flower is working in a way more analogous to the cochlear membrane in a human or the arista of a fruit fly: it's the thing whose vibrations are amplified by its free structure and who send the patterns generated by their neurons on to the nervous system in order to work out how to respond. There may be more amplification structures beyond the petals, but I'm not sure why flowers would need to increase their acoustic sensitivity in this way.
posted by sciatrix at 12:50 PM on January 11 [10 favorites]

On This Page

Find "Hz" .......... no matches

It was nearly maddening to read this long and fairly detailed article without seeing a numerical value for any of the many frequencies of sound they must be looking at.

I don't blame Ed Yong for this, because such thorough scrubbing would almost have to be editorial policy -- so come on Atlantic, your targeted demographic cannot possibly be that innumerate!
posted by jamjam at 1:02 PM on January 11 [1 favorite]

Bees also do a lot of communicating by vibrating their comb, which is why I never use plastic comb and only use foundationless frames so they can build their own comb to the shapes and sizes and thicknesses they need. I love nature so freaking much.

Did you know that bees actually debate about real estate?
posted by Sophie1 at 1:07 PM on January 11 [6 favorites]

Somewhat unrelated but completely unrelated... I have a theory -- totally untested and unverified -- that when a dog spends time sniffing the urine of another dog, his/her body is changing the chemical make-up of the liquid they're about to urinate, and that a dog urinating 3 different times in a matter of minutes will expel three chemically different urines which will have some common elements unique to that dog, but other elements unique to each urination that are only present because of the process of sniffing the urine of the previous dog(s) that urinated in that spot.

I don't know how to prove it using my one dog and elements in a normal home, but goddamnit I know I am right.
posted by dobbs at 1:45 PM on January 11 [5 favorites]

I'm in camp "if detecting sound waves in the air isn't hearing, then what is?" over here. If confirmed, this seems like a fairly clear-cut (if limited in scope) case of hearing in plants, to me.
posted by Anticipation Of A New Lover's Arrival, The at 2:06 PM on January 11 [2 favorites]

Plants can also react to light, by growing or orienting themselves towards it, but we don't call that "seeing", we call it phototropism.
posted by LionIndex at 2:36 PM on January 11 [3 favorites]

It's like how my thermometer can feel changes in temperature, and adjust the level of its mercury accordingly.
posted by demonic winged headgear at 2:44 PM on January 11 [3 favorites]

In electronic engineering, people talk about radio receivers hearing signals all the time, and that's not even sound waves. Nobody cares.

You can say plants sense air pressure waves in the range 5 to 50 Hz, or you can say they hear bees buzz. I know which I'd write in a science news story.
posted by Devonian at 2:44 PM on January 11 [9 favorites]

It’s a cool story, but absent peer review I can hardly fault Metafilter for discussing the merits of terminology instead. My grain of salt is completely obscuring the flower behind.
posted by lazaruslong at 2:51 PM on January 11 [1 favorite]

My first thought is, can I use this for winemaking? They only tested evening primrose, but what about, say, elder or dandelion or clover or ...
posted by ragtag at 3:02 PM on January 11

Are you using the nectar in winemaking? I know nothing about that, but it's a cool idea.
posted by sciatrix at 3:05 PM on January 11

There're a lot of wine recipes that use the whole flower, some of which are quite delicate, so variations in the nectar might matter.

If sugar is the only part that increases in concentration, it's probably not too interesting (since you always have to add a bunch of sugar anyway), but if other compounds increase in concentration, too... anyway, it'd be fun to test.

(Elderflower is my favorite flower wine by far, you should make some this summer if you can.)
posted by ragtag at 3:40 PM on January 11 [4 favorites]

Obligatory mention of Sue Burke's wonderful Semiosis, an amazing novel about sentient plants.
posted by danhon at 5:27 PM on January 11 [1 favorite]

I'm curious whether bee behavior exploits this, e.g. do bees buzz and hover near flowers longer than strictly needed for travel in order to promote the creation of sweeter nectar? Do bees return to flowers after a few minutes to collect sweeter nectar? Do bees favor flowers that other bees have just visited? etc.
posted by Davenhill at 6:07 PM on January 11 [8 favorites]

Not peer reviewed but seems so unsurprising that I don't see any reason for skepticism.

But on describing it as hearing--I do think it is used in part to make it seem surprising and then of course get the backlash. Our skin can feel light waves at certain frequency and intensity and has biochemical reactions to light even when we can't consciously feel it. We don't say skin is an organ we see with. It's interesting on its own merits, without necessitating an analogy-to-very-different-human-cognitive ability.
posted by mark k at 8:21 PM on January 11 [1 favorite]

We don't say skin is an organ we see with.

Human skin is constantly exposed to solar light containing visible and ultraviolet radiation (UVR), a powerful skin carcinogen. UVR elicits cellular responses in epidermal cells via several mechanisms: direct absorption of short-wavelength UVR photons by DNA, oxidative damage caused by long-wavelength UVR, and, as we recently demonstrated, via a retinal-dependent G protein-coupled signaling pathway. Because the human epidermis is exposed to a wide range of light wavelengths, we investigated whether opsins, light-activated receptors that mediate photoreception in the eye, are expressed in epidermal skin to potentially serve as photosensors. Here we show that four opsins—OPN1-SW, OPN2, OPN3 and OPN5—are expressed in the two major human epidermal cell types, melanocytes and keratinocytes, and the mRNA expression profile of these opsins does not change in response to physiological UVR doses. We detected two OPN3 splice variants present in similar amounts in both cell types and three OPN5 splice isoforms, two of which encode truncated proteins. Notably, OPN2 and OPN3 mRNA were significantly more abundant than other opsins and encoded full-length proteins. Our results demonstrate that opsins are expressed in epidermal skin cells and suggest that they might initiate light–induced signaling pathways, possibly contributing to UVR phototransduction.
posted by Celsius1414 at 6:31 AM on January 12 [5 favorites]

Defining "hearing" as something only pertaining to human ears or ears in general sounds to me like defining "moving about" as only something done with legs. Poor birds and snakes and fish and bacteria have never moved an inch in their entire life!

Or to put it more seriously, in cases such as this one, a definition can be either morphological or functional, that is, how it's built up, or what does it do? Broadly speaking, morphological definitions tend to end up in the sort of silliness as above more often than functional definitions. But not always, of course. And in this particular case i'm not sure which is the better type of definition, to be honest.
posted by Pyrogenesis at 8:15 AM on January 12 [3 favorites]

I work with species that have vastly different hearing ranges to humans. I am currently embarking on a study of very soft vocalizations just at the edge of the hearing range of some humans. (If we're describing sensory modalities in terms of human perceptions, are vocalizations around 20kHz fair game or not? They're generally things 20-something humans can hear, and just as generally something 50-something humans can not hear. Who's human?)

This idea that "hearing" or "sight" can only apply to senses that humans perceive is frankly ludicrous to me, as someone who routinely works in animal communication and sense and perception. Seriously. You would be laughed out of any conference on the subject.
posted by sciatrix at 8:43 AM on January 12 [3 favorites]

Who's human?

This is more of an issue in ethics rather than physiology, and therefore tangential to your point, but there's a basic tenet (i think it may be called) that virtually every definition of human-nonhuman difference will leave some humans outside of "humanity proper", and this has only ever had pernicious (and sometimes outright genocidal) consequences. So, yes, who is human? is a question that does not need an answer.
posted by Pyrogenesis at 8:59 AM on January 12 [3 favorites]

;) It's a rhetorical question for that reason--I meant to point to the ethical issue of defining a single range of perceptive sensitivities as inherently human and non-human, and do so in such a way that, ah, many people were shocked by the idea that older adults (including many MeFi community members) might then be written off as non-human. Of course this also pertains to many humans with disabilities, which is very close to the front of my mind as I write this; my own partner has low-frequency hearing loss and so I'm thinking about defining 'human' perceptive ranges from that lens as well.

I agree completely: that question does not need an answer, but defining senses in terms of what "humans" can and cannot perceive raises some very, very nasty questions. I would like for folks pushing that line of reasoning to consider the sorts of deeply nasty questions that might be lurking under their assumptions.
posted by sciatrix at 9:08 AM on January 12 [4 favorites]

In this, we are very much of the same mind, sciatrix. I quite literally got a PhD for punching human exceptionalism in the face. Well, punching philosophically. But definitely in the face. :D
posted by Pyrogenesis at 9:32 AM on January 12 [4 favorites]

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