Cover artwork by Ale Silva
Summary
Vision without eyes? Intelligence without a brain? Are plants more akin to us than we have been prepared to acknowledge? Or are they different in ways we will forever strain to imagine? One way or another, a vine with some unusual abilities is shaking the field of botany to its foundations.
On this episode: Zoë Schlanger (author of the newly-released, New York Times bestselling book The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth) takes us to the misty rainforests of Chile and back to report on what might just be the world’s most extraordinary plant — hidden in plain sight.
Click here to read a transcription of this episode
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Show Notes and Credits
Ed. note: To expand on “no one quite knows what a plant really is,” that was to say that there is no single trait that is comprehensive or exclusive to all plants, or a single description which can circumscribe the clade. The most obvious example is photosynthesis, which is lacking in many organisms which are "plants" by consensus, and present in many others which are not. That's life!
This episode was produced by Mendel Skulski and Adam Huggins, and was written by Zoë Schlanger and Mendel Skulski
With music by Modern Biology, Mort Garson, Hotspring, Thumbug, and Sunfish Moon Light.
Special thanks to Fiona Glen, Gianni Fontana, and Eden Zinchik
This episode includes audio recorded by sniperous, Alexbuk, dersinnsspace, Andy_Westcott, Enri2991co, and TRP, accessed through the Freesound Project, and protected by Creative Commons attribution licenses; work by Kevin MacLeod from the Free Music Archive; as well as clips from Acharya Jagadish Chandra Bose, The Secret Life of Plants, and The Kirlian Witness, utilized under fair use.
Citations
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Baluška, F., & Reber, A. (2019) Sentience and Consciousness in Single Cells: How the First Minds Emerged in Unicellular Species. Bioessays, 41(3):e1800229. doi: 10.1002/bies.201800229
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Gianoli, E., González-Teuber, M., Vilo, C. et al. (2021) Endophytic bacterial communities are associated with leaf mimicry in the vine Boquila trifoliolata. Sci Rep 11, 22673 (2021). https://doi.org/10.1038/s41598-021-02229-8
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Transcription
Introduction Voiceover 00:02
You are listening to Season Five of Future Ecologies
Mendel Skulski 00:10
Okay, here we go.
Adam Huggins 00:12
You know the drill.
Mendel Skulski 00:13
Mendel,
Adam Huggins 00:13
Adam,
Mendel Skulski 00:14
Future Ecologies.
Adam Huggins 00:15
and this is the last episode of our fifth season.
Mendel Skulski 00:19
Thanks for coming with us!
Adam Huggins 00:20
And don't worry, we will be back soon. In the meantime, we're going to be keeping the podcast feed warm and cozy over the summer with a few extra treats for your ears. Today, we've got something really special. Because it's a story about plants.
Mendel Skulski 00:37
It's more of a mystery about plants. Because despite our budding interest, our story today reveals that many leaves remain unturned.
Adam Huggins 00:46
The story comes to us from journalist and friend of the show, Zoe Schlanger, the author of the newly released, New York Times best-selling book, The Light Eaters — How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth.
Mendel Skulski 01:03
Zoë took one of our recorders to the jungles of Chile and back to report on what might just be the world's most ordinary, extraordinary plant. We'll let her take it from here. So, without further ado, this is Everything Will Be Vine.
Introduction Voiceover 01:23
Broadcasting from the unceded, shared and asserted territories of the Musqueam, Squamish, and Tsleil-Waututh, this is Future Ecologies – exploring the shape of our world through ecology, design, and sound.
Zoë Schlanger 02:08
Journalists in my line of work tend to be focused on death. Or the harbingers of it — disease, disaster, decline. That is how climate journalists mark time as the earth passes benchmark after grim benchmark on its way into the foreseen crisis. There’s only so much of this that one person can take. Or perhaps my tolerance was thin and easily worn out after years of focus on droughts and floods. In recent years I’d begun to feel numb and empty. I needed some of the opposite.
Zoë Schlanger 02:46
What, I wondered, is the opposite of death? Creation, perhaps. A sense of becomings instead of endings. Plants are that, given as they are to continuous growth. They’d soothed me all my life, long before studies came out confirming what we already knew — that time spent among plants can ease the mind better than a long sleep. Living in a dense city, I’d walked in the park under a canopy of yews and elms when I needed to clear my head; I’d spent long minutes gazing at the new leaves forming on my potted philodendrons when my nerves were fried. Plants are the very definition of creative becoming — they are in constant motion, albeit slow motion, probing the air and soil in a relentless quest for a livable future.
Zoë Schlanger 03:40
A life spent constantly growing yet rooted in a single spot comes with tremendous challenges. To meet them, plants have come up with some of the most creative methods for survival of any living thing, us included. Many are so ingenious that they seem nearly impossible for an order of life we’ve mostly relegated to the margins of our own lives, the decoration that frames the theatrics of being an animal. Yet there they are all the same, these unbelievable abilities of plants, defying our anaemic expectations. Through conversations with scientists around the world I would learn that their way of life is so astonishing, that no one really knows the limits of what a plant can do. In fact, it seemed that no one quite knows what a plant really is.
Zoë Schlanger 04:32
This is, of course, a problem for the scientific field of botany. Or it’s the most exciting thing to happen to it in a generation, depending on how comfortable you feel with seismic shifts in what you once thought to be true. As I looked deeper, I would find a scientific field eating itself alive with contradictions — points of contention multiplying as fast as the mysteries. But something in me was attracted to this lack of neat answers. Who doesn’t feel both drawn to and repulsed by the unknown?
Zoë Schlanger 05:11
In the 19th century, naturalist Alexander Von Humboldt wondered aloud why being outdoors evoked something existential and true. “Nature everywhere speaks to man in a voice that is familiar to his soul,” he wrote; “Everything is interaction and reciprocal,” and therefore nature “gives the impression of the whole.” Humboldt went on to introduce the European intellectual world to the concept of the planet as a living whole, with climatic systems and interlocking biological and geological patterns bound up as a “net-like, intricate fabric.” This was Western science’s earliest glimmer of ecological thinking, where the natural world became a series of biotic communities, each acting upon the others.
Zoë Schlanger 06:02
The question that I found mired in controversy was whether plants could be considered intelligent — and, for an even bolder minority, whether they could be considered conscious and communicative. For all of their amazing, adaptive behaviour, were they sensate agents? Or, were they each simply acting out a predetermined genetic script?
Zoë Schlanger 06:27
Although I had come to this corner of the scientific world at an exciting time, these questions were anything but new. At the turn of the 20th Century, Jagadish Chandra Bose, a physicist-turned-biologist in Kolkata, India, had begun to experiment and measure the electrical responses of plants, and became convinced that they shared a functional similarity to those in animal tissues.
JC Bose biopic 06:52
1901, the Royal Institution, London. He gave a lecture demonstration of his latest experiment.
The Secret Life of Plants 07:00
Touching the leaves of Mimosa pudica with a cotton soaked in ether, Bose demonstrates the fainting response in a plant.
The Secret Life of Plants 07:08
The Bose experiments were denied publication by the Royal Society. By daring to suggest that electrical responses are present in plants, he had offended the learned members.
Zoë Schlanger 07:19
Despite inventing instruments of unprecedented precision across several disciplines, Bose would be expunged from the scientific canon for his fringe beliefs — a fate not shared by Alexander Graham Bell, who was driven to invent the telephone in hopes of communicating with the dead; or Thomas Edison, whose experiments ranged into telekinesis and telepathy. Dark-skinned and Indian, however, Bose and his ideas were denied a place in Western textbooks for nearly a century.
Zoë Schlanger 07:52
Popular books were a different story. In 1973, the publication of The Secret Life of Plants took the world by storm. 5 years later, a film by the same name, with a soundtrack by Stevie Wonder.
08:06
Plants have been wired into a complex computer. The change of mood as they react to the crowds of visitors will be converted into musical expression. As the people move among the plants, the sounds they hear are the plants reacting to their presence. An ephemeral exchange of energy linking to diverse life forms, becomes a symphony of emotions.
Zoë Schlanger 08:37
At the dawn of New Age culture, the world was ready to inhale ideas about how plants were just as alive as we are. It was an immediate and meteoric success, offering an elysian new way to attend to the living earth.
08:51
In some mysterious way, the plant which is attached to the instrument is able to feel the mutilation of its comrade.
Zoë Schlanger 08:59
The Secret Life of Plants was a glimpse at a society on the verge of direct communication with its leafy brethren. It would inspire thousands of hours of one-sided conversations, and some very worn-out cassettes of Wolfgang Amadeus Motzart.
Zoë Schlanger 09:15
And it would turn out to be a beautiful collection of myths.
The Kirlian Witness 09:19
During intensive periods of meditation with plants, I learned to channel my energies and enter new states of being. After spending many hours in deep concentration, I am able to transcend my physical boundaries and allow my own spirit to commune with the spirit of my plant.
Zoë Schlanger 09:44
Many scientists would try and fail to reproduce the tantalising “research” the book presented, eventually deemed “fallacious and unprovable”. According to botanists working at the time, the damage that Secret Life caused to the field cannot be overstated. The twin gatekeepers of science — funding boards and peer review boards — closed the doors to any proposals with a whiff of plant “behaviour”.
Zoë Schlanger 10:16
Over the last 15 years, that tide has finally begun to turn, with a gentle swell in both research funding and academic publications. The march of technology, genetic sequencing and advanced microscopes, has made it possible to come to previously outlandish conclusions with real rigour. But, still sensitive to the fallout from the Secret Life, and due to the squishy, nebulous implications of the word, most scientific authors don’t use terms like “intelligence” to describe what they find. Nonetheless, their results suggested that plants were much more sophisticated than anyone had dared think.
Zoë Schlanger 10:57
From the nerve-like action potentials first observed by Bose, to capabilities of memory, hearing, recognition of kin, and incredible interactions with insects, the papers probing remarkable plant behaviours are growing from a trickle to a fairly robust stream.
Zoë Schlanger 11:18
One such paper caught my attention. It documented a vine doing something that should have been impossible — a magic trick that few animals have mastered, and that no accepted plant mechanism could explain.
Zoë Schlanger 11:32
So, in April 2022, I flew due south for 13 hours — first from New York City to Santiago, and from there to Puerto Montt. Then, after driving for another 2 hours, past seemingly endless fields of potatoes bordered by rivers and lakes, I arrived into the Valdivian temperate rainforests of southern Chile. Not unlike parts of the Pacific Northwest, the climate was cool and misty, and every available space was absolutely brimming with plant life. The constant sights of green and sounds of rain blanketed my senses in a vibrant static hum. In 2014, a Peruvian ecologist named Ernesto Gianoli had discovered that a vine, common to these rainforests, was able to mimic the shape of almost any plant it grew beside... a botanical chameleon.
Ernesto Gianoli 12:33
[Spanish]
Zoë Schlanger 12:34
I'm not finding what I'm looking for. It seems like they may have cut them.
Ernesto Gianoli 12:43
[Spanish]
Zoë Schlanger 12:44
I thought they were right here.
Zoë Schlanger 12:48
Unfortunately, the sudden notoriety had made this little vine a target for poachers. It's appropriate then that it has a particular talent for camouflage.
Ernesto Gianoli 12:58
But here I found...
Zoë Schlanger 13:02
Oh, wow it's so tiny.
Ernesto Gianoli 13:03
This is Boquila, yeah it’s so tiny, This is Boquila and this is Rhaphithamnus. At first glance you’d say it’s the same. Quite difficult to tell who's who.
Zoë Schlanger 13:13
This is Ernesto Gianoli himself. And in his hands, Boquila trifoliolata — a slender, climbing vine, with leaves in clusters of three. Here, one strand of Boquila was winding its way up a tree, Rhaphithamnus spinosus. On the part of the vine climbing the tree, its leaves had transformed: now a dark glossy green, shrunk to a fraction of their original size, and tapered to a point. And this was just one example of Boquila’s mimicry. Ernesto and his colleagues have found Boquila modelling itself on more than 20 species, and counting!
Ernesto Gianoli 13:52
So far, what we knew about mimicry was a one to one relationship. This species A mimics this species B. But then, comes along Boquila and says no, I can mimic very different species.
Zoë Schlanger 14:08
In the world of plants, mimicry is otherwise quite limited — shaped by special circumstances of coevolution. Like in the case of rye, once culled as an unwanted weed by early farmers. It was effectively selected to blend in so well with the fields of wheat that it became a cereal in its own right. Or certain types of mistletoe, which are each obliged to parasitize a particular host plant, tapping directly into its vascular system. The leaves of Australian she-oak mistletoe are strikingly similar to Australian she-oak, likewise the leaves of eucalyptus mistletoe resemble those of eucalyptus. Evolution has sculpted these plants to blend in with their specific surroundings, but on an animal timescale their appearance is fixed. Not so, with Boquila.
Ernesto Gianoli 14:59
The same individual can mimic two different species.
Zoë Schlanger 15:04
Boquila’s mimicry is spontaneous and flexible. A single vine may climb across several different plants and change its leaves accordingly.
Ernesto Gianoli 15:13
I mean, in terms of size, one to ten ratio. And in terms of shape, and color, vein patterns — a broad array of traits. What is mimicry? Similar colours, maybe similar shapes. But this goes beyond that.
Zoë Schlanger 15:33
What’s more, direct contact is unnecessary for Boquila to model itself after another plant. It may simply be growing nearby.
Zoë Schlanger 15:40
Whoa. That's huge.
Ernesto Gianoli 15:43
Yeah it's huge. And also this, as I told, this wavy...
Zoë Schlanger 15:48
Uh huh. The wavy edge.
Ernesto Gianoli 15:51
Yeah wavy edge.
Zoë Schlanger 15:52
Wow. That's unbelievable. I mean, that's like, what 15, 16 times the size over there?
Ernesto Gianoli 16:00
Yes, exactly. Here, small Boquilas. But starts growing larger and larger. Not all the plants, of course — not all the leaves, of course.
Zoë Schlanger 16:09
So if you were an herbivore, your first impression would be...?
Ernesto Gianoli 16:15
That it's another species.
Zoë Schlanger 16:16
Yeah. Wait, is this Boquila?
Ernesto Gianoli 16:18
Yes.
Zoë Schlanger 16:20
It's even got the yellowing.
Ernesto Gianoli 16:22
And if we look carefully around there are five more.
Zoë Schlanger 16:29
We are in a spot totally surrounded by Boquila on all sides. It's sort of a glen of Boquila. There's maybe 10 or 15 other species of plants, all growing up as thick bushes, and the Boquila is twining around all of them. And on almost every single one I'm walking by, you have to look very closely. But the Boquila has shifted its shape. In some areas of its vines to match. Most of these species, in some places, the leaf is almost the size of my hand to match long, large leaves of one species and 10 meters away, it's smaller than my pinky nail to match a species with very small, dark, glossy leaves that have a strong vein down the middle and the Boquila matches that vein and that gloss perfectly too. It's just astounding. And the longer I spend staring at an area the more Boquila appear, but it takes a while so if I was an herbivore, I for sure would be tricked. If I was a deer walking through here, I just can't imagine if they're visually guided how they’d distinguish between these plants.
Zoë Schlanger 17:56
And not all of these model plants are endemic to this rainforest. Ernesto showed me it next to a plant, creeping buttercup, that had only recently been introduced, sometime in the last 20 years. Here, Boquila’s duplication was strikingly partial and imperfect. It almost felt like witnessing a young artist practising their still-life sketches — actively refining their skill in rendering the world.
Zoë Schlanger 18:23
Every time Ernesto goes out into the field to study Boquila, he and his colleagues discover it modelling itself on yet another species. I was present for the addition of two plants to this ever-growing list. First, a species of maidenhair fern, so far the only documented instance of Boquila mimicking a fern, which I found myself. And second, an overstory tree known as Notro.
Ernesto Gianoli 18:47
This is the first record of Boquila doing something with Notro. This shape of elongated leaves is quite rare to observe in Boquila.
Zoë Schlanger 18:58
Still riding high off of my own small contribution, I asked Ernesto what it felt like to be the first one to notice Boquila’s magic trick.
Ernesto Gianoli 19:08
What is the dream of a kid who likes science? To make a discovery, right? A dinosaur bone or whatever. It was close to that... Close to that dream of the kid. But still, for it to be really fulfilled, I need to see the mechanism elucidated.
Zoë Schlanger 19:30
And in the hopes of elucidating the mysterious mechanism of Boquila, two competing hypotheses have been proposed — both of them revolutionary to plant science.
Ernesto Gianoli 19:41
To crack the code of Boquila immediately will lead us to crack a general code of plants. They go hand by hand, I mean. Understanding Boquila will imply understanding plants. That’s my feeling.
Zoë Schlanger 20:04
The first proposal comes from František Baluška, founding member of the Society for Plant Neurobiology, later conservatively renamed the Society for Plant Signalling and Behavior. František is a controversial figure. Unlike most of his peers, he is a loud and proud champion of plant intelligence — in fact, he evangalizes the subjective consciousness of all cellular life.
Zoë Schlanger 20:32
His hypothesis is as surprising as it is concise. He believes that plants can see.
František Baluška 20:40
Vision in plants is controversial, but it is strange that it is. Because plants evolved from algae and algae have vision. So, if algae have vision, why should plants lose this very useful ability? So, I am surprised that people are surprised that the plant should see, because if the algae see why not plants?
Zoë Schlanger 21:02
The suggestion that plants have a sense of sight goes back to 1905, when the German scientist Gottlieb Haberlandt described how structures on the surface of leaves could function as simple optics, affording plants thousands or even millions of tiny eyes.
František Baluška 21:18
Of course, vision in plants is not like our humans vision. You know, they don't have an eye like we. They have cells on the epidermis, these cells will act as a lens and will transmit any object you will expose to these cells on the other side. This was experimentally shown but ignored.
Zoë Schlanger 21:40
Haberlandt’s theory would go on to fascinate Charles Darwin’s son, Francis, but ultimately it was forgotten. How could a plant, apparently without a nervous system or anything we recognize as a brain, resolve an image?
František Baluška 21:54
Everything is projected on the next layer. And how the cells in the next layer are processing the images and sending messages further in the plant, no one knows.
Zoë Schlanger 22:04
Since Haberlandt, plants have been revealed to have more kinds of photoreceptors on their surface than are found in the human eye. There should be no surprise that light matters to plants. Light is literally matter, to plants. As any sighted person knows, the qualities of light convey a wealth of useful information. Still, it’s a big claim to say that plants are not just weather stations, but telescopes.
22:32
Of course, this could be studied, but first, the science must acknowledge this ability and then the agencies which give money for research should be willing to give money for future research, but up until now, nothing happens, you know, all what is done now is just our hobby.
Zoë Schlanger 22:49
František points to new research on several close evolutionary cousins of plants. A model cyanobacteria with an eyespot that can sense a light’s direction and move towards it. Next, a dinoflagellate that builds a structure that stunningly resembles a lens and retina — a chimeric assemblage of plastids and mitochondria, no less. And, of course, he points to Boquila.
23:14
There is no way how we would explain this without some kind of vision.
Zoë Schlanger 23:19
So, as outlandish as it may sound at first, a kind of plant “vision” is not entirely out of the question, and is one of the few explanations that has been offered to make sense of Boquila. But Ernesto is not convinced that vision is the mechanism behind this unassuming vine’s abilities.
Ernesto Gianoli 23:38
Plants don't need to see in order to do great things. How can texture, how can thickness be told from an image? And don't forget that there are some features that are hidden.
Zoë Schlanger 23:56
Case in point, the very first plant I saw Boquila copy with my own eyes — Rhaphithamnus spinosus. This tree’s leaves curl over at the end, creating a spiny tip or spike. Likewise, in its mimicry, so does Boquila. But looking down from above, this distinguishing feature of Raphitamnus is simply not visible.
Ernesto Gianoli 24:20
You have to feel! You have to put your finger on the underside of the leaf. How this is able to see the underside of a leaf when they are placed in a particular direction that cannot make this possible?
Zoë Schlanger 24:35
Could it be that Boquila was truly covered in eyelike organs, and was somehow able to integrate this information across different parts of its body — carefully observing the Rhaphithamnus from all angles? Or was it a hole in the plant-vision theory?
Ernesto Gianoli 24:52
I think this is too much of an anthropocentric view of the phenomenon.
Zoë Schlanger 24:57
As we strain to understand how Boquila can accomplish the seemingly impossible, itself just one example from a wave of newly-discovered plant capabilities, the charge of “anthropomorphism” looms heavy in the minds of many scientists. The risk of discussing plant sensation, perception, or cognition is that such language is inescapably tied to our sensation, perception, and cognition; that habituation with our animal faculties biases us to interpret plants on familiar, human terms, rather than on their own.
František Baluška 25:34
Most people are not very happy with these words like "pain", "cognition", and "intelligence", and "vision", and "hearing". So they think this is forbidden for plants, somehow. When you do a science, you should start with a simple system and then to go to the more complex. And we would not have this problem with anthropomorphism if we would start our sciences with bacteria, then algae, protozoa, protists, and then some plants — lower plants, higher plants — animals, and then humans at the end. You all the time are blamed by some kind of anthropomorphism, if you find something similar to humans, you know. Of course, we are in evolution connected. And now everything — every this term — is loaded with human activities. So if you say sleep, pain, cognition, anything, they say you try to humanize plants. We try to convince them that we say "plant cognition". It is not a human cognition. It is a plant-specific cognition.
Zoë Schlanger 26:35
Intelligence is a loaded word, perhaps overly connected to our ideas of academic achievement. It’s been weaponized against fellow humans for millennia, used to divide people into hierarchies of worth and power. Yet it is, by its very definition, still a word that contains the germ of what we mean by alert, awake to the world, spontaneous, responsive, decision-making. From the Latin interlegere — to discern, to choose between.
Zoë Schlanger 27:11
So do plants see? Or does an assumed primacy of vision render plants as lesser animals — diminishing these green bodies, and leaving no room for the recognition that they may deploy means that far exceed the human.
Ernesto Gianoli 27:28
It's very human in nature, to try to put plants within the frameworks that we are comfortable to deal with. But sorry, plans are different. So, prepare. Prepare to be challenged. Prepare to be proven wrong.
Mendel Skulski 27:50
When we come back, Ernesto has his own theory to explain this remarkable plant plasticity.
Adam Huggins 27:57
Plastic plants?!
Mendel Skulski 27:58
Those too... after the break.
Zoë Schlanger 28:23
For all the times he has seen Boquila trifoliolata, Ernesto had noticed something. Its mimicry is rarely total. Instead, it’s patchy. Some Boquila just look like… Boquila, even on a vine climbing a tree. This patchiness reminded him of the stochastic look of leaf spots and wilts and mottling. That is, it reminded him of the infection patterns of bacteria and viruses.
Zoë Schlanger 28:51
Over the past few decades, another biological revolution has been unfolding. A new appreciation for the so-called “microbiome” — the communities of single-celled organisms living in and on everything else. Famously, in any given person, there are about as many non-human cells than there are human cells. No longer are microbes considered to be exclusively vectors of disease and decay, but are now also recognized as essential collaborators in digestion, mood, and ultimately health. And humanity is not unique in this regard. Effectively all animals, like termites, fundamentally rely on their microbiome.
Zoë Schlanger 29:35
To most people, the essence of a termite is its ability to digest wood. Research has shown that this ability is conferred not by the genes of the termite, but by bacteria living within them. Correspondingly, those bacteria rely on other, smaller bacteria living within them. This is the dizzyingly nested perspective that pioneering evolutionary biologist Lynn Margulis first popularized as the “holobiont”. She defined the holobiont as a composite organism made of many organisms working in concert. It includes the microbiome, but also the macrobiome — the larger beings in which and upon which the microbiomes live.
Zoë Schlanger 30:19
Margulis proposed that complex multicellular life first came into being when microbes of different abilities teamed up, eventually fusing into one entity, most notably incorporating mitochondria and chloroplasts. She believed that these sorts of intercellular symbioses may have been more important to our evolutionary history than the slow, random mutation science believed to be the source of all evolutionary change.
Ernesto Gianoli 30:46
Don't forget that once the mitochondria was a bacteria. It was kind of a parasite that was welcomed by the cell, saying "Okay, you will make energy and I will give you a home." And that work very well so far.
Zoë Schlanger 31:10
Although initially ignored and ridiculed, her theory of endosymbiosis is now widely accepted as fact. “The completely self-contained ‘individual’ is a myth that needs to be replaced with a more flexible description,” Margulis wrote, with her son Dorian Sagan, “Each of us is a sort of loose committee.”
Zoë Schlanger 31:33
This state of nature is one of interpenetration and mingling that defies easy categorization. It occupies a middle place, both in the material reality of the world and in our understanding of it. To Báyò Akómoláfé, a Yoruba poet and philosopher, this middle “is not halfway between two poles; it is porousness that mocks the very idea of separation.” He describes our collective biological reality as a state of “brilliant between-ness” that “defeats everything, corrodes every boundary, spills through marked territory, and crosses out every confident line.”
Zoë Schlanger 32:19
What if, Ernesto wondered, this was the key to Boquila? What if its flexible appearance was an expression of a flexible holobiome? He conceived an experiment.
Ernesto Gianoli 32:33
It is very important to understand the experimental design. There's this Boquila plant mimicking other plants. So we'll focus on one particular interaction — Boquila and this tree called Rhaphithamnus. So Boquila and the tree. We spotted this tree with Boquila growing onto it. And specifically, we took leaves of Boquila doing the trick, I mean, leaves of Boquila resembling leaves of the tree. And — this is very important — leaves from the same individual Boquila that we're not mimicking the tree leaves. So we have these triplet. Leaves of the tree, Boquila doing the trick, and Boquila being just the standard Boquila.
Zoë Schlanger 33:24
Each pair of Boquila leaves, both mimicking and non-mimicking, were picked from the same vine, and the same distance from the tree. They gathered these three sets of leaves from 5 sites, and brought them all back to the lab.
Ernesto Gianoli 33:38
We analyzed the communities of leaf endophytic bacteria,
Zoë Schlanger 33:45
Leaf endophytes are the microbiome of the leaf. The bacteria living within its tissues.
Ernesto Gianoli 33:50
There is not one species of bacteria, there's hundreds.
Zoë Schlanger 33:54
Ernesto’s hypothesis was that if the microbiome played some part in Boquila’s abilities, then the community of bacteria in the mimic leaf should resemble that of the tree, and differ significantly from the non-mimic.
Ernesto Gianoli 34:09
And that's exactly what the results showed.
Zoë Schlanger 34:12
The leaves that successfully mimicked the Rhaphithamnus shared 255 distinct species of endophytes — more than triple those shared by the non-mimicking leaves.
Ernesto Gianoli 34:24
I think this is strong evidence of the involvement — I cannot say more than that — the involvement somewhat of bacteria in this phenomenon of leaf mimicry. One possibility, I think, is that in a way, these microbes partially control for instance, leaf shape, and this opens the avenue for research on this direction of genetic control, epigenetic control by bacteria and so on.
Zoë Schlanger 34:57
Ernesto is hinting at something with profound implications. He suspects that bacteria and viruses exert influence on the shape of all plants — perhaps by ferrying genes and RNA directly, or perhaps by selectively activating or silencing pre-existing parts of the plant genome.
Ernesto Gianoli 35:19
What literature tells us is that microbes are able to modify gene expression of other organisms. This can be airborne, like a bath of microbes, cloud of microbe, whatever you prefer.
Zoë Schlanger 35:40
The holobiome makes it difficult to delineate where one organism ends and another begins, metaphorically, but also very literally. What lives inside also often lives on and around. Each of us creatures, like Pigpen from the Peanuts, a blurry cloud of activity; a burst of flavour in the atmospheric soup.
Ernesto Gianoli 36:03
And then we are forced to conceive that all plants are constantly exposed to this process.
Zoë Schlanger 36:12
But why then just Boquila? Why aren’t all plants, or animals too for that matter, integrating each other’s features on contact? Well, we can’t know for sure that they don’t — at least on some subtle level. Boquila itself was described by Western botany in 1782, and it took us more than 200 years to notice it could do this. Could there be other mimics all over the world, hiding in plain sight?
Zoë Schlanger 36:44
Or is Boquila simply unique, and particularly porous? Maybe most plants only speak in the holobiome code of their own species, while Boquila cracked some universal cypher — permitting its appearance to be overwritten by its neighbours, for its own adaptive advantage.
Zoë Schlanger 37:04
In the first paper ever published on Boquila’s mimicry, Ernesto and his colleagues measured how copying the leaves of its surroundings correlated with less herbivory. From this view, Boquila’s talents could be the undirected outcome of natural selection — agency and intelligence not required.
Zoë Schlanger 37:28
One experiment poses a threat to Ernesto’s microbial hypothesis. In 2021, a study was published claiming to demonstrate Boquila growing on, and mimicking, a plastic plant. Of course, such a synthetic model has no holobiome to offer, and the authors claimed it as a strong support for plant vision.
Zoë Schlanger 37:50
However, this paper was met with criticism. Ernesto felt that the experimental controls were very weak, and took issue with the analysis. The study was a collaboration between an unaffiliated independent researcher — an amateur scientist — along with a student of František Baluška. František himself is editor-in-chief of the journal in which the paper was published, drawing complaints of an undeclared conflict of interest.
Zoë Schlanger 38:18
But all the negative attention hasn’t discouraged František and his student, Felipe Yamashita, from looking further. František reports that they have yet-unpublished data detailing how Boquila is capable of mimicking nothing more than a photograph of a leaf.
František Baluška 38:35
Yes, because we have no data that the Boquila is mimicking, not only a plastic houseplant, which is published, but we have now data that it is mimicking even pictures. So, if you provide the Boquila with the pictures of leaves, different kinds of plants, then the Boquila start within two, three days, making some mimicking of these pictures.
Zoë Schlanger 38:56
Ironically, František and Ernesto have a very similar intuition about why the other’s hypothesis is wrong. That is, the sheer breadth of Boquila’s ability to emulate.
František Baluška 39:08
Because the Boquila is mimicking many physical parameters, it is mimicking the shapes, color, texture, size and so on. So, it is not easy to transmit such information by some kinds of bacteria. And even if there are some different bacteria on mimicking leaves like on the non-mimicking, it is not any evidence that the bacteria are having something to do with the mimicking. For me, this story is really not able to explain everything. I think it is only possible with some kind of the vision
Ernesto Gianoli 39:43
I would say very lightly, "Show me the pictures." Because there are no pictures in that paper. If Boquila is mimicking plastic plants, this is very easy. Take a picture and show it to us, as I've done in every paper or article I have written.
Ernesto Gianoli 40:01
I am a scientist. I want to understand. I don't want to be proven right. I don't want to be famous. I want to understand. Hopefully be able to see the solution of this mystery within my lifetime.
Zoë Schlanger 40:21
One of the strangest things about Boquila isn’t the plant itself, it’s the near total lack of research attention. To the few scientists attempting to tease out its mysteries, even Ernesto, it remains a side project.
Zoë Schlanger 40:36
This may partly be lingering skepticism or trepidation from within the scientific community, but it’s also partly practical. Boquila is just not easy to work with, compared to typical laboratory plants — so called “model organisms”. So far, it has been challenging to grow from cuttings in a greenhouse, although František says they are making good progress. Still, the patchiness of its mimicry challenges traditional statistical methods.
Zoë Schlanger 41:09
For the time being, Ernesto and František may disagree on the most promising mechanism to explain Boquila. But they share at least one thing: an admiration for the 20th century philosopher Karl Popper.
Zoë Schlanger 41:23
Popper is widely held to be a father of the modern scientific method and its premise of falsification. Briefly, he put forward the idea that scientific theories are never really proven to be true, they may only be falsified — or in other words, disproven. According to Popper, science does not sit upon a bedrock foundation of truth. Instead, the great scaffolding of all scientific theory is supported only by pilings in swampy ground. To quote Popper, "the piles are driven down from above into the swamp, but not down to any natural or given base. And if we stop driving the piles deeper, it is not because we have reached firm ground. We simply stop when we are satisfied that the piles are firm enough to carry the structure, at least for the time being."
Zoë Schlanger 42:21
So we will always have more questions than answers. Are plants more akin to us than we have been prepared to admit? Or are they different in ways we will forever strain to imagine? Can we call them cunning in their own right? Or will such language always be too human?
Zoë Schlanger 42:44
We share our planet with and owe our lives to a form of life at once alien and familiar. On what basis do we owe them our respect and appreciation? In the words of ethnobotanist Timothy Plowman "They can eat light. Isn't that enough?"
Zoë Schlanger 43:07
The more we learn about plants, the more their complexities seem to multiply. The swamp, it turns out is full of life.
Adam Huggins 43:30
Zoë Schlanger is the author of “The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth”.
Mendel Skulski 43:40
And in which the story of Boquila is just one chapter. “The Light Eaters” is available now, wherever you get books.
Adam Huggins 43:48
This episode of Future Ecologies was produced by Mendel Skulski, and me, Adam Huggin
Mendel Skulski 43:54
With music by Modern Biology, Mort Garson, Hotspring, Thumbug, and Sunfish Moon Light
Adam Huggins 44:03
Cover art by Ali Silva
Mendel Skulski 44:05
And with special thanks to Fiona Glen, Gianni Fontana, and Eden Zinchik.
Adam Huggins 44:11
Thanks also to our patrons. Future Ecologies is a sort of loose committee — a holobiome with each and every one of you. We would not exist without your continuous support, inoculating us against a hostile media economy, inspiring us with horizontally transferred memes, and most of all, helping us grow — slowly and steadily, upwards towards the light.
Mendel Skulski 44:36
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Adam Huggins 44:37
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Mendel Skulski 45:06
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Adam Huggins 45:13
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Mendel Skulski 45:16
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Adam Huggins 45:25
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