Saturday, December 19, 2020

The Secret of Holobionts


"Braiding Sweetgrass" is a wonderful book, the kind that's best digested a few pages at a time. (h/t Erik Assadourian). In it, the author, Robin Wall Kimmerer, happily moves back and forth from the uses of her Native American ancestors and her knowledge as biologist. She never uses the concept of "holobiont," but the book teems of holobionts on almost every page.
I am about halfway through it, and the book remains full of surprises. Here is what I read this morning, while drinking my coffee. It is about how the ancient Native Americans had found a way to optimize their plots of land by planting together three different seeds: corn, beans, and squash, poetically referred to as the "Three Sisters." Kimmerer goes on describing the details of exquisitely intricate ways in which these three species collaborate with each other, maximizing the supplying of nutrients to all three. She says.
"It’s tempting to imagine that these three are deliberate in working together, and perhaps they are. But the beauty of the partnership is that each plant does what it does in order to increase its own growth. But as it happens, when the individuals flourish, so does the whole. In reciprocity, we fill our spirits as well as our bellies."
And that's the true secret of holobionts.

Thursday, December 10, 2020

On the Importance of Having Limbal Rings. The Evolution of Humankind


This short movie, Vikaari, has recently appeared on the "Dust" site and I think has several interesting features, relevant to the concept of holobionts. 
It is very well done as a movie, although it is deeply contradictory in many aspects. For one thing, it is a narrative disaster. First, the movie tells you that the Vikaari, children born without a visible iris in the eyes, are good people, and the target of Nazi-like bad guys. Then, we see the Vikaari killing their pursuers using their psychokinetic powers in bloody and cruel ways, apparently without any regret. Needless to say, this completely destroys the narrative tension of the movie and leaves you totally baffled about what the filmmakers wanted to say.

Indeed, I think the filmmakers were badly confused on several planes. First of all, in their decision of presenting this "new race" of children as something that will replace current human beings, engaged in destroying their own planet. Is this a hope or a fear? Difficult to say, but surely evolution doesn't work in that way. 

And then, why the choice of iris-less eyes as a defining mark? Most people rarely consciously perceive the characteristics of the irises of their fellow human beings. But the shape of the iris tells us much of the genetic inheritance of a person -- on this point, the film-makers got it right, although in reverse. A human being without a visible iris is not a modern human.
The iris is an easily modified, highly visible human trait. There is a whole genetic story in the human iris. From what we can say, light-colored eyes have been rare, although DNA studies indicate that they did exist in the Mesolithic period. Curiously, Europe is the continent where, nowadays, light-colored eyes are most common. But it is only a few centuries ago that light-colored irises start to appear in paintings. If they had existed before, surely painters would have noted them and shown them in their paintings. Green eyes are a modern trait in Europe, they seem to come from Northern Asia. They do spread easily because they are a typical "epigamic" trait. They give a certain advantage in the sexual competition for mates. 
And then, there are limbal rings. The dark ring that surrounds the iris. Also a typical epigamic signal, they are likely to be a feature of the modern main organism of the human holobionts. Here you see the eyes of Sarah Brightman, a modern human specimen, notable for their light green color and well detectable limbal rings. As epigamic signals go, Ms. Brightman is surely beaming them out loud and clear!

Note the difference from other mammalian eyes. Most animals, even our close relatives, the apes, have dark eyes, no limbal rings, and not even a large and well detectable sclera. You see it in the image: this (probably) female bonobo doesn't look at all like Sarah Brightman, although she also surely sends powerful epigamic signals to the males of her species. 
So, why do the Vikaari of the movie have no irises and no pupil? They are, actually, the specular version of the "black eyed people," characters of a recent horror movie. In both cases, filmmakers understood that the lack of sclera or of the iris is a characteristic of a creature that is not fully human. A new species (as in Vikaari) or an otherworldly evil creature (as in "black eyed creatures"). No wonder that regular humans react with great perplexity and sometimes violently. And their violence is reciprocated in Vikaari
The existence of these films shows our limited understanding, and also limited tolerance, of what makes humans human. A small difference in the extent of the sclera or in the color of the iris is sufficient to turn otherwise fully human creatures into enemies, at least in these fiction pieces. But we all know very well that it happens also in the real world for other, no more important genetic traits, such as skin color. 
There is a thin line that separates the horrible from the attractive: nobody would be killed for having green eyes, but the white-eyed Vikaari could be if they existed for real. But that's the way evolution works. Sometimes gradually, sometimes in bumps. The human holobiont of the future will not be the same as it is now and it was in the past. It is the giant holobiont that we call the ecosphere that changes all the time. Onward, fellow holobionts!

Finally, for your curiosity, the "Statue of a Standing Nude Goddess," presently at the Louvre Museum and coming from excavations in the Middle East. Note the eyes without irises. It is not clear if that was a bug or a feature: once they had decided to use rubies for the eyes of this statuette, there was no way they could have shown irises or pupils. But maybe it was intentional: this figure may have been supposed to be somewhat otherworldly or even threatening. Note the horns on her head, a typical attribute of the Moon Goddess. Already at the time when it was made, probably the 2nd century CE, goddesses were rather unpopular and suspicious, not unlike our modern witches. 



Friday, December 4, 2020

The Loving Reaper as a Holobiont. An Interpretation by Jenny Jinya

I don't think I'll engage in commenting the details of this story by Jenny Jinya, the young German lady who has been creating incredible stories (see here, here and here.). After all, we all know that the way to boredom lies in telling the details. But try to take a look at this story. It is not just a moving story, it has an unbelievable depth. It resonates of so many motives and ideas that are part of human history that it left me breathless: the Goddess, Death, the Otherworld, kindness, piety, benevolence, mercy, and much more. 

But the bewildering element of this story is how all these things are linked together. Jenny Jinya has truly understood how the universe works: life and death need each other and neither could exist alone. The holobiont concept is not just about symbiosis, it is about communication. And the universe is a giant holobiont that moves, changes, grows, shrinks, expands, returns, and restarts, all because its elements communicate with each other and the result is the never-ending cycle of life and death. Sometimes, we use the term "love" for this kind of communication and it is truly the most powerful force in the universe.



Thursday, December 3, 2020

Can Plants Perceive Us? The Opinion of Professor Suzanne Silard


What could be more holobiontic than this? Words of Suzanne Simard, as reported by the New York times.
“I think these trees are very perceptive,” she said. “Very perceptive of who’s growing around them. I’m really interested in whether they perceive us.” I asked her to clarify what she meant. Simard explained that trees sense nearby plants and animals and alter their behavior accordingly: The gnashing mandibles of an insect might prompt the production of chemical defenses, for example. Some studies have even suggested that plant roots grow toward the sound of running water and that certain flowering plants sweeten their nectar when they detect a bee’s wing beats. “Trees perceive lots of things,” Simard said. “So why not us, too?”


Sunday, November 22, 2020

A New Holobiont in Gaia's Family


Had you ever heard of the "Plastisphere"? Well, it is a new ecosystem that thrives on the plastic islands in the sea created by human activity. 
The term was coined in 2013, but these little critters are still thriving nowadays as you can see in a more recent article
For sure, they'll soon have plenty of food in the form of the six billion (yes, 6x10^9!) plastic face masks discarded everyday by humankind and, eventually, ending up floating somewhere in the ocean. 
And here is how the plastic plate appears to our little friends, the microbes. Bon Appetit!

Friday, November 20, 2020

The Wolf Song. A Few Minutes of Bliss in a Difficult Time

A splendid song, splendidly sung by Jonna Jinton, Swedish singer. The images are haunting and beautiful, suggesting the beauty of the forest inhabited by wolves, humans, and other creatures that form a single system, holobionts within the greater holobiont that covers the land. A few minutes of bliss, welcome in the difficult times we are living. 

These are the words in Swedish ("vargen" means wolves) -- Here you can find a more traditional version. Note how gentle and compassionate is the song, with the mother understanding the hunger and the distress of the wolf and willing to give it a pig tail or a chicken shank.

Vargen ylar i natten skog
Han vill men kan inte sova
Hungern river i hans varga buk
O det är kallt i hans stova
Du varg du varg, kom inte hit
Ungen min får du aldrig
Vargen ylar i natten skog
Ylar av hunger o klagar
Men jag ska gen en grisa svans
Sånt passar i varga magar
Du varg du varg, kom inte hit
Ungen min får du aldrig
Sov mitt barn i bädden hos mor
Låt vargen yla i natten
Men jag ska gen en hönsa skank
Om ingen annan har tatt den
Du varg du varg kom inte hit
Ungen får du aldrig
Ungen den får du aldrig

And here is a version in English (translated using Google, revised using common sense, as I don't speak Swedish. May not be perfect).

The wolf howls in the night forest 
He wants to but cannot sleep 
Hunger tears in his wolf belly 
Oh, it's cold in his den
You wolf you wolf, do not come here 
You'll never get my kid 
The wolf howls in the night forest 
Howls of hunger and complains 
But I'm gonna give it a pig tail 
That kind of thing fits in wolf stomachs 
You wolf you wolf, do not come here 
You'll never get my kid 
My child slept in her mother's bed 
Let the wolf howl at night 
But I'm gonna give it a chicken shank 
If no one else has taken it 
You wolf you wolf do not come here 
You never get the kid 
My kid, you'll never get it

Friday, November 13, 2020

Sex Among Holobionts: Love is a Horizontal Thing


  Marc Chagall (1887-1985) is reported to have said, "Only love interests me, and I am only in contact with things that revolve around love."  His paintings have a certain "holobiontic" quality. This one, "Les Amoureux de Vence" was painted in 1957,


What do holobionts, empathy, and harmony have in common with sex? One thing: they are all forms of horizontal transmission of information. We tend to see ourselves as multicellular organisms and, for us, sex is indeed a "horizontal" thing, in a certain sense. 

But, sex was not invented by multicellular thing. On this planet, sex is mostly something that bacteria engage in, freely exchanging genetic materials among themselves. It is free love that goes on all the time among single-celled creatures. And it is the way they evolve. It is by exchanging genetic materials that bacteria have become more and more capable to resist to the human attacks against them by means of antibiotics.

And even viruses, which can't reproduce by themselves, have sex with each other. It is just that they can only do that when two different viruses find themselves in the same host cell. That can become even a little weird when the two viruses come from different previous hosts, say a pangolin and a human being. In any case, viruses evolve very fast, that's why almost every year a new wave of influenza spreads over the world. 

For larger holobionts, such as human beings, the situation is different when you consider the reproductive mechanism of the main organism, the human one. Two human organisms exchange genetic information, but then this information must be "read" in a complex process that involves the birth of a new human being (and, unfortunately, the death of the old one). It is slow: in terms of evolutionary prowess, viruses and bacteria run circles around us. Fortunately, our immune system can also change fast enough to match the new threats and we are also defended by the "good" biome that form the human holobiont, the bacterial and viral symbionts we carry with us. And we are part of the larger holobiont we call the ecosystem.

Holobionts are a fractal system: the true embodiment of the poem of Jonathan Swift

The Vermin only teaze and pinch
Their Foes superior by an Inch.
So, Nat'ralists observe, a Flea
Hath smaller Fleas that on him prey,
And these have smaller yet to bite 'em,
And so proceed ad infinitum:

And so it goes.


Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)