The strange ability of sea sponges that has intrigued scientists and philosophers

Let’s ask a question…

Would it still be you if we erased your memories?

And if we cut off their heads and put them in one jar and their bodies in another and keep them alive. What jar would you say it was in?

What if we split all your cells and then rebuilt you cell by cell… would it be you again?

Sorry for the rude question, but let’s try to familiarize ourselves with a slippery and elusive concept: our sense of self.

What are you but your body?

Where are you inside your body and how much can we manipulate your body without affecting your core self?

To help us with these complex questions, we turned to one of the simplest creatures on the planet: the sponge.

“People don’t understand how sponges can do so much with so little,” says marine biologist Sally Leys, a professor of biological sciences specializing in sponges at the University of Alberta in Canada.

These aquifer animals, which have existed for at least 5 million years, are actually giant tubes that filter water.

Sponges have no muscles, organs, nervous systems or brains, so you might assume they have no thoughts, emotions or self-awareness.

However, they manage to do something amazing…

From cloud to sponge

The lab experiment described below is brutal but not deadly, allowing scientists to study various aspects of animal biology while also providing insights into how the first organisms formed.

“If you take a sponge and run it through a mesh as small as 20 microns, there are several cells that connect as they move and collide and organize themselves to gradually form the whole body,” he says. expert.

Sponges can actually do this: they reassemble themselves from a kind of living mud at the bottom of the sea.

It’s like a superpower.

The classic experiment, Leys says, is done with a blue and red sponge that, after going through the mesh, becomes a spinning purple cloud of cells under the right conditions and given enough time (about a week to 10 days). a blue sponge and… a red sponge.

“Thus, they have the ability to determine the self from the non-me.”

big question

Sponges have a kind of self-awareness that is encoded directly into their individual cells.

But the million-dollar question is whether the self-renewing sponge is the same sponge, or was a new animal created in these 10 days, a clone from an extinct animal?

It’s hard to know.

It depends on how much of your memories, your personality, and other things we think make up the “I” move from the original sponge to the reconstructed sponge.

But if we’ve just determined that sponges don’t have brains… then they shouldn’t have personalities or memories, right?

Another surprising thing about sponges is that, in a way, they have these things.

“You can actually see that there are things that bother them,” Leys says.

Why does the sponge get irritated?

“He’s uncomfortable with movement, so if you knock on the table, he’ll feel the vibrations and spit out what we call a sneeze.”

“It takes about an hour to relax again. So basically you have to do something else until the irritation subsides.”

“Sometimes students postpone experiments because some sponges will be uncomfortable if you do them in the morning.”

“We learn to learn about their characters by working with them in the labs.”

And can they learn something?

“This is possible in the sense that they are able to recognize a situation they have encountered before.”

Leys says he once managed to train a sponge to stick to Petri dishes the way he wanted.

At first the sponge would become a ball and the scientist would reopen it. This process was repeated several times.

“On day five the sponge started doing exactly what I wanted, in such cases they can learn and adapt.”

And do they remember what they learned after they broke up and reintegrated?

“Good question! The populations we’re working with have learned a few things. For example, they’ve adapted to freshwater by going through regeneration processes.”

“The question is how many times you can take a sponge and reduce it to cells, allowing them to recombine without stopping as they were before.”

Which brings us to the beginning of this text: our own awareness.

And the teleportation paradox.

Star wars?

Yes, we’re talking about traveling at the speed of light between galaxies at the touch of a button.

Ever since science fiction began toying with the possibility of teleportation in the late 19th century, the idea has intrigued philosophers such as Charlie Huenemann of Utah State University in the USA.

Develops a hypothetical scenario.

“I’m stranded on Mars. The fuel tanks on my return ship have exploded and no rescue team can come and rescue me,” imagines Huenemann.

“Fortunately my ship has a teleporter. The machine scans my body and produces an incredibly detailed diagram, a clear picture of every cell and neuron, which is then transmitted back to Earth where a new ‘I’ is created. It is built using available raw materials. “

Sounds good: salvation at the touch of a button. What is the problem?

“I can logically understand why this should work, because I’m just a certain cell configuration, and a carbon molecule is no more like me than another carbon molecule. As long as everything is arranged the same way,” says the philosopher.

But it is not that simple.

Remember we’re talking about a paradox, so a question arises: Is the Machine transporting you across the Universe or is it killing you and recreating a new version of you on Earth, with all your memories and personality intact, now thinking you are you? . ?

“I think I would die in teleportation on Mars, and someone very similar to me would show up on Earth.”

“I would have had all the cellular structure, all the neural connections, etc. to think it was me, and it’s not clear that my copy of the Earth is wrong.”

“Anything that made me think it was me would be found on Earth in that replica.”

But if your memories, your molecular and neural structure are yours and everything is a carbon copy, why not?

“That’s what I find very interesting about this thought experiment.”

“What this teaches us is that, in a deep sense, there is no ‘I’ as an indivisible unit that may or may not make the leap from Mars to Earth.”

In other words, this self-awareness? ‘I know it’s me’? In reality it is an illusion.

“Indeed, many philosophers have called the self the ‘user illusion’. It is an illusion that originates in our lives. ‘I feel like I am the same person yesterday and hope to be the same person tomorrow’.

“But if we try to go further and ask, ‘Is there a permanent ‘me’ that stays the same over time?’ That’s when a thought experiment like a teleporter teaches us: no, it doesn’t.”

Identity crisis

So even if you feel like you are the same person as yesterday, things are different: the weather, the food, the people you interact with, the way you do it, your mood…

Maybe what you are is a repetition of who you were yesterday and not exactly the same person.

Also, what makes you not what you are? Is it the arrangement of your atoms, your genetics, or what is encoded in your cells? but also where are you from.

Huenemann says, “Most of our identity is built on our relationships with other people: the society you live in, the job you have, etc.”

Let’s try to do another thought experiment without having to leave the planet.

When you go to bed tonight, you will lie down and sleep. And when you become unconscious, your awareness of yourself will somehow dissolve.

While you sleep, your body and brain transform. Many of your cells will change and it is possible for you to wake up to new neural pathways.

Is the ‘you’ waking up in the morning the same ‘you’ sleeping the night before?

Maybe yes or maybe no: it is possible for the illusion of “I” to recur every morning.

There is no way to know…

* This article is based on the episode “Sea-Sponges and the Illusion of Self” of the BBC series NatureBang. if you want to hear in english, Click here.

– This text was published at https://www.bbc.com/portuguese/curiosidades-63126056.