Creepy, right. I mean, WHY ARE THERE FACES IN THESE THINGS??

We all know there’s really no face in any of these things, they’re just harmless images of trees, rocks, cars, cakes, capsicums, flowers and buildings with no real person (or their skull) hiding in them.

Then why do we see faces in them? And why is it that everyone can see them?

Firstly, this phenomenon is called pareidolia.

(It already sounds like a creepy doll)

Secondly, there’s still a lot we don’t understand about it. This post explains a little of what we do.

Sometimes, all our brains really need to see a face in an object is three dots: two for the eyes and one for the mouth.

So even a simple bowling ball can look like someone staring back at you in shock.

But it's not just about being able to detect three dots.

Our brains are pretty sensitive to the arrangement of these features and the interactions they have with light and each other.

If they are spaced just right, oriented in just the right way and mimic the natural shadows of a face, voila! Pareidolia.

But if things go wrong? Like if you change the spacing, or orientation? The illusion quickly disappears.

Why though?

Why is it so easy for us to see faces in random things?

Well, our brains are really good at detecting faces. Like, ridiculously good.

We can pick out a face from a crowd, recognise a familiar person, and even notice a face-like pattern in a completely unrelated object incredibly quickly.

And this isn’t just because faces are familiar to us. Our brains have specialised machinery for processing them.

One of the most famous of these is the fusiform face area, tucked away in the brain’s temporal lobe. It’s involved in recognising faces and figuring out things like whose face we’re looking at.

This is especially important because, as a very social species, knowing who’s a person and how close they are to us can be the difference between a friend, a stranger, or a potential threat.

So perhaps it’s not surprising that our brains sometimes make mistakes, because the cost of missing a real face could be much greater than the cost of spotting a face that isn’t there.

In fact, this phenomenon has been seen in some other primates too! Which suggests that our tendency to spot faces where there aren't any might not be uniquely human.

So the next time you see Voldemort hiding in a tree trunk, don’t worry. It’s just your brain trying to keep you socially up-to-date by working just a little too hard.

And that’s why your brain sees faces in random objects in 452 words.

Hope you enjoyed reading this, and see you next time!

Got a strange biology or biotechnology question you’d like answered? Send it my way.

Thanks for reading this, !

If you enjoyed this article, I’d love to have you around.

Plus, The Petri Dish is still small enough that you get to help shape what it becomes.

Subscribe (it’s free!) and you’ll get every new article delivered straight to your inbox.

Subscribe now

New long-form science stories, bite-sized Mini Dishes and the occasional strange biology rabbit hole arrive every week.

I’ll save you a seat.

Thanks for reading and see you next time!

DISCLAIMER: This Mini Dish is just a little longer than 500-words because vaccines are a bit complicated to explain. Hope you enjoy reading this!

What’s the earliest vaccine you remember taking?

For me it was this Rubella vaccine my school was giving all of us 8-year-olds for free in school.

I remember walking into the ocean-themed kindergarten class with dark blue walls painted with little fishes, starfish and whales, and sitting on this red plastic stool. As I sat, completely undeterred by the fact that someone was going to be poking a needle in my arm, my teacher asked me what I ate for breakfast.

‘Poha?’, I said, unsure of why I needed to talk. I wanted to feel the pain and look at how the nurse pushed the chemical mix into my bloodstream, making me forever immune to the supervillains floating around in the air.

But how? How does a little squirt of liquid prevent me from getting sick?

To answer that, let’s look at the system our body relies on to protect us from all the invaders waiting to feed off of our nutrients and cosy living conditions to grow: the immune system.

This system is interesting because it is ruthless. It’s willing to destroy anything it thinks poses a threat to the rest of the body, but it also needs to know what actually counts as a threat.

One clue comes from antigens: molecular structures on the surface of all cells that the immune system can recognise. Think of them as molecular barcodes.

B cells, a special type of immune cells, can produce antibodies, proteins designed to recognise specific antigens. When those antibodies encounter their target, they can neutralise the pathogen or flag it for destruction.

And every single time your immune system fights an unknown pathogen, some of these B cells used to produce antibodies become memory cells, cells that remember the antigens the pathogen usually displays so that the next time it attacks, your immune system can recognise the same threat much faster.

The problem with this though is that fighting a new infection is hard.

Every time you fall sick, your body suffers from the effects of both the infection trying to use up all its resources and the immune system trying to kill it while not really caring too much about collateral damage.

That’s bad because people who are more vulnerable to illnesses like newborns, pregnant people and aged people can be severely endangered by these infections.

So to get around this scientists created vaccines!

Vaccines are basically weakened pathogens, or parts of them, like an antigen, that give the immune system a safe way to meet something that it can recognise when the real pathogen enters the body.

Think of it like giving your immune system a practice dummy instead of an actual experienced fighter to practice against.

Some vaccines even give your immune system instructions that teach your cells to temporarily make a particular antigen. These are called mRNA vaccines and were what were used most widely during the COVID-19 pandemic.

So when your immune system sees this unfamiliar antigen, weakened pathogen or find the instructions needed to make the antibody against the pathogen, it mounts a response against it, and B cells produce antibodies that recognise it. Some of those B cells also become memory cells.

Later on, if and when the actual pathogen arrives, your immune cells already know what to expect, what to look for, and most importantly how to defeat the unwelcome invaders, making the massacre shorter and more effective while also reducing collateral damage to the body’s own cells.

And that’s how vaccines work in 581 words. See you next time!

Got a strange biology or biotechnology question you’d like answered? Send it my way.

Thanks for reading this, !

If you enjoyed this article, I’d love to have you around.

Plus, The Petri Dish is still small enough that you get to help shape what it becomes.

Subscribe (it’s free!) and you’ll get every new article delivered straight to your inbox.

Subscribe now

New long-form science stories, bite-sized Mini Dishes and the occasional strange biology rabbit hole arrive every week.

I’ll save you a seat.

Happy (belated) Independence Day! 🇮🇳

Three days ago, India celebrated its 80th Independence Day, marking the day the country gained the freedom to find its own direction.

Which some animals are surprisingly good at, at least geographically.

Birds, turtles, even bacteria. A few of them can actually find their way through the air and water by using something really close to a built-in compass: Earth’s magnetic field.

But how does this actually work?

It’s kind of a mystery. Plus, it’s different in different organisms.

The overall ability to do this is called magnetoreception and has been found in a wide range of organisms. Everything from birds who use the magnetic field during migration and sea turtles who use it to navigate the oceans to magnetotactic (it’s a word) bacteria that can literally swim along the Earth’s magnetic field lines.

But detecting a magnetic field isn’t exactly like seeing an imaginary sign pointing north, it’s a little different.

For birds, the leading idea is that their eyes have a protein called cryptochrome.

When blue light hits the protein, it creates something called a radical pair, two nearby atoms/molecules with unpaired electrons. These radicals react to the magnetic field, potentially giving the bird information about where the field goes.

Meanwhile, bacteria take a more literal approach.

Magnetotactic bacteria, manufacture tiny membrane-bound structures called magnetosomes. These are made of magnetic mineral crystals and are arranged in chains inside the cell, acting kind of like a microscopic compass needle, orienting the bacteria along the Earth’s magnetic field.

And, guess what? They’ve even been found in India in several lakes, such as Lonar Lake in Maharashtra, pretty close to me, actually. Here, both north-seeking and south-seeking bacteria have been found.

Which is incredible!

We built compasses, GPS, and maps just to figure where on Earth we are and where we should be.

Meanwhile, some organism have been navigating the Earth’s magnetic field for millions of years.

I’m jealous.

And that’s how some animals can detect Earth’s magnetic field in 327 words. See you again!

If you enjoyed this article, I’d love to have you around.

Plus, The Petri Dish is still small enough that you get to help shape what it becomes.

Subscribe (it’s free!) and you’ll get every new article delivered straight to your inbox.

Subscribe now

New long-form science stories, bite-sized Mini Dishes and the occasional strange biology rabbit hole arrive every week.

I’ll save you a seat.

Exam season officially ended yesterday… at least for me.

That means today’s the day I start life anew.

No stress.

No obsessing over the steps of mitosis, the grammar of my essay, or what one random soldier had for lunch during World War I.

But looking back on the past few weeks, I noticed something strange.

Every time I sat down in an exam hall, pen in hand and paper open on my desk, my brain seemed to forget the things I’d spent hours upon hours revising and remember the most random facts imaginable.

The lyrics to this random song I heard five whole years ago.

That wombats poop cubes. (it’s true, it helps them keep their poop in one place and mark their territory)

Funny in hindsight, but not so funny when you’re staring at Question 6.

So why does our brain seem to remember the weird stuff instead of the things we actually need?

And more importantly...

Can we use that to our advantage?

The first thing to know is that your brain doesn’t store memories like a filing cabinet, neatly labelling one folder “important” and another “random facts.”

Instead, every memory is made up of networks of neurons connecting with one another. The more connections a memory has, the easier it becomes to find again later.

So what makes a memory build stronger connections?

Usually, it’s novelty.

Things that are surprising, funny, emotional or just plain bizarre grab your attention. That extra attention triggers the release of chemicals like dopamine and norepinephrine, which help strengthen the memory as it’s being stored.

Which is why “wombats poop cubes” often survives the test of time better than “the third stage of mitosis.”

Yup.

But exams introduce another problem.

When you’re stressed, your body releases hormones like cortisol and epinephrine. In small amounts, they help you stay alert and help the memories stick, but too much can make it harder for your brain to retrieve the exact memory you’re looking for.

It’s a little like trying to find one specific book while someone keeps switching the library lights on and off.

The book is still there somewhere.

It’s just harder to find.

Meanwhile, those strange little facts already have an advantage. They’re connected to stories, jokes, surprising images or conversations you’ve had before. Your brain has built more pathways leading to them, so they’re often easier to retrieve.

So, can we use this to our advantage?

Absolutely.

Instead of simply reading your notes over and over again, make them memorable and force your brain to make more pathways connecting them.

How?

It’s simple.

Turn mitosis into a tragic story.

Turn latitude into layers of a cake.

Remember musical notes as the instructions for making a hat from scratch.

Once you’ve done that, obsessively quiz yourself about whatever topic is coming for the exam, because active recall like this makes your brain practice retrieving that particular piece of information at a moment’s notice, like you would do in an exam.

And that’s all! The science of inconvenient memories, plus making it useful, in 498 words.

See you next time!

If you enjoyed this article, I’d love to have you around.

Plus, The Petri Dish is still small enough that you get to help shape what it becomes.

Subscribe (it’s free!) and you’ll get every new article delivered straight to your inbox.

Subscribe now

New long-form science stories, bite-sized Mini Dishes and the occasional strange biology rabbit hole arrive every week.

I’ll save you a seat.

If you liked reading this and have a question, or maybe just want to share feedback…

Leave a comment

Last Tuesday, we turned adult cells into induced pluripotent stem cells, essentially turning them into biological blank pages with far more potential than their grown-up versions.

Need a recap?

Here’s your ticket:

Right.

So now that we’ve all hit Cmd + Z on our cells (hopefully only metaphorically), let’s find out about something just a bit more important.

What do we even do with these?

Because here at The Petri Dish, ‘just because’ isn’t a great research strategy.

From Fairytale to Future

Fairy tales tend to end once the magic works.

Stem cells were a little different.

Scientists had discovered cells capable of becoming almost anything in the body, opening the door to a future of regenerative medicine. There was just one problem.

Most pluripotent stem cells came from embryos, making them as ethically controversial as they were scientifically exciting. Besides, they weren’t always an ideal match for the patient receiving them, increasing the risk of immune rejection.

And that’s why Yamanaka’s discovery means so much, because we aren’t as dependent on embryonic stem cells and the ethical problems they bring with them.

Instead of relying on embryonic stem cells, scientists could take an ordinary adult cell, such as a skin or blood cell, and reprogram it into an induced pluripotent stem cell using the four Yamanaka factors.

Suddenly, pluripotent stem cells weren’t something researchers had to find. They were something they could create, often from a patient’s own cells. That meant fewer ethical concerns, a lower risk of immune rejection, and an entirely new toolbox for studying disease, testing medicines and repairing the human body.

Fix-A-Person Toolkit

Right now, patients who need a tissue or organ transplant often spend months or even years on waiting lists, hoping a compatible donor becomes available. But what if, instead of waiting for a donor, we could grow the exact cells a patient needs?

Much less waiting and worrying about compatibility

Just making stem cells from the patients own tissue.

Of course, donor tissue would still be crucial, but we won't need to rely solely on them for transplant.

Instead, scientists can take a patients own skin or blood cells, rewind them using Yamanaka factors into iPSCs and guide them into becoming exactly the cell type the patient needs.

Need dopamine-producing neurons for someone with Parkinson’s disease? Make neurons.

Need insulin-producing beta cells for someone with Type 1 diabetes? Make beta cells.

Need new heart muscle after a heart attack? Make cardiomyocytes.

Because these cells come from the patient’s own body, they’re far more likely to be recognized as “self”, reducing the risk of immune rejection compared with cells from another donor.

Of course, this isn't as simple as ordering replacement parts from Amazon (although that would be pretty convenient). Many of these therapies are still being tested in clinical trials, and scientists are still figuring out how to make them safer, more reliable and available to more people.

This is important because for centuries, medicine has focused on managing disease.

Regenerative medicine asks a different question.

What if, instead of managing what’s broken, we could rebuild it?

Share

The Petri dish Patient

Every medicine has to be tested before it reaches a patient.

Traditionally, that has meant testing on cells grown in labs, then on animals and, eventually, human volunteers.

The problem?

Cells growing in a flat dish don’t always behave the same way they would inside a living organ.

Mice may share around 85% of their genes with us, but they’re still... well, mice.

And by the time a treatment reaches human trials, researchers have to navigate complex ethical considerations. Besides, no two people are exactly alike, so a drug that works brilliantly for one person may not work nearly as well for another.

So what if, before trying a medicine on you and observing its effects inside your body, doctors could test it on a sort of mini body/organ double?

Same DNA. Almost the same function. Just not inside your body.

Well, sort of.

Scientists can take a patient’s skin or blood cells, rewind them into iPSCs, and then guide them into becoming the same type of cells affected by their disease. Those cells can even be encouraged to organize themselves into tiny, simplified versions of organs called organoids.

No, they’re not miniature people. They’re miniature models.

Mini brains.

Mini intestines.

Mini lungs.

Mini retinas.

Because they’re grown from a patient’s own cells, these organoids carry that person’s DNA. They allow scientists to watch diseases develop, understand what goes wrong inside the body and test potential medicines before they ever reach the patient.

Instead of treating people like averages, scientists are beginning to tailor treatments to the individual.

Because one person’s disease can behave very differently from another’s, even when they share the same diagnosis.

I mean, if we can tailor a suit or a chair to fit one person perfectly, surely we can dream a little bigger than one-size-fits-all medicine.

Mother Gothel 2.0

If you were ever a die-hard Tangled fan like 3-year-old me was, you’d know that Rapunzel’s magical golden hair didn’t just heal people.

It made them young again.

And as ridiculous as that sounds in practice, biology does have a parallel to it.

Yamanaka factors. (yup, they’re here again)

Like Rapunzel’s hair, the Yamanaka factors can do more than just create stem cells. Given for just the right amount of time, they can rewind a cell just enough for it to become younger and healthier without erasing its identity altogether.

But here’s an obvious question.

If making cells younger is a good thing...

Why not just turn every cell in the body into an iPSC?

Because you'd end up with something much closer to a tumour than a twenty-year-old.

So scientists tried something different.

Instead of undoing differentiation so much so that the specialized cell turns into a stem cell, they tried to limit it just enough to age it back by a bit.

Think of it like holding Cmd/Ctrl + Z on your document until it erases everything on the page versus tapping it again and again just enough to remove the mistakes on the page.

That’s exactly what researchers call partial cellular reprogramming.

In mice, it has helped damaged optic nerves regenerate, improved muscle repair and reversed some biological signs of aging. Scientists are now exploring whether the same approach could one day help treat age-related diseases in humans.

Ok, that sounds amazing, but does that mean we’ll all be celebrating our 150th birthday one day?

Probably not. At least not anytime soon.

Why?

Because pressing undo often has some unintended consequences…

Like deleting your whole document and quitting the app.

Can’t say that’s ever happened to me.

The Problem with Pressing Undo

Ok fine, it has.

And I’m sure it’s happened to most of us.

But compared to pressing undo on a cell’s biology? It’s pretty forgiving.

One extra tap on a document might cost you a paragraph, while one extra tap inside a cell might just cost it its identity or worse: cancer.

Because c-Myc, one of the four Yamanaka factors we met in Part 1 doesn’t just help rewind cells, it’s also an oncogene. That means if it isn’t carefully controlled, it can encourage cells to divide uncontrollably, which is exactly what cancer is: cells growing when they shouldn’t.

And that’s why scientists have to be incredibly careful with these factors, because the goal isn’t usually to rewind a cell as far back as possible, but just enough that something changes without serious consequences.

The End?

As a three-year-old, I thought Rapunzel’s magic belonged exactly where it was, in a fairytale, and growing older, I accepted that healing impossible diseases, replacing damaged organs and turning back the clock were ideas best left to Disney.

But it turns out, biology had other plans.

Even then, we’re still a long way from growing replacement organs on demand or celebrating our 150th birthdays and many of the ideas we’ve explored are still making their way through laboratories and clinical trials. Some may never even become everyday medicine.

Twenty years ago, the idea of turning an ordinary skin cell back into a stem cell sounded just as impossible, yet now it seems a bit closer to reality.

Maybe that’s the real magic.

Not that we can press Ctrl + Z on a cell, but the fact that science really can make the impossible possible.

What do you think are some ways science has turned the impossible possible?

Let me know in the comments below.

Leave a comment

If you enjoyed this article, I’d love to have you around.

Plus, The Petri Dish is still small enough that you get to help shape what it becomes.

Subscribe (it’s free!) and you’ll get every new article delivered straight to your inbox.

Subscribe now

New long-form science stories, bite-sized Mini Dishes and the occasional strange biology rabbit hole arrive every week.

I’ll save you a seat.

Between Rapunzel’s magical hair and Elsa’s ice powers, it was an easy choice. I wanted Rapunzel’s magic.

Not because it was impossibly long, although that was definitely a bonus, but because it could do something far more interesting.

It could heal wounds.

It could restore youth.

It could, quite literally, turn back time.

As I grew older, I accepted that powers like those belonged in fairy tales. After all, how could anyone possibly heal the body or reverse aging in real life?

Turns out, biology found another way. One that doesn’t involve a glowing golden flower hidden on a hillside.

All you really need are the right cells and a sprinkle of the right proteins.

Let’s begin with the cells. Stem cells.

Subscribe now

Everywhere and Nowhere

Stem cells are surprisingly difficult to find. Especially if you’re an adult.

And yet, without them, you’d have no skin, no blood and no way to digest your food.

Basically, you’d be dead.

So where are they?

Hiding.

Tucked away in little, stem cell neighbourhoods, called stem cell niches deep inside your gooey bone marrow, nestled in the folds of your slimy intestines, and quietly waiting beneath your skin.

Most of the time, they’re just existing as backup until your body actually needs them. Like when it needs more blood cells, intestinal cells, skin cells, or even more stem cells.

In adults, they’re only present in a few places, but in an embryo or a zygote, they’re everywhere!

One key difference, though, is that while embryonic stem cells can turn into almost any cell type, making them pluripotent, adult stem cells can only turn into a few different cell types.

For example, bone marrow stem cells can only turn into the cells present in the blood: white blood cells, red blood cells, and platelets.

Embryonic stem cells, though, can become almost any cell in your body, from neurons and heart muscle cells to skin cells and liver cells.

But the most interesting thing? Every stem cell, adult or embryonic, has the same DNA.

Actually, so does every other cell in your body.

So if every cell contains the same genetic instructions, why does one become a neuron while another becomes a white blood cell?

DNA Fairies Factors

No, DNA does not come with tiny fairies bestowing different traits on different cells

Wait.

Actually it kind of does.

They’re not fairies of course, they’re proteins called transcription factors.

Tiny fairy godmothers deciding whether CinDNArella gets dressed as a neuron, a lung cell, a skin cell or just keeps waiting as a stem cell.

They don’t make decisions consciously, they simply bind to specific stretches of DNA and determine if those genes will get transcribed into mRNA, a type of RNA that ribosomes (protein factories) translate to get the instructions for making proteins.

Those proteins ultimately determine how a cell is built, what it can do and, eventually, what kind of cell it becomes.

How do these fairies factors decide which genes to latch onto?

It’s based on internal and external influences.

For example, as stem cells divide, daughter cells inherit many of the same proteins and molecules as their parent, making them more likely to follow the same developmental path.

That’s an internal influence.

An external influence would be if a cell receives signals from the cells around it to differentiate into another type of cell and starts making the transcription factors it needs for it.

And that’s how stem cells shape-shift into specialized cells.

But is it reversible?

For many years the accepted answer was: no.

Once a cell had chosen its job, the decision was permanent.

Then, in 2006, four proteins changed everything.

Leave a comment

Yamanaka and the Four Proteins

If this were another Disney film, I’d introduce you to Flora, Fauna, Merryweather and Maleficent.

Biology, unfortunately, picked Oct4, Sox2, Klf4 and c-Myc instead.

Three of these four transcription factors work fairly well, but the fourth, c-Myc, is incredibly powerful but also an oncogene, meaning it can increase the risk of cancer if not carefully controlled.

So what did Yamanaka do?

His hypothesis was surprisingly simple:

Embryonic stem cells must contain a small set of transcription factors that keep them in a stem cell state. If I can identify those factors and introduce them into an adult cell, maybe I can rewind its identity.

To test that idea, Yamanaka and his team started with twenty four candidate genes that were active in embryonic stem cells and introduced them all into ordinary adult cells.

One by one, they removed genes from the mix, asking the same question each time:

Does it still work? Is it still a stem cell?

Eventually, they discovered that just four were enough: Oct4, Sox2, Klf4 and c-Myc.

Over a few weeks, adult skin cells with these factors slowly stopped behaving like skin cells. They switched off skin genes, switched on stem cell genes and gradually regained the remarkable flexibility they had lost during development, reverting back to their state before it differentiated and becoming an iPSC: an induced pluripotent stem cell.

These cells are capable of becoming any cell type again. It’s kind of like biology’s equivalent of Cmd Z, except way slower.

For the first time, scientists had shown that cellular identity wasn't permanent. A mature cell could be persuaded to become young again, and this concept is what brought Dr. Yamanaka the Nobel Prize in 2012.

A Biological Wormhole

For most of modern biology, we thought differentiation was a one way ticket.

Imagine it like this.

You’re studying to be a doctor, and years of school, countless exams and endless cups of coffee later, you’ve built a very specific set of skills. You can diagnose diseases, interpret scans and prescribe treatments.

Now imagine someone asks you to become an architect instead.

Not by taking another few years to train, but by changing some neural pathways and instructions in your brain.

It sounds impossible, right?

And for so long, biologists thought cells worked the same way. Once a stem cell became a neuron, skin cell or muscle cell, it had committed to that identity forever. The genetic program that made it a stem cell was thought to be permanently shut down.

Yamanaka’s experiment showed that this wasn’t true.

The instructions were never deleted.

They were simply turned off.

By introducing just four transcription factors, he wasn’t giving the cell new DNA or editing its genome. He was persuading it to read a different chapter of the instruction manual it had carried all along.

That was the revolutionary part.

It shows that our cells still remember how to be something else.

And that’s amazing.

Share The Petri Dish

Infinity and Beyond

Maybe Rapunzel’s magical hair had more truth and science in it than we thought.

Pressing Cmd Z in cells raises an obvious question, though. If we can persuade an ordinary cell to become young again...

What’s next?

Could we persuade organs to go back a few years? Whole organisms?

Or are we opening the door to something much bigger and stranger?

Find out more next week when we explore the endless possibilities in stem cell research.

Grow with us… not in a cancerous way.

If you enjoyed this article, I’d love to have you around.

Plus, The Petri Dish is still small enough that you get to help shape what it becomes.

Subscribe (it’s free!) and you’ll get every new article delivered straight to your inbox.

New long-form science stories, bite-sized Mini Dishes and the occasional strange biology rabbit hole arrive every week.

I'll save you a seat.

It’s finally monsoon! At least where I live.

Monsoon is easily my favorite season of the year, especially at the very beginning, when the clouds seem to burst open and the whole world suddenly smells like rain.

Earthy. Fresh. Sleep-inducing.

But where is that smell coming from?

I remember trying to catch raindrops on the tip of my tongue as a little kid, only to discover that rain is basically tasteless. So how does something with almost no taste suddenly fill the air with that unmistakable rainy day smell?

Like a lot of the things we talk about here, it’s all thanks to our little friends: microbes.

Microbes? In rain?

Not quite.

Yes, there are tons of microbes in rain, but they aren’t the ones responsible for that rainy-day smell we call petrichor (a portmanteau of the words petros, stone and ichor, the blood of the gods in Greek mythology).

The real stars are tiny soil bacteria called Streptomyces. During dry weather, they produce a molecule called geosmin. When raindrops hit the ground, they trap tiny air bubbles that spray back up into the air, carrying geosmin with them and that’s the earthy smell you’re breathing in.

It isn’t just geosmin though. It’s usually a mix of geosmin, oils that plants make in dry periods and a hint of ozone from before a big thunderstorm.

So it makes sense that this year’s monsoon in Mumbai has smelled especially strong. It arrived after a long dry spell, giving soil bacteria plenty of time to produce geosmin before the first rains released it into the air.

Oh and fun fact about geosmin: Humans can detect geosmin at concentrations as low as 5–10 parts per trillion. By some estimates, that’s around 200,000 times more sensitive than a shark’s ability to detect blood in water, although the exact comparison depends on the shark species and detection threshold being used.

Scientists aren’t entirely sure why, but one leading idea is that it helped our ancestors detect rain or fresh water nearby. After all, where there’s rain, there’s often fresh vegetation, growing plants, and eventually, more food and better survival.

And that’s why rainy days smell so, well, rainy in 370 words. See you next time!

If you liked reading this and have a question, or maybe just want to share feedback…

Leave a comment

And if you’d like to join forces with other science enthusiasts…

Every summer, the signature red mango box would arrive at my house.

It was always a welcome sight in the sticky heat of May because it meant juicy mango slices for breakfast and deliciously ice-cold aamras after dinner.

But these boxes never arrived full of soft, sweet, ripened mangoes, but with rock-hard sour, green ones that didn’t belong anywhere near aamras.

So we left them alone in their box, straw and all.

A week later, we’d open it to find the raw mangoes had vanished. In their places were golden mangoes. Sweeter, softer, and much tastier.

What had happened in the dark straw-stuffed box?

And why don’t oranges do the same?

It’s actually got very little to do with the straw.

The real magician here is the mango.

Mangoes are climacteric fruits, just like bananas, apples, plums and avocados, which means they continue ripening even after they’ve been picked, because as they mature, they release a natural plant hormone called ethylene.

Think of it like a floating message that basically tells the fruit, “It’s time.”

Once it gets the message, dense starches begin turning into sweet sugars, the hard flesh softens, green chlorophyll fades away to reveal yellow and orange pigments, and the familiar sweet mango aroma starts to develop.

All the straw does is create a warm, well-ventilated environment that helps trap some of the ethylene gas around the fruit, making them ripen faster.

Oranges, on the other hand, play by a different set of rules.

They, along with lemons, pineapples, cherries and strawberries ,are non-climacteric fruits, which means they don’t produce much ethylene after being picked because they’re supposed to be getting all of it from its plant. Once they’re harvested, they won’t become significantly sweeter or riper. They’ll simply get older and yuckier.

Today, commercial fruit growers use the same principle on a much larger scale. Instead of straw-filled boxes, many use carefully controlled ripening rooms where temperature, humidity, and ethylene levels are monitored to ensure every mango ripens evenly.

So the next time you see a box of raw mangoes tucked away in straw, remember: the straw isn’t the magician.

It’s just giving the mangoes the perfect place to finish the job themselves.

And that was 381 words. See you next time!

If you liked reading this and have a question, or maybe just want to share feedback…

Leave a comment

And if you’d like to join forces with other science enthusiasts…

Everyone’s welcome!

Hey!

Welcome to The Mini Dish, a new corner of The Petri Dish dedicated to curious science in 500 words.

We’re kicking things off with a question I found myself wondering: Why doesn’t honey ever spoil?

Got a strange biology or biotechnology question you’d like answered? Send it my way.

Imagine opening a jar of honey that was sealed over 3,000 years ago.

It sounds like the setup to a horror movie. You slowly twist the lid open in a cloud of dust, brace yourself for the smell, and immediately regret every decision that led you there.

Except... the honey would probably still be edible. And might even taste alright.

In fact, archaeologists have uncovered pots of honey in ancient Egyptian tombs that have remained edible for thousands of years when sealed properly.

So how can something made by bees survive that long when a loaf of bread barely lasts a week?

The answer isn’t magic. It’s a brilliant combination of chemistry, biology, and a little help from bees.

The first secret to food longevity is sugar… lots of it.

Honey is made up of around 80% sugar and less than 20% water, so any fungi or bacteria or whatever microbe finds itself unlucky enough to be in it thirsts to death.

Kind of like being in a desert with unlimited food and no water.

Then comes the acidity.

Honey has a naturally low pH, so if somehow a microbe survives dying of thirst, it still has to deal with the acidity making life difficult.

And the final trick up the bees’ stripey sleeves?

Glucose Oxidase.

While churning up their honey, they add an enzyme called glucose oxidase, so when small amounts of moisture enter the honey, this enzyme slowly produces tiny amounts of hydrogen peroxide, the same antiseptic found in many first-aid kits.

Not enough to harm you, but just enough to discourage microbes from taking root.

And there you have it.

Put those three defenses together, and honey becomes one of nature’s most effective preservatives.

Of course, honey isn’t completely indestructible. If water gets into the jar or it’s stored improperly, yeast can begin to grow and fermentation can occur, turning your immortal honey into something that’s very mortal, but still impressive.

So the next time you drizzle honey onto your toast, or in your tea, remember: you’re eating one of the few foods that could probably outlive you... and maybe even an empire.

And that was 350 words. See you next time!

If you liked reading this and have a question, or maybe just want to share feedback…

Leave a comment

And if you’d like to join forces with other science enthusiasts…

Everyone’s welcome!

Last week, we met the xenobots: bizarre little living machines built from frog cells.

Not met them yet?

Here’s your ticket:

So now that you’ve met them, shaken them by the cilia, and all caught up, here’s a question.

Who made them?

And more importantly...

What happens when these little frog-bots leave the Petri dish?

Spoiler alert: It’s not frog-led world domination... at least not yet.

The Designer

Let’s start with question 1: Who designed them?

I know what you’re thinking.

“Obviously the scientists.”

And you’d actually be right... kind of.

If I asked you, or even an experienced engineer, to design a machine, chances are you’d base it on something you’ve seen before. Wheels. Legs. Wings. Nature is full of inspiration, and our brains naturally build on what we already know.

AI’s a bit different though. Instead of starting with one clever idea, it starts with thousands of random ones that are usually terrible.

Why?

That sounds like a terrible strategy, but it works because of evolution.

The initial batch of randomly generated body plans is tested to see how well they perform their task. The ones that don’t do well are discarded, while the plans that kind of do work live to see another simulation where they’re copied and tweaked, so each new version is a little different from the originals, a bit like mutation.

Then the cycle repeats. Generation after generation, the designs get a little better, until eventually the AI is left with a handful of body plans that perform remarkably well.

One of my favourite explanations of how an AI like this works is from this video:

It’s not about the AI used to make xenobots, but the underlying concept is remarkably similar.

Worth a watch if you’re curious.

And that’s how scientists ended up with the xenobot designs they built from real frog cells. Not because the AI thought Pac-Man would look cool, but because it happened to be the one that performed the task best.

But does it have to be a frog?

Next Gen

If frog cells can be coaxed into a new structure with new roles and functions... could human cells do the same?

Turns out, they can.

Introducing... anthrobots!

Instead of using frog embryonic cells, anthrobots are built from a single adult human cell taken from the skin lining the trachea, the tube carrying air to your lungs.

The cell is then allowed to grow and multiply over 2 weeks to make a little ball that is the anthrobot.

Like frog skin cells, these cells come equipped with thousands of tiny cilia which are normally used to sweep mucus out of your airways so you don’t choke, but in the anthrobot, they act as tiny paddles, pushing the entire machine through its surroundings.

That’s already very exciting, but there’s more.

Researchers found something they weren’t even looking for.

Anthrobots can help heal damaged nerves.

When they were placed near injured nerve tissue, they would encourage neurons within it to reconnect, essentially stitching it back together.

They weren’t designed to, but they somehow could, opening a whole world of possibilities for them.

But what does the future hold for anthrobots, xenobots and any other living machines that follow?

Crossroads

This section of this article is probably the most difficult to write.

Not because xenobots and anthrobots lack potential. They do.

It’s because nobody really knows where they’ll take us.

I think that’s both the beautiful yet unsettling thing about some breakthroughs. When they’re first discovered, they often seem unnecessary, impractical, or simply bizarre. It’s only years, sometimes decades, later that we realise just how important they are.

And even then, we don’t always know whether they’ll make the world better, worse, or simply different.

I mean, xenobots could one day become biodegradable sensors, quietly exploring places where clunky mechanical robots struggle to survive. They might monitor the health of oceans or soils, lighting up or sending signals when they detect toxic chemicals.

Anthrobots could be even more personal. Because they’re built from human cells, researchers hope they could one day be tailor-made for individual patients, perhaps delivering drugs with incredible precision, repairing damaged tissues, or helping treat diseases in ways conventional medicine simply can’t.

Of course, those possibilities are still just that: a glimpse into a distant future that may or may not happen.

And that’s exactly why this technology finds itself at the same crossroads as so many breakthroughs before it.

Who decides what’s an acceptable use?

Where do we draw the line between curing disease, enhancing the human body, and engineering life itself?

And perhaps the biggest question of all:

Just because we can... should we?

What do you think?

Leave a comment

Or leave a message…

New ideas are always welcome. :)

Subscribe now

The first time I saw a frog in real life was when I was playing in the little playground in the garden near my building. It was twilight, so visibility, especially for a little kid, was really low.

I was stomping around in my pair of old white Crocs and making up a game to play with the others in the playground, when I heard a croak near the stairs leading up to the slide.

Ribbbbit-ribbit!

I squatted to take a closer look, squinting my eyes in the darkness.

And there I saw a frog.

Except it wasn’t one of those wise old frogs from my storybooks, it was a belching, mottled, puke-green amphibian.

Eugh!

But oddly enough, that first impression of frogs didn’t really last, because years later I discovered that those storybooks with frogs in them were sort of right.

Not because frogs dispense wisdom, turn into princes, or grant wishes, but because they’ve helped scientists create one of the strangest and controversial inventions in modern biology: xenobots.

Tiny, programmable, living dead robots.

But not in the way you’re probably thinking, because there’s no code, no metal, no silicon, and definitely no zombies involved.

So... what are they?

Let’s find out!

Xenopus laevis

Ever heard of it?

Maybe, maybe not. But chances are you’ve never given this unassuming frog a second thought. That would be a mistake.

For decades, this slimy frog has been a biology lab star. Scientists have done countless experiments on these little things to study how embryos develop, how cells communicate and even how organs form.

More recently though, they’ve lent a part of their name, plus a couple of cells from embryos, to biology’s most unusual creations, xenobots.

The Recipe

At first glance, they look boring. Just a bunch of pale beige blobs in a Petri dish. No blinking lights, fancy sensors or messy wiring that suggest that it’s a bot.

But then, when you see them move around their dish, that’s when it strikes you.

It’s a zombie.

Ok, not really. It’s a robot.

They spin in circles, crawl across the dish, occasionally bump into one another and simply... carry on.

Which raises a pretty obvious question: Who’s controlling them?

Well, surprise! Nobody is.

So how did the team of biologists and computer scientists from Tufts University, University of Vermont, and the Wyss Institute at Harvard University make this little wonder?

Here’s the recipe (don’t try it at home):

Xenobot 1.0

That was the recipe, the guide scientists followed to make the next generations of xenobots, each better than the next.

And it all began with the humble, boredom-inducingly slow Xenobot 1.0.

Freshly freed from the microscopic chisel and hammer, Xenobot 1.0 wasn’t going to win any races. It was slow, wobbly, kinda crazy and had no idea where it was going.

Which is incredible, honestly.

These tiny blobs of living heart and skin cells could move all by themselves without a brain or controller telling them what to do. Heart cells moved in perfect synchronicity like tiny engines, while skin cells provided the structure, allowing this adorable blob to crawl across its dish and explore its world.

It wasn’t smart in the way that they could think, feel, or decide like animals do, but it didn’t really need to, because Xenobot 1.0 was all about proving that ordinary cells from a frog can be coaxed into a completely new living form.

More importantly, it was a milestone because for the first time, researchers weren’t just studying living systems, they were designing one.

Xenobot 2.0

Xenobot 1.0 was a huge leap, but like every first version, it had its flaws.

For starters, using heart cells as tiny engines wasn’t exactly practical. They worked, but only for so long.

So the scientists went back to the supercomputer.

This time, they ditched the heart cells altogether. Instead, Xenobot 2.0 was built entirely from skin cells.

I know, it sounds like a downgrade, but this is actually better for the purpose of moving around because skin cells come with an unexpected upgrade: thousands of microscopic hair-like structures called cilia.

Normally, these help move mucus around in our lungs or propel microorganisms through water, but on a xenobot, they become millions of tiny oars that beat in synchrony, gently pushing the bundle of cells through its water world without needing a single muscle cell.

Another upgrade? 2.0 could repair itself in 15 minutes after being cut or damaged, making it far more resilient than 1.0, and it also had memory.

Not the kind that helps you remember (forget) a distant cousin’s birthday or where you left those keys. The sort that’s powered by mRNA injected into the embryo before its cells were harvested so that the whole organism would fluoresce when exposed to certain conditions like a certain wavelength of light, leaving behind a record that the event had happened.

Not bad for something with no brain.

But that’s not even the best this little bundle of cells can do. Wait till you read about...

Xenobot 3.0

Just when everyone thought, “Well that’s it. Sounds a bit scary, but at least they won’t multiply!”

Scientists discovered they could.

Don’t panic. They weren’t splitting in half like bacteria or laying tiny xenobot eggs. In fact, they were reproducing in a way that was unknown till then.

Scientists scattered thousands of loose frog cells into a Petri dish and sprinkled some xenobots in it and as the xenobots wandered around, they swept the loose cells into little piles which stuck together over time, organizing themselves into brand-new xenobots capable of moving and reproducing on their own.

This process is called kinematic self-replication, and although it sounds like something out of a sci-fi movie, it only worked in the lab and under super specific conditions, and continued reproduction isn’t possible because it needs to keep finding loose cells like those in its dish.

In other words, they can’t take over the world or even survive outside the lab as far as we know.

And here’s the strangest part.

The famous Pac-Man shape that made this possible wasn’t designed by a human at all.

It was discovered by an artificial intelligence.

But that’s a story for another day, sometime next week.

Maybe those storybooks weren’t completely wrong after all.

I mean, frogs don’t grant wishes, but every now and then, they help scientists create and discover something that feels almost just as magical.

Next week, we’ll meet the unexpected architect behind the xenobot.

So... what do you think? What could we use these xenobots for? And should we be making them in the first place?

Leave a comment

or send a message on The Petri Dish group chat.

If you liked this post and you think someone you know would too, subscribe and share it.

Subscribe now

Share

Stay tuned for the continuation of this post next week!

It doesn’t matter if it’s the kind of forest where gnarled trees silently rise from cool, grassy ground or the sort where monkeys howl, branches crack and birds call over each other in thick, humid air. That forest you’ve been in probably has an internet of its own.

No, I don’t mean the internet that lets you scroll through Instagram. I mean the type that you might remember Dr. Grace talking about from the first Avatar movie. The sort that connects things (trees, in this case) and lets them share the stuff of life with each other.

Nutrients, chemical signals, even poisons.

So what is this internet? What happens in it? And why do we even need this to exist?

Let’s find out…

Logging in

It’s called mycorrhiza, or if you prefer, The Wood Wide Web, and plants first logged into this web of mycelium around 500 million years ago when they were just migrating from water to land with the help of… Fungi!

Back when plants were just a slimy mess found in water, they had no way to break into the tough, rocky ground and access water and nutrients inside. That’s why they entered a mutualistic (both sides benefit) symbiosis with fungi who had already figured this out.

This relationship is crucial for the survival of both fungi and plants and continues today, even after plants evolved their own roots.

Fine, thread-like strands of fungi extend far beyond a plant’s roots, reaching places roots alone never could. In return for sugars produced by the plant, the fungi supply water and nutrients from the soil.

Don’t mistake this for generosity though, because it’s really just trade (in most cases, at least).

And because these fungal threads connect multiple plants at once, they don’t just support individual plants, they link entire forests together.

Tall mother trees send extra carbon to younger trees, attacked plants signal others to ready defenses, and fungi provide nitrogen to trees they’re connected to.

It’s really another ecosystem, just underground.

The WWW’s Hackers

But like the internet, this seemingly utopian web has its fair share of manipulative users that take advantage of this mycorrhizal network to benefit themselves.

Some plants use the Wood Wide Web to get all or most of their nutrients, which causes a lot of them, like Voyria tenella and Monotropa uniflora, to lose their chlorophyll (the pigment that does photosynthesis in plants) and become completely dependent on the mycorrhizal networks beneath the soil yet oddly successful.

Meanwhile, others use these deep networks to poison competition.

Black walnut (Juglans nigra) trees, for example, release the toxin juglone into the network to stun or kill neighbours while Spotted Knapweed (Centaurea stoebe / maculosa) plants send catechin, another toxin to nearby plants to slow their growth.

A lot of plants also use the web to send false signals of an attack to other plants, causing neighbours to waste resources on unnecessary defense, weakening them.

All of this good and bad stuff adds up to create a system that is extraordinarily complex, very messy and strangely similar to our WWW.

Stayin’ Alive

So if this network can be exploited, manipulated, and even weaponised… why do we even need it?

Because despite all the cheating, poisoning, and freeloading, most of the time, the system still works… well enough.

Part of that is because it’s an ecosystem.

Ecosystems are chaotic but they’re important because they don’t usually allow an animal to come on top (ahem…humans) as balance is all they’re about. If there aren’t any black walnut trees or Voyria plants then there will probably be an excess of the photosynthetic plants.

It’s all about checks and balances.

The other part of why this network, well, works comes down to the fungi themselves, because they aren’t all playing the same game.

Some, often called saprotrophic fungi, act more like decomposers. They break down dead matter to quickly grab nutrients like nitrogen, and are really important for recycling what’s already there.

Others, like ectomycorrhizal fungi (I know, it’s a mouthful), take a different approach. Instead of working alone, they partner with trees, trading nutrients for sugars produced through photosynthesis. But even they still need nitrogen for themselves and for sharing with the trees around them and that’s where it turns competitive, because both groups are after the same limited resource.

Since saprotrophic fungi decompose organic matter rich in proteins and therefore nitrogen, they often get to it first. Ectomycorrhizal fungi, on the other hand don’t do that.

That’s why they’ve evolved ways to siphon nutrients and even release chemical compounds that suppress their competitors, turning the battle into a constant, invisible tug-of-war that is skewed in the ectomycorrhizal fungi’s favor.

And since they’re extremely important for plant growth, the more of them that exist, the faster plants grow and the more carbon is stored. This way, they’re helping forests become the massive carbon sinks they’re known as.

“What else are fungi good for?” you may ask.

Check out this post to learn about these fantastic fungi and other planet-saving organisms!👇

Tipping the Scales

Alright.

So mycorrhiza are good at knitting together trees into carbon-slurping, climate-saving super(hero)-forests and great at increasing collaboration and competition among the plants in these forests because like any other ecosystem above ground or deep below, it’s dependent on balance.

And like usual, humans love tipping the scales unknowingly.

Every time we pump way too much nitrogen fertilizer into our farmlands, some of it’s leaching out into surrounding forests where saprophytic fungi gobble it up in order to grow faster than their ectomycorrhizal peers can, putting their competitors at a huge disadvantage.

Meanwhile, we cut down the trees that the ectomycorrhizal fungi need, causing them to starve like a turtle on a plastic trash diet.

We’re sabotaging these beautiful networks and essentially sabotaging ourselves because we depend on them too.

In the end, you might not be able to scroll through Instagram on your phone in the forest, but the trees can, passing messages, resources, and even sabotage through a mycorrhizal network that never logs off.

And seeing that is worth being isolated from the rest of the human world.

What part of the mycorrhizal network surprised you most?

And what would you like us to talk about next time?

Leave a comment

Living in the city is fantastic!

All of the (mostly) easy transportation, great opportunities, and high tech everything just makes life feel so exciting, doesn't it? And it's even better for budding scientists because you're exposed to all sorts of laboratories, ideas and people that seem like they're straight out of a sci-fi book.

These labs are the source of almost everything we own today.

Plastic? Yes.

Penicillin? Mhm.

High-fructose corn syrup? That too.

Every medicine and vaccine you've ever taken? Of course.

But are these the best laboratories we could get? Do they have the most accurate practices with the most relevant results?

These questions and many more are extremely important, especially now when the world desperately needs new innovations to solve concerning global problems related to the environment and our interactions with other life.

So let's try flipping the question on its head. Are labs always clean, sterile, blinding white spaces with dangerous-looking (and sounding) apparatuses and well controlled environments?

And is solely focusing on modern inventions and discoveries really the best way forward? Or are we missing out on something far more ancient?

Let's find out...

Playing the Long Game

Here’s a riddle:
Modern laboratory experiments rarely last more than a few decades. But another lab has been running for billions of years. It encompasses everything and excludes nothing, though only a few have truly studied its lessons.

Answer: The lab is Earth itself with all its life forms and ecosystems. It’s everywhere, from the thickest rainforests to the driest deserts and the deepest oceans, and it has been experimenting since the planet’s very beginning.

Unlike the polished white rooms we picture when we say “lab,” Earth’s laboratory is messy, chaotic, and unpredictable. But that’s exactly why it works.

Every drought, flood, storm, or volcanic eruption is a trial. Every new mutation, migration, or extinction is a data point. Over billions of years, life has run experiments on every possible scale, from microbes tinkering with metabolism to forests figuring out how to recycle entire nutrient cycles.

And the results? Ecosystems so resilient they can bounce back after asteroid impacts, ice ages, and climate swings. That’s innovation and adaptation on a level no human-made lab can replicate.

This lab has always been running, its lessons written in rivers, forests, soils, and skies. Yet, only a few have been paying attention as a way of life.

For millennia, Indigenous peoples have been the true students of this grand laboratory, not because they wanted to, but because they had to.

They didn’t just watch nature, they lived with it, tested it, and passed their results down as stories, rituals, and practices. They figured out medicines, food systems, and climate resilience centuries before ‘scientist’ was even a word.

The Haudenosaunee tribes of North America figured out symbiosis between plants and applied it to increase crop production.

Meanwhile, the rest of the world mostly ignored the lab notes.

At best, we treated them as folklore.

At worst, we erased them and the people who created them.

The Haudenosaunee tribes of North America figured out symbiosis between plants and applied it to increase crop production. Their “Three Sisters” method (corn, beans, and squash grown together) is a great example of this. Corn gives beans a pole to climb, beans fix nitrogen into the soil, and squash leaves shade the ground to lock in moisture and block weeds.

In the Amazon, Indigenous communities developed knowledge of medicinal plants so deep that 25% of Western pharmaceuticals such as anti-cancer compounds, painkillers, fever reducers, and others, trace back to the discoveries of these plants.

On the other side of the world, Southern Indian farmers practiced agroforestry which consists of layering spices, trees, and crops in forest-like systems. Instead of clearing land for monocultures, they mimicked ecosystems, creating farms that resisted drought, boosted biodiversity, and produced premium spices and other foods without chemical fertilizers or pesticides.

Compare this to the way humanity currently creates technology.

Our modern inventions often come from short-term trials in sterile labs, designed to solve one problem at a time with.

Need higher crop yields? Chemical fertilizers.

Pests becoming resistant? Stronger pesticides.

Need cheap calories? Refined sugar and oils.

Each solution works in the moment but usually creates three new problems for the future because they simply aren’t tested enough in the real world where nothing is controllable and everything is chaotic, messy and full of uncertainties.

Where Indigenous science worked with complexity, modern science tends to… not.

The Three Sisters don’t need synthetic fertilizer or weeding because the system balances itself. Agroforestry doesn’t need massive irrigation because the trees hold water and cycle nutrients naturally. Controlled burns by Indigenous populations don’t destroy forests, instead they root out dead and vulnerable plant matter to prevent mega fires.

One system takes centuries to refine and proves itself across generations. The other relies on rapid fixes that often backfire when scaled globally.

That’s not to dismiss modern science because without it, antibiotics, vaccines, and space telescopes wouldn’t exist.

But maybe the path forward isn’t choosing one over the other.

Maybe it’s finally acknowledging that Earth’s billion-year lab and Indigenous centuries-long experiments hold insights we can’t afford to keep ignoring.

And that’s what’s beginning to happen.

Shared Wisdom

If modern science is already has so much potential to benefit us and ancient indigenous science practices have helped humans live in harmony with the environment, what might happen if we combine the two?

A lot, really.

For tens of thousands of years, Aboriginal Australians have used fire as a tool for a special type of agriculture suited to their environment. Through “cultural burning,” they lit small, low-intensity fires to clear underbrush, renew grasses, and keep forests healthy.

To colonial settlers, this looked reckless because for them, fire = danger.

Suppression policies literally smothered the practice for decades, until environments began to degrade and catastrophic wildfires swept the continent. Now, scientists and land managers are working with Aboriginal fire-keepers to bring back those traditions.

The results are striking: healthier soils, safer landscapes, and ecosystems that recover faster from climate extremes. And best of all… way fewer wildfires.

Meanwhile in Mexico City, ancient chinampas are rising from the ruins.

These are floating garden islands that the Aztecs once built to grow crops while also maintaining a clean water system. Indigenous farmers restore canals and soils through this ancient technique while researchers use modern tech to help filter polluted waters and monitor yields.

A little more to the South is Brazil’s Xingu region where Indigenous women are partnering with scientists to collect and store thousands of seeds from across the Amazon Rainforest.

Why? Because threats like climate change and deforestation are threatening the area and future reforesting campaigns need to have the necessary seeds to regrow the biodiverse ecosystem that existed earlier.

That’s why the Indigenous communities here use the knowledge honed over centuries of oral traditions to find the right seeds while scientists create databases and restoration plans that accelerate the efforts.

In short, it’s time for us to recognize that indigenous peoples have been running Earth’s longest laboratory for millennia. Modern science is only just catching up and it’s doing remarkably too. When the two join hands, the result is immense and sustainable in the long term.

A Woven Future

Culture and science aren’t opposites but really two sides of the same coin.

One began as a means of survival that eventually led to relative harmony between humans and the world around us while the other began as a way to question, measure, and push beyond what was known, unlocking forces and technologies our ancestors couldn’t imagine.

On their own, they have the potential, but leave many gaps unfilled. Like the threads of a tapestry.

Culture is patient yet strong but may struggle to adapt to a rapidly changing world. Science fixes things quickly but sometimes loses sight of responsibility, ethics, and the meaning of innovation.

When woven into a tapestry, they become beautiful, flexible and resilient, lending their strengths to each other while filling in the gaps.

Modern science is only just learning to understand this and implementation is still a work in progress, but where it is being used, results are astonishing.

The real challenge is making sure that people and the wisdom they have aren’t an afterthought but the foundation of the future.

Enjoyed reading? Learnt a bit? Share it with friends, families, and literally anyone else you think needs to know about this.

Share

Share The Petri Dish

Oh, and subscribe if you want more science content!

When was the last time you washed your hands? Five minutes ago? An hour or two? A day? Maybe, if you’re icky enough, a week?

Well, whenever you washed your hands, got a vaccine or even popped an antibiotic, you probably did it to prevent becoming sick or cure a sickness, right?

For most of our history, this simply wasn't an option. I mean, are you really going to waste precious water to wash off mud from your day in the farm just to get them dirty again the next day? No way!

And Germ Theory, antibiotics and vaccines? Make way for the four humours, miasma and bloodletting!

Now though, we are way more literate and a whole lot more obsessed with sterilization. Scrubbing, sanitizing and sterilizing ourselves more often than not.

This works great for us! Lower mortality rates, better overall health and life spans. What's not to love?

Let's find out, shall we?

Into the unknown

Our journey begins with an empire on a big, bustling island. Its citizens are diverse, living all over the place and in harmony with the natives. It's massive, with roughly the same population as the locals themselves.

Why? Because while IRL colonial rulers were more 'conquer, conquer, get rich', this empire prefers keeping trade. Trading with locals for resources and services is more profitable for them, because then they get to live on the island and reap its benefits forever!

Citizens help natives with tech and services like maintenance while natives give them food and energy resources while also giving them a nice place to live by not kicking them out.

But not every citizen is good or even remotely useful.

Some are criminals, stirring up trouble and harming the island.

Others are heroes, working towards the delicate harmony and welfare of both the island and the empire.

Still others are just... there. Literally just taking up space to defend against criminals invading from other islands.

Now. Where do you think this island is? Actually, what do you think this island is? What is this empire? The natives?

You.

The natives are your cells: muscle cells, intestinal cells, immune cells, skin cells, etc. And the empire? Your microbiome or in other words, the trillions of bacteria, fungi and other itty-bitty bugs in and on your whole body.

Now read this whole section again and think about this.

Feels different now, doesn't it? Now that you can see and even feel just how fragile this symbiosis is within you and every other living and dead animal on Earth.

Starting from birth, these ‘invaders’ come from all sorts of interactions.

Born naturally, played in the mud, or been in other worryingly unhygienic interactions? That’s a few billions more citizens added.

But what if it all crumbled?

What if you turns against its colonists?

What if the empire turns on you?

The War Against Yourself

Ever seen a picture of war-devastated country? They often feature many corpses, spent weapons, sad and terribly impoverished people.

But look closer. What's happened to the land?

The ground is scarred. Forests turned to ash, rivers poisoned, fields barren. War doesn’t just kill people, it kills the land that sustains them. And that’s exactly what happens when we wage war on our inner empire.

The battlefield isn't far away, it’s you.

But what are the weapons here? If you're thinking: "Mud, dirt and unhygienic stuff?" or "Perhaps, animal products?" or "Maybe, it's pollution?", you're wrong.

The weapons we have at our disposal are nothing like real weapons, yet oh-so-similar.

Each of these is like a knife. Use it one way and one could save hundreds. Use it a bit differently and one can kill those hundreds.

Weapon #1: Antibiotics

Antibiotics are lifesavers. Before them, being alive on its own was a struggle and mortality rates were sky-high.

Antibiotics range from medicines to antibacterial soaps and sanitizers.

They’re basically chemicals that, when consumed by the target microbe group (eg. bacteria), jam machinery that are crucial for survival and therefore murdering them in cold blood. They generally don’t hurt animal cells because they’re built differently and have different mechanisms.

For example, penicillin kills bacteria by disrupting the creation of cell walls by binding to one of the compounds that helps create it and preventing the walls from being constructed, while also stimulating the release of molecules that quickly break down the weakened bacteria. This is important because bacteria are constantly remaking their cell walls to cope with damage and without it, survival is impossible.

The problem is, these are more like carpet bombing (as Kurzgesagt said) and less like precision weapons, especially in the delicate balance of the gut microbiome. Like an earthquake across the empire’s island that kills many inhabitants versus a tsunami that only kills people living at the coast.

And when the empire’s neighborhoods are flattened like that, it’s not just the criminals who die. The heroes, the neutral citizens, the space-fillers, all gone.

Sometimes the damage isn’t too bad and most people recover pretty fast. Other times, the wounds stay… forever.

The empire is left scarred and fragile, with empty spaces begging to be occupied.

And if someone’s really unlucky? The strongest, nastiest criminals (and some heroes and fillers) that antibiotics couldn’t kill stay hidden under the rubble of the attack, capturing your body’s island until you’re absolutely gutted.

Superbugs.

Once they take root, they’re almost impossible to evict, and the empire never really recovers the same balance again.

That’s when diseases caused by gut microbiome imbalance pop up. Irritable Bowel Syndrome, colorectal cancer, obesity, Type 2 diabetes and even non-gut stuff like anxiety and depression.

Why? Because your gut has a direct phone line to your brain and the messengers are chemicals made by your microbes.

Tryptophan from turkey, chia seeds and eggs is turned into serotonin and melatonin. Microbes whip up dopamine and epinephrine from tyrosine found in almonds and seeds and the Indole-3-Lactic Acid from fermented foods like kimchi is processed into a powerful antioxidant called Indole-Proprionic Acid.

All of this… gone!

And we aren’t the only ones eating antibiotics. There’s pigs, cows, chickens, fish, and other domesticated animals that we eat that are also regularly dosed with antibiotics to avoid disease and this accelerates the creation of superbugs that eventually reach and infect humans too.

Weapon #2: Diet

Ever heard the saying, “you are what you eat”? Well, your empire takes that very literally.

Every bite you take isn’t just feeding you, it’s feeding the trillions of citizens inside you.

• Fiber from veggies, grains, nuts → microbes ferment it into short-chain fatty acids (like butyrate) that strengthen your gut lining, reduce inflammation, and keep the immune system balanced.

• Polyphenols from fruits, tea, and spices → act as both food for beneficial microbes and weapons against bad ones.

• Fermented foods (kimchi, yogurt, kombucha) → bring in reinforcements, boosting diversity in the empire.

That’s like a steady supply of rich resources flowing into the empire. The heroes thrive, the neutral citizens keep the peace, and even the troublemakers get kept in check. Balance.

But modern life doesn’t exactly run on balance.

• Ultra-processed food = tons of sugar, salt, refined fats, and almost no fiber.

• Artificial additives = emulsifiers and preservatives that chip away at gut lining.

• Constant snacking = no downtime for the empire to repair itself.

That’s like shipping in crates of shiny but hollow supplies. Useless for most citizens. The heroes start to starve. The space-fillers can’t hold the line.

Even criminals suffer.

Overall diversity dips and the empire is starved and weakened.

Because desperate times call for questionable measures, the empire turns on the natives. Our cells. Our mucus lining. All of it is eaten away slowly by the microbes that once helped us.

With less fiber, microbes stop producing short-chain fatty acids like butyrate, which normally keep the gut wall sealed tight. Cracks form. This “leaky gut” lets bacteria and their byproducts seep into the bloodstream, triggering the immune system into constant, low-grade war.

Processed carbs fuel the greediest criminals, who pump out byproducts that cause cravings for more sugar, trapping the unfortunate habitat into an excruciating cycle of addiction. The empire is no longer protecting you, it’s protecting itself at the cost of your body.

And preservatives, emulsifiers, sweeteners? That’s like chemical smog settling over the island, eroding defenses and suffocating what little diversity is left.

And the result isn’t just obesity or diabetes. It’s a whole-body crisis: inflammatory bowel disease, weakened immunity, even mood disorders, because starving microbes stop producing the neurotransmitters and metabolites your brain needs.

Weapon #3: Lifestyle

Every empire needs fresh air, trade, and the occasional new citizen to stay strong. Close the borders, choke the environment, and the empire doesn’t fall overnight — it withers.

That’s exactly what our modern lifestyles do.

We scrub, sanitize, and sterilize everything we touch. We live indoors, cut off from soil, animals, and nature.

And it doesn’t stop there.

Pollution seeps in like toxic fog, from pesticides in our food to microplastics in our water. Sedentary habits weaken the empire further, since exercise normally sparks microbial diversity and resilience.

Sleep deprivation?

Stress?

Those are like constant curfews and riots within the empire, keeping everyone on edge and draining resources.

All of this is manageable if you get the right start in life

But lots of empires don’t.

Rising numbers of C-sections skip the crucial microbe transfer from mother to baby when one is born naturally. Formula feeding misses the prebiotics and antibodies in breast milk that act like the seeds for a healthy empire. By the time some kids even begin to build their empire, they’re already short-staffed.

So modern life isn’t just draining existing empires. It’s creating half-built empires that just can’t work.

The result isn’t dramatic explosions or famines but erosion.

Year after year, the empire loses diversity. Citizens die out, new allies or even criminals never arrive, and diversity plummets. Slowly, silently, the island becomes fragile, ready to collapse at the first big hit.

And that big hit always comes.

It might be a course of antibiotics for an ear infection or a really long fast food phase. Maybe it’s just stress from exams, work, or sleepless nights.

For a strong empire, these are skirmishes it can recover from. For a weak, eroded empire, they’re earthquakes that level neighborhoods.

Once the cracks form, rebuilding is hard. Citizens that once cooperated vanish forever. Whole communities of species of microbes that protected your gut, trained your immune system, and even made brain chemicals, die off.

With them go your defenses.

• Fewer microbes training your immune system → more allergies and autoimmune conditions.

• Fewer microbes balancing your metabolism → higher risks of obesity and diabetes.

• Fewer microbes making neurotransmitters → increased anxiety, depression, even cognitive decline.

And when the empire goes down, it will drag everyone with it… including the native communities of cells.

Is this it?

An empire scarred with empty neighborhoods. Heroes gone. Streets abandoned. Cracks in the walls where criminals slip in. It’s still your inner empire, but it’s fragile, weaker, and slower to respond when danger comes knocking.

Why?

Because this was never a war against them. It was a war against ourselves.

So is that all? Will we never be able to fix this?

Far from it: they can regrow.

Give them the right conditions and citizens return. Feed them fiber, plants, fermented foods the empire rebuilds. Move your body, sleep well, and stress a little less. Touch grass once in a while, maybe even grow some.

The best part? It’s fun!

So next time you gulp an antibiotic for a mild cold, eat a greasy pizza, or wash your hands too many times a day, remember that your choices are more consequential than you think… for you and for the whole mini-empire living within.

Liked this post? Share it with friends, family, and anyone else who needs it or would like to learn about this!

Share

Share The Petri Dish

Oh, and subscribe for more awesome science-y content!

Ever seen a freshly painted brick wall turn into one covered in moss, algae and lichen?

In my hometown, it’s pretty common. Just last year, a wall was painted peach and lilac with drawings of celebrities. A month later… not a hint of the paint but instead, a green goop covered the whole wall.

Some areas were sludgy while other were textured, a bit like... leaves?

I remember it taking ages for whoever had to paint it next to remove it and it made me wonder... What is this stuff? How is it so resilient and fast-growing? What does it taste like?

I soon found the answer to these questions…except the last one.

Now, looking back, I realize how fascinating this goo is, because it isn't just a nuisance but a powerful tool in scientists' toolbox for making sustainable tech… like biodiesel.

Really, biodiesel?

Yes, really. Let's start with the gunk itself, likely some ooey-gooey, slippery algae.

It might seem like pond scum or mega sea-trees but algae is actually a biological powerhouse. It produces up to 70% of the Earth’s oxygen, grows almost anywhere, and scientists are now learning how to turn it into everything from clean fuels to biodegradable plastics. In other words, the goo on the wall could one day fuel a car.

Here’s how:

1. Grow: Synthetic algae ponds/photobioreactors are filled with water and the nutrients (nitrogen and phosphorous) necessary for algae to grow. Exposure to sunlight and plenty of carbon dioxide allow it to grow fast.

2. Harvest and Dry: Various processes are used to create a sediment of algal biomass which is then removed from its growing area to be dried to remove excess moisture.

3. Extract: Oils from within the plant are extracted through two methods: compression and/or solvents like hexane, methanol or ethanol

4. Transesterification: The algae oil is chemically rearranged with alcohol so it turns into biodiesel that engines can actually use. The leftovers are glycerol, the same stuff that ends up in soap and cosmetics.

Want to make your own DIY algae biofuel? Check this out:

Tada! You’ve now got a nice biodiesel that regular diesel vehicles can run on.

What makes it extra special is how little land and food it competes with, compared to the alternatives. Because while one acre of land can yield only 300L of biodiesel made of sunflowers, algae can yield up to 20,000-80,000L, all without taking up valuable food resources.

And that’s just algae… only one organism turned into one product.

How does turning the stuff that rots your bread into styrofoam, leather, and bacon sound?

Mushroom Boom

Styrofoam is super lightweight, soft, cushiony, large and great for packaging fragile items.

What’s it not good for? The environment and landfills.

Styrofoam is bulky so it takes up tons of space in landfills while also being non-biodegradable and highly toxin absorbent, killing any animals that eat it from a combination of feeling really full and being poisoned.

So to solve this issue and completely remove Styrofoam from the packaging and insulation equation, scientists have created an alternative made from agricultural waste and mycelium.

It’s simple: manufacturers fill plastic molds with compost, straw and plant bits before sprinkling on some mushroom spores. Within a week, the foam is ready to be taken out of the mold, package a product, and be shipped across the world.

The best part? It’s compostable!

According to the company ‘Ecovative’ who first manufactured this product, mycelium packaging is 100% bio based, ocean safe and compostable while mimicking some other properties of styrofoam like fire-resistance and hydrophobia.

And that’s not all that our beloved fungi stars can do.

Bacon alternatives can be created by tweaking the growth a bit and you’ll get aerial mycelium that can be sliced, processed for flavor, and fried to create a product similar to bacon and real meat, minus the slaughter and environmental costs, plus tons of health benefits like fibre and low-fat content.

Vegan leather is even easier. Use the same process used to grow aerial mycelium for bacon and process it differently to make a leather-like sheet.

Fascinating, right?

But let’s zoom in now. Turning such big organisms into alternative tech is cool, but turning tiny stuff into life-saving tech? That’s crazy.

Let’s dive in.

Tiny Assassin → Big Lifesavers

We all remember COVID-19, don’t we? The masks, the Zoom birthdays, the empty streets. A virus that turned the whole world upside down and left a black hole of memories in its wake.

One thing I do remember, however, is how many people got infected by the virus and lost their lives and to 9 year old me, it seemed like viruses hate us with a passion.

But here’s the thing: not all viruses are out to get us. Some are tiny assassins that actually save lives and may even be our secret weapons in an upcoming crisis.

Welcome to the world of bacteriophages! Teeny-tiny little alien-y viruses that gruesomely destroy all sorts of bacteria, from the inside out.

This is not good for the bacteria, but it’s great for us, especially when AMR is becoming an even larger threat to humanity.

With bacteria outsmarting antibiotics faster than we can make new ones, phages step in as precision killers tailored to wipe out only the harmful bugs while leaving the good ones alone.

Here’s how.

Phages have two main weapons against their target bacteria, which they use depending on what they’ve evolved to do.

Weapon #1: the Lytic cycle

This is the phage’s grenade… except it turns the target bacterium into a grenade factory in the process. It does this by basically injecting the bacterium with phage DNA of its own and tricks the bacterium into using it to make more phages.

Soon, the poor bacterium gets filled up with tons of bacteriophages which eventually make it lyse and spew out its insides like a deflated water balloon, leaving phages to continue the cycle.

Weapon #2: the Lysogenic cycle

This is basically a time bomb that the bacteriophage injects into the target bacterium. Similar to the lytic cycle, the phage injects DNA into the target, but unlike it, phage reproduction doesn’t start immediately. Instead, the DNA integrates into the host’s genome and stays there, waiting for the right moment.

As the host replicates itself to create more bacteria, it also replicates its DNA and the piece of the phage’s DNA. Soon, the phage DNA switches to the lytic cycle and the bacteria unknowingly start producing phages and… well you know how that one goes.

This isn’t just theory. Phage therapy has already saved patients with antibiotic-resistant infections. People who had almost no options left.

Viruses that once terrified us are now becoming weapons of hope.

Mirror, mirror on the wall.

That wall back home wasn’t just slathered in slime. It was covered with the future of tech.

A future where waste is practically nonexistent.

A future where silicon is replaced by mycelium.

A future where people don’t go to computer labs and factories to make the next big thing but to the ponds, garbage cans and walls of the world.

A future where awe isn’t rare. It’s the reality.

And this post is just a taste of what’s to come, so I encourage every one of you to go out there and explore. Google’s a library, Youtube’s a treasure chest, but your surroundings are a living lab just waiting to surprise you.

Because next time you walk past a slimy wall or a moldy loaf of bread, don’t just wrinkle your nose. You might just be looking at the building blocks of the future.

So take a minute to share this with your friends and get out there and explore!

Share

Share The Petri Dish

Oh, and subscribe if you liked this.

Tamatoa’s sparkle might be fictional, but bioluminescence is very real.

And it’s much older than any animated crab.

From glowing algae in the ocean to shining fungi on land, nature has been experimenting with light for millions of years.

But why do living things glow at all? And how does it work?

What is bioluminescence?

Ever seen a firefly on a hot summer night? Or anglerfish with their glowing sac of light hanging from their head?

That’s bioluminescence.

It’s a chemical reaction that happens inside some living organisms, and it involves a protein called luciferin and an enzyme called luciferase.

When these are combined with oxygen, a compound called oxyluciferin is made, creating light!

In the Wild

Bioluminescence is a super versatile tool, and many organisms use it.

1. Attracting Prey
   Anglerfish use a glowing lure on their head to draw in unsuspecting prey in the deep sea, dazzling fish into being eaten.

2. Avoiding Predators
   Hatchetfish use counter-illumination (glowing along their undersides) to match the faint light from above and stay hidden from predators below.

3. Finding Mates
   Fireflies flash patterns of light unique to their species to communicate and attract potential mates.

4. Spore Dispersal
   Bioluminescent mushrooms may be using their glow to attract insects that help spread their spores through forests and decaying wood.

5. Camouflage
   Squid sometimes glow to match their surroundings or confuse predators with bursts of light, acting as a sort of invisibility cloak.

6. Defense
   Plankton emit light when disturbed, possibly to startle predators or draw attention from larger predators that might chase the original threat away.

Fun Fact! Most deep sea critters emit blue light because it travels farthest into water.

Uses in Biotech

Bioluminescence isn’t just a cool trick in nature, it’s also a powerful tool in science.

In medicine, researchers use bioluminescent proteins to track how diseases spread, how cells behave, and even the expression of some genes.

It’s also used in environmental science. Some engineered bacteria glow in the presence of toxins, making them living sensors for pollution. These could potentially save a lot of electricity and money, making them to accessible to farmers who could use these to monitor crops.

There’s even research into glowing plants and algae as sustainable lighting sources. It’s still a bit early, but it could definitely be a real innovation in the future.

Quiz Yourself!

Want to test your glow-know? Try this quiz:

Glow or No!

Or if you’d like to engage with other readers, join the Petri Dish chat!

Have a question? Share it in the comments below!

Hey ! Nice to see you here

I’ve thought about starting something like this for a while. A place where science feels less like a subject and more like something alive, useful and fun.

So why now?

Because biotech is exploding.
Because tech is reshaping everything.
And because even though it’s everywhere, in our schools, news, food and climate, most people still feel like they’re not part of the conversation.

I wanted to change that.

This space is for the curious.

If you’ve ever wondered how CRISPR works, why climate tech matters, or what xenobots are, you’ll feel right at home here.

If you’ve ever said “I wish science felt more like a conversation, not a lecture” this space is for you too.

What kind of community is this?

The Petri Dish isn’t just a newsletter. It’s a community of budding citizen scientists.

It’s a space where students, science lovers, and just generally curious humans can ask questions, explore real-world biotech, and grow their understanding.

You don’t need a background in science to belong here. You just need a mind that wonders.

Here’s the deal:

I do the deep dives, ask the weird questions, and untangle the complicated stuff.

You get:

• Short, simple explainers on biotech topics

• Hands-on experiments and thought challenges

• Debates on real-world science issues

• Connections to SDGs and ethical questions

• Weekly-ish posts (not daily, not overwhelming)

And all of this for free! No paywall, no stress. Just good science.

One last thing

If this sounds like your kind of space, , I’d love for you to join the community.
We’re just getting started, but it already feels like something that matters.

Thanks for being here,

Aanyaa.