Tonsils, appendix, gallbladder: is anything actually useless?

Summary

Podcast Summary: “Tonsils, appendix, gallbladder: is anything actually useless?”
Podcast: What's That Rash?
Host: ABC Australia
Episode Date: April 28, 2026

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Main Theme

This episode of “What’s That Rash?” dives into the human body’s so-called “vestigial” organs—parts like the tonsils, appendix, gallbladder, and wisdom teeth that people often consider useless or expendable. Hosts Dr. Norman Swan and Tegan Taylor explore the history, real-world function, and evolutionary backstory of these body parts, explaining what happens if they’re removed and whether the label “vestigial” truly fits.

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Key Discussion Points & Insights

1. What Are Vestigial Organs?

(02:09 - 05:07)

• Definition and Context: The conversation opens with definitions—whether organs like tonsils, appendix, or gallbladder are truly “useless,” or simply “nice to haves.”

• Classic Examples:

  • Wisdom teeth: Likely remnants from ancestors who needed more teeth to chew tough plant material.
  • Tailbone (coccyx): Remnant of the tails our distant ancestors once had.
  • Plica semilunaris: (Third eyelid fold) a tiny leftover membrane in the eye, echoing animals like crocodiles.
  • Ear muscles: Some humans can wiggle their ears, which hints at ancestral abilities to rotate ears like dogs or horses.

  “Wisdom teeth are probably just a throwback to when we needed a full mouth of teeth, including the back, to chew on very difficult fibres.”
  — Norman Swan (03:25)

• Fun Fact: The ability to wiggle ears is a vestige with no modern function but interesting evolutionary roots.

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2. Dangers of Poor Understanding

(05:40 - 07:29)

• The episode cautions against assuming something is useless just because science doesn’t (yet) know its function.

• Historical Perspective:

  • The pineal gland was once thought useless but later shown to produce melatonin, crucial for regulating sleep.
  • 19th century anatomists like Widersheim listed up to 86 human organs as vestigial—many of which serve important functions.

• Changing Medical Practice:

  • Tonsil removal was previously very common, even done “prophylactically,” but a better understanding has raised the bar for elective removal.

  “Just because you lack understanding of what an organ does does not mean that it's actually an unnecessary part of the body.”
  — Norman Swan (06:17)

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3. Tonsils: Not Vestigial After All

(07:29 - 11:13)

• Current Understanding:

  • Tonsils are an important part of the immune and lymphatic systems, producing immune cells and antibodies (e.g., IgA).
  • Once removed routinely, now there is a much higher threshold because of their role in immunological defense.

  “They kind of taste potential infections as they’re coming into the body.”
  — Tegan Taylor (08:25)

• Long-Term Effects of Removal:

  • Slightly increased risk of allergic and infectious diseases, but no strong evidence of increased cancer risk.
  • Some studies detect associations (like higher IBS rates), but it’s hard to prove causation due to confounding factors.

  “It looks as though it's safe if you need to have it.”
  — Norman Swan (11:00)

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4. Appendix: More Than a Useless Tube

(11:13 - 16:34)

• Function:

  • Once assumed vestigial, the appendix is now believed to play a role in immune functions and serve as a “safe house” for gut microbiome (beneficial bacteria).
  • Can become dangerous if infected (appendicitis).

  “Like the tonsil, [the appendix] is thought to be an immune organ. It's also thought to be a safe house for the microbiome.”
  — Norman Swan (12:32)

• Anecdote:

  • Legendary story of Dr. Leonid Rogozov, who performed his own appendectomy in Antarctica in 1961 after diagnosing himself with acute appendicitis.
    (13:38-14:27)

  “He instructed his fellow Antarctic explorers... gave himself local anaesthetic, took out his own appendix.”
  — Tegan Taylor (14:00)

• Modern Insights:

  • Recent research suggests appendectomy is associated with increased risk of certain conditions (IBD, infections, colorectal cancer), though causality is unclear.
  • Surgical removal may be necessary if appendicitis has progressed, but it is not a “simple” operation in some cases.

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5. Gallbladder: Small but Significant

(16:55 - 18:17)

• Role:

  • Stores and concentrates bile from liver, releasing it to help digest fats.
  • Can form gallstones, which can be dangerous if symptomatic.

  “The gallbladder takes bile from the liver when it's not needed... and when it's needed, the gallbladder squirts it out into the bowel... to absorb fat from food.”
  — Norman Swan (17:14)

• What Happens After Removal:

  • Some people experience trouble digesting fats (especially initially), but the body generally adapts over time.
  • Removal justified if gallstones cause symptoms or complications.

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6. General Advice: Is Removal Safe?

(18:17 - 18:48)

• Risk vs. Benefit Framework:

  • All removals come down to whether the risks of keeping the organ outweigh the risks and impacts of removal.
  • Strong indications for surgery include repeated infections (tonsils), acute appendicitis, or symptomatic gallstones.

  “It's all about risk versus reward or risk versus benefit...”
  — Norman Swan (18:19)

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Memorable Quotes & Moments

• Norman’s Self-Assessment:

  "What an intact 51 year old you are, Norman Swan."
  — Tegan Taylor (01:24)

• Evolutionary Humor:

  “Have you married a crocodile?”
  — Tegan Taylor, on the plica semilunaris (04:22)

• Appendicitis in Antarctica:

  “He instructed his fellow Antarctic explorers... gave himself local anaesthetic, took out his own appendix."
  — Tegan Taylor (14:00)

• Take-home Wisdom:

  “Just because you lack understanding of what an organ does does not mean that it’s actually an unnecessary part of the body.”
  — Norman Swan (06:17)

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Important Timestamps

• 02:09: Introduction to “vestigial” organs
• 03:25: Discussion of wisdom teeth and chewing history
• 04:11: Discovery of the plica semilunaris (“third eyelid”)
• 05:40: Dangers of assuming organs are useless
• 07:29: How perceptions about tonsils have changed
• 09:34: Evidence on tonsillectomy long-term impacts
• 11:13: Appendices and why surgeons once considered them vestigial
• 12:32: Appendix as an immune organ and microbiome reservoir
• 13:38-14:27: Story of the self-performed Antarctic appendectomy
• 17:14: What the gallbladder does
• 18:19: Summing up: risk vs. reward for removing these organs

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Podcast Tone & Language

Engaging, humorous, and clear, with lots of storytelling. The hosts keep science accessible, mixing fun facts, personal anecdotes, and up-to-date research—perfect for listeners seeking practical medical insights without jargon.

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Conclusion

This episode dispels myths around “useless” body parts, making it clear that many such organs deemed vestigial play meaningful roles—particularly in immunity and digestion. The decision to remove them is always about balancing risks and benefits, and medicine’s evolving understanding continues to reveal the functions of these fascinating body features.

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For listeners considering or facing surgery for tonsils, appendix, or gallbladder, the episode offers reassurance: removal can be safe and necessary, but these organs do more for us than previously believed.

Transcript

[Tegan]

ABC Listen. Podcasts, radio, news, music and more.

[Peter Martin]

I'm Peter Martin, host of the Economy Stupid where we find economics in relationships.

[Tegan]

She only wants a man if he's really, really good.

[Peter Martin]

In the Reserve Bank Board, I knew.

[Norman Swan]

I knew everybody on the board knew recession was coming.

[Peter Martin]

And in food, it's about the cup

[Norman Swan]

of diesels required through the life cycle to get that chicken patty on your burger.

[Peter Martin]

The Economy Stupid. Search for the Economy Stupid on ABC Listen or wherever you get your podcasts.

[Norman Swan]

So, Tegan, do you have an appendage you'd rather not have?

[Tegan]

No, I think my body is fine just as it is. What are you trying to tell me, Norman?

[Norman Swan]

Nothing, just wondering, really. I've been pondering on that.

[Tegan]

I've been pondering on my appendages.

[Norman Swan]

No, no, no. Well, really, it's an excuse for everything's about me. There's an appendage I'd rather not have.

[Tegan]

Is there?

[Norman Swan]

I'd quite like to have teeth that don't need fillings, you know, so there's lots of organs that I think I'd rather have in good shape rather than bad shape. But no, I'm quite happy with all my appendages.

[Tegan]

Fair enough. Actually, shall we do a little appendage checklist? I'm interested to know how many of these items you still have within your body.

[Norman Swan]

All right, cool.

[Tegan]

Your appendix, I do. Tonsils, I do. Gallbladder, I do. Wisdom teeth, I do. What an intact 51 year old you are, Norman Swan.

[Norman Swan]

I know. God knows what it's going to be like in 20 years time, but, you know.

[Tegan]

Well, this is kind of.

[Norman Swan]

Can I ask about yours?

[Tegan]

Yes, please.

[Norman Swan]

So have you got all these things?

[Tegan]

I have everything except for one wisdom tooth which had to be removed. Oh, remember that?

[Norman Swan]

Because we did a session on wisdom teeth.

[Tegan]

We did. Got one single wisdom tooth that had to be removed. My other ones that came through are still there. So. Yes. This wasn't there.

[Norman Swan]

Something odd that you only had three to start with?

[Tegan]

Are we gonna do the show or not?

[Norman Swan]

Okay, let's do the show. You're listening to. What's that Rash.

[Tegan]

It's the show where we answer the health questions everyone is asking.

[Norman Swan]

And this week we're asking about appendages you might not need.

[Tegan]

Well, yeah, we're talking about things that maybe are useless. Question mark. Jane and Cass have both emailed us. Jane says I'm about to have my gallbladder removed. My question is, how does the body compensate, if at all, without this organ? Cass is also on the wait list to have her gallbladder removed and is wondering if we can remove bits such as tonsils, gallbladders, appendices, et cetera. Why do we have them in the first place? So, yes, let us talk today about what some people might think of as vestigial organs. Others sort of feel like maybe we could call them nice to haves, maybe not must haves.

[Norman Swan]

Yeah. Well, before we sort of zero in on the organs being asked about, let's talk about what probably are truly vestigial. Wisdom teeth are probably one of them.

[Tegan]

Well, I mean, we did do a whole or three, in my case, wisdom teeth. We did a whole episode of whatsat rash on wisdom teeth. Fairly early in the piece, I went back and refreshed my memory on it. You should too, by searching wisdom teeth in the WhatsApp rash feed. And I was surprised to find that they are less useful than I. Than I thought that there are certain, especially certain ethnic groups that are much less likely to have wisdom teeth at all than others.

[Norman Swan]

Indeed. And they're probably just a throwback to when we needed a full mouth of teeth, including the back, to chew on very difficult fibres.

[Tegan]

So that's one thing I think everyone. When I think about vestigial parts of the human body, I think about the tailbone, the coccyx, which, I mean, the name is there. We used to. Well, our ancestors had tails. We don't. There's still a bone there. There you go. I wouldn't want to get rid of it. But it's not like we've got a tail waving around behind us anymore.

[Norman Swan]

And then there's the plica semilunaris. Some people might say plica semilunaris.

[Tegan]

I don't say either because I'd never heard of that thing before you said it just now.

[Norman Swan]

So it's when you're gazing into your loved one's eyes and you see in the corner of their eye, next to the nose, a little fold in the conjunctiva.

[Tegan]

Oh, like a third eyelid.

[Norman Swan]

And that's exactly what it's the vestige of third eye.

[Tegan]

Like a crocodile.

[Norman Swan]

Yeah. So maybe you've married a crocodile. I mean, who knows?

[Tegan]

Have you married a crocodile? No, I don't think I've seen this in a humor before. Maybe I haven't been gazing hard enough, closely enough.

[Norman Swan]

Some people do have that fold there to a different. I think a lot of people do have the fold. It's just hard to see. But some people, it encroaches a little bit on the eye. So. Yep, there's A plecosamularis. And then there are the ear muscles.

[Tegan]

I love this because I'd never really thought about the fact that some people can wiggle their ears and others can't. And I'd never thought deeply about what that means. But, of course, lots of other animals, mammals, are able to move their ears around like horses and my dogs. And the idea that humans maybe at one stage were able to do that, I find very endearing and very endearing.

[Norman Swan]

So when you see somebody able to wiggle their ears, they're a vestige of a time gone by.

[Tegan]

So the other structures I want to talk about today are the sorts of ones that we usually leave where they are unless something goes wrong with them. So I suppose the big ones are. Well, I rattled them off at the beginning to you, Norman. The appendix, tonsils, gallbladder, which is, of course, what Cass and Jane have been asking us about. And then wisdom teeth as well. Like, they're the sorts of things that things seem to go wrong with them, not uncommonly, but we don't take them out as a prophylactic. We leave them there unless something goes wrong. And sometimes they have more of a function than may we once thought.

[Norman Swan]

Yeah, danger territory. When you start to think that something's vestigial. Once upon a time, people thought that the pineal gland in the brain was vestigial.

[Tegan]

We talked about the pineal gland actually at length in our episode that we did on melatonin when we did sleep timber a couple of years ago. It's called the pineal gland because it's shaped like a pine cone. Adorable. But it's where melatonin is produced in the brain. But we didn't discover that until the late 1950s, which is pretty late in the piece when it comes to hormones. The idea that something that produces melatonin, which is such a buzzword at the moment, the idea that that would be useless is kind of crazy looking back.

[Norman Swan]

Indeed. So just because you lack understanding of what an organ does does not mean that it's actually an unnecessary part of the body. And as we learn more, we find that things that may have looked as though they're vestigial may in fact not be.

[Tegan]

I mean, if you look back in history, you see there's. When we started talking about evolution, especially, you know, Charles Darwin a little later, Weidersheim. These people who were trying to categorize how we evolved as different species, and Charles Darwin listed a whole bunch of things that he said were vestigial. And we've talked about most of them, ear muscles, wisdom teeth, appendix, tailbone, body hair, like you said. Widersheim published a book called the Structure of Man in the late 1800s, talking about 86 human organs he considered vestigial. And one of them was, as you say, the pineal gland. And the more we look, the more we see about how useful some of these organs are that we might not have otherwise understood. Like tonsils, for instance. We used to kind of whip them out the minute they got infected in kids. And now there's actually quite a high bar you've got across if you're going to have a tonsillectomy.

[Norman Swan]

Well, in fact, they used to whip them out even before you got infected as a prophylactic procedure, classically on the kitchen table.

[Tegan]

So you've still got your tonsils. You obviously dodged that when you were a kid.

[Norman Swan]

Yeah, we didn't have a very big kitchen table, so we didn't have a kitchen table. We couldn't afford one.

[Tegan]

Luxury.

[Norman Swan]

Yeah. So the tonsils can be an annoying organ, particularly in childhood repeated infections. They can become enlarged, obstruct, breathing, all sorts of issues with tonsils. And the temptation has always been to remove them to improve your quality of life and perhaps risk of serious infection occurring. Like a tonsillar abscess, for example, in the neck. But it turns out that tonsils are not a vestigial organ.

[Tegan]

No, they're part of our immune system. They're actually quite an important part of our lymphatic and immune system.

[Norman Swan]

Yep. They're part of our defences against the external world infections coming in to the body.

[Tegan]

They are, they kind of taste potential infections as they're coming into the body.

[Norman Swan]

Yeah. So it's not surprised they become infected themselves. But it turns out that they are part of the way our immune system works. They produce cytokines, which are the short acting or even long acting chemicals which stimulate and control our immune system. They're involved in B cells, which are cells which produce antibodies. They're involved in the production of IgA, which is again, not surprising because IgA is the antibody that helps us with surface immunity. So it turns out that tonsils are an important part of our immune system. The question is, do we harm ourselves by removing them?

[Tegan]

And so I suppose the standard of evidence is higher now than it used to be. Like they still perform tonsillectomies, but you sort of have to have had a certain number of infections to a certain level of severity for your medical team to kind of go, okay, the risks have been outweighed by the Benefits. Now we're going to take these out rather than just kind of whipping them out and not thinking about what potential knock on effects there could be.

[Norman Swan]

Yeah, and until recently, there weren't very many studies really looking at the long term effects of tonsillectomy. Mostly they looked at the benefits of tonsillectomy in people who've been having recurrent infections and their life was miserable and so on. And in kids with obstructive breathing. There are clear benefits of a child getting a better night's sleep. Turns out, though, there are some long term effects of tonsillectomy. There are probably increased risks of allergic disease, infectious disease, no increased risk of cancer. As far as we can see. There have been quite sufficient sophisticated studies looking at this. For example, in one study of tens of thousands of people, there was an increased risk of irritable bowel syndrome and tonsil removal. But you have to remember that people who have the tonsils out are not normal, healthy people. Well, they're normal in every sense, except that their tonsils become infected. They may be snoring, they may have had reduced sleep. There may be other reasons why their tonsils have become infected. And therefore are the conditions they get later in life because of the biological makeup or because the tonsils are removed. And it's really hard to define that. One study in particular used a technique called Mendelian randomization, which is really creating a synthetic randomized trial to see whether or not there is a true effect, cause and effect of removing tonsils on various downstream conditions in life. And they found it hard to differentiate long term effects from in fact, the effect of having recurrent tonsillitis. So they found it pretty safe. Look, bottom line, it looks as though it's safe if you need to have it.

[Tegan]

So tonsils are one of those things where whipping them out, it's no joke if you've ever had that surgery. But they're fairly accessible. You can get to them without having to say, open up someone's abdomen, which you have to do if you want to remove something like a gallbladder or an appendix. Appendices especially, are organs that for a long time, until pretty recently, we kind of didn't really appreciate how important they were.

[Norman Swan]

Indeed. So again, this was thought to be a vestige, like the wisdom teeth of a time where we needed a longer bowel to be able to digest indigestible food. I think it's the koala bear that has a very long.

[Tegan]

Not a bear, it's a marsupial nomen.

[Norman Swan]

The koala Marsupial. But the appendix, like some of these pseudo vestigial organs, is not a vestigial organ. It's associated with a part of the small bowel. The appendix is funny. It's kind of part of the large bowel, the colon, the first part of the colon also connected to the last part of the small bowel, where there's quite a lot of immune tissue, lymphatic tissue in the small bowel. They're called pears, patches. It's what get infected during typhoid, for example. And this immune tissue does spread into the appendix and the appendix, like the tonsil is thought to be an immune organ. It's also thought to be a safe house for the microbiome.

[Tegan]

Really?

[Norman Swan]

Yeah. So it stores, tucked away in this little tube, our gut, bacteria and other organisms, which. The theory is they're ready to repopulate the bowel if the bowel gets damaged in any way and needs to be reinfected, if you like, with microorganisms, that they come from the appendix. That's theory. But when they look at the microbiome of the appendix, it's often quite rich. And, of course, that's one reason why it gets infected. It can get blocked and then infected behind it.

[Tegan]

So that sounds really important. Although an infected appendix is no joke. And you actually. Did you. It's still a thing. You can't be a doctor, Norman. You can't be a doctor in Antarctica if you have an appendix. Did you know this?

[Norman Swan]

Yes. I knew there were surgeries that you needed to have to be on Antarctica.

[Tegan]

If you want to go to Antarctica for other reasons, it's fine. But there's some pretty gnarly reasons why, if you're the doctor, because there's usually only one in Antarctica over winter, you're not allowed to have an appendix. Do you want to guess at what the reason for this is?

[Norman Swan]

So you don't have to operate on yourself?

[Tegan]

Yeah, because someone did. Someone literally took out their own appendix in Antarctica one winter. It was actually a Russian doctor in 1961. His name was Leonid Rogozov and he. In my notes, I have this in all caps, removed his own appendix. He got sick, realized, like, he was able to diagnose himself with acute appendicitis, realised there was going to be no way to evacuate him and knew that without an appendectomy, he would die. So he instructed his fellow Antarctic explorers on what to do, basically, to hold the surgical retractors and a mirror, gave himself local anaesthetic, took out his own appendix. When he saw the state of his appendix, when he opened himself up, he realised just how serious it was that he it would have ruptured without intervention. And he was back on duty two weeks later.

[Norman Swan]

What a hero. I mean, these days the option exists to treat it with antibiotics. We recently covered this on our sister podcast, the Health Report. And the worry has been because when you get cancer in the appendix, it's a particularly unpleasant kind of cancer and it's one of those cancers that's been rising. And one of the theories here is that the trend to treat appendicitis with antibiotics has left appendices in place that may have malignant tissue, whereas otherwise they would have been removed with appendicitis preventing the onset of cancer. Anyway. There's been a recent study suggesting that if that's the case, you can actually pick the people who may have a malignancy there. And it's usually a long course of symptoms in an older person, usually over the age of 60. So you can eliminate that sort of risk. But they have looked at the long term effects of removing the appendix and it is associated with inflammatory bowel disease, like Crohn's disease, increased risk of infection and increased risk of colorectal cancer. Now, again, you've got to differentiate between what caused the appendicitis in the first place, what sort of people may get appendicitis, and whether or not that's the cause of inflammatory bowel disease, infection and colorectal cancer. So it's just an association, it's not cause and effect, but it emphasizes that it may not be harm free. Removing the appendix, but equally, if you've got untreated appendicitis, as you've just shown with your Russian friend, it can be pretty dangerous, I must say. It's not a simple operation. You can go in thinking that to the right hand, bottom right hand corner of your abdomen going, thinking it's going to just pop out at me when you go in there. And sometimes, indeed it does magically, but sometimes some people have got really long, almost koala length appendices that go up under your bowel towards the liver. And to dissect them out, particularly when they're inflamed, becomes a major operation. And in my case when I had to call for help.

[Tegan]

Wow. There is a really good reason why I went into journalism and not medicine. Norman, that really does sound terrifying.

[Norman Swan]

Indeed. But you want help nearby and you don't want a newly graduated doctor like me operating on you. Although I have operated on, I had A great six month surgery. I was going to become a surgeon at one point and I did remove a gallbladder. The other question that we've been asked

[Tegan]

today, we need to talk about gallbladders because poor Jane and Cass have been listening to us talk about wiggling ears and tailbones and tonsils and they both specifically asked about gallbladders. I suppose it would be a good to start with, what does the gallbladder actually do? I don't think of a gallbladder as being vestigial. It does have a function.

[Norman Swan]

It's certainly not vestigial. The gallbladder takes bile from the liver when it's not needed. So bile helps to dissolve fats in the bowel. And then when it's needed, the gallbladder squirts it out into the bowel, the small intestine, and it helps your body absorb fat from food. And what happens in the gallbladder because its very function increases the risk of stones. Because you've got the bile coming into the gallbladder, it's stored there, it's static fluid. And it's easy to imagine how gallstones can emerge. Certainly if you've got symptomatic gallstones, the complications of having gallstones that are untreated are significant and therefore there are good reasons for removing the gallbladder.

[Tegan]

So what? It's obviously got to function. It's important. How does our body adjust to having it removed?

[Norman Swan]

So you do have trouble digesting fats and that may actually have an unpleasant effect when you go to the bathroom. I'm not going to go into that. People might be eating as we talk, but usually it settles down with time.

[Tegan]

What's the bottom line that we have for our question askers this week?

[Norman Swan]

It's all about risk versus reward or risk versus benefit. If you're having recurrent tonsillitis, your life is miserable, you've developed abscesses, there's actually a risk from the infection itself or you've got obstructed breathing or child has get it out. With the appendix, it's similar. If you've got a grossly affected appendix and it's gone too far for antibiotics, then you want that out. And with the gallbladder, pretty straightforward. If you've got gallstones and they're symptomatic, probably better out than in.

[Tegan]

Jane Cass. Thank you both so much for your questions. You can ask us a question by emailing thatrashbc.net au and who's written in this week into the mailbag? Yeah, Rami says. Big fan of you too, especially Dr. Norman and the Mediterranean Diet, two of the MVPs. However, I am hurt over your fruit advice. This is in relation to our episode last week about whether you can get away with not eating fruit, Rami says. I have fruit as a meal anytime with some bread and olive oil. My wife marvels at that.

[Norman Swan]

Very Roman of you, Rami. Very Roman.

[Tegan]

The original Mediterraneans. Christy says, I was listening to you talking about fruit and vegetables and it reminded me of my niece. Her dad is a plant biologist and I was in the shops with her. She had been told that she could pick a piece of fruit to have. I suggested tomatoes, cucumbers and capsicum because they are fruit too. She looked at me with the disdain that only a four year old can manage and said there's no such thing as vegetables. Which is apparently because in plant biology there's no distinction between fruits and vegetables. Apparently plants just fruit to produce seeds and it's all just a human social invention.

[Norman Swan]

Out of the mouths of babes.

[Tegan]

Exactly.

[Norman Swan]

Or into the mouths of babes.

[Tegan]

I guess you would say both. Both. Both ways. Well, that is it for what's that rash. You can email us thatrashbc.net au and

[Norman Swan]

we'll see you next week.

[Tegan]

See.