Bang Goes The Theory (2009) s04e06 Episode Script

'On today's show, Liz investigates the science of GM' How do you introduce it into the plant genome? We actually use blank .
22-calibre bullets.
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Dr Yan tries to shatter glass' (SHATTERlNG) Brilliant! '.
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and l try and cure Jem's dust allergy.
' Let me pitch this to you.
Meet my friend, the worm.
'That's Bang Goes The Theory' What have l got to lose? '.
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revealing your world, with a bang.
' Hello, welcome to Bang Goes The Theory.
Now, some areas of science will inevitably attract more controversy than others - and GM, or genetic modification, is definitely near the top of that list, so l went to Hawaii to see GM in action.
Oontroversial biotechnology is definitely not the first thing that comes to mind when you think about Hawaii, especially since this US state has an incredible and fragile biodiversity.
But over the last ten years, these islands have become one of the world's leading centres in research of GM, or genetically modified, foods.
Scientists here set the standard back in 1998 when they produced this papaya, the first genetically modified fruit deemed fit for human consumption by the US Food and Drug Administration.
'So why is GM so prevalent here? 'Well, in Hawaii, tropical fruit is very big business.
'For decades, the islands have dominated the supply of papaya to mainland USA and to Japan, 'bringing in a staggering 1 7 million dollars a year.
'But keeping up with that kind of demand means very intensive farming.
' One of the biggest problems with intensive agriculture is vulnerability to disease.
Now, as early as the 1940s, Hawaiian papaya growers were struggling against a virus called ringspot that invaded the islands and decimated their crops.
The farmers tried to move the papaya, but the disease hopped from island to island with incredible ease, and by 1997, the entire Hawaiian papaya industry was facing collapse.
'Step forward GM, and researcher Dr Dennis Gonsalves.
' Look at this fruit here.
- You notice that these have ringspots.
- Gosh.
This thing here? 'Dennis grew up on a Hawaiian sugar plantation, and knows how important agriculture is to the islanders.
So to save the papaya industry, he turned to what was then the very new science of genetic engineering.
' The scientists proposed that if you take a gene from the pathogen - that's in this case the virus - and you insert it into the host, you will make that host resistant to the virus.
So there's something in the DNA, or the genetic make-up of the virus, that can actually protect another organism from it, if you extract that particular sequence? Yes, that was the hypothesis in 1985.
We had to isolate that specific gene out of the virus, and then clone it.
You extract it, you make multiple copies How do you introduce it into the plant genome? We actually shot it in - we used a gene gun, and what we did is, we coated tungsten pellets, which would be the bullets.
How small are we talking here? Oh, microns.
We then propelled it using a gene gun at that time, we used blank .
22-calibre bullets to fire it into the cells.
Now, out of the millions of cells that the gene went into, some of them pick up the gene, and then the gene gets inserted into the nucleic acid.
That's incredible.
lncredible! You're literally shooting viral DNA into your papaya cells, and it gets inside the nucleus, - and inserts itself into the existing genome.
- Right.
- How did it work? - lt really saved the industry.
No doubt about it.
'But saving the industry came at a cost.
'First, Hawaii lost its valuable Japanese customers.
'They didn't want to buy GM foods until more research was done 'into the effects on health and the environment.
Then, it turned out that the variety they used to create the GM papaya had another problem of its own.
This is the papaya which is genetically modified to be ringspot-resistant.
This type is more prone to an infection by a root fungus similar to the one that caused the lrish potato famine, and now, this fungus is threatening to decimate the entire papaya industry all over again.
'So, 25 years later, it's back to the lab for a second dose of GM.
' So, David, tell me what you did to deal with this problem that arose with the GM papaya.
Well, what is amazing is grapes, and grape plants, are naturally resistant to this fungus.
lt contains a gene, for an enzyme with the technical name stilbene synthase.
But rather than using a gun to shoot the new gene into the papaya, they smuggle it in in a very clever way, using a bacteria.
And so we have a solution of the agrobacteria here, containing this grape DNA.
We then take the clusters of papaya cells, which are grown here, and we mix them in here with the agrobacteria.
And under those conditions, the agrobacteria will infect these papaya cells.
So they've got the grape DNA inside them - Right.
- And now they grow?.
- They're multiplying.
- They're multiplying.
And here's an example of a baby papaya genetically engineered plant with all the leaves forming, and you can now start to see roots forming on the bottom.
So at what stage does this little baby plant make its way to the farmer? Actually the plant has to go through a number of tests to make sure it's substantially equivalent to non-engineered fruit.
So once those tests are done, the Environmental Protection Agency and the Food and Drug Administration and the USDA get to review all the data of the tests, and then it's released to the farmer as seed.
So, did you eat the papaya? l ate the papaya, to be polite, but l would be lying if l said l didn't think about it for a split second beforehand.
lt's a very complicated science.
- Did it taste nice, the papaya? - Yeah, it was quite sweet.
Well, l think everybody, or certainly a lot of people, are very confused by the whole GM question, but looking at that film it clearly seems to work in terms of protecting crops against disease, and if you look at the big picture l guess you could argue that since we've had agriculture we've been manipulating plants.
lsn't this just an extension of that? What's the problem? Absolutely, and it's important to point out that every crop is dealt with as a case-by-case scenario, and it goes through stringent regulations etc But l think the main concerns arise because genes are incredibly complicated things.
We're only beginning to understand how little we know about our own genome, so all that junk DNA we learnt about in school, it's not junk DNA - our genes interact in really intricate ways that we still don't fully understand.
OK? So, some scientists say it's absolutely fine, there's no problems, other scientists raise issues like - can we just find out a little more about long-term effects to genes? So, for example, can gene flow happen between the crop and bacteria in the soil? Oan genes end up in human beings? What are the long-term effects to human health? Those questions are still being raised with regards to GM crops.
ll don't know, l just have to trust somebody else on these things.
l spend my professional life trying to get on top of the world of science yet l watch your film, l know a little bit more about GM crops, but l could not hazard a guess of the full implications of putting some of the DNA of a virus into the genome of a papaya.
lt's a beautiful technology in one sense, but then the beauty of science is that there is always still more to learn, and certainly this is the case with something as complex as GM.
Let me give you a few examples of some of the issues that are raised.
As with the case with papaya, GM papaya crops do cross-breed with non-GM papaya crops.
That's what happened in Hawaii.
And that's why Japan were so strict about banning the import of papaya, because of the cross-contamination issue.
Other issues that come to mind are things like, if you're growing a pest-resistant crop, that means you're possibly pushing the resistance of those pests till they become very difficult to kill.
And the other things are scientists are asking questions like, do GM crops affect the ecosystems in which they're grown? What are the long-term effects of - Do microbes get affected in the soil, etc? - Yeah.
And they just are simply pushing for more research into that area.
But as always with science, the research will continue and hopefully we'll know more about those kind of questions in the future.
And it could be brilliant.
lt's an astonishing piece of technology.
lt is.
And at the end of the day, 23 countries are now cultivating GM crops - everything from virus-resistant lettuce to pineapples that stay riper longer.
lt's a complicated science, but it's definitely working with certain crops.
We just need to keep our finger on the pulse of it.
Absolutely.
lt's a complex science, it's a fascinating science - and we like fascinating science.
Now, moving on - one in four of us has an allergy, and that figure is rising by five per cent every year.
lt's predicted that by 2015, half of us may be affected.
So, some people may think we may be facing an allergy epidemic.
So what better place to get to the root of the problem than a paintball centre.
'The white-shirted soldiers of the body's immune system are out on patrol.
' Allergic reactions happen when the immune system reacts to something that's normally completely harmless.
'But me and my fellow white blood cells are taking no chances.
' Anything that prompts a reaction, whether it's harmless or not, is called an allergen.
Thinking the body's under attack, the white blood cells produce proteins called antibodies and they locate the allergens.
These could be anything from a pollen grain, to an insect bite.
They then latch onto them, and destroy them.
At the same time, histamine is released to promote blood flow in your tissues, and it's this that causes the familiar allergy symptoms - itchy eyes, runny nose and swelling.
'Those antibodies stay in the bloodstream, protecting against future attacks.
'Which is why you get the same reaction every time you're exposed to something you're allergic to.
'But why are some of us more susceptible than others?' lf your parents suffer from allergies, it's quite likely that you will too, but allergies are increasing too fast for them to simply be passing from generation to generation.
Something else must be causing our immune systems to go into overdrive.
'And some research suggests our obsession with cleanliness could be partly to blame.
'lt's been called the hygiene hypothesis, and suggests that being 'exposed to a bit of dirt when you're growing up 'may be less harmful than you might think - 'which could be why children growing up on farms 'are far LESS likely to have allergies.
' l think people, certainly in the past, have been quite worried about dirt.
For good reason - in dirt you've got lots of bacteria, parasites, that might be quite bad for you and l think we've sort of cleaned our act up quite a lot in society, we've got good public health, hygiene, that has protected us against lots of bugs.
The unforeseen consequence of that is we've almost become TOO clean, and as a result our immune systems are not being challenged properly, and we're developing all these allergic diseases that you see quite a lot of now.
And l think the problem is, if you don't get the right education of your immune system early on, you start responding to things that you SHOULDN'T respond to.
For example, pollen or dust, where you can get this allergic reaction which is really your immune system responding where it shouldn't.
Your immune system's made a mistake.
'But some scientists reckon they've found a surprising ally in the fight against allergies.
'They believe animals like pigs harbour parasitic worms that 'may help to correct those mistakes in our immune systems.
' Oertainly in this country, or many of the developed countries many years ago we would have had quite a lot of micro-organisms in our system, including parasitic worms, and these have inadvertently been protecting us.
The normal immune response you would have to get rid of the worm is this allergic-type reaction.
So the worms have evolved to damp down that reaction, so that they can live in harmony with us.
As a result of that, they benefit us by preventing this allergic reaction.
So l think scientists looking at this now are thinking, can we re-worm people to protect them against allergies? You're talking about introducing foreign worms into the gut? Yes.
And the research people have been looking at is looking at hookworms, to treat people against asthma and hay fever, or looking at the pig whipworm, to treat people against inflammatory bowel disease.
- lnteresting hypothesis - Yes, indeed.
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but, this is new research, so far from definitive.
But it sounds good.
And without knowing the final details of the science behind all of that, l do remember, growing up as a kid, being encouraged to get out there and mucky, because it was healthier, and l was always surrounded by cats and dogs.
l may be reading too much into this, but as a kid l grew up in a fairly rural environment - there were cats, dogs, animals, mud, pretty much from day one - and l had no allergies at all, then l moved to London about 15 years ago - l did start developing allergic reactions.
- lnteresting.
Although l should say at this point, health standards which have increased since the Middle Ages have probably saved countless lives! So being clean is good.
But Jem, saying you've got an allergy you've just given me an idea for a foolhardy medical experiment.
- Are you hearing alarm bells? Because l am.
- l am.
- l've got a plan - Time to move on! This week, Dr Yan, he's answering a question from Georgios in London - how do you shatter a glass using sound? Today, l'm going to explain the power of sound - using this.
Now, sound is always caused by something vibrating, like this violin string.
When that vibrates, it hits air molecules - and those air molecules hit other air molecules, which in turn hit further air molecules and so on, passing a wave of compressed air, a sound wave, from the musical instrument.
The faster that vibration, then the more frequently the air molecules are hit, and that's called the frequency of the sound.
This is a high frequency (HlGH-PlTOHED NOTE) .
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and this is a low frequency.
(LOW-PlTOHED NOTE) But whatever the frequency, if that sound wave hits an object, some of the vibrations can get transferred, causing the object to vibrate too.
That's where the wine glass comes in.
'l want to see this wine glass vibrate, so l'll put a straw in 'and a little strip of paper, so l can really see it go.
' And l'll play the sound through a speaker - which doesn't change the frequency, but does change the force of the wave and allows me to direct it at this wine glass.
Now, there might be some broken glass, so l'm going to put these on, and, safety first - earplugs Let's go.
(HE PLAYS A SERlES OF ASOENDlNG NOTES) Now, at the moment the vibrations are tiny, you probably didn't see much at all.
But watch what happens when l do this.
(HE PLAYS OSOlLLATlNG HlGH-PlTOHED NOTES) 'The straw and strip of paper are vibrating all over the place!' So what makes it so different? Well, it's to do with something called resonance.
Different objects have different frequencies at which they really want to vibrate, and those are called resonant frequencies.
l can figure out a resonant frequency of my wine glass by doing this (DlNG!) Now, if the frequency of the sound wave hitting that glass matches that preferred frequency, the vibrations don't just travel through it, but they also build up - causing the amplitude, the size of the vibrations, to increase.
Right - let's try it again, but a bit louder.
'Just as before, l'm only increasing the volume of the sound, not changing its frequency.
' (HE PLAYS OSOlLLATlNG HlGH-PlTOHED NOTES) 'And when the vibrations get REALLY big, the glass just can't handle it any more.
' (HE LAUGHS) Brilliant! But why DO things actually resonate? Well, have a look at this flat piece of glass here.
When sound waves hit this, the molecules in it vibrate and cause the neighbouring molecules to vibrate too.
So a wobble can go down this glass, a bit like a Mexican wave, and when it reaches the end it bounces back.
And so wobbles are passing up and down along the length of this glass.
Now, mostly those little random wobbles cancel each other out.
But, if they're spaced with exactly the right timing, then when a wobble comes to the end and bounces back again, it meets another wobble coming in the opposite direction, and they combine, increasing the bend in the glass, amplifying the wobbleand the object resonates.
'But the best spacing to achieve this resonance 'depends on the object's properties.
' Obviously this is a different size and shape and heaviness to the wine glass, and it doesn't ring out in the same way.
(HOLLOW OLlOK) 'lt sounds like l'll need something with a lower frequency than the violin.
' To help, l've built this box with speakers in it.
l'll put the glass down flat on the top.
l'll adjust these so that they don't interfere with the wobble.
Finally, l'll put some salt on top, just so l can see where the class is wobbling the most.
Right.
Let's give it a go.
'Now for something a little deeper.
' (HE LAUGHS) Right, let's try this.
(HE PLAYS LOW, RESONATlNG NOTES) 'Look, you can see the vibrations by this jumping salt.
'lt needs a much lower frequency to resonate than the wine glass 'right at the bottom of our hearing range.
' (ORAOKlNG) Ooh, not bad on the old violin, Dr Yan.
You might understand the science behind that, but still, every time l see that solid glass wobbling, it's a thing of beauty.
Beautiful film, beautiful photography.
Talking of sound science, l've got something l want you to listen to.
l'll play you a series of notes, and l want you to tell me, is the last note of the series higher or lower than the first? Listen to this.
l'll play them now.
(A SEEMlNGLY ASOENDlNG SOALE) Yeah? Got that? Which one? - Higher.
- You'd THlNK higher l'll make it easier for you - you can do this at home - l'll play just the first note, and the last note.
Just the first note and the last note.
Here we go.
(THE TWO NOTES APPEAR TO HAVE SWlTOHED AROUND ) - Hang on - l'll do it one more time.
- That's really weird! - The first note and the last note, now - Now it's lower! - Now it's lower.
lt's called the Shepard tone illusion.
lt's weird.
Now, time to return to the hygiene hypothesis.
Are we too clean? Do we need a bit more dirt in our lives? Will a bit of dirt make us less allergic to things? l came up with a bit of an experiment.
To put this to the test, we are going to a) need somebody who is allergic to something, b) somebody with a robust constitution, and c) Jem Stansfield.
- l think l fit the bill.
- Perfect.
- Are you are allergic to anything? - Yes - Good.
What? - Household dust.
Not workshop dust, but dusty sofas, carpets, curtains, that kind of thing.
Perfect.
Oome with me.
Jem, l've recreated in this basement your worst dust allergy nightmare scenario.
We've got old furniture, old cushionsand the ''piece of resistance'' this carpet.
- Are you ready for this? - Yes.
- Yes.
Are you happy about this? - No.
OK, let the dust storm commence.
Dude, what you've now managed to do is kick off that allergy that l was talking to you about, and you appeared sympathetic to earlier on.
Well, you look bad Eyes running, nose going.
You're suffering.
l do feel bad, Dallas.
My eyes are worse than they normally are.
Would you be prepared to try anything to overcome your dust allergy? No, l wouldn't say ANYTHlNG but l would go to quite some lengths - cos it's pretty annoying.
- OK, look at this.
Meet my friend, the worm.
That's it coming out of its little egg.
Would you be prepared to eat that egg and have a worm hatch inside you? Yes.
lf l can see.
(KNOOKlNG) Oome in 'That was an easy sell.
'So, l've armed Jem with a pot of tasty-looking pig whipworm eggs 'and dispatched him off to an allergies expert to make sure he's healthy enough to take them.
' Let's look at you.
Open your mouth wide 'To make sure it really lS dust causing his problems, the doctor 'injects tiny doses of the most common allergens into Jem's arm.
' Look at those lovely reactions to house dust mite and, you've come up to cat.
Are you good for this, Jem? Have the lumps on your arm gone down? lt appears as though l am a perfect specimen, so long as l stay away from household dust and cats.
OK.
So do you think you're ready to take the worms? Dallas, bring it on.
Word of warning.
This is still under trial, so it hasn't been clinically approved yet.
A few people have had a bit of a dicky tummy.
OK.
But l trust you, and l think it could be a small price to pay to find out if it will cure an allergy, and it might push the understanding of medical science.
ln that case, l want you to take these worms once a fortnight for the next two months.
Great.
'OK, this is it.
Jem knows the score.
'There's no backing out now.
Good luck, my friend.
' What have l got to lose? Tastes OK.
Jem, you poor wee pet.
That looked awful! Yeah.
lt certainly far exceeded my dust tolerance.
And what's worse, it wasn't just bad then, but it left me over-sensitised for the next 24 hours.
So the hotel l was staying in that night, which was OK but a bit dusty, l was like that, all night.
- Aww, you poor thing.
- Let's look at where we are.
We're past halfway through the experiment.
You've been taking the worms for six weeks.
- How are you feeling? Any side-effects? - Absolutely none.
- Good.
So you're still alive.
- Yep.
Have you had any allergic reactions SlNOE you took the worms? l had one allergic response to some dusty place l was in maybe a couple of days after l took the first lot but nothing since.
lnteresting.
l think we should do something a bit unscientific.
for your entertainment, quite honestly - we have a dusty rug up there.
Shall we just see how you're getting on? l know l felt sorry for you, but can l help? You can help.
ls this the last thing we're doing today? Errthis is the last thing we'll do today.
We'll give it a good old whack.
Your allergy came on quite early when we did it last time in the basement.
Yeah, and when the doctor tested me, l came up in massive welts.
- l'm properly allergic.
- Oome on, let's do it.
Ready? Three, two, one! Go.
Ooh, that's disgusting! Breathe in, Jem! Breathe in.
OK, whatever! (LlZ LAUGHS) - OK, that's enough.
Get off - How do you feel? That's really bad l think that'd get anybody, regardless of allergy.
- Eyes going? - Not as bad as last time.
Maybe it's working, - For now, that's it for this week say goodbye boys - Goodbye - Here, more more