{"version":"1.0.0","segments":[{"startTime":0.54,"endTime":1.95,"body":"- Thank you very much, Martin,"},{"startTime":1.95,"endTime":5.28,"body":"and thank you all for coming tonight."},{"startTime":5.28,"endTime":6.36,"body":"For those of you joining me"},{"startTime":6.36,"endTime":7.71,"body":"here in the room, good evening."},{"startTime":7.71,"endTime":9.75,"body":"For those of you joining me online,"},{"startTime":9.75,"endTime":12.585,"body":"good morning, good afternoon, good night,"},{"startTime":12.585,"endTime":15.51,"body":"wherever and whatever"},{"startTime":12.585,"endTime":15.51,"body":"you are drinking, eating,"},{"startTime":15.51,"endTime":17.07,"body":"doing whilst you're listening to this."},{"startTime":17.07,"endTime":19.8,"body":"It's a really great pleasure to be here."},{"startTime":19.8,"endTime":22.38,"body":"And what I want to try"},{"startTime":19.8,"endTime":22.38,"body":"and do over the course"},{"startTime":22.38,"endTime":23.67,"body":"of the next 45 minutes,"},{"startTime":23.67,"endTime":26.19,"body":"and indeed over the rest of this series"},{"startTime":26.19,"endTime":28.8,"body":"is to convince you that actually,"},{"startTime":28.8,"endTime":30.6,"body":"all the really important stuff"},{"startTime":30.6,"endTime":33.45,"body":"on this planet is invisible."},{"startTime":33.45,"endTime":35.73,"body":"And if you don't need"},{"startTime":33.45,"endTime":35.73,"body":"a microscope to see it,"},{"startTime":35.73,"endTime":37.794,"body":"it's probably quite boring."},{"startTime":37.794,"endTime":41.85,"body":"So, everything that we're going"},{"startTime":37.794,"endTime":41.85,"body":"to talk about is microbial,"},{"startTime":41.85,"endTime":45.99,"body":"invisible and still"},{"startTime":41.85,"endTime":45.99,"body":"really, really important."},{"startTime":45.99,"endTime":47.01,"body":"And I want to see if I can try"},{"startTime":47.01,"endTime":49.053,"body":"and illustrate that to start off with,"},{"startTime":49.053,"endTime":51.66,"body":"with a subject that is"},{"startTime":49.053,"endTime":51.66,"body":"very close to my heart"},{"startTime":51.66,"endTime":53.91,"body":"and my stomach, which is food."},{"startTime":53.91,"endTime":55.95,"body":"So I hope you'll join with me in this"},{"startTime":55.95,"endTime":58.23,"body":"and give me a quick show of hands"},{"startTime":58.23,"endTime":60.81,"body":"if you have in the last 24 hours"},{"startTime":60.81,"endTime":63.063,"body":"had a meal that includes soy sauce."},{"startTime":64.59,"endTime":65.49,"body":"There's a couple down here."},{"startTime":65.49,"endTime":66.75,"body":"Those of you online"},{"startTime":65.49,"endTime":66.75,"body":"can't see the audience."},{"startTime":66.75,"endTime":67.583,"body":"Keep your hands up."},{"startTime":67.583,"endTime":68.416,"body":"Don't put your hands down."},{"startTime":68.416,"endTime":70.59,"body":"Okay, now add your hand"},{"startTime":70.59,"endTime":72.45,"body":"if you've had an alcoholic drink,"},{"startTime":72.45,"endTime":74.01,"body":"and are accepting to admit it."},{"startTime":74.01,"endTime":74.94,"body":"Okay, there's a couple."},{"startTime":74.94,"endTime":75.96,"body":"Yep, marvelous."},{"startTime":75.96,"endTime":76.793,"body":"Chocolate."},{"startTime":76.793,"endTime":77.82,"body":"Who's eaten chocolate"},{"startTime":76.793,"endTime":77.82,"body":"in the last 24 hours?"},{"startTime":77.82,"endTime":79.44,"body":"Keep your hands up, hands up."},{"startTime":79.44,"endTime":80.73,"body":"Marvelous. Doing quite well."},{"startTime":80.73,"endTime":81.72,"body":"Still a few people."},{"startTime":81.72,"endTime":83.7,"body":"Have you had a bread product,"},{"startTime":83.7,"endTime":85.893,"body":"toast, sandwich, something else?"},{"startTime":86.73,"endTime":88.83,"body":"Okay, those of you haven't"},{"startTime":86.73,"endTime":88.83,"body":"put your hand up at all."},{"startTime":88.83,"endTime":90.36,"body":"Have you eaten a plant,"},{"startTime":90.36,"endTime":93.42,"body":"a land plant in the last 24 hours?"},{"startTime":93.42,"endTime":94.38,"body":"Yes. Excellent."},{"startTime":94.38,"endTime":96.406,"body":"I think everyone's put"},{"startTime":94.38,"endTime":96.406,"body":"their hand up, right?"},{"startTime":96.406,"endTime":99.9,"body":"All of those things require microbes"},{"startTime":99.9,"endTime":101.73,"body":"to get to your stomach eventually."},{"startTime":101.73,"endTime":105.06,"body":"So chocolate, soy source,"},{"startTime":101.73,"endTime":105.06,"body":"they're fermentation products."},{"startTime":105.06,"endTime":108.3,"body":"Their fermentation is created by microbes."},{"startTime":108.3,"endTime":109.29,"body":"Bread, as you know."},{"startTime":109.29,"endTime":113.58,"body":"Alcoholic drinks are also"},{"startTime":109.29,"endTime":113.58,"body":"fermentation products of microbes."},{"startTime":113.58,"endTime":115.83,"body":"And almost all land plants"},{"startTime":115.83,"endTime":118.23,"body":"require for really abundant growth"},{"startTime":118.23,"endTime":120.75,"body":"a very close symbiotic relationship"},{"startTime":120.75,"endTime":122.67,"body":"with invisible microbes in the soil,"},{"startTime":122.67,"endTime":123.933,"body":"so-called mycorrhiza."},{"startTime":125.07,"endTime":127.71,"body":"So it's reasonable to say, I"},{"startTime":125.07,"endTime":127.71,"body":"think, that without microbes,"},{"startTime":127.71,"endTime":131.28,"body":"we would essentially have no"},{"startTime":127.71,"endTime":131.28,"body":"food or at least no nice food."},{"startTime":131.28,"endTime":133.56,"body":"And that's a kind of"},{"startTime":131.28,"endTime":133.56,"body":"really fundamental part"},{"startTime":133.56,"endTime":135.81,"body":"of understanding the world around us."},{"startTime":135.81,"endTime":138.24,"body":"We've thought a lot, most of us,"},{"startTime":138.24,"endTime":140.22,"body":"about microbes over the"},{"startTime":138.24,"endTime":140.22,"body":"last couple of years,"},{"startTime":140.22,"endTime":141.96,"body":"as Martin alluded to."},{"startTime":141.96,"endTime":143.31,"body":"They have unfortunately touched"},{"startTime":143.31,"endTime":145.38,"body":"most of our lives in the most drastic"},{"startTime":145.38,"endTime":149.04,"body":"and unpleasant way in the shape of COVID."},{"startTime":149.04,"endTime":151.5,"body":"But there are many, many"},{"startTime":149.04,"endTime":151.5,"body":"really positive stories"},{"startTime":151.5,"endTime":153.48,"body":"about microbes and I want to emphasize"},{"startTime":153.48,"endTime":154.59,"body":"some of those as I take you"},{"startTime":154.59,"endTime":156.78,"body":"on a bit of a journey about this."},{"startTime":156.78,"endTime":158.55,"body":"So food is obviously"},{"startTime":158.55,"endTime":160.32,"body":"one of those really positive stories."},{"startTime":160.32,"endTime":161.153,"body":"Lots of these things."},{"startTime":161.153,"endTime":162.45,"body":"I didn't even mention cheese,"},{"startTime":162.45,"endTime":163.41,"body":"one of my favorite foods."},{"startTime":163.41,"endTime":166.02,"body":"Lots and lots of cheeses,"},{"startTime":163.41,"endTime":166.02,"body":"obviously yogurt,"},{"startTime":166.02,"endTime":168.873,"body":"all these fermented dairy"},{"startTime":166.02,"endTime":168.873,"body":"products are all microbial."},{"startTime":170.73,"endTime":172.77,"body":"If, however, we move away from food,"},{"startTime":172.77,"endTime":175.35,"body":"if you've ever stood on"},{"startTime":172.77,"endTime":175.35,"body":"the White Cliffs of Dover,"},{"startTime":175.35,"endTime":178.32,"body":"or indeed any chalk upland in the UK"},{"startTime":178.32,"endTime":179.49,"body":"or elsewhere in the world,"},{"startTime":179.49,"endTime":182.25,"body":"you have also got microbes"},{"startTime":179.49,"endTime":182.25,"body":"to thank for that,"},{"startTime":182.25,"endTime":184.08,"body":"because you are literally standing"},{"startTime":184.08,"endTime":186.33,"body":"on the dead bodies of millions, billions,"},{"startTime":186.33,"endTime":188.4,"body":"trillions of ancient microbes"},{"startTime":188.4,"endTime":190.5,"body":"when you stand on any kind of chalk cliff."},{"startTime":191.61,"endTime":192.99,"body":"If you've been to a rainforest,"},{"startTime":192.99,"endTime":196.05,"body":"this is the Amazon rainforest,"},{"startTime":192.99,"endTime":196.05,"body":"but any other rainforest,"},{"startTime":196.05,"endTime":197.43,"body":"you've been probably admiring"},{"startTime":197.43,"endTime":200.4,"body":"the trees around you,"},{"startTime":197.43,"endTime":200.4,"body":"the bushes around you,"},{"startTime":200.4,"endTime":201.96,"body":"unaware perhaps of the fact that"},{"startTime":201.96,"endTime":203.28,"body":"actually all of those plants"},{"startTime":203.28,"endTime":204.78,"body":"are intimately connected"},{"startTime":204.78,"endTime":207.72,"body":"by an invisible web of fungi in the soil."},{"startTime":207.72,"endTime":210.03,"body":"And those fungi are really fundamental"},{"startTime":210.03,"endTime":211.59,"body":"to the process of plant growth."},{"startTime":211.59,"endTime":213.66,"body":"So without those invisible microbes,"},{"startTime":213.66,"endTime":215.79,"body":"we would not have that rainforest"},{"startTime":215.79,"endTime":217.26,"body":"where you've been on holiday,"},{"startTime":217.26,"endTime":219.66,"body":"or indeed where millions of people live"},{"startTime":219.66,"endTime":221.283,"body":"and have their existence."},{"startTime":222.69,"endTime":223.8,"body":"And then of course the last,"},{"startTime":223.8,"endTime":225.15,"body":"and this might have happened"},{"startTime":223.8,"endTime":225.15,"body":"to you this morning,"},{"startTime":225.15,"endTime":226.59,"body":"if you were racing for the door,"},{"startTime":226.59,"endTime":228.96,"body":"you were a bit late for work"},{"startTime":226.59,"endTime":228.96,"body":"or for school or for wherever,"},{"startTime":228.96,"endTime":230.43,"body":"and you thought I'll"},{"startTime":228.96,"endTime":230.43,"body":"grab an apple on the way,"},{"startTime":230.43,"endTime":231.81,"body":"and you put your hand into the fruit bowl,"},{"startTime":231.81,"endTime":234.33,"body":"and what you got was a"},{"startTime":231.81,"endTime":234.33,"body":"kind of squishy brown"},{"startTime":234.33,"endTime":235.8,"body":"unpleasant thing."},{"startTime":235.8,"endTime":237.362,"body":"Oh, I was going to say, \"You"},{"startTime":235.8,"endTime":237.362,"body":"probably thanked microbes.\""},{"startTime":237.362,"endTime":239.64,"body":"You probably didn't"},{"startTime":237.362,"endTime":239.64,"body":"thank microbes actually."},{"startTime":239.64,"endTime":240.75,"body":"But microbes have done that."},{"startTime":240.75,"endTime":243.72,"body":"They have turned your pristine apple"},{"startTime":243.72,"endTime":244.77,"body":"into a bowl of mush,"},{"startTime":244.77,"endTime":247.95,"body":"because they are the ultimate decomposers."},{"startTime":247.95,"endTime":250.83,"body":"They create all the compost"},{"startTime":247.95,"endTime":250.83,"body":"that we use in our gardens."},{"startTime":250.83,"endTime":252.09,"body":"And of course at the last,"},{"startTime":252.09,"endTime":253.5,"body":"I think as a microbiologist,"},{"startTime":253.5,"endTime":255.36,"body":"this is kind of a sort of satisfying"},{"startTime":255.36,"endTime":257.76,"body":"feeling that at the very end of my life,"},{"startTime":257.76,"endTime":260.04,"body":"I will be beautifully recycled"},{"startTime":260.04,"endTime":262.74,"body":"into all sorts of other"},{"startTime":260.04,"endTime":262.74,"body":"things by microbes."},{"startTime":262.74,"endTime":263.91,"body":"And all the bits of me"},{"startTime":263.91,"endTime":266.61,"body":"will turn into bits of other people,"},{"startTime":266.61,"endTime":268.323,"body":"earthworms, plants,"},{"startTime":269.28,"endTime":271.11,"body":"all kinds of interesting molecules"},{"startTime":271.11,"endTime":275.37,"body":"with the power of microbes"},{"startTime":271.11,"endTime":275.37,"body":"to decompose and recycle."},{"startTime":275.37,"endTime":277.05,"body":"And indeed, it's been calculated"},{"startTime":277.05,"endTime":279.81,"body":"that if we lost all our microbial life,"},{"startTime":279.81,"endTime":281.73,"body":"we'd only make it about six days"},{"startTime":281.73,"endTime":284.28,"body":"on before we drowned in"},{"startTime":281.73,"endTime":284.28,"body":"our own level of rubbish."},{"startTime":284.28,"endTime":286.29,"body":"Because without that decomposition,"},{"startTime":286.29,"endTime":288.33,"body":"we would almost instantly be overwhelmed"},{"startTime":288.33,"endTime":290.16,"body":"by all the things that are currently"},{"startTime":290.16,"endTime":291.993,"body":"being broken down around us."},{"startTime":293.19,"endTime":295.29,"body":"So microbes are really"},{"startTime":293.19,"endTime":295.29,"body":"fundamentally important."},{"startTime":295.29,"endTime":296.73,"body":"The other really nice thing"},{"startTime":296.73,"endTime":299.46,"body":"I think about microbes is"},{"startTime":296.73,"endTime":299.46,"body":"that you can study them,"},{"startTime":299.46,"endTime":300.72,"body":"you can learn a lot about them"},{"startTime":300.72,"endTime":302.34,"body":"without even kind of leaving your home."},{"startTime":302.34,"endTime":303.42,"body":"If you study, you know,"},{"startTime":303.42,"endTime":304.92,"body":"if you're a biologist who"},{"startTime":303.42,"endTime":304.92,"body":"studies, I don't know,"},{"startTime":304.92,"endTime":307.02,"body":"penguins or polar bears,"},{"startTime":307.02,"endTime":308.76,"body":"you've got to travel quite a long way"},{"startTime":308.76,"endTime":309.93,"body":"to see those in their habitat,"},{"startTime":309.93,"endTime":312.12,"body":"and you have to dress"},{"startTime":309.93,"endTime":312.12,"body":"up really warm as well."},{"startTime":312.12,"endTime":313.71,"body":"Whereas if you're a microbiologist,"},{"startTime":313.71,"endTime":316.797,"body":"you can study microbes"},{"startTime":313.71,"endTime":316.797,"body":"right here and right now."},{"startTime":316.797,"endTime":318.777,"body":"And I hope I can demonstrate that"},{"startTime":318.777,"endTime":320.22,"body":"with the help of a volunteer."},{"startTime":320.22,"endTime":322.02,"body":"There'll be several calls"},{"startTime":320.22,"endTime":322.02,"body":"for volunteers tonight."},{"startTime":322.02,"endTime":323.49,"body":"Please work with me."},{"startTime":323.49,"endTime":326.67,"body":"This is the moment if your,"},{"startTime":323.49,"endTime":326.67,"body":"you know, wife, husband,"},{"startTime":326.67,"endTime":328.74,"body":"children, parents, employer"},{"startTime":328.74,"endTime":331.59,"body":"do not know you are here, don't volunteer."},{"startTime":331.59,"endTime":332.97,"body":"Otherwise, please do volunteer."},{"startTime":332.97,"endTime":334.047,"body":"So I'm hoping, could I have a volunteer"},{"startTime":334.047,"endTime":334.88,"body":"for this first thing?"},{"startTime":334.88,"endTime":336.06,"body":"I promise to return you unharmed."},{"startTime":336.06,"endTime":337.59,"body":"I can see a hand right at the back."},{"startTime":337.59,"endTime":338.76,"body":"Excellent. Come on down."},{"startTime":338.76,"endTime":340.29,"body":"Well done. Brave person."},{"startTime":340.29,"endTime":343.639,"body":"Can we have a round of"},{"startTime":340.29,"endTime":343.639,"body":"applause for this brave soul?"},{"startTime":343.639,"endTime":347.52,"body":"(audience applauding)"},{"startTime":347.52,"endTime":348.48,"body":"Got to run your way down."},{"startTime":348.48,"endTime":349.83,"body":"I can't even see you yet with the lights,"},{"startTime":349.83,"endTime":351.21,"body":"but here they come."},{"startTime":351.21,"endTime":352.203,"body":"Bravo."},{"startTime":354.42,"endTime":356.37,"body":"Come and join me on stage."},{"startTime":356.37,"endTime":357.3,"body":"You're about to be be seen"},{"startTime":357.3,"endTime":358.56,"body":"by all those people watching this"},{"startTime":358.56,"endTime":359.7,"body":"with their cup of coffee at home."},{"startTime":359.7,"endTime":360.78,"body":"Excellent. What's your name?"},{"startTime":360.78,"endTime":361.613,"body":"- Brandy."},{"startTime":361.613,"endTime":362.7,"body":"- Brandy. Thank you, Brandy."},{"startTime":362.7,"endTime":363.72,"body":"You are an absolute hero."},{"startTime":363.72,"endTime":366.84,"body":"So, Brandy has kindly volunteered"},{"startTime":366.84,"endTime":368.25,"body":"to be my first volunteer here,"},{"startTime":368.25,"endTime":369.66,"body":"and I'm going to ask a"},{"startTime":368.25,"endTime":369.66,"body":"very difficult question"},{"startTime":369.66,"endTime":370.493,"body":"of the rest of you."},{"startTime":370.493,"endTime":371.52,"body":"You don't have to answer."},{"startTime":371.52,"endTime":373.773,"body":"What species is Brandy?"},{"startTime":374.79,"endTime":376.203,"body":"Could I have a hand?"},{"startTime":377.25,"endTime":378.81,"body":"Someone said Homo sapiens."},{"startTime":378.81,"endTime":380.01,"body":"Homo sapiens, yeah."},{"startTime":380.01,"endTime":382.17,"body":"Human, not really."},{"startTime":382.17,"endTime":383.013,"body":"Sorry, Brandy."},{"startTime":384.15,"endTime":385.77,"body":"Close, but not really."},{"startTime":385.77,"endTime":388.02,"body":"You know, superficially,"},{"startTime":385.77,"endTime":388.02,"body":"yes, Homo sapiens."},{"startTime":388.02,"endTime":389.73,"body":"Actually, what you're looking at here"},{"startTime":389.73,"endTime":391.29,"body":"is an amazing illustration"},{"startTime":391.29,"endTime":394.71,"body":"of a fantastic microbial ecosystem,"},{"startTime":394.71,"endTime":396.84,"body":"because what you see in front of you"},{"startTime":396.84,"endTime":401.55,"body":"is not one organism, one Homo sapiens,"},{"startTime":401.55,"endTime":404.19,"body":"but millions, in fact billions,"},{"startTime":404.19,"endTime":407.55,"body":"approximately 39 trillion bacteria"},{"startTime":407.55,"endTime":409.02,"body":"seething inside Brandy."},{"startTime":409.02,"endTime":409.92,"body":"It's not just you."},{"startTime":409.92,"endTime":410.753,"body":"Inside me as well."},{"startTime":410.753,"endTime":412.35,"body":"Inside all of us, okay?"},{"startTime":412.35,"endTime":413.4,"body":"By our best estimates,"},{"startTime":413.4,"endTime":414.48,"body":"the average human body"},{"startTime":414.48,"endTime":417.57,"body":"has about 39 trillion live microbes"},{"startTime":417.57,"endTime":419.01,"body":"at any one point, okay?"},{"startTime":419.01,"endTime":422.58,"body":"That is undoubtedly more"},{"startTime":419.01,"endTime":422.58,"body":"live microbial cells"},{"startTime":422.58,"endTime":424.23,"body":"than you have human cells."},{"startTime":424.23,"endTime":426.09,"body":"So to a first approximation, I'm afraid,"},{"startTime":426.09,"endTime":427.77,"body":"Brandy, you're not actually human."},{"startTime":427.77,"endTime":429.36,"body":"You're mostly something else,"},{"startTime":429.36,"endTime":432.03,"body":"with a little bit of human on the surface."},{"startTime":432.03,"endTime":432.863,"body":"But on the other hand,"},{"startTime":432.863,"endTime":433.95,"body":"you can be really pleased that"},{"startTime":433.95,"endTime":435.21,"body":"you are a unique habitat,"},{"startTime":435.21,"endTime":437.76,"body":"more unique probably than"},{"startTime":435.21,"endTime":437.76,"body":"the Amazon rainforest."},{"startTime":437.76,"endTime":439.26,"body":"So, you know, people travel a long way"},{"startTime":439.26,"endTime":440.307,"body":"and pay a lot of money to see that."},{"startTime":440.307,"endTime":442.98,"body":"But in front of you, you"},{"startTime":440.307,"endTime":442.98,"body":"have a fantastic ecosystem."},{"startTime":442.98,"endTime":443.813,"body":"Don't go away."},{"startTime":443.813,"endTime":444.646,"body":"Hold on, don't go away."},{"startTime":444.646,"endTime":445.953,"body":"I've got one more task for you."},{"startTime":446.79,"endTime":448.32,"body":"So, one of the problems about this,"},{"startTime":448.32,"endTime":450.6,"body":"this number, 39 trillion bacteria,"},{"startTime":450.6,"endTime":452.49,"body":"it's a really big and challenging number."},{"startTime":452.49,"endTime":454.95,"body":"So let me help you visualize that a bit,"},{"startTime":454.95,"endTime":456.03,"body":"and I'm going to pass this to you."},{"startTime":456.03,"endTime":459.27,"body":"So, in this envelope I have"},{"startTime":456.03,"endTime":459.27,"body":"some poppy seeds, okay?"},{"startTime":459.27,"endTime":460.74,"body":"Not illegal poppy seeds, by the way."},{"startTime":460.74,"endTime":462.45,"body":"They're just sort of the"},{"startTime":460.74,"endTime":462.45,"body":"ones you put on there."},{"startTime":462.45,"endTime":463.74,"body":"I'm going to pass that to"},{"startTime":462.45,"endTime":463.74,"body":"you, Brandy, to hold on."},{"startTime":463.74,"endTime":467.487,"body":"So those 39 trillion bacteria"},{"startTime":467.487,"endTime":468.653,"body":"are very, very small, okay?"},{"startTime":468.653,"endTime":470.553,"body":"This is a typical bacteria"},{"startTime":470.553,"endTime":471.66,"body":"that you can see in front of you."},{"startTime":471.66,"endTime":474.66,"body":"This is E. coli, Escherichia coli."},{"startTime":474.66,"endTime":475.98,"body":"It's a very common bacteria"},{"startTime":475.98,"endTime":479.13,"body":"found in intestines of all"},{"startTime":475.98,"endTime":479.13,"body":"mammals, including ourselves."},{"startTime":479.13,"endTime":481.05,"body":"It's about a micrometer long,"},{"startTime":481.05,"endTime":483.45,"body":"so about 1000th of a millimeter long."},{"startTime":483.45,"endTime":485.25,"body":"So invisible, okay?"},{"startTime":485.25,"endTime":486.81,"body":"And it's very difficult to imagine"},{"startTime":486.81,"endTime":487.68,"body":"what that might look like."},{"startTime":487.68,"endTime":488.513,"body":"So what I'm going to do"},{"startTime":488.513,"endTime":489.346,"body":"is I'm going to ask you to tip out"},{"startTime":489.346,"endTime":491.462,"body":"a few of those seeds into your hand,"},{"startTime":491.462,"endTime":493.11,"body":"in a second, or take a pinch or whatever."},{"startTime":493.11,"endTime":494.16,"body":"If you spill them on the carpet,"},{"startTime":494.16,"endTime":495.9,"body":"we'll apologize later, that's fine."},{"startTime":495.9,"endTime":497.25,"body":"So I've chosen poppy seeds"},{"startTime":497.25,"endTime":498.54,"body":"just because they're quite small,"},{"startTime":498.54,"endTime":501.06,"body":"but big enough for, I was going"},{"startTime":498.54,"endTime":501.06,"body":"to say for everyone to see."},{"startTime":501.06,"endTime":502.05,"body":"You probably can't see them."},{"startTime":502.05,"endTime":502.883,"body":"Brandy can, right?"},{"startTime":502.883,"endTime":503.716,"body":"They're quite small, right?"},{"startTime":503.716,"endTime":504.96,"body":"About the size of a grain sand."},{"startTime":504.96,"endTime":507.27,"body":"So, you can show those to the audience."},{"startTime":507.27,"endTime":509.55,"body":"So I want you to imagine for a moment"},{"startTime":509.55,"endTime":512.88,"body":"that each of Brandy's,"},{"startTime":509.55,"endTime":512.88,"body":"39 trillion microbes"},{"startTime":512.88,"endTime":515.76,"body":"is the size of one of"},{"startTime":512.88,"endTime":515.76,"body":"those poppy seeds, okay?"},{"startTime":515.76,"endTime":517.14,"body":"So they're like this."},{"startTime":517.14,"endTime":520.08,"body":"How big would Brandy"},{"startTime":517.14,"endTime":520.08,"body":"have to be, do you think,"},{"startTime":520.08,"endTime":521.64,"body":"to accommodate her micros?"},{"startTime":521.64,"endTime":522.663,"body":"Any guesses?"},{"startTime":524.73,"endTime":526.32,"body":"It's the size of the room,"},{"startTime":524.73,"endTime":526.32,"body":"someone said, I heard."},{"startTime":526.32,"endTime":527.67,"body":"This room?"},{"startTime":527.67,"endTime":528.503,"body":"It's quite big."},{"startTime":529.41,"endTime":531.536,"body":"Any improvements on that?"},{"startTime":531.536,"endTime":532.591,"body":"- [Audience Member] The size of England."},{"startTime":532.591,"endTime":533.424,"body":"- Five, what, sorry?"},{"startTime":533.424,"endTime":534.382,"body":"- [Audience Member] The size of England."},{"startTime":534.382,"endTime":535.215,"body":"- The size of England."},{"startTime":535.215,"endTime":536.735,"body":"Not quite that big, you"},{"startTime":535.215,"endTime":536.735,"body":"will be delighted to know."},{"startTime":536.735,"endTime":538.824,"body":"It's very difficult to"},{"startTime":536.735,"endTime":538.824,"body":"buy clothes in that size."},{"startTime":538.824,"endTime":540.51,"body":"But you would have to be,"},{"startTime":540.51,"endTime":542.07,"body":"if we grew each of your microbes"},{"startTime":542.07,"endTime":543.39,"body":"the size of a poppy seed,"},{"startTime":543.39,"endTime":544.98,"body":"we'd need to make Brandy about the size"},{"startTime":544.98,"endTime":546.45,"body":"of five Olympic swimming pools"},{"startTime":546.45,"endTime":550.32,"body":"to accommodate those"},{"startTime":546.45,"endTime":550.32,"body":"microbes inside your gut."},{"startTime":550.32,"endTime":553.29,"body":"And so that I think is"},{"startTime":550.32,"endTime":553.29,"body":"a kind of very visible"},{"startTime":553.29,"endTime":555.03,"body":"reminder of just how diverse this is."},{"startTime":555.03,"endTime":557.61,"body":"Imagine looking out across"},{"startTime":555.03,"endTime":557.61,"body":"five Olympic swimming pools"},{"startTime":557.61,"endTime":559.32,"body":"filled with these tiny seeds,"},{"startTime":559.32,"endTime":562.59,"body":"each one a unique living microbe"},{"startTime":562.59,"endTime":563.67,"body":"that you're carrying around"},{"startTime":563.67,"endTime":565.59,"body":"every day of your life inside your gut."},{"startTime":565.59,"endTime":566.423,"body":"Fantastic. Thank you very much."},{"startTime":566.423,"endTime":567.33,"body":"Now, you can keep the poppy seeds."},{"startTime":567.33,"endTime":568.59,"body":"You can sprinkle them on a window box"},{"startTime":568.59,"endTime":569.423,"body":"and see if you get any poppies."},{"startTime":569.423,"endTime":570.256,"body":"Thank you very much."},{"startTime":570.256,"endTime":571.763,"body":"Round of applause for our first volunteer."},{"startTime":572.643,"endTime":574.77,"body":"(audience applauding)"},{"startTime":574.77,"endTime":576.157,"body":"Everyone else in the"},{"startTime":574.77,"endTime":576.157,"body":"audience is now thinking,"},{"startTime":576.157,"endTime":576.99,"body":"\"Oh my goodness,"},{"startTime":576.99,"endTime":578.7,"body":"I'm not going to volunteer"},{"startTime":576.99,"endTime":578.7,"body":"for anything anymore.\""},{"startTime":578.7,"endTime":581.94,"body":"Okay, so microbes are"},{"startTime":578.7,"endTime":581.94,"body":"enormously important."},{"startTime":581.94,"endTime":583.02,"body":"They're incredibly tiny."},{"startTime":583.02,"endTime":584.85,"body":"They're amazingly diverse."},{"startTime":584.85,"endTime":586.44,"body":"Where then did they come from?"},{"startTime":586.44,"endTime":589.95,"body":"So I want to start by taking"},{"startTime":586.44,"endTime":589.95,"body":"you back just a day or two,"},{"startTime":589.95,"endTime":592.11,"body":"about four and a half billion years"},{"startTime":592.11,"endTime":595.23,"body":"to the start of the planet as we know it."},{"startTime":595.23,"endTime":597.54,"body":"And we obviously, by definition,"},{"startTime":597.54,"endTime":601.02,"body":"know very little about what"},{"startTime":597.54,"endTime":601.02,"body":"the early Earth looked like."},{"startTime":601.02,"endTime":603.54,"body":"But based on a whole variety of science,"},{"startTime":603.54,"endTime":605.22,"body":"we know it was pretty hot."},{"startTime":605.22,"endTime":607.77,"body":"There was no life, obviously."},{"startTime":607.77,"endTime":609.84,"body":"There were, at that stage of time,"},{"startTime":609.84,"endTime":611.88,"body":"a lot of energetic events,"},{"startTime":611.88,"endTime":614.49,"body":"meteor strikes, lightning strikes,"},{"startTime":614.49,"endTime":617.61,"body":"and a very, very different"},{"startTime":614.49,"endTime":617.61,"body":"chemical composition, okay?"},{"startTime":617.61,"endTime":621.033,"body":"This was an Earth completely"},{"startTime":617.61,"endTime":621.033,"body":"unlike the Earth we have today."},{"startTime":622.38,"endTime":625.77,"body":"And as far as we know, for"},{"startTime":622.38,"endTime":625.77,"body":"the first 600 million years,"},{"startTime":625.77,"endTime":629.103,"body":"more or less, there is no"},{"startTime":625.77,"endTime":629.103,"body":"evidence for life on Earth."},{"startTime":630.03,"endTime":632.55,"body":"However, during that 600 million years,"},{"startTime":632.55,"endTime":634.56,"body":"stuff was happening,"},{"startTime":634.56,"endTime":637.26,"body":"and we almost by"},{"startTime":634.56,"endTime":637.26,"body":"definition cannot work out"},{"startTime":637.26,"endTime":639.06,"body":"exactly what happened."},{"startTime":639.06,"endTime":641.4,"body":"But there are some reasonable assumptions"},{"startTime":641.4,"endTime":644.94,"body":"we can make based on some"},{"startTime":641.4,"endTime":644.94,"body":"pretty good scientific evidence."},{"startTime":644.94,"endTime":648.12,"body":"So we know under the"},{"startTime":644.94,"endTime":648.12,"body":"conditions of the early Earth,"},{"startTime":648.12,"endTime":650.22,"body":"it is possible to recreate"},{"startTime":650.22,"endTime":652.65,"body":"relatively complex molecules, okay?"},{"startTime":652.65,"endTime":655.2,"body":"From a very simple chemical soup"},{"startTime":655.2,"endTime":657.633,"body":"with energy provided by"},{"startTime":655.2,"endTime":657.633,"body":"things like lightning."},{"startTime":658.5,"endTime":660.45,"body":"So you can create things like amino acids,"},{"startTime":660.45,"endTime":663.243,"body":"which are the building blocks of proteins."},{"startTime":664.38,"endTime":665.79,"body":"And I think a reasonable assumption"},{"startTime":665.79,"endTime":667.23,"body":"for how life might have begun"},{"startTime":667.23,"endTime":669.54,"body":"is when we consider that"},{"startTime":667.23,"endTime":669.54,"body":"some of these simple"},{"startTime":669.54,"endTime":671.76,"body":"chemicals can come together to form"},{"startTime":671.76,"endTime":674.55,"body":"what's called a polymer,"},{"startTime":671.76,"endTime":674.55,"body":"so a multiple linkage."},{"startTime":674.55,"endTime":677.31,"body":"A long, complicated molecule."},{"startTime":677.31,"endTime":680.16,"body":"And some of those long polymer compounds"},{"startTime":680.16,"endTime":683.04,"body":"can undergo activities on themselves."},{"startTime":683.04,"endTime":687.24,"body":"So for example, we know of"},{"startTime":683.04,"endTime":687.24,"body":"molecules called RNA Aptimas,"},{"startTime":687.24,"endTime":690.21,"body":"which are long strings of molecules"},{"startTime":690.21,"endTime":693.33,"body":"that are capable of cutting"},{"startTime":690.21,"endTime":693.33,"body":"and sticking themselves."},{"startTime":693.33,"endTime":695.25,"body":"And so I think a reasonable assumption"},{"startTime":695.25,"endTime":697.95,"body":"early on in this"},{"startTime":695.25,"endTime":697.95,"body":"proto-planet, if you like,"},{"startTime":697.95,"endTime":701.79,"body":"is that in that sea"},{"startTime":697.95,"endTime":701.79,"body":"over 600 million years,"},{"startTime":701.79,"endTime":702.78,"body":"the power of lightning"},{"startTime":702.78,"endTime":706.2,"body":"and other energetic processes"},{"startTime":702.78,"endTime":706.2,"body":"was creating molecules"},{"startTime":706.2,"endTime":708.8,"body":"that could come together"},{"startTime":706.2,"endTime":708.8,"body":"to form polymers like this."},{"startTime":709.71,"endTime":712.83,"body":"We also know that many of these"},{"startTime":709.71,"endTime":712.83,"body":"polymers can self template."},{"startTime":712.83,"endTime":714.33,"body":"They can create, if you like,"},{"startTime":714.33,"endTime":717.42,"body":"a mirror image of themselves,"},{"startTime":714.33,"endTime":717.42,"body":"like a jigsaw puzzle."},{"startTime":717.42,"endTime":720.0,"body":"And so you can end up with a molecule"},{"startTime":720.0,"endTime":721.59,"body":"that looks a little bit like this."},{"startTime":721.59,"endTime":723.15,"body":"And this, people in the audience"},{"startTime":723.15,"endTime":724.29,"body":"might already be familiar with,"},{"startTime":724.29,"endTime":727.11,"body":"looks a little bit like things like DNA,"},{"startTime":727.11,"endTime":729.12,"body":"so the molecule that today creates"},{"startTime":729.12,"endTime":730.653,"body":"all of our genetic material."},{"startTime":731.7,"endTime":732.87,"body":"And the very neat thing about"},{"startTime":732.87,"endTime":734.07,"body":"these kind of polymers is that"},{"startTime":734.07,"endTime":736.2,"body":"you can then strip them apart."},{"startTime":736.2,"endTime":738.72,"body":"And when you do that, you"},{"startTime":736.2,"endTime":738.72,"body":"end up with two halves"},{"startTime":738.72,"endTime":742.5,"body":"which can self template"},{"startTime":738.72,"endTime":742.5,"body":"a new copy of themselves."},{"startTime":742.5,"endTime":744.42,"body":"And so I think you see in one go here"},{"startTime":744.42,"endTime":746.25,"body":"that over a very long period of time,"},{"startTime":746.25,"endTime":748.8,"body":"it's possible for spontaneous chemistry"},{"startTime":748.8,"endTime":752.04,"body":"to create molecules that"},{"startTime":748.8,"endTime":752.04,"body":"can copy themselves,"},{"startTime":752.04,"endTime":755.13,"body":"and thereby lay the first"},{"startTime":752.04,"endTime":755.13,"body":"kind of start, if you like,"},{"startTime":755.13,"endTime":758.493,"body":"the principles that may"},{"startTime":755.13,"endTime":758.493,"body":"go on to create life."},{"startTime":759.66,"endTime":761.82,"body":"But a self-templating molecule in itself"},{"startTime":761.82,"endTime":763.74,"body":"is obviously a very long way removed"},{"startTime":763.74,"endTime":765.66,"body":"from a microbe or even a cell."},{"startTime":765.66,"endTime":769.113,"body":"This is not life, this is"},{"startTime":765.66,"endTime":769.113,"body":"just the basis of life."},{"startTime":770.1,"endTime":772.98,"body":"To move from a chemical in a soup"},{"startTime":772.98,"endTime":775.38,"body":"to something that is alive,"},{"startTime":772.98,"endTime":775.38,"body":"you need a second step."},{"startTime":775.38,"endTime":776.52,"body":"And that second step is you need"},{"startTime":776.52,"endTime":778.83,"body":"to somehow compartmentalize it, okay?"},{"startTime":778.83,"endTime":781.56,"body":"We don't live as diverse compounds"},{"startTime":781.56,"endTime":782.393,"body":"spread across the Earth."},{"startTime":782.393,"endTime":785.28,"body":"We live as encapsulated entities, okay?"},{"startTime":785.28,"endTime":787.78,"body":"Things that have a membrane,"},{"startTime":785.28,"endTime":787.78,"body":"that have a boundary."},{"startTime":789.06,"endTime":790.89,"body":"So what does it take then to move"},{"startTime":790.89,"endTime":792.75,"body":"from being a free living molecule"},{"startTime":792.75,"endTime":794.79,"body":"into a cell, as we might know it?"},{"startTime":794.79,"endTime":796.02,"body":"And what it takes is a membrane,"},{"startTime":796.02,"endTime":798.93,"body":"something that will separate"},{"startTime":796.02,"endTime":798.93,"body":"inside from outside,"},{"startTime":798.93,"endTime":800.22,"body":"that will create something"},{"startTime":800.22,"endTime":803.583,"body":"that is different from"},{"startTime":800.22,"endTime":803.583,"body":"the environment around it."},{"startTime":805.14,"endTime":806.55,"body":"And so what you do is you can imagine"},{"startTime":806.55,"endTime":808.92,"body":"taking these free living"},{"startTime":806.55,"endTime":808.92,"body":"replicating molecules"},{"startTime":808.92,"endTime":810.0,"body":"and encapsulating them"},{"startTime":810.0,"endTime":811.59,"body":"in some kind of bags,"},{"startTime":810.0,"endTime":811.59,"body":"some kind of membrane."},{"startTime":811.59,"endTime":812.91,"body":"And now you have something"},{"startTime":812.91,"endTime":814.29,"body":"that looks a little bit like a cell."},{"startTime":814.29,"endTime":816.33,"body":"It has a different set of chemicals"},{"startTime":816.33,"endTime":818.823,"body":"inside to the ones outside,"},{"startTime":819.849,"endTime":821.85,"body":"and that seems like a relatively"},{"startTime":819.849,"endTime":821.85,"body":"elaborate thing to do."},{"startTime":821.85,"endTime":822.887,"body":"So how might you create a membrane?"},{"startTime":822.887,"endTime":825.93,"body":"I know that seems a bit kind"},{"startTime":822.887,"endTime":825.93,"body":"of, you know, \"Jackanory.\""},{"startTime":825.93,"endTime":828.03,"body":"But actually, this process is something"},{"startTime":828.03,"endTime":830.79,"body":"that many of us do actually"},{"startTime":828.03,"endTime":830.79,"body":"on quite a regular basis."},{"startTime":830.79,"endTime":832.65,"body":"If you've ever made an"},{"startTime":830.79,"endTime":832.65,"body":"oil and vinegar dressing."},{"startTime":832.65,"endTime":834.51,"body":"Anyone made an oil and vinegar dressing?"},{"startTime":834.51,"endTime":835.41,"body":"Yes. Excellent."},{"startTime":835.41,"endTime":836.243,"body":"Very good."},{"startTime":836.243,"endTime":837.96,"body":"So you take your oil and your vinegar."},{"startTime":837.96,"endTime":840.6,"body":"The oil usually sits on top of the vinegar"},{"startTime":840.6,"endTime":842.58,"body":"and looks kind of, you know, greasy."},{"startTime":842.58,"endTime":843.63,"body":"And then if you're a good chef,"},{"startTime":843.63,"endTime":845.43,"body":"you give it a shake or you give it a stir"},{"startTime":845.43,"endTime":847.8,"body":"and you get, hopefully,"},{"startTime":845.43,"endTime":847.8,"body":"these little droplets, right?"},{"startTime":847.8,"endTime":848.633,"body":"Am I right?"},{"startTime":848.633,"endTime":849.75,"body":"Yes. A bit of nodding."},{"startTime":849.75,"endTime":853.79,"body":"Those droplets of oil are"},{"startTime":849.75,"endTime":853.79,"body":"kind of a large version"},{"startTime":853.79,"endTime":854.82,"body":"of what's called a micelle."},{"startTime":854.82,"endTime":857.61,"body":"So the oil does not want to"},{"startTime":854.82,"endTime":857.61,"body":"be dissolved in the water."},{"startTime":857.61,"endTime":858.69,"body":"It wants to cling to itself."},{"startTime":858.69,"endTime":860.46,"body":"It forms a little bag."},{"startTime":860.46,"endTime":861.99,"body":"And if you were to do that"},{"startTime":861.99,"endTime":863.01,"body":"with some other molecules"},{"startTime":863.01,"endTime":864.87,"body":"in your oil and vinegar dressing,"},{"startTime":864.87,"endTime":866.91,"body":"that liked being in that environment,"},{"startTime":866.91,"endTime":869.4,"body":"they would go into those little micelles,"},{"startTime":869.4,"endTime":870.3,"body":"called partitioning."},{"startTime":870.3,"endTime":871.133,"body":"They would enter the micelle"},{"startTime":871.133,"endTime":872.19,"body":"and they would sit in there,"},{"startTime":872.19,"endTime":874.17,"body":"'cause they like that environment better."},{"startTime":874.17,"endTime":876.24,"body":"And you would then have"},{"startTime":874.17,"endTime":876.24,"body":"created on the one hand"},{"startTime":876.24,"endTime":877.95,"body":"a very nice oil and vinegar dressing,"},{"startTime":877.95,"endTime":880.83,"body":"and on the other, the"},{"startTime":877.95,"endTime":880.83,"body":"beginnings of a protocell,"},{"startTime":880.83,"endTime":882.66,"body":"because you have created a membrane"},{"startTime":882.66,"endTime":885.69,"body":"out of oils which is"},{"startTime":882.66,"endTime":885.69,"body":"encapsulated within it"},{"startTime":885.69,"endTime":888.81,"body":"a different set of chemicals"},{"startTime":885.69,"endTime":888.81,"body":"to the ones outside."},{"startTime":888.81,"endTime":891.81,"body":"And this is precisely the kind of steps"},{"startTime":891.81,"endTime":894.09,"body":"that we think happened in the early Earth."},{"startTime":894.09,"endTime":897.81,"body":"These oils and fats were"},{"startTime":894.09,"endTime":897.81,"body":"created spontaneously."},{"startTime":897.81,"endTime":899.67,"body":"They don't like being a water matrix,"},{"startTime":899.67,"endTime":901.38,"body":"so they come together,"},{"startTime":899.67,"endTime":901.38,"body":"they cling to each other"},{"startTime":901.38,"endTime":902.88,"body":"and they form little balls."},{"startTime":902.88,"endTime":905.22,"body":"Inside those balls,"},{"startTime":902.88,"endTime":905.22,"body":"you can trap chemicals,"},{"startTime":905.22,"endTime":908.34,"body":"including some of those"},{"startTime":905.22,"endTime":908.34,"body":"self replicating chemicals,"},{"startTime":908.34,"endTime":909.57,"body":"and now you have something that"},{"startTime":909.57,"endTime":913.743,"body":"looks really like a membrane"},{"startTime":909.57,"endTime":913.743,"body":"bound replicating cell."},{"startTime":916.32,"endTime":917.97,"body":"This is slightly speculation."},{"startTime":917.97,"endTime":919.26,"body":"We can't ever go back in time."},{"startTime":919.26,"endTime":921.12,"body":"We can't see fossils from this period,"},{"startTime":921.12,"endTime":922.2,"body":"and even if we could see fossils,"},{"startTime":922.2,"endTime":923.25,"body":"they wouldn't be there anymore"},{"startTime":923.25,"endTime":924.96,"body":"because all the rocks from that long ago"},{"startTime":924.96,"endTime":926.64,"body":"have long ago been melted down"},{"startTime":926.64,"endTime":928.65,"body":"and reborn on the Earth."},{"startTime":928.65,"endTime":930.57,"body":"So we will never know for sure, probably,"},{"startTime":930.57,"endTime":933.09,"body":"but there is very plausible"},{"startTime":930.57,"endTime":933.09,"body":"scientific evidence"},{"startTime":933.09,"endTime":935.64,"body":"to think this is how life started."},{"startTime":935.64,"endTime":938.01,"body":"The problem though in studying that"},{"startTime":938.01,"endTime":940.983,"body":"is that all we have to go"},{"startTime":938.01,"endTime":940.983,"body":"on is what we have today."},{"startTime":941.94,"endTime":944.4,"body":"So what a lot of people do is search"},{"startTime":944.4,"endTime":946.53,"body":"for the simplest free living organisms"},{"startTime":946.53,"endTime":948.57,"body":"we know of and try and understand"},{"startTime":948.57,"endTime":952.92,"body":"from those what this early"},{"startTime":948.57,"endTime":952.92,"body":"life might have looked like."},{"startTime":952.92,"endTime":956.19,"body":"And that has been an"},{"startTime":952.92,"endTime":956.19,"body":"enormously successful strategy,"},{"startTime":956.19,"endTime":957.51,"body":"and a lot of that work is focused"},{"startTime":957.51,"endTime":959.58,"body":"in on this particular organism here."},{"startTime":959.58,"endTime":961.32,"body":"This is a lovely bacterium"},{"startTime":961.32,"endTime":963.42,"body":"called Mycoplasma genitalium."},{"startTime":963.42,"endTime":964.38,"body":"And for those of you who are feeling"},{"startTime":964.38,"endTime":965.61,"body":"very awake in the audience,"},{"startTime":965.61,"endTime":966.93,"body":"you will realize that second part"},{"startTime":966.93,"endTime":968.663,"body":"of its name suggests"},{"startTime":966.93,"endTime":968.663,"body":"where you might find it."},{"startTime":968.663,"endTime":972.57,"body":"This is a sexually transmitted bacterium."},{"startTime":972.57,"endTime":974.73,"body":"That part is slightly irrelevant though."},{"startTime":974.73,"endTime":976.08,"body":"What's really relevant is that"},{"startTime":976.08,"endTime":978.72,"body":"this is one of the simplest microbes"},{"startTime":978.72,"endTime":979.893,"body":"that we know of today."},{"startTime":980.85,"endTime":983.88,"body":"So simple in fact that a"},{"startTime":980.85,"endTime":983.88,"body":"group in the United States"},{"startTime":983.88,"endTime":986.4,"body":"have taken the genome of this organism"},{"startTime":986.4,"endTime":987.84,"body":"and they have synthesized"},{"startTime":987.84,"endTime":990.81,"body":"all of that DNA in a lab artificially."},{"startTime":990.81,"endTime":992.76,"body":"They have put that entire genome"},{"startTime":992.76,"endTime":996.21,"body":"into an empty cell and recreated this life"},{"startTime":996.21,"endTime":999.06,"body":"from a machine built genome,"},{"startTime":999.06,"endTime":1001.06,"body":"which I think is an amazing achievement."},{"startTime":1002.0,"endTime":1004.73,"body":"But it's really important"},{"startTime":1002.0,"endTime":1004.73,"body":"to realize that this,"},{"startTime":1004.73,"endTime":1006.65,"body":"the simplest microbe we know of,"},{"startTime":1006.65,"endTime":1009.11,"body":"is still vastly more complex"},{"startTime":1009.11,"endTime":1010.79,"body":"than what would've been the early life"},{"startTime":1010.79,"endTime":1011.69,"body":"on the early Earth."},{"startTime":1011.69,"endTime":1014.843,"body":"This is still an incredibly"},{"startTime":1011.69,"endTime":1014.843,"body":"complicated organism."},{"startTime":1016.13,"endTime":1020.63,"body":"It has about 475 genes, okay?"},{"startTime":1020.63,"endTime":1021.65,"body":"This is pretty simple."},{"startTime":1021.65,"endTime":1024.08,"body":"We have about 20,000"},{"startTime":1021.65,"endTime":1024.08,"body":"genes to make a human,"},{"startTime":1024.08,"endTime":1025.253,"body":"so it's pretty simple."},{"startTime":1026.54,"endTime":1028.91,"body":"But even those 475 genes,"},{"startTime":1028.91,"endTime":1031.243,"body":"they are written in the alphabet of DNA,"},{"startTime":1031.243,"endTime":1034.67,"body":"in this so-called DNA"},{"startTime":1031.243,"endTime":1034.67,"body":"base pairs or DNA letters."},{"startTime":1034.67,"endTime":1038.75,"body":"And those 475 genes, in total, that recipe"},{"startTime":1038.75,"endTime":1042.143,"body":"is just over half a"},{"startTime":1038.75,"endTime":1042.143,"body":"million DNA letters, okay?"},{"startTime":1044.12,"endTime":1045.56,"body":"To put that into context,"},{"startTime":1045.56,"endTime":1048.47,"body":"if you were to write this out as a book,"},{"startTime":1048.47,"endTime":1051.14,"body":"that book to create this single bacteria"},{"startTime":1051.14,"endTime":1054.11,"body":"would be about the same length"},{"startTime":1051.14,"endTime":1054.11,"body":"as \"Sense and Sensibility.\""},{"startTime":1054.11,"endTime":1055.888,"body":"I don't know if you've read"},{"startTime":1054.11,"endTime":1055.888,"body":"\"Sense and Sensibility,\""},{"startTime":1055.888,"endTime":1057.89,"body":"but you know, it's a great"},{"startTime":1055.888,"endTime":1057.89,"body":"story, but it's not short."},{"startTime":1057.89,"endTime":1059.09,"body":"It's not the kind of thing you read,"},{"startTime":1059.09,"endTime":1060.92,"body":"you know, in between three tube stops."},{"startTime":1060.92,"endTime":1063.32,"body":"And it's probably not where"},{"startTime":1060.92,"endTime":1063.32,"body":"you started your reading,"},{"startTime":1063.32,"endTime":1065.0,"body":"unless you were a real child prodigy."},{"startTime":1065.0,"endTime":1065.99,"body":"You know, when you were four,"},{"startTime":1065.99,"endTime":1066.823,"body":"you probably didn't pick this"},{"startTime":1066.823,"endTime":1068.65,"body":"off the shelves and start reading it."},{"startTime":1069.53,"endTime":1071.51,"body":"So thinking about how we build"},{"startTime":1071.51,"endTime":1074.48,"body":"from modern life to understand early life"},{"startTime":1074.48,"endTime":1075.44,"body":"is sort of like, you know,"},{"startTime":1075.44,"endTime":1078.8,"body":"if you had never come across"},{"startTime":1075.44,"endTime":1078.8,"body":"the written word before."},{"startTime":1078.8,"endTime":1080.96,"body":"There were no books in the world."},{"startTime":1080.96,"endTime":1082.67,"body":"You'd never learned to read or write,"},{"startTime":1082.67,"endTime":1083.69,"body":"and the only thing you had"},{"startTime":1083.69,"endTime":1085.91,"body":"to go on was a copy of"},{"startTime":1083.69,"endTime":1085.91,"body":"\"Sense and Sensibility.\""},{"startTime":1085.91,"endTime":1088.31,"body":"It'd be quite hard to work out"},{"startTime":1088.31,"endTime":1090.083,"body":"how early language evolved."},{"startTime":1091.4,"endTime":1092.48,"body":"And so I often get questions from people"},{"startTime":1092.48,"endTime":1094.167,"body":"saying things like, well you know,"},{"startTime":1094.167,"endTime":1095.33,"body":"\"If this is all true"},{"startTime":1095.33,"endTime":1097.22,"body":"and all this early life was like this,"},{"startTime":1097.22,"endTime":1099.11,"body":"then why don't we still see it"},{"startTime":1099.11,"endTime":1100.22,"body":"out there in the environment now?"},{"startTime":1100.22,"endTime":1103.61,"body":"Why can't we go and find"},{"startTime":1100.22,"endTime":1103.61,"body":"these early life forms?\""},{"startTime":1103.61,"endTime":1105.41,"body":"And you know, my answer to that is,"},{"startTime":1105.41,"endTime":1108.38,"body":"it's kind of like, you"},{"startTime":1105.41,"endTime":1108.38,"body":"know, anything in life."},{"startTime":1108.38,"endTime":1110.6,"body":"It progresses and as things progress,"},{"startTime":1110.6,"endTime":1113.146,"body":"the older less efficient versions die out."},{"startTime":1113.146,"endTime":1113.979,"body":"You know, I don't know about you,"},{"startTime":1113.979,"endTime":1114.83,"body":"but I haven't often seen people"},{"startTime":1114.83,"endTime":1117.59,"body":"walking around in a"},{"startTime":1114.83,"endTime":1117.59,"body":"loin cloth, for example,"},{"startTime":1117.59,"endTime":1119.45,"body":"because clothing has moved on,"},{"startTime":1119.45,"endTime":1121.88,"body":"and it's quite hard to find loin cloths."},{"startTime":1121.88,"endTime":1123.59,"body":"It's quite hard to find airplanes"},{"startTime":1123.59,"endTime":1126.02,"body":"that look like the Wright"},{"startTime":1123.59,"endTime":1126.02,"body":"brothers' airplane,"},{"startTime":1126.02,"endTime":1128.06,"body":"because they're no longer fit for purpose."},{"startTime":1128.06,"endTime":1129.29,"body":"And for the same reason,"},{"startTime":1129.29,"endTime":1130.94,"body":"we cannot find cells"},{"startTime":1130.94,"endTime":1132.53,"body":"that are even simpler than this,"},{"startTime":1132.53,"endTime":1134.18,"body":"because those simple cells have been"},{"startTime":1134.18,"endTime":1137.27,"body":"superseded by these more evolved ones."},{"startTime":1137.27,"endTime":1138.92,"body":"And consequently, whatever we find"},{"startTime":1138.92,"endTime":1141.02,"body":"as the simplest organisms today"},{"startTime":1141.02,"endTime":1143.57,"body":"will always be much, much more complex"},{"startTime":1143.57,"endTime":1145.673,"body":"than the early ones on the early life."},{"startTime":1148.34,"endTime":1151.31,"body":"So, hopefully I've convinced you"},{"startTime":1151.31,"endTime":1153.89,"body":"that at some point about 600 million years"},{"startTime":1153.89,"endTime":1157.31,"body":"after it formed, life arose on Earth."},{"startTime":1157.31,"endTime":1158.9,"body":"And let me take a little detour here"},{"startTime":1158.9,"endTime":1160.936,"body":"to give you a brief"},{"startTime":1158.9,"endTime":1160.936,"body":"history of life on Earth,"},{"startTime":1160.936,"endTime":1162.68,"body":"and when I say brief, I say really brief."},{"startTime":1162.68,"endTime":1165.89,"body":"So this is a time chart of the history"},{"startTime":1165.89,"endTime":1166.79,"body":"of the planet, more or less."},{"startTime":1166.79,"endTime":1168.23,"body":"It is not linear, just to point out."},{"startTime":1168.23,"endTime":1169.61,"body":"So right down here at the bottom,"},{"startTime":1169.61,"endTime":1171.44,"body":"four and a half billion years ago"},{"startTime":1171.44,"endTime":1172.85,"body":"is when we think the Earth formed."},{"startTime":1172.85,"endTime":1175.583,"body":"Right up here at the"},{"startTime":1172.85,"endTime":1175.583,"body":"top is the present day."},{"startTime":1176.72,"endTime":1178.19,"body":"Just to put it into perspective,"},{"startTime":1178.19,"endTime":1179.21,"body":"we're up here somewhere."},{"startTime":1179.21,"endTime":1181.04,"body":"I can come back to that in a moment."},{"startTime":1181.04,"endTime":1182.9,"body":"But what we've been talking about so far"},{"startTime":1182.9,"endTime":1185.54,"body":"is this period of time at"},{"startTime":1182.9,"endTime":1185.54,"body":"the start of the planet"},{"startTime":1185.54,"endTime":1189.8,"body":"when there was no sign of"},{"startTime":1185.54,"endTime":1189.8,"body":"life, about 600 million years."},{"startTime":1189.8,"endTime":1191.99,"body":"And then we're just getting into this part"},{"startTime":1191.99,"endTime":1194.42,"body":"when cellular life first cropped up,"},{"startTime":1194.42,"endTime":1195.953,"body":"what looks like a bacteria."},{"startTime":1197.3,"endTime":1199.94,"body":"This is also a very, very"},{"startTime":1197.3,"endTime":1199.94,"body":"difficult thing to grasp,"},{"startTime":1199.94,"endTime":1201.53,"body":"and so I'm going to borrow"},{"startTime":1199.94,"endTime":1201.53,"body":"another volunteer, if I may."},{"startTime":1201.53,"endTime":1203.93,"body":"Can I have a different"},{"startTime":1201.53,"endTime":1203.93,"body":"volunteer this time?"},{"startTime":1203.93,"endTime":1205.13,"body":"Everyone's seen what happened to Brandy"},{"startTime":1205.13,"endTime":1206.54,"body":"and they're like, \"No, no.\""},{"startTime":1206.54,"endTime":1208.94,"body":"Please, anyone care to volunteer?"},{"startTime":1208.94,"endTime":1211.04,"body":"I won't give you poppy seeds, I promise."},{"startTime":1211.04,"endTime":1212.33,"body":"I might have to pick"},{"startTime":1211.04,"endTime":1212.33,"body":"on someone, if no one."},{"startTime":1212.33,"endTime":1213.47,"body":"Yes, at the back. Fantastic."},{"startTime":1213.47,"endTime":1214.833,"body":"Thank you, whoever that is."},{"startTime":1214.833,"endTime":1216.113,"body":"I can only see the hand."},{"startTime":1216.979,"endTime":1217.812,"body":"- [Emily] It's Emily."},{"startTime":1217.812,"endTime":1219.5,"body":"- Oh, it's a familiar volunteer."},{"startTime":1219.5,"endTime":1220.333,"body":"Well done, Emily."},{"startTime":1220.333,"endTime":1223.25,"body":"Thank you very much. (laughs)"},{"startTime":1223.25,"endTime":1224.51,"body":"You missed the warning I gave to people"},{"startTime":1224.51,"endTime":1226.37,"body":"that if your significant other"},{"startTime":1224.51,"endTime":1226.37,"body":"doesn't know you're here,"},{"startTime":1226.37,"endTime":1227.6,"body":"this is a bad moment."},{"startTime":1227.6,"endTime":1228.44,"body":"Thank you very much."},{"startTime":1228.44,"endTime":1229.46,"body":"Right, I'm going to pass you this"},{"startTime":1229.46,"endTime":1230.54,"body":"very exciting thing, Emily."},{"startTime":1230.54,"endTime":1232.34,"body":"This is a nail file."},{"startTime":1232.34,"endTime":1234.113,"body":"You may extract the nail file."},{"startTime":1235.19,"endTime":1236.877,"body":"So, oh, I was going to say,"},{"startTime":1236.877,"endTime":1238.04,"body":"\"Whilst you do that, you"},{"startTime":1236.877,"endTime":1238.04,"body":"can hold your hand out,\""},{"startTime":1238.04,"endTime":1239.48,"body":"but it's difficult to extract a nail file"},{"startTime":1239.48,"endTime":1240.913,"body":"whilst you hold your hand out."},{"startTime":1241.94,"endTime":1242.78,"body":"Fantastic. Right, okay."},{"startTime":1242.78,"endTime":1245.3,"body":"And can you extend one arm like this?"},{"startTime":1245.3,"endTime":1246.62,"body":"Brilliant. Okay."},{"startTime":1246.62,"endTime":1248.51,"body":"So I want you to imagine."},{"startTime":1248.51,"endTime":1250.58,"body":"I hope you've got good"},{"startTime":1248.51,"endTime":1250.58,"body":"muscle strength. (laughs)"},{"startTime":1250.58,"endTime":1252.65,"body":"I want you to imagine the start of life"},{"startTime":1252.65,"endTime":1254.75,"body":"is roughly where Emily's nose is, okay?"},{"startTime":1254.75,"endTime":1256.517,"body":"It's four and a half billion years ago,"},{"startTime":1256.517,"endTime":1258.413,"body":"and we're migrating our way down the arm."},{"startTime":1258.413,"endTime":1259.85,"body":"What we've been talking about so far,"},{"startTime":1259.85,"endTime":1262.58,"body":"the first 600 million"},{"startTime":1259.85,"endTime":1262.58,"body":"years, no life at all,"},{"startTime":1262.58,"endTime":1265.39,"body":"which is about from Emily's"},{"startTime":1262.58,"endTime":1265.39,"body":"nose to her shoulder, okay?"},{"startTime":1265.39,"endTime":1266.69,"body":"So there's no life at all."},{"startTime":1268.52,"endTime":1270.47,"body":"We had early bacteria life"},{"startTime":1270.47,"endTime":1272.6,"body":"and nothing else for about"},{"startTime":1272.6,"endTime":1275.27,"body":"another 600 to a billion years,"},{"startTime":1275.27,"endTime":1277.49,"body":"right down to somewhere here on her arm."},{"startTime":1277.49,"endTime":1279.41,"body":"Okay, now I want you"},{"startTime":1277.49,"endTime":1279.41,"body":"to take your nail file,"},{"startTime":1279.41,"endTime":1280.64,"body":"Emily, and out here, humans were."},{"startTime":1280.64,"endTime":1283.61,"body":"Take your nail file and"},{"startTime":1280.64,"endTime":1283.61,"body":"file one nail on this side."},{"startTime":1283.61,"endTime":1284.71,"body":"I won't do it for you."},{"startTime":1285.56,"endTime":1286.7,"body":"Yep, that's fine. Perfect."},{"startTime":1286.7,"endTime":1288.5,"body":"No, don't overdo it. (laughs)"},{"startTime":1288.5,"endTime":1290.33,"body":"Okay, send your arm again."},{"startTime":1290.33,"endTime":1291.163,"body":"Thank you very much."},{"startTime":1291.163,"endTime":1293.9,"body":"Emily has just removed all modern humans."},{"startTime":1293.9,"endTime":1295.31,"body":"Okay, we've gone."},{"startTime":1295.31,"endTime":1296.99,"body":"That is the brief period of time"},{"startTime":1296.99,"endTime":1297.823,"body":"that we have existed."},{"startTime":1297.823,"endTime":1298.86,"body":"If you can do it one more time."},{"startTime":1298.86,"endTime":1300.59,"body":"Don't over do it."},{"startTime":1300.59,"endTime":1301.423,"body":"Perfect, that's fine."},{"startTime":1301.423,"endTime":1302.256,"body":"Yeah, thank you very much."},{"startTime":1302.256,"endTime":1304.37,"body":"And now, we've removed everything"},{"startTime":1304.37,"endTime":1306.05,"body":"back to when we split from chimpanzees."},{"startTime":1306.05,"endTime":1307.85,"body":"They've gone too, okay."},{"startTime":1307.85,"endTime":1310.01,"body":"That is the tiny fraction of time"},{"startTime":1310.01,"endTime":1313.01,"body":"in which anything resembling, you know,"},{"startTime":1313.01,"endTime":1315.35,"body":"really advanced life forms"},{"startTime":1313.01,"endTime":1315.35,"body":"has been on the planet,"},{"startTime":1315.35,"endTime":1318.59,"body":"whereas bacteria have occupied"},{"startTime":1315.35,"endTime":1318.59,"body":"all of this chunk here."},{"startTime":1318.59,"endTime":1319.76,"body":"That's great, thank you very much, Emily."},{"startTime":1319.76,"endTime":1321.41,"body":"You can take the nail file as a souvenir."},{"startTime":1321.41,"endTime":1322.282,"body":"Bravo."},{"startTime":1322.282,"endTime":1325.449,"body":"(audience applauding)"},{"startTime":1326.57,"endTime":1328.67,"body":"So we've had this vastness of time"},{"startTime":1328.67,"endTime":1330.473,"body":"in which we're this tiny, tiny blip."},{"startTime":1331.82,"endTime":1334.07,"body":"But in that vastness of"},{"startTime":1331.82,"endTime":1334.07,"body":"time, some really major"},{"startTime":1334.07,"endTime":1335.585,"body":"and exciting events have happened,"},{"startTime":1335.585,"endTime":1336.47,"body":"and one of the ones I want to draw"},{"startTime":1336.47,"endTime":1338.21,"body":"your attention to is back here."},{"startTime":1338.21,"endTime":1341.48,"body":"For about 600 million years or so,"},{"startTime":1341.48,"endTime":1343.61,"body":"bacteria kind of rocked around."},{"startTime":1343.61,"endTime":1345.95,"body":"They were using primarily chemicals"},{"startTime":1345.95,"endTime":1348.32,"body":"in the early Earth to"},{"startTime":1345.95,"endTime":1348.32,"body":"replicate themselves,"},{"startTime":1348.32,"endTime":1351.323,"body":"to gain their energy,"},{"startTime":1348.32,"endTime":1351.323,"body":"to build new structures."},{"startTime":1352.34,"endTime":1357.34,"body":"But then at roundabout sort"},{"startTime":1352.34,"endTime":1357.34,"body":"of 3.4 ish billion years,"},{"startTime":1357.89,"endTime":1360.23,"body":"we think, one of these bacteria"},{"startTime":1360.23,"endTime":1362.72,"body":"evolved a mechanism to harness energy,"},{"startTime":1362.72,"endTime":1365.18,"body":"not from chemicals but from sunshine,"},{"startTime":1365.18,"endTime":1366.353,"body":"from light, okay?"},{"startTime":1366.353,"endTime":1368.803,"body":"This is early photosynthesis."},{"startTime":1369.717,"endTime":1371.88,"body":"The first photosynthesis that happened"},{"startTime":1371.88,"endTime":1373.523,"body":"was a very different"},{"startTime":1371.88,"endTime":1373.523,"body":"sort of photosynthesis"},{"startTime":1373.523,"endTime":1376.04,"body":"than the one we think"},{"startTime":1373.523,"endTime":1376.04,"body":"about today in plants."},{"startTime":1376.04,"endTime":1379.76,"body":"This was using sunlight but"},{"startTime":1376.04,"endTime":1379.76,"body":"not using carbon dioxide,"},{"startTime":1379.76,"endTime":1382.49,"body":"not building sugars in the"},{"startTime":1379.76,"endTime":1382.49,"body":"way that we think of today,"},{"startTime":1382.49,"endTime":1384.26,"body":"but rather using chemicals"},{"startTime":1384.26,"endTime":1385.88,"body":"that were abundant in the early Earth."},{"startTime":1385.88,"endTime":1388.28,"body":"Things like hydrogen sulfide, for example,"},{"startTime":1388.28,"endTime":1389.482,"body":"which if you happen to know,"},{"startTime":1389.482,"endTime":1391.13,"body":"that's the very unpleasant eggy smell"},{"startTime":1391.13,"endTime":1392.81,"body":"you get from a rotten egg"},{"startTime":1392.81,"endTime":1394.88,"body":"or lots of other unpleasant processes"},{"startTime":1394.88,"endTime":1397.25,"body":"that we will not talk about tonight."},{"startTime":1397.25,"endTime":1400.07,"body":"You can use that molecule,"},{"startTime":1397.25,"endTime":1400.07,"body":"that smelly molecule"},{"startTime":1400.07,"endTime":1402.533,"body":"in a sort of photosynthesis"},{"startTime":1400.07,"endTime":1402.533,"body":"to create energy."},{"startTime":1403.88,"endTime":1404.797,"body":"This went on for a little while,"},{"startTime":1404.797,"endTime":1406.25,"body":"couple of hundred million years,"},{"startTime":1406.25,"endTime":1408.44,"body":"and then in the next step,"},{"startTime":1408.44,"endTime":1409.85,"body":"a microbe evolved a mechanism"},{"startTime":1409.85,"endTime":1413.3,"body":"to take that same energy and"},{"startTime":1409.85,"endTime":1413.3,"body":"use not hydrogen sulfide,"},{"startTime":1413.3,"endTime":1416.303,"body":"but to use carbon dioxide"},{"startTime":1413.3,"endTime":1416.303,"body":"in the atmosphere."},{"startTime":1417.47,"endTime":1419.81,"body":"This fundamental step"},{"startTime":1417.47,"endTime":1419.81,"body":"was quite remarkable."},{"startTime":1419.81,"endTime":1421.52,"body":"So here, this is a modern"},{"startTime":1419.81,"endTime":1421.52,"body":"picture, obviously."},{"startTime":1421.52,"endTime":1422.353,"body":"I haven't got a camera"},{"startTime":1422.353,"endTime":1424.85,"body":"from three and a half billion years ago."},{"startTime":1424.85,"endTime":1427.4,"body":"But these are modern day examples"},{"startTime":1427.4,"endTime":1429.8,"body":"of that first sort of"},{"startTime":1427.4,"endTime":1429.8,"body":"photosynthetic microbe."},{"startTime":1429.8,"endTime":1432.29,"body":"These are things like"},{"startTime":1429.8,"endTime":1432.29,"body":"green sulfur bacteria"},{"startTime":1432.29,"endTime":1435.17,"body":"living here in Yellowstone"},{"startTime":1432.29,"endTime":1435.17,"body":"Park in the US, okay."},{"startTime":1435.17,"endTime":1437.36,"body":"They are using sunlight"},{"startTime":1437.36,"endTime":1439.46,"body":"to essentially eat hydrogen sulfide"},{"startTime":1439.46,"endTime":1442.793,"body":"and other, to us, noxious"},{"startTime":1439.46,"endTime":1442.793,"body":"chemicals in the hot springs."},{"startTime":1443.84,"endTime":1446.3,"body":"But in the pool, there"},{"startTime":1443.84,"endTime":1446.3,"body":"are also more modern"},{"startTime":1446.3,"endTime":1447.65,"body":"photosynthetic organisms"},{"startTime":1447.65,"endTime":1449.69,"body":"that are using that sunlight to harness"},{"startTime":1449.69,"endTime":1450.95,"body":"carbon dioxide in the atmosphere,"},{"startTime":1450.95,"endTime":1453.083,"body":"like a plant does to create sugar."},{"startTime":1454.13,"endTime":1455.81,"body":"And this remarkable discovery"},{"startTime":1455.81,"endTime":1459.29,"body":"laid a pathway to a completely different"},{"startTime":1459.29,"endTime":1461.3,"body":"sort of evolution on the planet."},{"startTime":1461.3,"endTime":1463.64,"body":"And we can see that by"},{"startTime":1461.3,"endTime":1463.64,"body":"using chemical means"},{"startTime":1463.64,"endTime":1466.79,"body":"to look at the abundance of"},{"startTime":1463.64,"endTime":1466.79,"body":"oxygen in the atmosphere."},{"startTime":1466.79,"endTime":1470.6,"body":"Because when an organism"},{"startTime":1466.79,"endTime":1470.6,"body":"that is photosynthetic"},{"startTime":1470.6,"endTime":1474.29,"body":"takes carbon dioxide and uses"},{"startTime":1470.6,"endTime":1474.29,"body":"sunlight to build sugars,"},{"startTime":1474.29,"endTime":1476.18,"body":"it releases a waste product,"},{"startTime":1476.18,"endTime":1478.073,"body":"and that waste product is oxygen."},{"startTime":1479.18,"endTime":1481.58,"body":"Up until this point in"},{"startTime":1479.18,"endTime":1481.58,"body":"the history of life,"},{"startTime":1481.58,"endTime":1484.19,"body":"oxygen was almost non-existent, okay?"},{"startTime":1484.19,"endTime":1486.833,"body":"The atmosphere had"},{"startTime":1484.19,"endTime":1486.833,"body":"essentially no oxygen in it."},{"startTime":1488.0,"endTime":1490.61,"body":"And what happened early"},{"startTime":1488.0,"endTime":1490.61,"body":"on, around here somewhere,"},{"startTime":1490.61,"endTime":1492.23,"body":"so this is about threeish"},{"startTime":1490.61,"endTime":1492.23,"body":"billion years ago,"},{"startTime":1492.23,"endTime":1494.75,"body":"is photosynthesis occurred."},{"startTime":1494.75,"endTime":1496.28,"body":"It started to produce oxygen,"},{"startTime":1496.28,"endTime":1498.92,"body":"but you did not get oxygen"},{"startTime":1496.28,"endTime":1498.92,"body":"into the atmosphere,"},{"startTime":1498.92,"endTime":1500.42,"body":"because at this point,"},{"startTime":1500.42,"endTime":1503.6,"body":"the Earth had a large"},{"startTime":1500.42,"endTime":1503.6,"body":"amount of iron around"},{"startTime":1503.6,"endTime":1504.74,"body":"that was not oxidized."},{"startTime":1504.74,"endTime":1506.0,"body":"It was free iron."},{"startTime":1506.0,"endTime":1506.99,"body":"And as most of us will know,"},{"startTime":1506.99,"endTime":1510.35,"body":"if you leave iron out in an"},{"startTime":1506.99,"endTime":1510.35,"body":"oxygen environment, it rusts."},{"startTime":1510.35,"endTime":1512.993,"body":"It becomes yellow and orange."},{"startTime":1514.28,"endTime":1515.21,"body":"So what happened initially"},{"startTime":1515.21,"endTime":1517.16,"body":"was these early photosynthetic organisms"},{"startTime":1517.16,"endTime":1519.23,"body":"started pouring out oxygen"},{"startTime":1517.16,"endTime":1519.23,"body":"and it didn't matter."},{"startTime":1519.23,"endTime":1522.35,"body":"The oxygen got eaten up"},{"startTime":1519.23,"endTime":1522.35,"body":"by all that available iron"},{"startTime":1522.35,"endTime":1524.6,"body":"and nothing changed in the atmosphere."},{"startTime":1524.6,"endTime":1527.27,"body":"But at a certain point,"},{"startTime":1524.6,"endTime":1527.27,"body":"they ran out of iron,"},{"startTime":1527.27,"endTime":1531.44,"body":"and now free oxygen began to"},{"startTime":1527.27,"endTime":1531.44,"body":"accumulate in the atmosphere."},{"startTime":1531.44,"endTime":1533.06,"body":"And we're talking about a time here"},{"startTime":1533.06,"endTime":1535.88,"body":"around 2 billion years ago, okay?"},{"startTime":1535.88,"endTime":1536.96,"body":"If you look at this graph,"},{"startTime":1536.96,"endTime":1539.21,"body":"you can see this is the level"},{"startTime":1536.96,"endTime":1539.21,"body":"of oxygen in the atmosphere,"},{"startTime":1539.21,"endTime":1540.53,"body":"and this is modern day up here."},{"startTime":1540.53,"endTime":1544.04,"body":"We're up at about 20%"},{"startTime":1540.53,"endTime":1544.04,"body":"oxygen in the atmosphere."},{"startTime":1544.04,"endTime":1546.68,"body":"Here, 2 billion years ago,"},{"startTime":1546.68,"endTime":1548.98,"body":"we're at less than 2%"},{"startTime":1546.68,"endTime":1548.98,"body":"oxygen in the atmosphere,"},{"startTime":1548.98,"endTime":1551.66,"body":"so only a 10th of what we have today."},{"startTime":1551.66,"endTime":1554.51,"body":"But nonetheless, this change was enough"},{"startTime":1554.51,"endTime":1556.97,"body":"to cause catastrophic mass extinction,"},{"startTime":1556.97,"endTime":1560.0,"body":"probably the first major mass extinction"},{"startTime":1560.0,"endTime":1561.047,"body":"on the planet, okay."},{"startTime":1561.047,"endTime":1563.78,"body":"And I think there's a kind"},{"startTime":1561.047,"endTime":1563.78,"body":"of slightly bitter irony"},{"startTime":1563.78,"endTime":1566.48,"body":"about the fact that back"},{"startTime":1563.78,"endTime":1566.48,"body":"here 2 billion years ago,"},{"startTime":1566.48,"endTime":1568.85,"body":"microbes started putting"},{"startTime":1566.48,"endTime":1568.85,"body":"a gas into the atmosphere"},{"startTime":1568.85,"endTime":1571.85,"body":"and wiped out most other"},{"startTime":1568.85,"endTime":1571.85,"body":"life forms on the planet."},{"startTime":1571.85,"endTime":1573.2,"body":"And now here in the modern day,"},{"startTime":1573.2,"endTime":1574.88,"body":"we are also putting a"},{"startTime":1573.2,"endTime":1574.88,"body":"gas into the atmosphere"},{"startTime":1574.88,"endTime":1576.35,"body":"and doing a pretty good job of wiping out"},{"startTime":1576.35,"endTime":1578.45,"body":"other organisms at the same time."},{"startTime":1578.45,"endTime":1580.723,"body":"So there's a kind of"},{"startTime":1578.45,"endTime":1580.723,"body":"interesting parallel there."},{"startTime":1582.02,"endTime":1586.43,"body":"This early photosynthesis"},{"startTime":1582.02,"endTime":1586.43,"body":"eliminated millions,"},{"startTime":1586.43,"endTime":1588.71,"body":"billions probably, of early species."},{"startTime":1588.71,"endTime":1592.34,"body":"However, it also provided an atmosphere"},{"startTime":1592.34,"endTime":1593.69,"body":"that allowed the evolution"},{"startTime":1593.69,"endTime":1595.64,"body":"of a whole range of new species,"},{"startTime":1595.64,"endTime":1597.11,"body":"and in many ways laid the ground"},{"startTime":1597.11,"endTime":1598.67,"body":"for essentially everything we see today."},{"startTime":1598.67,"endTime":1603.02,"body":"Most organisms we study today"},{"startTime":1598.67,"endTime":1603.02,"body":"rely on oxygen for life."},{"startTime":1603.02,"endTime":1605.723,"body":"And so this changed the"},{"startTime":1603.02,"endTime":1605.723,"body":"course of evolution."},{"startTime":1608.45,"endTime":1609.95,"body":"So, so far in our journey"},{"startTime":1609.95,"endTime":1611.51,"body":"through the history of life on Earth,"},{"startTime":1611.51,"endTime":1613.55,"body":"we've had the evolution of first cells,"},{"startTime":1613.55,"endTime":1616.34,"body":"we've had the evolution of photosynthesis,"},{"startTime":1616.34,"endTime":1618.92,"body":"and now a really radical event happens."},{"startTime":1618.92,"endTime":1622.55,"body":"We had a major shift in"},{"startTime":1618.92,"endTime":1622.55,"body":"the complexity of microbes,"},{"startTime":1622.55,"endTime":1624.8,"body":"okay, from, and wait for it now."},{"startTime":1624.8,"endTime":1626.06,"body":"It's going to be a really big difference."},{"startTime":1626.06,"endTime":1628.88,"body":"From very simple organisms"},{"startTime":1626.06,"endTime":1628.88,"body":"that look like this,"},{"startTime":1628.88,"endTime":1631.37,"body":"to really incredibly advanced organisms"},{"startTime":1631.37,"endTime":1633.26,"body":"that look like this, which"},{"startTime":1631.37,"endTime":1633.26,"body":"I think you all agree"},{"startTime":1633.26,"endTime":1636.41,"body":"look completely different, obviously."},{"startTime":1636.41,"endTime":1637.88,"body":"And you would immediately recognize"},{"startTime":1637.88,"endTime":1640.193,"body":"to be vastly more complicated than these."},{"startTime":1641.99,"endTime":1644.42,"body":"These apparently similar organisms"},{"startTime":1644.42,"endTime":1647.39,"body":"are the next major leap"},{"startTime":1644.42,"endTime":1647.39,"body":"in cellular complexity,"},{"startTime":1647.39,"endTime":1648.41,"body":"because these things on the right,"},{"startTime":1648.41,"endTime":1651.14,"body":"this is Saccharomyces"},{"startTime":1648.41,"endTime":1651.14,"body":"cerevisiae, the baker's yeast,"},{"startTime":1651.14,"endTime":1652.37,"body":"the one that you put in your bread,"},{"startTime":1652.37,"endTime":1654.71,"body":"or your beer, if you brew beer."},{"startTime":1654.71,"endTime":1656.24,"body":"This is a classical bacteria."},{"startTime":1656.24,"endTime":1657.44,"body":"This is actually Staph aureus,"},{"startTime":1657.44,"endTime":1660.173,"body":"the thing that causes"},{"startTime":1657.44,"endTime":1660.173,"body":"MRSA or wound infections."},{"startTime":1661.1,"endTime":1662.06,"body":"They're a little bit different in scale."},{"startTime":1662.06,"endTime":1662.893,"body":"They look very similar,"},{"startTime":1662.893,"endTime":1665.36,"body":"but inside, they are radically different,"},{"startTime":1665.36,"endTime":1670.36,"body":"because this thing here has"},{"startTime":1665.36,"endTime":1670.36,"body":"complicated internal structures."},{"startTime":1671.09,"endTime":1673.67,"body":"Almost all bacteria have very little"},{"startTime":1673.67,"endTime":1674.9,"body":"in the way of internal structures."},{"startTime":1674.9,"endTime":1675.733,"body":"They're a ball."},{"startTime":1675.733,"endTime":1677.297,"body":"They have some DNA to control their genes"},{"startTime":1677.297,"endTime":1679.88,"body":"and they have lots of cellular machinery,"},{"startTime":1679.88,"endTime":1682.88,"body":"but they have no compartments within them."},{"startTime":1682.88,"endTime":1686.12,"body":"Whereas all eukaryotic"},{"startTime":1682.88,"endTime":1686.12,"body":"cells are subdivided"},{"startTime":1686.12,"endTime":1688.43,"body":"inside them into different"},{"startTime":1686.12,"endTime":1688.43,"body":"compartments, okay."},{"startTime":1688.43,"endTime":1689.45,"body":"They have things that look like this."},{"startTime":1689.45,"endTime":1690.53,"body":"Doesn't matter what they are."},{"startTime":1690.53,"endTime":1691.363,"body":"Compartments."},{"startTime":1691.363,"endTime":1692.45,"body":"The most obvious compartment"},{"startTime":1692.45,"endTime":1694.46,"body":"of which is one called the nucleus,"},{"startTime":1694.46,"endTime":1697.04,"body":"within which we store all"},{"startTime":1694.46,"endTime":1697.04,"body":"of our genetic material."},{"startTime":1697.04,"endTime":1699.53,"body":"So if you look at any"},{"startTime":1697.04,"endTime":1699.53,"body":"human cell, for example,"},{"startTime":1699.53,"endTime":1701.96,"body":"you will see inside it"},{"startTime":1699.53,"endTime":1701.96,"body":"a little compartment"},{"startTime":1701.96,"endTime":1703.61,"body":"in which you would find your DNA."},{"startTime":1703.61,"endTime":1706.22,"body":"It separates your genetic components"},{"startTime":1706.22,"endTime":1707.747,"body":"from other parts of the cell."},{"startTime":1707.747,"endTime":1710.51,"body":"And this was a major leap"},{"startTime":1707.747,"endTime":1710.51,"body":"forward in evolution,"},{"startTime":1710.51,"endTime":1711.74,"body":"because it allows all sorts"},{"startTime":1711.74,"endTime":1713.9,"body":"of interesting biology"},{"startTime":1711.74,"endTime":1713.9,"body":"that is not possible"},{"startTime":1713.9,"endTime":1715.883,"body":"if you don't partition up your cell."},{"startTime":1717.83,"endTime":1718.94,"body":"This step, as far as we know,"},{"startTime":1718.94,"endTime":1721.07,"body":"happened about 2 billion years ago, okay."},{"startTime":1721.07,"endTime":1723.53,"body":"So about halfway through our journey,"},{"startTime":1723.53,"endTime":1725.873,"body":"if you like, from early"},{"startTime":1723.53,"endTime":1725.873,"body":"Earth to modern day."},{"startTime":1727.07,"endTime":1728.84,"body":"And one of the most amazing, I think,"},{"startTime":1728.84,"endTime":1732.26,"body":"discoveries of my life"},{"startTime":1728.84,"endTime":1732.26,"body":"has been the process"},{"startTime":1732.26,"endTime":1733.25,"body":"by which this happened,"},{"startTime":1733.25,"endTime":1735.65,"body":"because it's truly remarkable"},{"startTime":1735.65,"endTime":1738.5,"body":"to understand where these"},{"startTime":1735.65,"endTime":1738.5,"body":"eukaryotes came from."},{"startTime":1738.5,"endTime":1740.333,"body":"And we think, in fact we"},{"startTime":1738.5,"endTime":1740.333,"body":"are fairly confident now,"},{"startTime":1740.333,"endTime":1744.11,"body":"that they came from a very unusual process"},{"startTime":1744.11,"endTime":1745.673,"body":"called endosymbiosis."},{"startTime":1746.72,"endTime":1748.28,"body":"So if you think 2 billion years ago,"},{"startTime":1748.28,"endTime":1749.617,"body":"there were all these different bacteria"},{"startTime":1749.617,"endTime":1751.394,"body":"out in the environment, and in fact,"},{"startTime":1751.394,"endTime":1754.19,"body":"there were two major types"},{"startTime":1751.394,"endTime":1754.19,"body":"of microbe at that time,"},{"startTime":1754.19,"endTime":1756.68,"body":"one called bacteria"},{"startTime":1754.19,"endTime":1756.68,"body":"and one called archaea."},{"startTime":1756.68,"endTime":1757.58,"body":"And to most people,"},{"startTime":1757.58,"endTime":1759.32,"body":"these things look absolutely identical."},{"startTime":1759.32,"endTime":1760.85,"body":"They're actually quite unrelated,"},{"startTime":1760.85,"endTime":1762.02,"body":"but they look very, very similar."},{"startTime":1762.02,"endTime":1764.39,"body":"You need a microscope to see both of them."},{"startTime":1764.39,"endTime":1766.76,"body":"Today, we can still"},{"startTime":1764.39,"endTime":1766.76,"body":"find this other lineage,"},{"startTime":1766.76,"endTime":1768.41,"body":"these archaea, but typically,"},{"startTime":1768.41,"endTime":1770.51,"body":"we find them in extreme environments."},{"startTime":1770.51,"endTime":1773.3,"body":"Places like hot springs under the ocean"},{"startTime":1773.3,"endTime":1775.883,"body":"or deep inside rock faces."},{"startTime":1777.17,"endTime":1780.56,"body":"Both of these early lineages of bacteria"},{"startTime":1780.56,"endTime":1782.51,"body":"likely survived on a mixture"},{"startTime":1782.51,"endTime":1785.06,"body":"of gaining chemicals from the environment"},{"startTime":1785.06,"endTime":1787.25,"body":"and eating each other, okay."},{"startTime":1787.25,"endTime":1788.33,"body":"This is not one of those bacteria,"},{"startTime":1788.33,"endTime":1789.88,"body":"but this is the kind of typical example"},{"startTime":1789.88,"endTime":1791.75,"body":"of microbes eating each other."},{"startTime":1791.75,"endTime":1794.75,"body":"You can see actually this is an ameba here"},{"startTime":1794.75,"endTime":1796.1,"body":"that's doing a very bad job of trying"},{"startTime":1796.1,"endTime":1798.53,"body":"to eat these little yeast"},{"startTime":1796.1,"endTime":1798.53,"body":"that we're feeding it here."},{"startTime":1798.53,"endTime":1800.69,"body":"Lots and lots of microbes today"},{"startTime":1800.69,"endTime":1802.82,"body":"live by eating other microbes."},{"startTime":1802.82,"endTime":1804.11,"body":"And indeed, it's very likely"},{"startTime":1804.11,"endTime":1806.66,"body":"they have done that ever"},{"startTime":1804.11,"endTime":1806.66,"body":"since the origins of life."},{"startTime":1808.16,"endTime":1809.3,"body":"And what we now believe is that"},{"startTime":1809.3,"endTime":1810.92,"body":"about 2 billion years ago,"},{"startTime":1810.92,"endTime":1813.29,"body":"one of these eating"},{"startTime":1810.92,"endTime":1813.29,"body":"events went badly wrong"},{"startTime":1813.29,"endTime":1815.84,"body":"or badly right, depending"},{"startTime":1813.29,"endTime":1815.84,"body":"on your perspective,"},{"startTime":1815.84,"endTime":1818.84,"body":"in that an early one of these cells,"},{"startTime":1818.84,"endTime":1822.08,"body":"these archaeal cells progressed to eat"},{"startTime":1822.08,"endTime":1823.067,"body":"one of these bacterial cells,"},{"startTime":1823.067,"endTime":1824.6,"body":"the little red one here,"},{"startTime":1824.6,"endTime":1826.16,"body":"and failed to kill it."},{"startTime":1826.16,"endTime":1827.87,"body":"And instead of having dinner,"},{"startTime":1827.87,"endTime":1830.66,"body":"these two set up a sort of"},{"startTime":1827.87,"endTime":1830.66,"body":"slightly unholy alliance,"},{"startTime":1830.66,"endTime":1832.22,"body":"a so-called endosymbiosis."},{"startTime":1832.22,"endTime":1834.53,"body":"The bacteria continued to live"},{"startTime":1834.53,"endTime":1836.3,"body":"within that archaeal cell,"},{"startTime":1836.3,"endTime":1837.92,"body":"and they formed a symbiotic,"},{"startTime":1837.92,"endTime":1840.143,"body":"so a mutually beneficial relationship."},{"startTime":1841.04,"endTime":1842.06,"body":"And this seems quite remarkable."},{"startTime":1842.06,"endTime":1843.38,"body":"It's even more remarkable"},{"startTime":1843.38,"endTime":1845.3,"body":"when you realize that this"},{"startTime":1843.38,"endTime":1845.3,"body":"has happened not just once,"},{"startTime":1845.3,"endTime":1848.09,"body":"but actually several times"},{"startTime":1845.3,"endTime":1848.09,"body":"in the history of life."},{"startTime":1848.09,"endTime":1849.23,"body":"Because subsequently,"},{"startTime":1849.23,"endTime":1852.65,"body":"probably many hundreds of"},{"startTime":1849.23,"endTime":1852.65,"body":"millions of years later,"},{"startTime":1852.65,"endTime":1853.85,"body":"this process happened again"},{"startTime":1853.85,"endTime":1858.14,"body":"when this dual partnership"},{"startTime":1853.85,"endTime":1858.14,"body":"ate a third bacteria,"},{"startTime":1858.14,"endTime":1859.97,"body":"a photosynthetic one in this case,"},{"startTime":1859.97,"endTime":1862.1,"body":"and created the lineage"},{"startTime":1859.97,"endTime":1862.1,"body":"that would eventually"},{"startTime":1862.1,"endTime":1864.263,"body":"lead to all plants, okay."},{"startTime":1865.73,"endTime":1868.1,"body":"These endosymbioses events"},{"startTime":1868.1,"endTime":1869.96,"body":"in which one organism starts to live"},{"startTime":1869.96,"endTime":1871.16,"body":"inside another organism,"},{"startTime":1871.16,"endTime":1873.92,"body":"and then very, very slowly over millions,"},{"startTime":1873.92,"endTime":1875.57,"body":"hundreds of millions of years"},{"startTime":1875.57,"endTime":1877.97,"body":"becomes unable to live independently,"},{"startTime":1877.97,"endTime":1880.34,"body":"appear to be incredibly unlikely, right?"},{"startTime":1880.34,"endTime":1883.64,"body":"It seems just vastly unlikely"},{"startTime":1880.34,"endTime":1883.64,"body":"this would ever happen."},{"startTime":1883.64,"endTime":1885.56,"body":"But actually, they're"},{"startTime":1883.64,"endTime":1885.56,"body":"nowhere near as unlikely"},{"startTime":1885.56,"endTime":1886.61,"body":"as you might expect."},{"startTime":1886.61,"endTime":1889.43,"body":"And if we look today around"},{"startTime":1886.61,"endTime":1889.43,"body":"the world of microbes,"},{"startTime":1889.43,"endTime":1892.28,"body":"there are many, many"},{"startTime":1889.43,"endTime":1892.28,"body":"examples where this happens."},{"startTime":1892.28,"endTime":1893.6,"body":"So for anyone, for example,"},{"startTime":1893.6,"endTime":1895.28,"body":"who's been to the Great Barrier Reef,"},{"startTime":1895.28,"endTime":1896.99,"body":"or indeed any coral reef,"},{"startTime":1896.99,"endTime":1900.11,"body":"you have been looking at"},{"startTime":1896.99,"endTime":1900.11,"body":"a great example of that,"},{"startTime":1900.11,"endTime":1902.96,"body":"because coral organisms, many of them,"},{"startTime":1902.96,"endTime":1905.54,"body":"live with obligate endosymbionts."},{"startTime":1905.54,"endTime":1906.373,"body":"So here's one here."},{"startTime":1906.373,"endTime":1907.88,"body":"This is one called Aiptasia,"},{"startTime":1907.88,"endTime":1909.47,"body":"and inside this coral,"},{"startTime":1909.47,"endTime":1912.44,"body":"you can see this little"},{"startTime":1909.47,"endTime":1912.44,"body":"tiny red blob here,"},{"startTime":1912.44,"endTime":1915.2,"body":"which is an endosymbiotic bacteria."},{"startTime":1915.2,"endTime":1916.34,"body":"And what you can see if I play this movie"},{"startTime":1916.34,"endTime":1917.687,"body":"is this little little"},{"startTime":1916.34,"endTime":1917.687,"body":"chap is rummaging around,"},{"startTime":1917.687,"endTime":1919.85,"body":"and that bacteria is staying firmly"},{"startTime":1919.85,"endTime":1922.88,"body":"ensconced within the coral microbe."},{"startTime":1922.88,"endTime":1924.38,"body":"And in fact, this is absolutely essential."},{"startTime":1924.38,"endTime":1928.043,"body":"This coral relies on"},{"startTime":1924.38,"endTime":1928.043,"body":"the metabolic processes"},{"startTime":1928.043,"endTime":1930.44,"body":"that that bacteria does"},{"startTime":1928.043,"endTime":1930.44,"body":"in order to survive."},{"startTime":1930.44,"endTime":1932.09,"body":"And actually, this is a"},{"startTime":1930.44,"endTime":1932.09,"body":"rather wonderful example,"},{"startTime":1932.09,"endTime":1934.13,"body":"I think, because it turns out that"},{"startTime":1934.13,"endTime":1936.05,"body":"it will sometimes throw this bacteria out"},{"startTime":1936.05,"endTime":1937.64,"body":"and then take in a new one,"},{"startTime":1937.64,"endTime":1938.57,"body":"and if it doesn't like the new one,"},{"startTime":1938.57,"endTime":1939.403,"body":"it'll throw it out again."},{"startTime":1939.403,"endTime":1941.24,"body":"And it can tell whether the bacteria's"},{"startTime":1941.24,"endTime":1943.04,"body":"going to kind of pull its weight or not."},{"startTime":1943.04,"endTime":1944.51,"body":"And if the bacteria starts to cheat,"},{"startTime":1944.51,"endTime":1945.77,"body":"it gets booted back out again,"},{"startTime":1945.77,"endTime":1947.48,"body":"which I think is very, very clever."},{"startTime":1947.48,"endTime":1950.48,"body":"This is the process by"},{"startTime":1947.48,"endTime":1950.48,"body":"which most corals survive"},{"startTime":1950.48,"endTime":1952.91,"body":"and produce coral reefs."},{"startTime":1952.91,"endTime":1955.07,"body":"Even cuter, I think, is a story"},{"startTime":1955.07,"endTime":1957.74,"body":"from one of my colleagues in Birmingham"},{"startTime":1957.74,"endTime":1960.26,"body":"who has been working on a fungal pathogen,"},{"startTime":1960.26,"endTime":1962.6,"body":"so a fungus that kills people, actually."},{"startTime":1962.6,"endTime":1964.58,"body":"This is one called Rhizopus."},{"startTime":1964.58,"endTime":1966.839,"body":"It causes a disease called mucormycosis,"},{"startTime":1966.839,"endTime":1968.84,"body":"which is a very, very"},{"startTime":1966.839,"endTime":1968.84,"body":"unpleasant, fortunately rare,"},{"startTime":1968.84,"endTime":1971.84,"body":"but extremely unpleasant"},{"startTime":1968.84,"endTime":1971.84,"body":"tissue destroying disease,"},{"startTime":1971.84,"endTime":1973.013,"body":"which kills people."},{"startTime":1973.97,"endTime":1976.4,"body":"This fungus, when it can"},{"startTime":1973.97,"endTime":1976.4,"body":"get into your wounds,"},{"startTime":1976.4,"endTime":1978.08,"body":"will germinate and it will grow like this,"},{"startTime":1978.08,"endTime":1979.67,"body":"and it will eat your tissues,"},{"startTime":1979.67,"endTime":1982.04,"body":"essentially, and lead to death."},{"startTime":1982.04,"endTime":1982.873,"body":"And one of the reasons that"},{"startTime":1982.873,"endTime":1984.89,"body":"it's very difficult to treat is that"},{"startTime":1984.89,"endTime":1986.69,"body":"this fungus has an amazing ability"},{"startTime":1986.69,"endTime":1988.55,"body":"to avoid the human immune system."},{"startTime":1988.55,"endTime":1990.35,"body":"So whilst it's happily munching"},{"startTime":1990.35,"endTime":1992.09,"body":"its way through your arm or your leg,"},{"startTime":1992.09,"endTime":1994.19,"body":"your immune system is"},{"startTime":1992.09,"endTime":1994.19,"body":"happily neglecting it,"},{"startTime":1994.19,"endTime":1995.24,"body":"which is not helpful."},{"startTime":1996.29,"endTime":1997.67,"body":"And for many years we've been trying"},{"startTime":1997.67,"endTime":1999.11,"body":"to understand, how can this be?"},{"startTime":1999.11,"endTime":2001.45,"body":"How can this incredibly damaging fungus"},{"startTime":2001.45,"endTime":2003.82,"body":"not to trigger an immune response?"},{"startTime":2003.82,"endTime":2005.08,"body":"And it turns out it does that"},{"startTime":2005.08,"endTime":2007.3,"body":"because it has a passenger"},{"startTime":2005.08,"endTime":2007.3,"body":"that is helping it out."},{"startTime":2007.3,"endTime":2009.79,"body":"If you look deep inside these fungi,"},{"startTime":2009.79,"endTime":2012.16,"body":"you see that inside each fungus cell"},{"startTime":2012.16,"endTime":2016.513,"body":"in blue here are tiny, tiny"},{"startTime":2012.16,"endTime":2016.513,"body":"bacteria, endosymbionts."},{"startTime":2017.35,"endTime":2019.63,"body":"These bacteria produce a toxin"},{"startTime":2019.63,"endTime":2022.57,"body":"which deters the human immune system,"},{"startTime":2022.57,"endTime":2023.56,"body":"and in doing so, of course,"},{"startTime":2023.56,"endTime":2025.15,"body":"they protect their fungal host"},{"startTime":2025.15,"endTime":2026.617,"body":"and therefore they protect themselves."},{"startTime":2026.617,"endTime":2028.93,"body":"And so this symbiosis is one, I think,"},{"startTime":2028.93,"endTime":2031.0,"body":"which offers really important"},{"startTime":2031.0,"endTime":2032.32,"body":"potential benefits clinically,"},{"startTime":2032.32,"endTime":2034.69,"body":"if we can understand it,"},{"startTime":2032.32,"endTime":2034.69,"body":"in terms of treatment."},{"startTime":2034.69,"endTime":2036.869,"body":"But again, a really"},{"startTime":2034.69,"endTime":2036.869,"body":"elaborate endosymbiosis"},{"startTime":2036.869,"endTime":2039.37,"body":"that has arisen probably"},{"startTime":2036.869,"endTime":2039.37,"body":"very recently in history."},{"startTime":2039.37,"endTime":2043.54,"body":"So not perhaps that"},{"startTime":2039.37,"endTime":2043.54,"body":"surprising that you would get"},{"startTime":2043.54,"endTime":2045.28,"body":"these kind of endosymbiotic events"},{"startTime":2045.28,"endTime":2048.913,"body":"that sometimes lead to"},{"startTime":2045.28,"endTime":2048.913,"body":"stable evolutionary change."},{"startTime":2051.43,"endTime":2052.63,"body":"Okay, so we're still back down here,"},{"startTime":2052.63,"endTime":2053.53,"body":"right at the bottom here."},{"startTime":2053.53,"endTime":2054.46,"body":"And you'll be pleased to know"},{"startTime":2054.46,"endTime":2055.66,"body":"that I'm rummaging my way"},{"startTime":2055.66,"endTime":2056.8,"body":"about as far as I'm going to go,"},{"startTime":2056.8,"endTime":2059.62,"body":"because all this bit at"},{"startTime":2056.8,"endTime":2059.62,"body":"the top is all big things"},{"startTime":2059.62,"endTime":2060.85,"body":"that I'm totally uninterested in,"},{"startTime":2060.85,"endTime":2062.98,"body":"that you can see with the naked eye."},{"startTime":2062.98,"endTime":2064.63,"body":"But there are a couple more steps"},{"startTime":2064.63,"endTime":2065.5,"body":"that I really want to talk about."},{"startTime":2065.5,"endTime":2067.75,"body":"So we've just talked about"},{"startTime":2065.5,"endTime":2067.75,"body":"these first eucaryotes."},{"startTime":2067.75,"endTime":2069.37,"body":"So, so far on our journey,"},{"startTime":2069.37,"endTime":2071.65,"body":"we've had early bacteria, okay."},{"startTime":2071.65,"endTime":2073.81,"body":"We've had the evolution of photosynthesis."},{"startTime":2073.81,"endTime":2076.21,"body":"We've had that first"},{"startTime":2073.81,"endTime":2076.21,"body":"big split, if you like,"},{"startTime":2076.21,"endTime":2078.67,"body":"into the photosynthetic eucaryotes"},{"startTime":2078.67,"endTime":2081.4,"body":"that will go on to become"},{"startTime":2078.67,"endTime":2081.4,"body":"algae and land plants,"},{"startTime":2081.4,"endTime":2084.013,"body":"and the non-photosynthetic"},{"startTime":2081.4,"endTime":2084.013,"body":"ones, like our cells."},{"startTime":2085.51,"endTime":2087.94,"body":"But when we think about biological forms,"},{"startTime":2087.94,"endTime":2090.19,"body":"different organisms,"},{"startTime":2087.94,"endTime":2090.19,"body":"what we come to realize"},{"startTime":2090.19,"endTime":2091.63,"body":"is that most of the ones we think about"},{"startTime":2091.63,"endTime":2093.31,"body":"are actually not microscopic."},{"startTime":2093.31,"endTime":2097.03,"body":"They're large multicellular organisms."},{"startTime":2097.03,"endTime":2098.92,"body":"And that raises the second question of,"},{"startTime":2098.92,"endTime":2102.79,"body":"how do these single"},{"startTime":2098.92,"endTime":2102.79,"body":"celled free living things"},{"startTime":2102.79,"endTime":2105.85,"body":"turn into large complex"},{"startTime":2102.79,"endTime":2105.85,"body":"multicellular organisms?"},{"startTime":2105.85,"endTime":2108.673,"body":"What is it that changes one for another?"},{"startTime":2109.78,"endTime":2111.61,"body":"And that is a fascinating problem"},{"startTime":2111.61,"endTime":2113.23,"body":"and one that I think gets to the heart"},{"startTime":2113.23,"endTime":2115.0,"body":"of thinking about what we're about,"},{"startTime":2115.0,"endTime":2116.35,"body":"because we think of ourselves,"},{"startTime":2116.35,"endTime":2118.54,"body":"humans, as single entities."},{"startTime":2118.54,"endTime":2119.373,"body":"When we picked on poor Brandy"},{"startTime":2119.373,"endTime":2120.907,"body":"at the start of this lecture, you know,"},{"startTime":2120.907,"endTime":2122.74,"body":"and saying actually, we think of ourselves"},{"startTime":2122.74,"endTime":2125.23,"body":"as one organism, but"},{"startTime":2122.74,"endTime":2125.23,"body":"we're not one organism."},{"startTime":2125.23,"endTime":2126.79,"body":"And even if you take away"},{"startTime":2126.79,"endTime":2129.82,"body":"all those trillions of"},{"startTime":2126.79,"endTime":2129.82,"body":"microbes that live in or on us,"},{"startTime":2129.82,"endTime":2131.71,"body":"we are still not really one organism."},{"startTime":2131.71,"endTime":2135.793,"body":"We are a very complex set of"},{"startTime":2131.71,"endTime":2135.793,"body":"cells coordinating together."},{"startTime":2136.81,"endTime":2139.27,"body":"So how might those single"},{"startTime":2136.81,"endTime":2139.27,"body":"cells grow together"},{"startTime":2139.27,"endTime":2141.04,"body":"in a way that forms"},{"startTime":2139.27,"endTime":2141.04,"body":"this multicellular life?"},{"startTime":2141.04,"endTime":2143.95,"body":"And we can get some clues by"},{"startTime":2141.04,"endTime":2143.95,"body":"looking at a modern microbe."},{"startTime":2143.95,"endTime":2146.86,"body":"So this is an organism"},{"startTime":2143.95,"endTime":2146.86,"body":"called a Volvox, okay?"},{"startTime":2146.86,"endTime":2150.61,"body":"And this is a multicellular"},{"startTime":2146.86,"endTime":2150.61,"body":"organism but only just."},{"startTime":2150.61,"endTime":2153.25,"body":"What you see is that this is a colony"},{"startTime":2153.25,"endTime":2156.85,"body":"of individual algal cells"},{"startTime":2153.25,"endTime":2156.85,"body":"that live together, okay?"},{"startTime":2156.85,"endTime":2158.83,"body":"It's one organism, sort of,"},{"startTime":2158.83,"endTime":2161.47,"body":"but it's also hundreds of"},{"startTime":2158.83,"endTime":2161.47,"body":"individual multicellular,"},{"startTime":2161.47,"endTime":2164.143,"body":"single celled organisms working together."},{"startTime":2166.12,"endTime":2167.92,"body":"So that gives us a little bit of a clue"},{"startTime":2167.92,"endTime":2169.51,"body":"about where these things"},{"startTime":2167.92,"endTime":2169.51,"body":"might have come from."},{"startTime":2169.51,"endTime":2171.07,"body":"One of the most amazing things"},{"startTime":2171.07,"endTime":2172.54,"body":"about multicellularity is that"},{"startTime":2172.54,"endTime":2175.3,"body":"it has arisen not once,"},{"startTime":2172.54,"endTime":2175.3,"body":"but multiple times."},{"startTime":2175.3,"endTime":2177.07,"body":"So all three of these"},{"startTime":2175.3,"endTime":2177.07,"body":"rather ugly organisms"},{"startTime":2177.07,"endTime":2180.73,"body":"on the board in front of you"},{"startTime":2177.07,"endTime":2180.73,"body":"are multicellular organisms."},{"startTime":2180.73,"endTime":2183.25,"body":"All three of them though have arisen"},{"startTime":2183.25,"endTime":2185.8,"body":"from a lineage which has independently"},{"startTime":2185.8,"endTime":2188.56,"body":"acquired multicellularity."},{"startTime":2188.56,"endTime":2191.53,"body":"In fact, in the history of"},{"startTime":2188.56,"endTime":2191.53,"body":"Earth as far as we know it,"},{"startTime":2191.53,"endTime":2196.0,"body":"multicellular organisms have"},{"startTime":2191.53,"endTime":2196.0,"body":"arisen 25 independent times,"},{"startTime":2196.0,"endTime":2197.77,"body":"which is quite extraordinary."},{"startTime":2197.77,"endTime":2200.17,"body":"So the lineage which went from being"},{"startTime":2200.17,"endTime":2203.26,"body":"individual yeast to complicated fungi,"},{"startTime":2203.26,"endTime":2205.75,"body":"that multicellular step happened there,"},{"startTime":2205.75,"endTime":2207.07,"body":"but it's completely unrelated"},{"startTime":2207.07,"endTime":2209.29,"body":"to the step which led"},{"startTime":2207.07,"endTime":2209.29,"body":"to a single celled ameba"},{"startTime":2209.29,"endTime":2210.85,"body":"turning into something that"},{"startTime":2209.29,"endTime":2210.85,"body":"looks quite frightening,"},{"startTime":2210.85,"endTime":2212.65,"body":"like this chap in the middle here."},{"startTime":2212.65,"endTime":2216.1,"body":"These things have occurred"},{"startTime":2212.65,"endTime":2216.1,"body":"again and again and again."},{"startTime":2216.1,"endTime":2218.77,"body":"And that brings us to this"},{"startTime":2216.1,"endTime":2218.77,"body":"very challenging question,"},{"startTime":2218.77,"endTime":2220.87,"body":"how can something as complicated"},{"startTime":2220.87,"endTime":2222.82,"body":"as becoming a multicellular"},{"startTime":2222.82,"endTime":2226.69,"body":"coordinated organism happen"},{"startTime":2222.82,"endTime":2226.69,"body":"25 independent times?"},{"startTime":2226.69,"endTime":2229.0,"body":"That seems highly unlikely."},{"startTime":2229.0,"endTime":2231.19,"body":"But actually, it's"},{"startTime":2229.0,"endTime":2231.19,"body":"nowhere near as unlikely"},{"startTime":2231.19,"endTime":2232.78,"body":"as you might think, and in fact,"},{"startTime":2232.78,"endTime":2236.53,"body":"it's so likely that it's"},{"startTime":2232.78,"endTime":2236.53,"body":"possible to achieve that"},{"startTime":2236.53,"endTime":2239.38,"body":"within a matter of weeks in a laboratory."},{"startTime":2239.38,"endTime":2241.45,"body":"And so this is a rather beautiful example"},{"startTime":2241.45,"endTime":2243.01,"body":"from a group in the United States,"},{"startTime":2243.01,"endTime":2244.54,"body":"Will Ratcliff's group,"},{"startTime":2244.54,"endTime":2247.15,"body":"where they have essentially recapitulated"},{"startTime":2247.15,"endTime":2248.62,"body":"the conditions that might allow"},{"startTime":2248.62,"endTime":2252.31,"body":"single celled organisms"},{"startTime":2248.62,"endTime":2252.31,"body":"to become multi celled."},{"startTime":2252.31,"endTime":2254.68,"body":"So they start with single celled yeast"},{"startTime":2254.68,"endTime":2257.23,"body":"that you can see on the"},{"startTime":2254.68,"endTime":2257.23,"body":"screen here in front of you."},{"startTime":2257.23,"endTime":2259.42,"body":"And then what they do"},{"startTime":2257.23,"endTime":2259.42,"body":"is they set conditions"},{"startTime":2259.42,"endTime":2262.78,"body":"that strongly favor multicellularity."},{"startTime":2262.78,"endTime":2266.08,"body":"And then you evolve this"},{"startTime":2262.78,"endTime":2266.08,"body":"yeast in a laboratory,"},{"startTime":2266.08,"endTime":2268.09,"body":"every generation trying to look for yeast"},{"startTime":2268.09,"endTime":2270.19,"body":"that are a little bit more multicellular."},{"startTime":2270.19,"endTime":2273.01,"body":"And remarkably swiftly, when you do that,"},{"startTime":2273.01,"endTime":2273.843,"body":"you end up with an organism"},{"startTime":2273.843,"endTime":2276.85,"body":"that is quite fundamentally"},{"startTime":2273.843,"endTime":2276.85,"body":"different, and here it is."},{"startTime":2276.85,"endTime":2278.98,"body":"So you can see in the top screen above me,"},{"startTime":2278.98,"endTime":2282.64,"body":"here is a new multicellular"},{"startTime":2278.98,"endTime":2282.64,"body":"yeast happily growing,"},{"startTime":2282.64,"endTime":2284.83,"body":"no longer as a single celled organism,"},{"startTime":2284.83,"endTime":2286.99,"body":"but as a multicellular colony."},{"startTime":2286.99,"endTime":2288.61,"body":"And in fact, if we do"},{"startTime":2286.99,"endTime":2288.61,"body":"some fancy microscopy,"},{"startTime":2288.61,"endTime":2289.99,"body":"you see these things are"},{"startTime":2288.61,"endTime":2289.99,"body":"absolutely beautiful."},{"startTime":2289.99,"endTime":2292.573,"body":"This is a three-dimensional"},{"startTime":2289.99,"endTime":2292.573,"body":"living organism now"},{"startTime":2292.573,"endTime":2295.09,"body":"that has these kind of"},{"startTime":2292.573,"endTime":2295.09,"body":"structures within it."},{"startTime":2295.09,"endTime":2298.27,"body":"And perhaps the most"},{"startTime":2295.09,"endTime":2298.27,"body":"remarkable thing to me"},{"startTime":2298.27,"endTime":2300.79,"body":"is when you look at the behavior of these,"},{"startTime":2300.79,"endTime":2303.88,"body":"these are now acting like a"},{"startTime":2300.79,"endTime":2303.88,"body":"true multicellular organism."},{"startTime":2303.88,"endTime":2304.72,"body":"So in the bottom corner,"},{"startTime":2304.72,"endTime":2306.34,"body":"you see one of these colonies"},{"startTime":2306.34,"endTime":2308.41,"body":"essentially growing, replicating,"},{"startTime":2308.41,"endTime":2312.46,"body":"dividing like a large"},{"startTime":2308.41,"endTime":2312.46,"body":"multicellular organism"},{"startTime":2312.46,"endTime":2314.59,"body":"and no longer like a single cell,"},{"startTime":2314.59,"endTime":2316.693,"body":"within a matter of weeks in the lab."},{"startTime":2317.62,"endTime":2320.02,"body":"And so I think this kind of process"},{"startTime":2320.02,"endTime":2322.42,"body":"sets the kind of groundwork, if you like,"},{"startTime":2322.42,"endTime":2325.36,"body":"the understanding for how individual cells"},{"startTime":2325.36,"endTime":2327.16,"body":"might ultimately have evolved"},{"startTime":2327.16,"endTime":2330.34,"body":"into all of these elaborate"},{"startTime":2327.16,"endTime":2330.34,"body":"multi-cellular organisms."},{"startTime":2330.34,"endTime":2331.99,"body":"And explains to some extent"},{"startTime":2331.99,"endTime":2334.48,"body":"why this process has happened 25 times"},{"startTime":2334.48,"endTime":2336.52,"body":"and not just once in the history of life."},{"startTime":2336.52,"endTime":2338.02,"body":"And of course, it remains to be seen"},{"startTime":2338.02,"endTime":2339.46,"body":"how different this might be"},{"startTime":2339.46,"endTime":2341.29,"body":"in all the different lineages"},{"startTime":2341.29,"endTime":2343.363,"body":"and multicellularity that we know of."},{"startTime":2344.62,"endTime":2345.88,"body":"And so these various steps that"},{"startTime":2345.88,"endTime":2347.26,"body":"I've talked about this evening"},{"startTime":2347.26,"endTime":2349.24,"body":"have together combined to produce"},{"startTime":2349.24,"endTime":2352.33,"body":"the whole diversity of life"},{"startTime":2349.24,"endTime":2352.33,"body":"that we have on the planet,"},{"startTime":2352.33,"endTime":2353.5,"body":"what Charles Darwin referred"},{"startTime":2353.5,"endTime":2356.26,"body":"to as these endless forms most beautiful."},{"startTime":2356.26,"endTime":2357.97,"body":"They've created structures"},{"startTime":2357.97,"endTime":2360.28,"body":"that range from the truly invisible,"},{"startTime":2360.28,"endTime":2361.9,"body":"absolutely minuscule viruses,"},{"startTime":2361.9,"endTime":2364.093,"body":"up to enormous things like blue whales."},{"startTime":2365.14,"endTime":2366.94,"body":"And that great diversity is something"},{"startTime":2366.94,"endTime":2368.95,"body":"that I want to touch"},{"startTime":2366.94,"endTime":2368.95,"body":"on in the next lecture,"},{"startTime":2368.95,"endTime":2369.97,"body":"when we're going to start to look"},{"startTime":2369.97,"endTime":2371.8,"body":"at how microbes have shaped"},{"startTime":2371.8,"endTime":2373.87,"body":"the kind of physical"},{"startTime":2371.8,"endTime":2373.87,"body":"environment around us,"},{"startTime":2373.87,"endTime":2376.48,"body":"and how some of these"},{"startTime":2373.87,"endTime":2376.48,"body":"tiny invisible organisms"},{"startTime":2376.48,"endTime":2380.11,"body":"have led to some really,"},{"startTime":2376.48,"endTime":2380.11,"body":"really macroscopic changes."},{"startTime":2380.11,"endTime":2381.281,"body":"So I hope you'll join me then"},{"startTime":2381.281,"endTime":2382.36,"body":"and have a look at some"},{"startTime":2381.281,"endTime":2382.36,"body":"of these organisms."},{"startTime":2382.36,"endTime":2385.095,"body":"In the meantime, thank you"},{"startTime":2382.36,"endTime":2385.095,"body":"very much for listening."},{"startTime":2385.095,"endTime":2388.262,"body":"(audience applauding)"},{"startTime":2389.68,"endTime":2390.88,"body":"- [Tim] Hi, my name is Tim."},{"startTime":2390.88,"endTime":2391.99,"body":"First of all, thank you very much"},{"startTime":2391.99,"endTime":2394.15,"body":"for this very interesting lecture."},{"startTime":2394.15,"endTime":2396.583,"body":"And I would like to ask"},{"startTime":2394.15,"endTime":2396.583,"body":"you about one thing,"},{"startTime":2396.583,"endTime":2399.58,"body":"what called is mitochondria."},{"startTime":2399.58,"endTime":2401.17,"body":"And we know what this mitochondria"},{"startTime":2401.17,"endTime":2403.09,"body":"also was a bacteria,"},{"startTime":2403.09,"endTime":2406.03,"body":"and now we know it's very"},{"startTime":2403.09,"endTime":2406.03,"body":"important for our life."},{"startTime":2406.03,"endTime":2407.41,"body":"So my question is,"},{"startTime":2407.41,"endTime":2411.07,"body":"how can I build more"},{"startTime":2407.41,"endTime":2411.07,"body":"mitochondria in my body?"},{"startTime":2411.07,"endTime":2412.15,"body":"Thank you."},{"startTime":2412.15,"endTime":2412.983,"body":"- Brilliant."},{"startTime":2412.983,"endTime":2413.816,"body":"That's a good start."},{"startTime":2413.816,"endTime":2414.97,"body":"Okay, so for people who might not"},{"startTime":2414.97,"endTime":2415.803,"body":"have heard the question,"},{"startTime":2415.803,"endTime":2417.76,"body":"the question was about mitochondria."},{"startTime":2417.76,"endTime":2420.97,"body":"And mitochondria are those first"},{"startTime":2420.97,"endTime":2422.86,"body":"endosymbiotic steps that I talked about."},{"startTime":2422.86,"endTime":2424.99,"body":"When I talked about a bacteria"},{"startTime":2424.99,"endTime":2426.67,"body":"engulfing a little red bacteria"},{"startTime":2426.67,"endTime":2428.77,"body":"as the very first endosymbiosis,"},{"startTime":2428.77,"endTime":2430.24,"body":"that little red bacteria"},{"startTime":2430.24,"endTime":2431.71,"body":"is what turned into the mitochondria."},{"startTime":2431.71,"endTime":2434.71,"body":"And we have now in all of"},{"startTime":2431.71,"endTime":2434.71,"body":"our cells of our bodies"},{"startTime":2434.71,"endTime":2437.47,"body":"these little endosymbiotic mitochondria."},{"startTime":2437.47,"endTime":2439.06,"body":"They are essentially energy machines."},{"startTime":2439.06,"endTime":2443.08,"body":"They create the energy that our cells use."},{"startTime":2443.08,"endTime":2444.61,"body":"And if you don't have mitochondria,"},{"startTime":2444.61,"endTime":2447.52,"body":"you lose your energy and your cell dies."},{"startTime":2447.52,"endTime":2449.41,"body":"So how can you create more mitochondria?"},{"startTime":2449.41,"endTime":2451.3,"body":"Well, the easiest way actually"},{"startTime":2451.3,"endTime":2453.34,"body":"is to do all those things that"},{"startTime":2453.34,"endTime":2455.5,"body":"we get told to do a lot of"},{"startTime":2453.34,"endTime":2455.5,"body":"and get really annoyed by,"},{"startTime":2455.5,"endTime":2457.87,"body":"like exercise and eat well."},{"startTime":2457.87,"endTime":2460.81,"body":"Because the mitochondria will replicate"},{"startTime":2460.81,"endTime":2462.13,"body":"independently of the cell."},{"startTime":2462.13,"endTime":2464.74,"body":"So you can have cells"},{"startTime":2462.13,"endTime":2464.74,"body":"that have one mitochondria"},{"startTime":2464.74,"endTime":2466.33,"body":"or cells that have hundreds,"},{"startTime":2466.33,"endTime":2468.64,"body":"and that control is based"},{"startTime":2468.64,"endTime":2470.05,"body":"on the kind of demand, if you like."},{"startTime":2470.05,"endTime":2471.55,"body":"So cells that you use a lot of energy"},{"startTime":2471.55,"endTime":2472.6,"body":"have more mitochondria,"},{"startTime":2472.6,"endTime":2474.85,"body":"and ones that don't use very much energy"},{"startTime":2474.85,"endTime":2477.31,"body":"don't generally have many mitochondria."},{"startTime":2477.31,"endTime":2479.71,"body":"So when you drive energy demand"},{"startTime":2479.71,"endTime":2481.21,"body":"by doing a lot of exercise, for example,"},{"startTime":2481.21,"endTime":2482.98,"body":"you will start to get more mitochondria"},{"startTime":2482.98,"endTime":2484.867,"body":"to meet that energy demand."},{"startTime":2484.867,"endTime":2486.31,"body":"You can also do things like, you know,"},{"startTime":2486.31,"endTime":2487.84,"body":"altitude training, for example."},{"startTime":2487.84,"endTime":2490.24,"body":"When you go up high,"},{"startTime":2490.24,"endTime":2491.41,"body":"your oxygen is less available,"},{"startTime":2491.41,"endTime":2493.78,"body":"that will trigger more mitochondria."},{"startTime":2493.78,"endTime":2495.64,"body":"You can also go in the other direction."},{"startTime":2495.64,"endTime":2497.29,"body":"So you can reduce your"},{"startTime":2495.64,"endTime":2497.29,"body":"mitochondrial number"},{"startTime":2497.29,"endTime":2498.79,"body":"by being incredibly lazy."},{"startTime":2498.79,"endTime":2499.96,"body":"There are also some drugs"},{"startTime":2499.96,"endTime":2501.19,"body":"that are particularly toxic"},{"startTime":2501.19,"endTime":2502.42,"body":"for mitochondria that will reduce them."},{"startTime":2502.42,"endTime":2505.9,"body":"So your mitochondrial number"},{"startTime":2502.42,"endTime":2505.9,"body":"is changing all the time."},{"startTime":2505.9,"endTime":2509.05,"body":"One thing that is particularly neat aside,"},{"startTime":2509.05,"endTime":2509.883,"body":"but might be of interest to people,"},{"startTime":2509.883,"endTime":2512.35,"body":"is that you inherit your mitochondria"},{"startTime":2512.35,"endTime":2514.36,"body":"separately from your nuclear gene."},{"startTime":2514.36,"endTime":2515.83,"body":"So all of us in this room,"},{"startTime":2515.83,"endTime":2518.56,"body":"you are a beautiful mix,"},{"startTime":2515.83,"endTime":2518.56,"body":"whether you like it or not,"},{"startTime":2518.56,"endTime":2521.2,"body":"of your mum and your dad's gene"},{"startTime":2521.2,"endTime":2522.82,"body":"for all of your nuclear genes."},{"startTime":2522.82,"endTime":2525.34,"body":"But your mitochondria"},{"startTime":2522.82,"endTime":2525.34,"body":"come only from your mum."},{"startTime":2525.34,"endTime":2527.14,"body":"So you have nothing to do"},{"startTime":2525.34,"endTime":2527.14,"body":"with your dad's mitochondria."},{"startTime":2527.14,"endTime":2528.34,"body":"So if you're feeling like you have"},{"startTime":2528.34,"endTime":2529.42,"body":"really low energy levels"},{"startTime":2529.42,"endTime":2530.5,"body":"and you're blaming your mitochondria,"},{"startTime":2530.5,"endTime":2532.75,"body":"it's your mum you have"},{"startTime":2530.5,"endTime":2532.75,"body":"to blame, not your dad."},{"startTime":2532.75,"endTime":2535.96,"body":"- Looking back at those"},{"startTime":2532.75,"endTime":2535.96,"body":"very, very early days,"},{"startTime":2535.96,"endTime":2537.76,"body":"how much is hypothetical"},{"startTime":2537.76,"endTime":2540.94,"body":"and how much can you"},{"startTime":2537.76,"endTime":2540.94,"body":"generate from experiment?"},{"startTime":2540.94,"endTime":2542.02,"body":"And how would you do that?"},{"startTime":2542.02,"endTime":2543.4,"body":"- Yeah, that's a good question."},{"startTime":2543.4,"endTime":2544.99,"body":"So very, very early,"},{"startTime":2544.99,"endTime":2547.72,"body":"I think it will always be"},{"startTime":2544.99,"endTime":2547.72,"body":"inevitably hypothetical."},{"startTime":2547.72,"endTime":2549.67,"body":"So those early spontaneous chemical."},{"startTime":2549.67,"endTime":2551.23,"body":"I mean, what we can do in a lab"},{"startTime":2551.23,"endTime":2553.21,"body":"is we can create conditions"},{"startTime":2553.21,"endTime":2555.01,"body":"under which those chemicals form,"},{"startTime":2555.01,"endTime":2557.29,"body":"and you can create chemicals"},{"startTime":2555.01,"endTime":2557.29,"body":"which self replicate."},{"startTime":2557.29,"endTime":2559.39,"body":"So you can do all the steps in the lab,"},{"startTime":2559.39,"endTime":2560.74,"body":"but whether that actually happened"},{"startTime":2560.74,"endTime":2562.69,"body":"in that early Earth in that sequence,"},{"startTime":2562.69,"endTime":2563.94,"body":"I think we'll never know."},{"startTime":2565.244,"endTime":2567.76,"body":"Endosymbiosis, I think"},{"startTime":2567.76,"endTime":2570.4,"body":"there's such good data that it can happen"},{"startTime":2570.4,"endTime":2572.98,"body":"and that it is an extremely"},{"startTime":2570.4,"endTime":2572.98,"body":"plausible mechanism"},{"startTime":2572.98,"endTime":2575.23,"body":"that I think that's not"},{"startTime":2572.98,"endTime":2575.23,"body":"really disputed anymore"},{"startTime":2575.23,"endTime":2576.88,"body":"about that process."},{"startTime":2576.88,"endTime":2578.29,"body":"So I think from that point on,"},{"startTime":2578.29,"endTime":2579.76,"body":"most things are fairly robust."},{"startTime":2579.76,"endTime":2582.58,"body":"But that very early, how"},{"startTime":2579.76,"endTime":2582.58,"body":"did you get a first cell,"},{"startTime":2582.58,"endTime":2584.26,"body":"how did that first cell replicate,"},{"startTime":2584.26,"endTime":2587.5,"body":"is I suspect always going"},{"startTime":2584.26,"endTime":2587.5,"body":"to be slightly nebulous,"},{"startTime":2587.5,"endTime":2589.27,"body":"although I'm dying to be proven wrong"},{"startTime":2589.27,"endTime":2590.103,"body":"when someone comes up"},{"startTime":2590.103,"endTime":2591.76,"body":"with totally incontrovertible evidence."},{"startTime":2593.11,"endTime":2593.943,"body":"- [Audience Member] Yeah, hi."},{"startTime":2593.943,"endTime":2594.776,"body":"Coming back to the point"},{"startTime":2594.776,"endTime":2598.42,"body":"of the 39 trillion bacterial"},{"startTime":2594.776,"endTime":2598.42,"body":"microbes in our body."},{"startTime":2598.42,"endTime":2599.253,"body":"How varied are they?"},{"startTime":2599.253,"endTime":2600.55,"body":"Are they all one type"},{"startTime":2600.55,"endTime":2603.483,"body":"or are they five types"},{"startTime":2600.55,"endTime":2603.483,"body":"or 39 trillion types?"},{"startTime":2603.483,"endTime":2605.02,"body":"- Yes, that's an excellent question."},{"startTime":2605.02,"endTime":2605.853,"body":"So the question is,"},{"startTime":2605.853,"endTime":2607.84,"body":"how diverse are those"},{"startTime":2605.853,"endTime":2607.84,"body":"39 trillion bacteria?"},{"startTime":2607.84,"endTime":2611.38,"body":"Very, very, very is the short answer."},{"startTime":2611.38,"endTime":2613.48,"body":"And the longer answer is,"},{"startTime":2613.48,"endTime":2617.59,"body":"so we know essentially by"},{"startTime":2613.48,"endTime":2617.59,"body":"doing DNA sequencing on poo,"},{"startTime":2617.59,"endTime":2620.71,"body":"lots of poo, that people have"},{"startTime":2620.71,"endTime":2622.36,"body":"amazingly complicated organisms."},{"startTime":2622.36,"endTime":2623.32,"body":"So we know, for example,"},{"startTime":2623.32,"endTime":2624.88,"body":"that there are organisms"},{"startTime":2624.88,"endTime":2626.95,"body":"for which we can find the DNA,"},{"startTime":2626.95,"endTime":2628.42,"body":"which we have never grown in lab,"},{"startTime":2628.42,"endTime":2629.62,"body":"which are unknown to science."},{"startTime":2629.62,"endTime":2632.89,"body":"So we're all harboring these"},{"startTime":2629.62,"endTime":2632.89,"body":"unknown bacteria anyway."},{"startTime":2632.89,"endTime":2634.3,"body":"We also know that each of us"},{"startTime":2634.3,"endTime":2635.8,"body":"has a very unique combination,"},{"startTime":2635.8,"endTime":2637.24,"body":"so no two people are the same."},{"startTime":2637.24,"endTime":2638.5,"body":"And you might have come across"},{"startTime":2638.5,"endTime":2639.4,"body":"a lot of interesting work"},{"startTime":2639.4,"endTime":2641.05,"body":"on things like fecal transplants."},{"startTime":2641.05,"endTime":2641.883,"body":"There's a lot of interest"},{"startTime":2641.883,"endTime":2644.53,"body":"in whether you can change"},{"startTime":2641.883,"endTime":2644.53,"body":"people's microbiomes,"},{"startTime":2644.53,"endTime":2646.03,"body":"that complement of bacteria"},{"startTime":2646.03,"endTime":2649.27,"body":"by essentially swapping"},{"startTime":2646.03,"endTime":2649.27,"body":"poo between people."},{"startTime":2649.27,"endTime":2651.22,"body":"And it works, it works quite well."},{"startTime":2651.22,"endTime":2652.54,"body":"But it's actually not just the body."},{"startTime":2652.54,"endTime":2654.34,"body":"So in fact, on your hand."},{"startTime":2654.34,"endTime":2655.173,"body":"I'll borrow Wendy."},{"startTime":2655.173,"endTime":2656.006,"body":"She's at the front here."},{"startTime":2656.006,"endTime":2657.154,"body":"Wendy, can I shake your hand?"},{"startTime":2657.154,"endTime":2657.987,"body":"There we go. Marvelous."},{"startTime":2657.987,"endTime":2659.77,"body":"I've just contaminated Wendy horribly."},{"startTime":2659.77,"endTime":2660.67,"body":"- Thank you."},{"startTime":2659.77,"endTime":2660.67,"body":"- Thank you very much."},{"startTime":2660.67,"endTime":2664.057,"body":"Because on our hands we have about 300,"},{"startTime":2665.495,"endTime":2667.15,"body":"400 different species of microbes"},{"startTime":2667.15,"endTime":2668.35,"body":"that live on our hands."},{"startTime":2668.35,"endTime":2670.33,"body":"Only 15% of those are shared"},{"startTime":2670.33,"endTime":2671.38,"body":"with all of us in the the room."},{"startTime":2671.38,"endTime":2673.21,"body":"So whenever you shake hands with someone,"},{"startTime":2673.21,"endTime":2676.12,"body":"you are scraping off all"},{"startTime":2673.21,"endTime":2676.12,"body":"these unique microbes"},{"startTime":2676.12,"endTime":2677.83,"body":"onto Wendy's hand and vice versa."},{"startTime":2677.83,"endTime":2681.22,"body":"The really good news is that"},{"startTime":2677.83,"endTime":2681.22,"body":"very rapidly afterwards,"},{"startTime":2681.22,"endTime":2683.71,"body":"the ones that are foreign"},{"startTime":2681.22,"endTime":2683.71,"body":"die out and disappear."},{"startTime":2683.71,"endTime":2686.02,"body":"For some reason, your microbial compliment"},{"startTime":2686.02,"endTime":2688.15,"body":"on your hand is kind of unique to you"},{"startTime":2688.15,"endTime":2689.38,"body":"and is very difficult to displace."},{"startTime":2689.38,"endTime":2691.03,"body":"So we have these sort of unique,"},{"startTime":2691.03,"endTime":2692.38,"body":"highly diverse ecosystems,"},{"startTime":2692.38,"endTime":2694.39,"body":"which we really are"},{"startTime":2692.38,"endTime":2694.39,"body":"just only just beginning"},{"startTime":2694.39,"endTime":2696.1,"body":"to scratch the surface of."},{"startTime":2696.1,"endTime":2696.933,"body":"- [Audience Member] I rather wonder about"},{"startTime":2696.933,"endTime":2698.8,"body":"the evolution of photosynthesis."},{"startTime":2698.8,"endTime":2699.91,"body":"It seems rather strange."},{"startTime":2699.91,"endTime":2701.68,"body":"It's not using the green"},{"startTime":2699.91,"endTime":2701.68,"body":"part of the spectrum."},{"startTime":2701.68,"endTime":2703.63,"body":"It seems to use the red and the blue."},{"startTime":2703.63,"endTime":2706.66,"body":"But the green is the most"},{"startTime":2703.63,"endTime":2706.66,"body":"active part of the spectrum."},{"startTime":2706.66,"endTime":2708.37,"body":"It's an evolutionary mistake, isn't it?"},{"startTime":2708.37,"endTime":2709.48,"body":"- Yeah, yeah, yeah."},{"startTime":2709.48,"endTime":2710.313,"body":"That's an excellent question."},{"startTime":2710.313,"endTime":2713.89,"body":"So the question is, why green?"},{"startTime":2713.89,"endTime":2715.81,"body":"Or indeed, and I remember many years ago"},{"startTime":2715.81,"endTime":2717.167,"body":"as undergraduate being"},{"startTime":2715.81,"endTime":2717.167,"body":"set an essay saying,"},{"startTime":2717.167,"endTime":2718.51,"body":"\"Why isn't the world black?\""},{"startTime":2718.51,"endTime":2720.04,"body":"Because if you want to harvest light,"},{"startTime":2720.04,"endTime":2721.15,"body":"it would seem like being black"},{"startTime":2721.15,"endTime":2723.73,"body":"is a very sensible color to be,"},{"startTime":2723.73,"endTime":2726.73,"body":"where you harvest all of the"},{"startTime":2723.73,"endTime":2726.73,"body":"spectrum, rather than green,"},{"startTime":2726.73,"endTime":2729.52,"body":"when you're by definition"},{"startTime":2726.73,"endTime":2729.52,"body":"reflecting green."},{"startTime":2729.52,"endTime":2731.8,"body":"And I think there's sort of"},{"startTime":2729.52,"endTime":2731.8,"body":"two possible answers there."},{"startTime":2731.8,"endTime":2733.09,"body":"So there are some pretty good reasons"},{"startTime":2733.09,"endTime":2735.49,"body":"why you wouldn't want"},{"startTime":2733.09,"endTime":2735.49,"body":"to be black, actually."},{"startTime":2735.49,"endTime":2736.78,"body":"So, which are largely to do"},{"startTime":2736.78,"endTime":2737.83,"body":"with kind of overdosing"},{"startTime":2737.83,"endTime":2742.51,"body":"and getting photodynamic"},{"startTime":2737.83,"endTime":2742.51,"body":"damage based on too much light."},{"startTime":2742.51,"endTime":2744.73,"body":"But why green is a very good question."},{"startTime":2744.73,"endTime":2745.93,"body":"In fact, it's not always green."},{"startTime":2745.93,"endTime":2747.73,"body":"So there are red algae,"},{"startTime":2745.93,"endTime":2747.73,"body":"for example, which are red,"},{"startTime":2747.73,"endTime":2750.25,"body":"and there are lots of"},{"startTime":2747.73,"endTime":2750.25,"body":"photosynthetic pigments"},{"startTime":2750.25,"endTime":2753.61,"body":"which are not green, but"},{"startTime":2750.25,"endTime":2753.61,"body":"the dominant one is green."},{"startTime":2753.61,"endTime":2755.29,"body":"And what you see is that"},{"startTime":2755.29,"endTime":2756.49,"body":"that is actually very efficient"},{"startTime":2756.49,"endTime":2759.52,"body":"based on the rest of"},{"startTime":2756.49,"endTime":2759.52,"body":"the biology of the cell."},{"startTime":2759.52,"endTime":2760.87,"body":"But your point is a very good one that,"},{"startTime":2760.87,"endTime":2762.55,"body":"of course, it's a bit"},{"startTime":2760.87,"endTime":2762.55,"body":"like when you started"},{"startTime":2762.55,"endTime":2764.14,"body":"to build a machine."},{"startTime":2764.14,"endTime":2766.9,"body":"If the first computer you buy is a PC,"},{"startTime":2766.9,"endTime":2768.76,"body":"then you tend to stay with PCs"},{"startTime":2768.76,"endTime":2769.9,"body":"because shifting over to Mac"},{"startTime":2769.9,"endTime":2770.8,"body":"is quite a lot of work,"},{"startTime":2770.8,"endTime":2772.66,"body":"and it's a little bit like"},{"startTime":2770.8,"endTime":2772.66,"body":"that in evolution, I think."},{"startTime":2772.66,"endTime":2774.85,"body":"If the early machinery works well"},{"startTime":2774.85,"endTime":2777.49,"body":"with what you have,"},{"startTime":2774.85,"endTime":2777.49,"body":"evolution's put you on a path"},{"startTime":2777.49,"endTime":2778.323,"body":"that will keep going that way."},{"startTime":2778.323,"endTime":2779.44,"body":"It's a very interesting question"},{"startTime":2779.44,"endTime":2781.9,"body":"to wonder if we played the tape of life"},{"startTime":2781.9,"endTime":2783.01,"body":"on Earth all over again,"},{"startTime":2783.01,"endTime":2784.27,"body":"would we still have green plants,"},{"startTime":2784.27,"endTime":2785.59,"body":"or might they be red, or orange,"},{"startTime":2785.59,"endTime":2786.61,"body":"or some other color?"},{"startTime":2786.61,"endTime":2788.5,"body":"So yeah, that's a very bad"},{"startTime":2786.61,"endTime":2788.5,"body":"answer to your question."},{"startTime":2788.5,"endTime":2789.76,"body":"Thank you. (laughs)"},{"startTime":2789.76,"endTime":2791.26,"body":"- [Audience Member] So at the beginning,"},{"startTime":2791.26,"endTime":2793.78,"body":"well, towards the first"},{"startTime":2791.26,"endTime":2793.78,"body":"third of your lecture,"},{"startTime":2793.78,"endTime":2797.892,"body":"you said that the important criteria"},{"startTime":2797.892,"endTime":2799.54,"body":"for the beginning of life"},{"startTime":2799.54,"endTime":2801.49,"body":"as life itself was the development"},{"startTime":2801.49,"endTime":2804.88,"body":"of a boundary for the formation of a cell."},{"startTime":2804.88,"endTime":2807.46,"body":"Would you say that's the"},{"startTime":2804.88,"endTime":2807.46,"body":"most important criteria"},{"startTime":2807.46,"endTime":2809.71,"body":"for considering life appeared?"},{"startTime":2809.71,"endTime":2812.92,"body":"Or like a few other important ones."},{"startTime":2812.92,"endTime":2816.61,"body":"What would be the"},{"startTime":2812.92,"endTime":2816.61,"body":"criteria for life itself?"},{"startTime":2816.61,"endTime":2818.173,"body":"- Yeah, I mean, those are"},{"startTime":2816.61,"endTime":2818.173,"body":"very difficult questions."},{"startTime":2818.173,"endTime":2819.28,"body":"It's a bit like asking someone"},{"startTime":2819.28,"endTime":2820.84,"body":"whether their left leg or their right leg"},{"startTime":2820.84,"endTime":2822.702,"body":"is more important to them."},{"startTime":2822.702,"endTime":2824.02,"body":"I mean, I think the membrane"},{"startTime":2824.02,"endTime":2826.39,"body":"is absolutely a fundamental part of life,"},{"startTime":2826.39,"endTime":2828.82,"body":"because it allows you to have"},{"startTime":2828.82,"endTime":2830.65,"body":"different chemistry on"},{"startTime":2828.82,"endTime":2830.65,"body":"one side from another."},{"startTime":2830.65,"endTime":2832.57,"body":"And what we see actually,"},{"startTime":2832.57,"endTime":2834.79,"body":"so someone mentioned"},{"startTime":2832.57,"endTime":2834.79,"body":"earlier about mitochondria,"},{"startTime":2834.79,"endTime":2836.02,"body":"which generate energy."},{"startTime":2836.02,"endTime":2837.79,"body":"The way they generate energy"},{"startTime":2837.79,"endTime":2840.01,"body":"is by having an internal membrane"},{"startTime":2840.01,"endTime":2842.8,"body":"and separating things,"},{"startTime":2840.01,"endTime":2842.8,"body":"a bit like a waterfall."},{"startTime":2842.8,"endTime":2844.72,"body":"So they have one set of"},{"startTime":2842.8,"endTime":2844.72,"body":"molecules on one side"},{"startTime":2844.72,"endTime":2847.03,"body":"and they let them"},{"startTime":2844.72,"endTime":2847.03,"body":"through a kind of turbine"},{"startTime":2847.03,"endTime":2848.98,"body":"to generate energy across that membrane."},{"startTime":2848.98,"endTime":2850.69,"body":"So the reason a membrane is so important"},{"startTime":2850.69,"endTime":2852.25,"body":"is it allows you to do different things"},{"startTime":2852.25,"endTime":2853.51,"body":"on one side from another."},{"startTime":2853.51,"endTime":2855.31,"body":"So I think it's fair to say"},{"startTime":2855.31,"endTime":2858.01,"body":"that without a membrane,"},{"startTime":2855.31,"endTime":2858.01,"body":"we would not have life."},{"startTime":2858.01,"endTime":2859.54,"body":"But it's also fair to say that"},{"startTime":2859.54,"endTime":2861.97,"body":"without a self replicating"},{"startTime":2859.54,"endTime":2861.97,"body":"chemical molecule,"},{"startTime":2861.97,"endTime":2863.14,"body":"you wouldn't have life."},{"startTime":2863.14,"endTime":2864.88,"body":"And without an ability to harvest energy,"},{"startTime":2864.88,"endTime":2865.713,"body":"you wouldn't have life."},{"startTime":2865.713,"endTime":2867.88,"body":"So I think all of these"},{"startTime":2865.713,"endTime":2867.88,"body":"things are critical."},{"startTime":2867.88,"endTime":2870.25,"body":"But I think generating a membrane"},{"startTime":2870.25,"endTime":2871.42,"body":"that allows you to enclose something"},{"startTime":2871.42,"endTime":2874.21,"body":"must have been something that"},{"startTime":2871.42,"endTime":2874.21,"body":"happened very, very early on."},{"startTime":2874.21,"endTime":2875.32,"body":"Whether it might even have happened"},{"startTime":2875.32,"endTime":2877.42,"body":"before a self replicating molecule"},{"startTime":2877.42,"endTime":2879.347,"body":"is an interesting question"},{"startTime":2877.42,"endTime":2879.347,"body":"and quite possible."},{"startTime":2879.347,"endTime":2881.38,"body":"It comes to Martin's point"},{"startTime":2879.347,"endTime":2881.38,"body":"about, will we ever know?"},{"startTime":2881.38,"endTime":2883.99,"body":"But yeah, it's absolutely a"},{"startTime":2881.38,"endTime":2883.99,"body":"fundamental step, definitely."},{"startTime":2883.99,"endTime":2884.95,"body":"- Do we know anything about"},{"startTime":2884.95,"endTime":2888.1,"body":"when membranes ceased"},{"startTime":2884.95,"endTime":2888.1,"body":"to be just an interface,"},{"startTime":2888.1,"endTime":2890.14,"body":"but became an active structure?"},{"startTime":2890.14,"endTime":2891.28,"body":"You know, 'cause they're involved"},{"startTime":2891.28,"endTime":2894.613,"body":"in so much transport"},{"startTime":2891.28,"endTime":2894.613,"body":"mechanisms, ionic exchange."},{"startTime":2896.183,"endTime":2898.36,"body":"What do we know about"},{"startTime":2896.183,"endTime":2898.36,"body":"when that all started?"},{"startTime":2898.36,"endTime":2899.62,"body":"- Yeah, very little indeed."},{"startTime":2899.62,"endTime":2902.35,"body":"I mean, there are now, if"},{"startTime":2899.62,"endTime":2902.35,"body":"you look at modern cells,"},{"startTime":2902.35,"endTime":2905.44,"body":"there are cells that have"},{"startTime":2902.35,"endTime":2905.44,"body":"incredibly simple membranes."},{"startTime":2905.44,"endTime":2907.09,"body":"I use that kind of slightly cautiously."},{"startTime":2907.09,"endTime":2908.98,"body":"So a red blood cells, for example,"},{"startTime":2908.98,"endTime":2910.45,"body":"that circulates in our blood"},{"startTime":2910.45,"endTime":2912.91,"body":"is a relatively simple membrane,"},{"startTime":2912.91,"endTime":2915.01,"body":"because that cell"},{"startTime":2912.91,"endTime":2915.01,"body":"essentially has one purpose,"},{"startTime":2915.01,"endTime":2916.3,"body":"which is to carry oxygen."},{"startTime":2916.3,"endTime":2919.09,"body":"And then you have incredibly"},{"startTime":2916.3,"endTime":2919.09,"body":"elaborate membranes."},{"startTime":2919.09,"endTime":2920.56,"body":"So at the end of a nerve,"},{"startTime":2920.56,"endTime":2922.24,"body":"so you know, when you're doing this,"},{"startTime":2922.24,"endTime":2924.64,"body":"there are nerves firing"},{"startTime":2924.64,"endTime":2926.56,"body":"and they're using just"},{"startTime":2924.64,"endTime":2926.56,"body":"an incredibly diverse"},{"startTime":2926.56,"endTime":2928.27,"body":"array of proteins at the"},{"startTime":2926.56,"endTime":2928.27,"body":"end of their membranes"},{"startTime":2928.27,"endTime":2929.56,"body":"to exchange molecules."},{"startTime":2929.56,"endTime":2931.72,"body":"So there are a whole range."},{"startTime":2931.72,"endTime":2933.22,"body":"I don't think there are any cells today"},{"startTime":2933.22,"endTime":2934.9,"body":"that have a membrane that is as simple"},{"startTime":2934.9,"endTime":2938.38,"body":"as it would've been, you"},{"startTime":2934.9,"endTime":2938.38,"body":"know, the origins of life."},{"startTime":2938.38,"endTime":2940.15,"body":"But when a membrane changed"},{"startTime":2940.15,"endTime":2942.01,"body":"from being just a physical barrier"},{"startTime":2942.01,"endTime":2944.8,"body":"to something that had a"},{"startTime":2942.01,"endTime":2944.8,"body":"kind of signaling role,"},{"startTime":2944.8,"endTime":2946.21,"body":"I think it is, again, probably a question"},{"startTime":2946.21,"endTime":2947.68,"body":"we will never know the true answer."},{"startTime":2947.68,"endTime":2950.26,"body":"- Some of the fungal mycelia"},{"startTime":2950.26,"endTime":2952.24,"body":"have complicated communication networks"},{"startTime":2952.24,"endTime":2953.8,"body":"which involve membrane"},{"startTime":2952.24,"endTime":2953.8,"body":"transfer, don't they?"},{"startTime":2953.8,"endTime":2956.38,"body":"So, we must know a little"},{"startTime":2953.8,"endTime":2956.38,"body":"bit about that timing."},{"startTime":2956.38,"endTime":2957.31,"body":"- You're preempting."},{"startTime":2957.31,"endTime":2958.75,"body":"You have to come back"},{"startTime":2957.31,"endTime":2958.75,"body":"for a future lecture,"},{"startTime":2958.75,"endTime":2960.43,"body":"because we have a whole lecture"},{"startTime":2960.43,"endTime":2962.83,"body":"on those elaborate membranes"},{"startTime":2960.43,"endTime":2962.83,"body":"and fungal mycelia."},{"startTime":2962.83,"endTime":2963.91,"body":"But yes, which you can see,"},{"startTime":2963.91,"endTime":2965.8,"body":"in fact, behind you here on the screen."},{"startTime":2965.8,"endTime":2968.77,"body":"Exactly. (laughs)"},{"startTime":2968.77,"endTime":2970.87,"body":"- [Audience Member] Is"},{"startTime":2968.77,"endTime":2970.87,"body":"it possible to imagine"},{"startTime":2970.87,"endTime":2973.84,"body":"any mechanism by which"},{"startTime":2970.87,"endTime":2973.84,"body":"acquired characteristics"},{"startTime":2973.84,"endTime":2974.86,"body":"can be inherited?"},{"startTime":2974.86,"endTime":2977.89,"body":"Or is that still believed"},{"startTime":2974.86,"endTime":2977.89,"body":"to be simply impossible?"},{"startTime":2977.89,"endTime":2978.99,"body":"- We're talking about the markers."},{"startTime":2978.99,"endTime":2980.38,"body":"So the question is,"},{"startTime":2980.38,"endTime":2982.99,"body":"can acquired characteristics be inherited?"},{"startTime":2982.99,"endTime":2984.64,"body":"And I think the answer actually to that"},{"startTime":2984.64,"endTime":2988.39,"body":"is definitively yes,"},{"startTime":2984.64,"endTime":2988.39,"body":"in some circumstances."},{"startTime":2988.39,"endTime":2991.3,"body":"So actually one example,"},{"startTime":2991.3,"endTime":2993.58,"body":"very simple example"},{"startTime":2991.3,"endTime":2993.58,"body":"would be prion diseases."},{"startTime":2993.58,"endTime":2996.07,"body":"So BSE in cattle,"},{"startTime":2996.07,"endTime":2998.98,"body":"scrapie in sheep, or CJD in humans,"},{"startTime":2998.98,"endTime":3001.23,"body":"where what you have is one protein"},{"startTime":3001.23,"endTime":3002.91,"body":"that converts another protein"},{"startTime":3002.91,"endTime":3005.1,"body":"into a pathogenic form,"},{"startTime":3005.1,"endTime":3008.82,"body":"and then that carries on,"},{"startTime":3005.1,"endTime":3008.82,"body":"that process carries on."},{"startTime":3008.82,"endTime":3010.77,"body":"Obviously in humans,"},{"startTime":3008.82,"endTime":3010.77,"body":"that is a fatal disease."},{"startTime":3010.77,"endTime":3013.68,"body":"But you have an equivalent in yeast,"},{"startTime":3013.68,"endTime":3016.95,"body":"a prion disease where those"},{"startTime":3013.68,"endTime":3016.95,"body":"faulty proteins, if you like,"},{"startTime":3016.95,"endTime":3019.8,"body":"can be inherited and go from"},{"startTime":3016.95,"endTime":3019.8,"body":"one generation to the other."},{"startTime":3020.79,"endTime":3022.14,"body":"Probably a much more relevant example"},{"startTime":3022.14,"endTime":3024.306,"body":"is around epigenetics."},{"startTime":3024.306,"endTime":3026.73,"body":"So when we express"},{"startTime":3024.306,"endTime":3026.73,"body":"so-called express genes,"},{"startTime":3026.73,"endTime":3028.77,"body":"and when your DNA is turned"},{"startTime":3026.73,"endTime":3028.77,"body":"into something useful"},{"startTime":3028.77,"endTime":3032.19,"body":"like a protein, that"},{"startTime":3028.77,"endTime":3032.19,"body":"process can be controlled"},{"startTime":3032.19,"endTime":3035.82,"body":"by chemical modifications on DNA"},{"startTime":3035.82,"endTime":3039.54,"body":"that are not genetic but"},{"startTime":3035.82,"endTime":3039.54,"body":"are nonetheless inherited."},{"startTime":3039.54,"endTime":3042.84,"body":"So for example, whether a"},{"startTime":3039.54,"endTime":3042.84,"body":"gene is expressed or not"},{"startTime":3042.84,"endTime":3044.64,"body":"sometimes depends on"},{"startTime":3042.84,"endTime":3044.64,"body":"whether you've inherited it"},{"startTime":3044.64,"endTime":3046.35,"body":"from your father or your mother,"},{"startTime":3046.35,"endTime":3048.12,"body":"not because the sequence"},{"startTime":3046.35,"endTime":3048.12,"body":"of the gene is different,"},{"startTime":3048.12,"endTime":3050.07,"body":"but because it has different marks on it."},{"startTime":3050.07,"endTime":3052.41,"body":"And this is one of the explanations"},{"startTime":3052.41,"endTime":3054.36,"body":"for why we see very interesting effects."},{"startTime":3054.36,"endTime":3056.55,"body":"So for example, in terms of diet,"},{"startTime":3056.55,"endTime":3057.383,"body":"so you might be aware,"},{"startTime":3057.383,"endTime":3058.68,"body":"this is very impressive data"},{"startTime":3058.68,"endTime":3059.98,"body":"from the Second World War"},{"startTime":3060.87,"endTime":3063.09,"body":"from the Netherlands where the population"},{"startTime":3063.09,"endTime":3065.67,"body":"encountered extreme starvation."},{"startTime":3065.67,"endTime":3069.51,"body":"And the mothers who"},{"startTime":3065.67,"endTime":3069.51,"body":"experienced starvation,"},{"startTime":3069.51,"endTime":3071.43,"body":"not only their children"},{"startTime":3069.51,"endTime":3071.43,"body":"but their grandchildren"},{"startTime":3071.43,"endTime":3073.47,"body":"had differing birth weights,"},{"startTime":3073.47,"endTime":3075.21,"body":"even though they themselves"},{"startTime":3073.47,"endTime":3075.21,"body":"had never encountered that."},{"startTime":3075.21,"endTime":3077.22,"body":"So that kind of shock had somehow left"},{"startTime":3077.22,"endTime":3079.59,"body":"an inheritable mark"},{"startTime":3077.22,"endTime":3079.59,"body":"that has been inherited,"},{"startTime":3079.59,"endTime":3080.797,"body":"and there are many more examples of that."},{"startTime":3080.797,"endTime":3082.17,"body":"I mean, I would caveat that"},{"startTime":3082.17,"endTime":3083.73,"body":"by saying still overwhelmingly,"},{"startTime":3083.73,"endTime":3086.63,"body":"almost everything about us is inherited"},{"startTime":3086.63,"endTime":3087.81,"body":"in a typical genetic way,"},{"startTime":3087.81,"endTime":3089.55,"body":"but there are some areas like that"},{"startTime":3089.55,"endTime":3091.2,"body":"where it's undoubtedly important."},{"startTime":3092.04,"endTime":3093.09,"body":"- [Audience Member] My question is,"},{"startTime":3093.09,"endTime":3096.13,"body":"because you touched how"},{"startTime":3093.09,"endTime":3096.13,"body":"life on Earth started."},{"startTime":3097.92,"endTime":3099.6,"body":"You haven't said anything about viruses."},{"startTime":3099.6,"endTime":3104.05,"body":"Do you think viruses evolved"},{"startTime":3099.6,"endTime":3104.05,"body":"from the bacteria cells?"},{"startTime":3104.05,"endTime":3106.29,"body":"Or they were completely"},{"startTime":3104.05,"endTime":3106.29,"body":"different life forms"},{"startTime":3106.29,"endTime":3109.26,"body":"that evolved independently?"},{"startTime":3109.26,"endTime":3110.093,"body":"Thank you."},{"startTime":3110.093,"endTime":3111.45,"body":"- Yeah, no, great question."},{"startTime":3111.45,"endTime":3114.69,"body":"So the fundamental feature of viruses"},{"startTime":3114.69,"endTime":3116.58,"body":"is that they're not truly alive"},{"startTime":3116.58,"endTime":3118.89,"body":"in the sense that they cannot"},{"startTime":3116.58,"endTime":3118.89,"body":"survive without a host."},{"startTime":3118.89,"endTime":3120.36,"body":"They can't do anything without their host."},{"startTime":3120.36,"endTime":3122.613,"body":"They rely on a host to do something."},{"startTime":3123.84,"endTime":3124.98,"body":"And in terms of when,"},{"startTime":3124.98,"endTime":3127.29,"body":"so my strong feeling is therefore that"},{"startTime":3127.29,"endTime":3128.79,"body":"even the very first virus"},{"startTime":3128.79,"endTime":3131.07,"body":"must have arisen after something else,"},{"startTime":3131.07,"endTime":3132.99,"body":"'cause it needed"},{"startTime":3131.07,"endTime":3132.99,"body":"something to predate upon."},{"startTime":3132.99,"endTime":3135.66,"body":"What we see today is that viruses"},{"startTime":3135.66,"endTime":3138.66,"body":"very clearly arise from other,"},{"startTime":3138.66,"endTime":3140.31,"body":"so often they are, for example,"},{"startTime":3140.31,"endTime":3141.9,"body":"bits of DNA from something else"},{"startTime":3141.9,"endTime":3145.65,"body":"that has kind of popped"},{"startTime":3141.9,"endTime":3145.65,"body":"out as a free living life,"},{"startTime":3145.65,"endTime":3148.17,"body":"and it acquires different"},{"startTime":3145.65,"endTime":3148.17,"body":"genes as it goes along."},{"startTime":3148.17,"endTime":3150.18,"body":"So what you can sometimes"},{"startTime":3148.17,"endTime":3150.18,"body":"see, for example,"},{"startTime":3150.18,"endTime":3152.97,"body":"is that a virus might"},{"startTime":3150.18,"endTime":3152.97,"body":"pick up a bit of host gene"},{"startTime":3152.97,"endTime":3155.01,"body":"and add it to its genome,"},{"startTime":3152.97,"endTime":3155.01,"body":"if it adds a benefit."},{"startTime":3155.01,"endTime":3157.41,"body":"So one of the examples is"},{"startTime":3155.01,"endTime":3157.41,"body":"if it can pick up a gene"},{"startTime":3157.41,"endTime":3159.24,"body":"that somehow confers the ability"},{"startTime":3159.24,"endTime":3161.52,"body":"to evade the immune"},{"startTime":3159.24,"endTime":3161.52,"body":"system, that's favored,"},{"startTime":3161.52,"endTime":3162.407,"body":"and so the virus now has that."},{"startTime":3162.407,"endTime":3165.18,"body":"And so you end up with viral evolution"},{"startTime":3165.18,"endTime":3167.22,"body":"by a kind of mix and match process"},{"startTime":3167.22,"endTime":3168.873,"body":"of stealing genes from others."},{"startTime":3169.707,"endTime":3171.66,"body":"So, I think they were slightly later,"},{"startTime":3171.66,"endTime":3173.76,"body":"but nonetheless,"},{"startTime":3171.66,"endTime":3173.76,"body":"undoubtedly very early on."},{"startTime":3173.76,"endTime":3176.58,"body":"So almost all bacteria"},{"startTime":3173.76,"endTime":3176.58,"body":"have viruses of them,"},{"startTime":3176.58,"endTime":3178.32,"body":"so-called bacteriophages."},{"startTime":3178.32,"endTime":3180.57,"body":"So they're not a recent"},{"startTime":3178.32,"endTime":3180.57,"body":"evolutionary event at all,"},{"startTime":3180.57,"endTime":3182.55,"body":"I think, but they must,"},{"startTime":3180.57,"endTime":3182.55,"body":"I think by definition,"},{"startTime":3182.55,"endTime":3184.743,"body":"have risen after the"},{"startTime":3182.55,"endTime":3184.743,"body":"very first life forms."},{"startTime":3185.786,"endTime":3186.619,"body":"- [Audience Member] I don't want"},{"startTime":3186.619,"endTime":3188.25,"body":"to lower the tone of the lecture."},{"startTime":3188.25,"endTime":3189.66,"body":"- Oh, please do. (laughs)"},{"startTime":3189.66,"endTime":3192.783,"body":"- [Audience Member] You"},{"startTime":3189.66,"endTime":3192.783,"body":"did mention poo swapping."},{"startTime":3192.783,"endTime":3194.22,"body":"I can't let that go."},{"startTime":3194.22,"endTime":3198.06,"body":"You've also talked about,"},{"startTime":3194.22,"endTime":3198.06,"body":"you know, hand shaking"},{"startTime":3198.06,"endTime":3199.8,"body":"and what's transmitted through that"},{"startTime":3199.8,"endTime":3201.003,"body":"and how it dies off, so."},{"startTime":3202.566,"endTime":3203.484,"body":"- Where do we go from that?"},{"startTime":3203.484,"endTime":3204.33,"body":"- [Audience Member] I tried to."},{"startTime":3204.33,"endTime":3205.23,"body":"- No, I like that."},{"startTime":3205.23,"endTime":3206.85,"body":"Yes, I mean, so that's"},{"startTime":3205.23,"endTime":3206.85,"body":"actually fascinating."},{"startTime":3206.85,"endTime":3208.68,"body":"So the place that this has been worked"},{"startTime":3208.68,"endTime":3211.29,"body":"on most extensively is with patients"},{"startTime":3211.29,"endTime":3214.95,"body":"with things like ulcerative"},{"startTime":3211.29,"endTime":3214.95,"body":"colitis, Crohn's disease,"},{"startTime":3214.95,"endTime":3217.23,"body":"where there is now pretty good evidence"},{"startTime":3217.23,"endTime":3220.29,"body":"that the particular microbiome you have,"},{"startTime":3220.29,"endTime":3221.64,"body":"so in some patients,"},{"startTime":3221.64,"endTime":3224.4,"body":"the diversity of bacteria and fungi"},{"startTime":3224.4,"endTime":3225.66,"body":"and everything else you have"},{"startTime":3225.66,"endTime":3228.45,"body":"is triggering damaging inflammation."},{"startTime":3228.45,"endTime":3230.31,"body":"And so if you switch that microbiome"},{"startTime":3230.31,"endTime":3233.58,"body":"in its entirety for a"},{"startTime":3230.31,"endTime":3233.58,"body":"healthier microbiome,"},{"startTime":3233.58,"endTime":3235.253,"body":"you can often get benefits."},{"startTime":3235.253,"endTime":3236.88,"body":"I mean, I should say it's not trivial."},{"startTime":3236.88,"endTime":3238.62,"body":"So first of all, you have to eradicate"},{"startTime":3238.62,"endTime":3240.39,"body":"all the microbes in your patient"},{"startTime":3240.39,"endTime":3243.3,"body":"by a really extensive"},{"startTime":3240.39,"endTime":3243.3,"body":"course of antibiotics,"},{"startTime":3243.3,"endTime":3246.18,"body":"and then essentially switch poo"},{"startTime":3246.18,"endTime":3248.07,"body":"together with all its compliments"},{"startTime":3248.07,"endTime":3249.243,"body":"from a healthy donor."},{"startTime":3250.11,"endTime":3253.08,"body":"And that has actually some quite profound"},{"startTime":3253.08,"endTime":3255.18,"body":"clinical benefits in some patients."},{"startTime":3255.18,"endTime":3256.56,"body":"There is a lot of interest now"},{"startTime":3256.56,"endTime":3258.06,"body":"in extending that to all"},{"startTime":3256.56,"endTime":3258.06,"body":"sorts of other things."},{"startTime":3258.06,"endTime":3258.893,"body":"So you might be aware,"},{"startTime":3258.893,"endTime":3259.8,"body":"there's a lot of media out there"},{"startTime":3259.8,"endTime":3262.29,"body":"about obesity and to"},{"startTime":3259.8,"endTime":3262.29,"body":"what extent is obesity,"},{"startTime":3262.29,"endTime":3264.27,"body":"you know, driven by microbes."},{"startTime":3264.27,"endTime":3265.17,"body":"And there's quite good evidence"},{"startTime":3265.17,"endTime":3267.81,"body":"actually that some people's microbiome"},{"startTime":3267.81,"endTime":3269.55,"body":"is much better at harvesting energy,"},{"startTime":3269.55,"endTime":3270.69,"body":"and therefore making you fatter"},{"startTime":3270.69,"endTime":3273.48,"body":"for the same amount of"},{"startTime":3270.69,"endTime":3273.48,"body":"inputs than other people's."},{"startTime":3273.48,"endTime":3275.25,"body":"And there's even some kind of emerging"},{"startTime":3275.25,"endTime":3276.93,"body":"but quite exciting evidence that"},{"startTime":3276.93,"endTime":3278.49,"body":"your microbiome might affect things"},{"startTime":3278.49,"endTime":3279.81,"body":"that we think of as being very individual,"},{"startTime":3279.81,"endTime":3281.28,"body":"like mood, for example."},{"startTime":3281.28,"endTime":3284.73,"body":"So, many mental health conditions,"},{"startTime":3284.73,"endTime":3286.5,"body":"there are differences"},{"startTime":3284.73,"endTime":3286.5,"body":"in microbiome content"},{"startTime":3286.5,"endTime":3287.88,"body":"between certain people"},{"startTime":3287.88,"endTime":3289.95,"body":"and people without those conditions."},{"startTime":3289.95,"endTime":3291.75,"body":"Lots and lots of caveats around that,"},{"startTime":3291.75,"endTime":3293.37,"body":"but I think, you know, the compliments,"},{"startTime":3293.37,"endTime":3294.48,"body":"your microbiome is probably doing"},{"startTime":3294.48,"endTime":3297.057,"body":"an awful lot more than we think it does."},{"startTime":3297.057,"endTime":3298.44,"body":"I'm not aware of any data that"},{"startTime":3298.44,"endTime":3299.79,"body":"your hands have a big impact."},{"startTime":3299.79,"endTime":3301.653,"body":"So Wendy, you're still safe, I think."},{"startTime":3303.72,"endTime":3304.553,"body":"- [Audience Member] I was just wondering"},{"startTime":3304.553,"endTime":3306.27,"body":"what the conditions in the lab"},{"startTime":3306.27,"endTime":3311.27,"body":"that we use to select"},{"startTime":3306.27,"endTime":3311.27,"body":"for multicellularity."},{"startTime":3311.306,"endTime":3312.36,"body":"- Yeah."},{"startTime":3312.36,"endTime":3313.62,"body":"No, actually, very, very simple."},{"startTime":3313.62,"endTime":3315.21,"body":"So essentially what they did"},{"startTime":3315.21,"endTime":3317.01,"body":"was they used a density gradient."},{"startTime":3317.01,"endTime":3319.77,"body":"So the bigger the clump,"},{"startTime":3319.77,"endTime":3320.67,"body":"the faster it falls."},{"startTime":3320.67,"endTime":3321.503,"body":"And this is something that, you know,"},{"startTime":3321.503,"endTime":3323.37,"body":"if you've done sort of"},{"startTime":3321.503,"endTime":3323.37,"body":"home brew or something,"},{"startTime":3323.37,"endTime":3324.45,"body":"you know, you wait for"},{"startTime":3323.37,"endTime":3324.45,"body":"your brew to happen,"},{"startTime":3324.45,"endTime":3325.53,"body":"then you let your yeast settle,"},{"startTime":3325.53,"endTime":3326.457,"body":"and you take the white off."},{"startTime":3326.457,"endTime":3327.81,"body":"And so, if you do that in a way"},{"startTime":3327.81,"endTime":3330.42,"body":"that you get the fastest falling,"},{"startTime":3330.42,"endTime":3333.06,"body":"i.e. the biggest clumpier organisms,"},{"startTime":3333.06,"endTime":3334.38,"body":"and you do it again and again and again,"},{"startTime":3334.38,"endTime":3335.55,"body":"what you very soon end up"},{"startTime":3335.55,"endTime":3337.38,"body":"with are organisms that only ever clump"},{"startTime":3337.38,"endTime":3338.94,"body":"and never grow freely."},{"startTime":3338.94,"endTime":3340.38,"body":"And I think actually"},{"startTime":3338.94,"endTime":3340.38,"body":"that's the kind of thing"},{"startTime":3340.38,"endTime":3341.88,"body":"that might have happened also naturally"},{"startTime":3341.88,"endTime":3343.05,"body":"in terms of early evolution,"},{"startTime":3343.05,"endTime":3345.21,"body":"because being multicellular has benefits."},{"startTime":3345.21,"endTime":3347.34,"body":"So if you think about, for"},{"startTime":3345.21,"endTime":3347.34,"body":"example, the shoreline,"},{"startTime":3347.34,"endTime":3349.8,"body":"being a big, lumpy, sticky thing"},{"startTime":3349.8,"endTime":3350.88,"body":"is probably quite beneficial"},{"startTime":3350.88,"endTime":3352.26,"body":"if you can stick to a rock"},{"startTime":3352.26,"endTime":3353.79,"body":"in a way that a single cell can't."},{"startTime":3353.79,"endTime":3355.17,"body":"But again, that's slightly speculation."},{"startTime":3355.17,"endTime":3357.12,"body":"But I think it's probably"},{"startTime":3355.17,"endTime":3357.12,"body":"not that difficult"},{"startTime":3357.12,"endTime":3358.29,"body":"to find conditions in nature"},{"startTime":3358.29,"endTime":3359.94,"body":"which stimulate multicellularity."},{"startTime":3361.68,"endTime":3363.18,"body":"- Well, thank you very much."},{"startTime":3363.18,"endTime":3365.61,"body":"It's very nice to be able"},{"startTime":3363.18,"endTime":3365.61,"body":"to conclude a lecture"},{"startTime":3365.61,"endTime":3367.41,"body":"saying that it wasn't a load of poo."},{"startTime":3368.64,"endTime":3370.44,"body":"- It was."},{"startTime":3368.64,"endTime":3370.44,"body":"- I'd like to thank Robin"},{"startTime":3370.44,"endTime":3371.64,"body":"for a fantastic lecture,"},{"startTime":3371.64,"endTime":3372.84,"body":"and thank you very much."},{"startTime":3374.274,"endTime":3375.288,"body":"- Thank you."},{"startTime":3375.288,"endTime":3376.874,"body":"(audience applauding)"}]}