How Did Life Begin? with Betül Kaçar

Eczema Treatment

0:00Eczema is unpredictable, but you can flare less with Epglyss, a once-monthly treatment for moderate to severe eczema. After an initial four-month or longer dosing phase, about 4 in 10 people taking Epglyss achieved itch relief and clear or almost-clear skin at 16 weeks. And most of those people maintain skin that's still more clear at one year with monthly dosing. Epglyss, LibriKizumab, LBKZ, a 250 milligram per 2 milliliter injection, is a prescription medicine used to treat adults and children 12 years of age and older who weigh at least 88 pounds or 40 kilograms with moderate to severe eczema, also called atopic dermatitis,

0:32that is not well controlled with prescription therapies used on the skin or topicals or who cannot use topical therapies. Epglyss can be used with or without topical corticosteroids. Don't use if you're allergic to Epglyss. Allergic reactions can occur that can be severe. Eye problems can occur. Tell your doctor if you have new or worsening eye problems. You should not receive a live vaccine when treated with Epglyss. Before starting Epglyss, tell your doctor if you have a parasitic infection. Ask your doctor about Epglyss and visit epglyss.lily.com or call 1-800-LILY-RX or 1-800-545-5979.

Hertz Car Rental

1:00You know, one of the nice things about Hertz right now is that they have a whole fleet of new cars. So whatever trip you're planning, it's easy to find a new car that fits your adventure. Heading out for a sunny drive? Then a new convertible with very little roof is for you. Considering a fishing trip with your mini-me? Then you need a new minivan that's anything but mini. And if you're planning on some stargazing, a new SUV will give you plenty of space. Get paired with our newest fleet yet at Hertz.com. StarTalk Radio is presented by Pluto TV.

1:32It's a universal truth. Pluto is not a planet. Pluto TV, on the other hand, holds a universe of free entertainment we can stream from our own planet. Check out the ever-expanding list of supernatural favourites including Fringe, The X-Files, Battlestar Galactica, and a full fleet of Star Trek series you can stream for free. No payment, just pure discovery. See what's landing on Pluto TV. Stream now.

Life Origins

2:03Pay never. You know, all our efforts to find life in the universe at some point needs a ground truth. So true. And that happens on Earth. Yes. We got one of the world's experts to think about life on Earth and how it got here and how it turned into what it became. Yeah. Going back three billion years. We're going into the way back. Way. Way back. Coming up on StarTalk. What would you do if an alien actually showed up? Would you shake its hand or run?

2:33Does it even have a hand to shake? In my latest book, Take Me to Your Leader, I explore not only how they might have gotten here, but what they might want and how you should respond. Because the real question is not, are we alone? It's, are we ready? By the way, I also narrated Take Me to Your Leader. And I'm duly informed that you can get a copy of that book or the audio book now, wherever books are sold. You should probably get the book sooner rather than later.

3:06You don't want to have a first alien encounter and not be ready for it. I'm just saying.

StarTalk Introduction

3:12Welcome to StarTalk. Your place in the universe where science and pop culture collide. StarTalk begins right now. This is StarTalk. Neil deGrasse Tyson, your personal astrophysicist. Got Chuck Knight with me. What's up, Neil? Chuck, it's about time we cover this subject. Okay. It's life on Earth and in the heavens. It is about time because, you know, it's been about four billion years.

3:44When the hell are we going to get to it? I'm going to, might as well do it. Might as well do it now. Might as well do it now. And there's an interesting diversity of expertise out there. Okay. Everybody taking the little bit of what their background enables them to study. Okay. And contribute to our understanding. Okay. Of what life is and what makes it tick. Yeah. And what's the difference between life here and elsewhere? What do you mean elsewhere?

4:09Well, we're going to find out. Oh, okay. We have with us, Bitul Kachar. Hi. Hello. Hi. Thanks for having me. Welcome to StarTalk.

Biologist Background

4:18Happy to be here. All right. So, you got all the pedigree here that's necessary for this conversation. Director of the NASA-funded MUSE, Metal Utilization and Selection Across Eons. Oh, wow. We got to get into, what's that about? Yeah. And there's the Eons. And there's the Kachar Lab. Did you found your own lab? Is that right? Yeah. Yeah. I run my own lab. Nice. That's bad. When people have their own labs, that's a bad. That's badass. That's pretty cool. That's, that's, that's. It's very Marie Curie of you.

4:49I hope my ending is the same. No. Well, the good part. Okay. That means if you create something in your lab, it comes after you first. Yeah. Yes. The creator. I live with that fact every day. It takes you for reminding me. You are professor at University of Wisconsin, Madison. Nice. In the Department of Bacteriology. Wow. Ooh. So, if you have that on a business card and you hand that to someone, do they just walk away from you? Or do they use gloves to take your car? Well, let me tell you, I don't have a lot of friends because of this. Oh, that's it? That's what I'm wondering. Yeah. But if you don't like bacteria, we can't be friends.

5:21So, let's get that straight. Oh, good point. Are we bacteria friendly here? Yeah, we are. Okay, good. Very good. Very good. Without it, would we even be? Would we even be? We wouldn't be. We would not be without bacteria, right? We wouldn't be able to breathe. Yeah, we wouldn't be, yeah, go ahead. We would make an attempt, but there wouldn't be any oxygen to breathe. Or digest our food. Right. Oh, so many things. It does the digesting. It does all the digesting, right? Right, right. Okay. See, we're friendly. Yeah, yeah, yeah. Wanted to make sure.

Resurrecting Enzymes

5:50So, you recently published a paper in Nature, which is the preeminent European Journal of Science, and it's, you resurrected ancient enzymes? What does that even mean? It's kind of scary, though. So, to resurrect anything as a biologist, that's got Jurassic Park written all over it. Oh, I was going with Jesus, but okay, Jurassic, I'll take the Jurassic Park.

6:21They both start with a J. Exactly. So, tell me what was the significance of that paper. Well, we, as you said in the beginning, there are many ways in which a scientist can study life, and we are, I would say, obsessed with understanding its origins and its first steps. And mind you, it's a bit different than life's origin. We are interested in what happened once life emerged, and what were the first steps, and how did life survive over eons, over billions of years, and how did it make it through this far?

6:54We are also interested in understanding the marks that life leaves behind. So, if I, you know, walk in the snow, you can tell my footsteps, at least for some time, and then snow melts, and my marks are gone, right? If I leave that kind of mark on rocks, like if I'm a dinosaur, you're able to track my past as well using this. But if I'm a microbe, how does this work? And we know that this is a microbial planet. Our planet is run by microbes. If you don't like microbes, wrong place for you. So, Beyonce was wrong. Who run the world? Not girls, microbes. And girls.

7:25See what happened? See what happened? She's all up in your situation. Don't even try next time. Just give up. No, look, I want to see. I see. I got your number. I got your number. Okay. So, in the end of the day, we are just vessels for microbes to do their work. Exactly. I mean, our gut, the gut feeling, I always find it funny. It's really, you know, microbial gut, right? Microbes scramble inside of you, and they live there. And you are basically a hostage for a microbe, as far as I can tell.

7:55I checked the numbers on this. One centimeter slice of your lower intestine, in there lives and works more microbes than the total number of humans who have ever been born. Nice. So, to them, we are just an anaerobic vessel of fecal matter. Right. So, yes, yes, that's, you know, an ugly bags of mostly water and anaerobic vessels of mostly fecal. I agree. We are very crappy. But it works. It works.

8:26But the whole point of this paper, though, is that, you know, as I mentioned, your marks can be erased. And life, what makes life so amazing on this planet, that it is an evolving system. It's not like geology, where you can find a rock, and you're lucky to find one, and you can analyze the fossils on them. But how do you replay the tape? How do you visit the past of something that constantly overwrites itself? Right. Because in geologists, they have a rock. Right. And it can sit there for hundreds of millions of years, and it's still the same rock. Exactly. It's the same rock. And another layer, that they have layers that they can go down and look at, too. Exactly. And if it's not covered by forests, which mostly our planet is, so we're not going to be able to find these rocks.

9:01And we have very few rocks that we can rely on in order to tell the story of the first two billion years of this planet. Of life. Well, you know what? Life and the planet. Because the first two billion years, about a year and a billion and a half of that life was present here. Yes. Right? Life happened to this planet really rapidly. So I don't think you can separate planet Earth from life. It's a pretty, it's been a pretty. It's nice. I like that. What is the timeline when you talk about whatever, molten state, cooling, life?

9:32What's that timeline? For a geologist, it's like a second. It's pretty fast. We're talking about 500 million years. Oh, wow. For us, that's, you know, a long time. That's a long time for you. But for a geologist, it's pretty rapid. So it happens fairly rapidly, and we rely on what life left behind. So you can imagine that probably it already took over the planet if we are able to find these remnants of life. The problem, however, is that we only work with a very few samples, because if you even call them samples, they're fossils. And so what do we do right now? So I'm a biologist. I like making things in the lab.

10:04I like touching organisms. I like playing with them. And I like genomes. I like genes. I love proteins. I love all of that. So our approach was to use the language of life, which is DNA, and resurrect the ancient language that is now extinct. And bring it back to life by cloning that extinct DNA inside the microbial organism, basically forcing the microbe to speak an ancient dialect to tell us something about their past. Well, if DNA barely survives a crime scene, then how do you know that?

10:34How do you know that? Because he uses bleats whenever he murders someone. That's how. So let me see if I understand this. You're using computer modeling based on the DNA we know, extrapolating, backstrapolating to a time where we don't have DNA available to us to get some handle on what that life might have been like. And in this case, it's not life that you created, but an enzyme that would be important for life at the time.

11:07Do I understand that correctly? Yeah, exactly. And in order to do this, you use the DNA manipulating tools, one of the CRISPR, I guess. We use CRISPR. We use all the different editing. The gene editing, that's what you've done. And is this the beginning of what will be a Jurassic Park of enzymes in your lab? We've been doing this for some time now with other systems. Yes, but it's definitely the beginning in the sense of linking this to biosignatures and connecting them to our understanding of life anywhere.

11:38So you'll be triangulating using these measurements, triangulating on what life at that time might have been doing. Exactly. That's very powerful. It is like bringing some ancient organism back to life and having a conversation with them. And, you know, most of the time you don't understand each other, right? And they now are awake in an environment that is very different. But we want them to tell us, so to speak, have a little conversation with them. Okay, we use the breadcrumbs that you left behind in order to track you. And we now know where you come from.

12:09We know where you came from. Yeah, exactly. We know where you live and we know where you came from. That's mafia right there. That is very much. Yeah, so now when do they escape and come together and create a life that kills us all? When does that happen? Well, I'm really glad you asked that question, Chuck, because it gives me a chance to explain. Where is she? We haven't seen her in weeks. She's tied to the back wall and the microbes are just in charge. Yeah. They become your overlords. Yeah, they're just like, how do you feel about being studied?

12:39Well, you're describing my worst nightmares. I have a question. If you know what the sample is going to be that you create, why do you have to create it? Well, we need to understand in what conditions it can trick us. We want to know if I give it a different guess, if I recapitulate ancient Earth, will it start tricking me? So you poke around at the thing you created. Oh, yeah. We created and then we wanted to see its limits. And you poke it. I want to see what it will look like if I create a Martian condition, for example. So that's the next step we're going for, for sure.

13:10I mean, this is a big problem for astrobiology because we always talk about, a Nicole's one, there's only one planet, there's only one life. But if you think about it, our life has gone through many, many, many, many, many different versions of itself. It reinvents. Like over 99.99% of everything that ever lived on this planet has gone extinct. It's gone. Yeah, yeah. And that includes likely microbes. We don't have an understanding of what kind of signatures they left behind and what alien life, which is our own past, may have looked like. However, if life is so good at creating new species, opportunistically, as an environment is changed,

13:46why hasn't there been more than one genesis of life on Earth? Why does all life have DNA in common? Why isn't there a whole other branch? If it's so quick, it was so easy to make life on Earth, why didn't it just happen 10 times? Not just branches within one tree, 10 different trees. An orchard of life. Orchard, I like that. Bushes. First of all, life may not be as good as you think, right? It may really need a planet to be at the right time, at the right place with it. Life is not just a thing that's by itself.

14:17Biology needs its container. And here it's planet Earth. So you cannot take the planet outside of life. They're together. That's the number one thing. Are we clear on this? Number two is that life is, we don't know to what degree it's a fluke accident, or to what degree it was determined to be the way it is now, right? We don't have much understanding of the chance and necessity that drives- Because you only have a sample of one. Exactly. Yeah, okay. I mean, we can play in the lab. We can create some conditions and replay and reverse and try to do these evolution experiments like we do. But fundamentally, we lack that understanding of to what degree life is able to recapitulate itself.

14:51And three, again, we don't know. Maybe there will be other planets, and that's our hope, right? That where we look and study what life can do. And you'll find a different tree. And I will tell you this, and this may actually blow your mind. Because it is true that, as far as we know, origin of life has happened once. And it's not the only thing, though, that transformed our planet that happened once. I like to think of these as singularities. These are evolutionary singularities that happened only once. And they completely transformed our planet. And I can only count to you a very few of them.

15:22One is origin of life, to what we know, one genesis. The second one is the production of oxygen. There is only one way that biology invented creating oxygen. It is crazy that that's even a thing. Only one way that this planet has done its way to create oxygen. And look how much everything we relate to as a living thing relies on this thing. It's a photosynthesis, basically. Exactly, oxygen photosynthesis. Either in the oceans or in the plant life that would come later. And plants are late, right? Yeah, they're much later than the oceans gave us oxygen.

15:53Animals want origins, right? Plants want origins. So these are the singularities that only happen. Nitrogen fixation want origins. So there are multiple things. As good as life is, it only happened once. I've heard the term nitrogen fixation. Explain that to me, please. Maybe I missed that day in chemistry class, but I have no idea what nitrogen fixation is. Ironically, I missed that day too, yet I studied it. So it's not an excuse. Call me out.

16:25Okay, gauntlet thrown, challenge accepted. I will, on my own, go learn nitrogen fixation. We rely on nitrogen. ATP needs nitrogen. Our DNA needs nitrogen. So it's essential to life as we know it. And we think that it is as old as about 3 billion years. So the first billion years of life didn't have biological fixation of nitrogen. So what do we mean by that? Luckily, there's a lot of nitrogen in the atmosphere. Lots. But it is not readily available to our cells. It cannot enter our cells as easily. It needs to be transformed. It's a triple bond.

16:57It's very, very strong. So life invented a way to break this bond and turn nitrogen into a form that is ammonia that is available for life. And that's been doing that for 3 billion years, relying on a single enzyme. So if that enzyme is ruined, the whole show collapses. Or so we thought. So we created an artificial way of fixing nitrogen. That's the Haber-Basch process, which is insane amount of energy. About 2% of the world's entire energy consumption goes through the production of artificial ammonia through artificial nitrogen fixation process using Haber-Basch.

17:34Think about that. And all fertilizer, agriculture, industry depends on this. You need to get nitrogen unbound to itself because in the atmosphere it's N2. So now you have a nitrogen atom available to work its way into the processes of life. Exactly. And that's nitrogen fixation. That's nitrogen fixation. That's the biological nitrogen fixation. It happens abiotically too. Like lightning fixes some nitrogen. So many people think that. Because it's got a lot of energy.

18:04You can break apart anything. Oh yeah. But we think that wasn't sufficient enough. After a while there was such demand for more nitrogen as organisms grew and more species diverged early on. That likely triggered biological production, biological production of nitrogen.

18:22Support for StarTalk Radio comes from talkaboutpd.com.

Peyronie's Disease

18:36Let's talk about a condition many people haven't heard of. And it turns out it's more common than you'd think. Peyronie's disease or PD for short. PD can happen when scar tissue builds up under the skin of the penis. This can cause a curve with a bump during an erection. And for some men lead to pain during intimacy and may impact mental health. It may also lead to anger and frustration, depression, lower self-esteem, and even withdrawal from sexual activity and physical intimacy. Because of this, some men could feel embarrassed or reluctant to talk about PD.

19:10The actual cause of PD isn't always known. In some cases, it may be linked to a minor injury or repeated injuries during sex or other physical activity. The good news is PD is treatable. If you notice a curve with a bump, a trusted urology specialist can help diagnose it and walk you through your options, including non-surgical treatment. To learn more about Peyronie's disease, visit talkaboutpd.com.

Cheers Restore

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20:43After you purchase, they will ask you where you heard about them. So please support our show and tell them that Chuck sent you. And by that, I mean STARTALK. You know, one of the nice things about Hertz right now is that they have a whole fleet of new cars. So whatever trip you're planning, it's easy to find a new car that fits your adventure. Heading out for a sunny drive? Then a new convertible with very little roof is for you. Considering a fishing trip with your Mini-Me? Then you need a new minivan that's anything but mini. And if you're planning on some stargazing, a new SUV will give you plenty of space.

21:16Get paired with our newest fleet yet at Hertz.com. I'm Joel Cherico, and I support STARTALK on Patreon. This is STARTALK with Neil deGrasse Tyson.

21:38So what's the value of you fixing nitrogen artificially if it's not what nature does? I'm so glad you asked this question. So this goes back to survival of life, right? Okay. Chuck. Yeah. That's not what we were—we had an argument before this whole show started. It wasn't really an argument. Don't bring your arguments from outside the show into the show. Well, no. Keep the arguments in the street. Listen, I left my argument in the street. She just bought it into this room. Okay. Okay. What was the argument? Well, no, the argument, I said—she made a very biologist statement.

22:11What was that? Life is about survival. Okay. I made a very philosophical statement. Which was? That is wrong. Okay. Let's get to the bottom of it. Go. Life is about survival. And it is about how the biological systems find ways to make it, basically, through the good and the bad. And I think there's a big inspiration out of this. It's not something that I'm afraid of facing, Chuck. So— That life finds a way. And it is through, most of the time, overcoming these insane challenges by coming up with very insane responses.

22:42Right. It doesn't—you know how we are told that in the face of conflict, like, find some corner, maybe be quiet, be political? Life doesn't do that. It's—you punch it, it punches back. Right? So now there's oxygen in the planet. We are two billion years in. And nitrogen fixation has evolved. Yes. But guess what? This enzyme, this whole biological system, hates oxygen. All right, what do I do now? There's all this oxygen in the environment. And I don't like oxygen. So how do I survive? It finds ways—we don't know exactly how and what—to protect itself from the dangers of nitrogen.

23:15It protected nitrogen fixation. So we created animals that thrive on oxygen. Oh, that is way— That's way down the line. Way down. Like, there's another, like, two billion years until we get there. Oh, wow. Yeah, there's another billion year for the cariots. There's another—if some biologists are listening to me, they may be like, how about all the heterocysts and all the systems that protect nitrogen organelles that blah, blah, blah. They were also later. All right? So we want to understand how nitrogen fixation survived oxidation. How did such dangerous thing manage to not kill this biological system?

23:45Because oxygen is highly caustic to so many things. Oh, yeah. Right. So when you created an ancient enzyme, was that a nitrogen-fixing enzyme? In this particular case, it is a nitrogen-fixing enzyme. We did this for carbon. We did this for informatics, for genetic—more replication system as well. But in this particular case, it is a nitrogen system. So going back to your original question, if this is so costly and we need all these fertilizers, what we are trying to do is not to reinvent a new agriculture, but maybe decrease our dependence on this energetically, globally, very demanding productions.

24:21We need better biological solutions. For fertilizer, for plants. Well, it wouldn't be for fertilizer, but to create more efficient nitrogen fixation, it would be the opposite thing, to maybe lessen our dependence on fertilizers. Right, got it, got it. So this is a beautiful example, in my very biased opinion, of how astrobiology and studying life in the universe by starting from here, our own place and our own past, can actually help our future. However, if we understand that how these essential systems made it thus far, we may be able to re-engineer them and repurpose them for better efficiency.

24:54Because our planet has gone through a lot. It's gone through many ups and downs. And we should not treat past as some useless waste. Because of our understanding, maybe limited understanding of evolution, we think that if something didn't make it, it was failure. But there are many reasons for an organism to just to not to not make it for no fault of nothing to their own. Right, exactly. Like T-Rex just got unlucky. I mean, also, they were not that bright, I think. I'm sorry about it. If any T-Rex is watching this, don't hate me.

25:26If the asteroid didn't take them out, there's no reason why T-Rex wouldn't still be outside the door. Well, they didn't have a planetary protection program. I know. Yeah, right. Well, if intelligence is a prerequisite for survival, I got news for you, people. We're all screwed. Okay? I don't want to put words in your mouth. You're exploring all the ways life has attempted to survive on the possibility or the likelihood that learning what those are could help us today. Exactly. This is not where it started, I'll be very honest.

25:57We just had this very basic curiosity about very basic processes of how and why. And how did things evolve? We don't have any understanding of any protein or any metabolism. How did they evolve at first place? I mean, think about that. Tell me any protein you love and I'll tell you. We have no idea how it originated on this planet. And that's a huge knowledge gap. But these questions inevitably led us to understand, create a new paradigm between the planet and microbiology, which I like to refer to as planetary microbiology. How does the microbe and bacteria and eukaryotes, how do they dance with the planet?

26:29Biology needs to completely transform itself and really evaluate molecules and cells and organisms from the perspective of the planet. We need to understand the planetary boundaries that constrain life in order to understand and maybe create a better future for ourselves as well because we rely on these organisms. Remind us what a eukaryote is. You said that very quickly in a sentence. How do I begin to explain myself? Well, I would, in my very biased opinion, it's a bacteria that escaped the metabolic trap and bacteria that got very, very lazy.

27:04It's basically, I would say, the next points in evolution. They are about 1.8 billion years old. They have more organelles, more complexity. They are our ancestor. And so our ancestors are 1.8 billion years old. We are eukaryotes. Plants are eukaryotes. So they have a cell nucleus? They have a nucleus. They have more complex organelles. So there's more going on. More going on. Exactly. There's a lot more going on. And they are more lazy. I mean, in general, life is lazy. It will always choose the laziest option. Take a look at cats and dogs at home.

27:36I think dogs sleep 20 hours a day. That's called smart. That's all. They're looking at us like- They're happy when you should get home, but they sleep the whole rest of the day. That's why they jump up and down and they're just like, all right, I'm tired. Seeing you just really exhausted me. I've got to go eat and then go back to sleep. Let's pivot to what we now think of as extremophiles. This has arisen in astrobiology as if life on Earth can thrive in exotic environments that might otherwise kill us, let's look in the universe at the exotic environments.

28:12It might help us think about ways of being alive that are not otherwise the 72 degree tide pool where, you know, as someone had said, you know, in generations past. So tell me about how this plays into thinking about extremophiles. Well, I don't think there's any corner on this planet that was not taken over or occupied by life at any point. There is no such thing as un-living, non-living on this planet. Okay. Everywhere. Everywhere. And thanks to NASA and the Astrobiology Program and their vision, I think decades ago, the understanding that we need to drill, we need to go to caves, we need to look into ice, we need to go all these crazy places where we think is completely barren of life.

28:54Because guess what? Under every rock, we find life. And now we call them extremophiles. But if you think about it, it's a bit of an outdated term, I think. Because what is extreme? I mean, it's very relative. Right. It's not extreme for them. Right. Exactly. I mean, just as extreme. What is it that they found underwater eruptions of volcanoes where it's highly toxic, water is extremely hot. And I forget the microorganisms that they found living there, and they're doing just fine.

29:24They're doing just fine. Someone's waste is someone's food, right? Right. This planet wastes nothing. Nothing goes to waste. And that's the beauty of all these organisms that sort of depend on each other. They cheat, they compete, they cooperate, but they find a way to survive. They find a way to make it. Why does it find a way?

29:43Pithola is loving every time she can say survive to me. So I like the idea that the word extremophile might be outdated. Kind of outdated, yeah. I love that. Yeah. Because. It's just life. It's just life. It's just life. It's not extreme life. It's not the X games. It's just life. It's extreme to us, you know, but it's all, again, coming from our. They would call us extremophiles. Absolutely. Life does many, many weird things, and it will not waste anything. It will eat the sunlight. It will eat acids.

30:14It will eat, you know, whatever. However, it will find a way, and that's thanks to metabolism, and all the, you know, what is the, that nice saying, life is an electron looking for a place to rest. Wait, wait, how much of a saying is that? It is. Everybody in the street, you know, all the kids are saying that. You know.

30:34They should be saying that. I'm just an electron looking for a place to rest. Looking for a place to rest. Wow. No, I'm just, I'm just a, a neutron trying to buy a drink, and the bartender says, for you, no charge. No charge.

30:50As long as we're doing, getting particle physics jokes. Was that too much biology for you already? I'm sorry. Uh-oh. Excuse me. Uh-oh.

30:58I mean. To escape, escape hatch just for a thing to come back in. So, remind us what precisely an enzyme does in a chemical reaction. Well, it does lower the thermodynamic barrier to speed up reactions. Oh, so, so we have reactions that might eventually happen by, but you put in another chemical that brings them together. Exactly. So, these are, these are the biologist's best friend and the chemist's best friend. Or reversed enemy, depending on what you study, right?

31:30Oh. So, and they're all protein. They're micro molecules. I love that you call them chemicals. It's true. Their life is chemistry. And memory, right? Everything's chemical. Everything's chemical. Some of my best friends are made of chemicals. Exactly. That's so funny. It's like when people say on a package, they're like, and it's chemical free. And I'm like, you're an idiot. There's no such thing as chemical free. Okay, sorry. You're chemical. They're also chemical, right? An ugly bag of mostly chemistry. I have to square a circle here from what you've said.

32:02We talk about life as thriving on earth, but so much of it was highly contingent on singularities of geologic, biologic, chemical phenomena in the history. So, you could just remove one of those singularities, and life is gone. Yeah. Yes. It's true. So, the contingency of life feels almost preordained.

32:36Yes. So, or could it be, based on what you just said, that we don't know how many other attempts have been made that just did not work, and this is where we are. Or, how many other singular moments could have happened. Could have happened, but that did not happen. That did not happen. Or happened, but we're erased, and we can't access them. Oh, right. Okay. There are three possibilities. Can you just reflect on the statistics of that? Well, I want to tell you first that what you said is very fundamental, because we think about past as some sort of foundation to our existence.

33:12We imagine, like, everything built on top of each other, and we stand on these solid grounds. Right. Newsflash, no. Okay. You know, you can imagine it's more like columns, right? And you remove one column, the building collapses. That's our past. So, we've got to be very careful about how much we rely on these biological phenomenon, thinking that we are in good hands. I mean, Earth, it took a really long time for what we depend on to evolve and to find its place. And it is not a foundation whatsoever. These are very delicate systems. You change the pH of a soil, you threaten biological nitrogen fixation.

33:44So, here's where I would push back. Like, yes, it's delicate for what it is, but you take away that pivot point, you take away this singularity, and a whole other system might have come up where we might be 10 times smarter than we are as humans. No. What? This won't happen. I mean, if you remove carbon fixation, we won't even have time to come up with a better solution. I mean, if you're thinking about human perspective, we're vanished first. Right? We are the first ones to go by now. So, there's some other species, so some other species rises up.

34:17Microbes. Microbes. They will be okay, obviously. They're going to be right. They're going to be fine. They are always okay. They will find, I mean, there won't be any humans to study them. Right. But they will be doing fantastic things. And they'll be like, thank God they're gone. Are you suggesting, because we went so long without oxygen, and all these life forms thriving in a carbon dioxide atmosphere or whatever. Microbial systems. Microbial systems. You're saying, without oxygen, that could be a five billion year planet of just microbes. Yeah, it will be, most likely. And eukaryotes, but they're also microbial. You're not going to make the complex life.

34:48It depends on how we define complexity. I don't know if consciousness would still evolve, but the chances of a human evolving again, I don't know. That's a very good question, but animals in general. Some other life form that gets more. I was going to say, everything has evolved. We are extremely fragile. I mean, isn't that true? Everything has evolved to where we are right now. Absolutely. Everything has evolved to everything, so it doesn't make a difference. I wish I could see the future. It would make my life much easier, especially because I study evolution. But there is no way to predict these things. What we can do, again, statistics, calculate to what degree we know the greenhouse gases will be messed up with the rapid changes that we are introducing,

35:21and to what degree life can keep up with this or not. If you use models to back predict. Can't you use it for future? Why can't you use it to forward predict? It's a complex system. That's how they do climate. Well, they do to some degree. We always talk about we need better models, but it's a model at the end of today, and life will trick you. Life will do things that you're not expecting. That you're not expecting. It's a complex system. Gotcha. Now, going back to the singularities again. I think you remove nitrogen fixation, half the world population starves. That's a big number.

35:52Biological nitrogen fixation. If we solely depend on artificial generation of nitrogen, that's the number, half the population of the world. So, these are, you know, big numbers, and our sustenance rely on these innovations, the oxygen we breathe, the food we eat, right? Everything depends on these things. Now, going back to the singularities, I do believe, and I want to believe, that there's more out there about our past that we simply cannot track. I mean, you can think of it as similar to resurrecting an ancient language, right?

36:22Egyptian language. How do we do this? We are lucky because we found Rosetta Stone. We could cross-compare some notes, and we can infer an ancient language, and suddenly everything made sense, and culturally we understand. So, whatever we can recover, we attribute the entire world history to that. Because it's the same thing as what we do when it comes to biology. Whatever we recover, we can attribute the past to that. And I think that's overwhelming to think about, but also extremely motivational and inspirational, that we may be completely wrong about our own past in terms of life and its history.

36:55And this is extremely important that we understand where we came from. I mean, don't you want to know your ancestors? You do, right? It's the ultimate— If there are anything like me, then no. It's the ultimate— I had a friend who said, I want to explore my roots, and all I dug up was dirt. Everybody, right? It's going to Greece and, you know, not reading about the Greek history, but just, you know, like skipping the museum and hitting the beach right away, and not being curious about anything that made that culture possible. So, I want to take on your point.

37:25That makes sense. There are people who'd like to think, and some of this just flows through your work, that there's this process, there's this stable phenomenon, and then something happens, and then something else happens, and there are these checkpoints, right? And then at the end, we exist as conscious entities. All right. And if you change any one of these points, then we don't exist. I don't have a problem with that. However, where is your latitude to ask, if something else happened, then something else would exist, making a life form vastly smarter than humans, or some other thing?

38:05What is the range of possibilities, rather than focus on the one that worked, how about all the others that could have worked, but just didn't have the occasion to do so, and could have had a way more advanced civilization than we have today? That's always a possible. There's always worse. There's always better, right? Like, so, we don't know. I think, so, you need to clarify this for me, because I don't know what you mean by, I guess, what bothers me is this understanding that life finds a way, can be dangerous.

38:35A little bit, because we assume that everything's going to be fine, because evolution has been doing its thing for billions of years, and even if we mess up things, it's a way to produce some kind of life. That's how, that's really what I'm saying. Nothing's going to make us. No, we're, no. You know, any break in the branch in our ancestral tree, we don't exist. All right, but whole other vertebrates will exist, and other, you know. Yeah. And dinosaurs, dinosaurs are around for hundreds of millions of years, far longer than Homo sapiens would have been around.

39:05Yep, yep. So, as far as they're concerned, they're quite successful. Yes. They didn't have a space program. If you, if you, yeah. If they had, they would have deflected that asteroid, you know. Oh, yes. Without a doubt. I want to keep open the possibility. We need not be the pinnacle of this evolutionary path. I'll be honest. I agree with that. That other evolutionary paths might have been differently fertile, but had a different kind of earth with different life forms. That's very true. And I think this whole earlier depiction of evolution, like from monkeys to humans, like maybe drew that picture in our minds that we think there's some direction to evolution.

39:39Right, right. There's no direction at all. So, we think A became B, B became C, C became D, and now boop, B appeared. And like I said, everything has evolved. In fact, everything that's here now evolved, and we still have, but based on what you just said, we still do have dinosaurs. They're called birds. So, dinosaur descendants. That's what I'm saying. Yeah, yeah, yeah. That's their evolution. Yeah. Right? And I want to add something to something you said earlier. Earlier on, we mentioned, well, how long did it take life to show up on earth? Because earth formed in the void, and it's a hot thing.

40:12And it's got to, right. So, so, life came around even faster than that. Because we have a period in the early earth, what we call the period of heavy bombardment. Oh, right. Where the solar system is vacuuming up the remnants. I know where this is going. Okay. So, so we are being pummeled. Pummeled. Pummeled. Right. Because there's still a lot of trash out there floating around. Correct. Correct. We're being pummeled. So, the official word would be, we're still accreting leftovers from the early, early solar system.

40:42Gotcha. So, my point is, you can take a thermometric measure of earth, and earth is way hotter than what would sustain complex molecules. So, you wait for that to cool down. Then you start the clock. If you do that, then life started here within one or 200 million years, not 500 million years. Faster than even, you don't start it when earth began. Right. You start it when earth could have possibly sustained a complex molecule. But doesn't it help you out?

41:13I mean, sure. Like, I think I was referring to the, what we can track in the rock record, right? Using the isotopes and that. So, we are really referring to some cell that already was doing its thing. I am not sure to what degree, like, based on our understanding of chemistry, yes, we do need some optimum temperature for certain complexity to emerge. But there is no reason for, again, early chemistry to also evolve from simplicity to chemistry. Chemistry can give rise to more, complexity gives rise to more complexity. Mahina ex-mahina, right? Like, you can have that original messiness.

41:46And out of that messy chemistry, there is more messy things that came out. So, you're saying that the noise that is in the very beginning is part of the process itself, or could be part of the process. I think so, but I think what Neil is pointing out is that what we think as life is different than life circa 100 million years past earth's formation, right? But, but we think in biology, at least, or at least when we think about the last universal common ancestor, that's already a fully fledged, can eat, can poop, has all the genetics and doing its thing, organism.

42:17Sure. But origin of life is different than that, right? So, origin of life could be a complete chemical system that can maintain itself and do its thing. So, there's likely some theory. I'm just saying that when you start the clock, you don't have to start it at the formation of earth. That's all I'm saying. You're saying start it at the place where it could happen. It could, where it could be sustained. It might be when, yes. Where it could be sustained. Exactly. That's actually really all I'm saying there. So, what was the thing that you guys found in your field that is the earliest form of an organism?

42:48Well, in biological terms, it is 4 billion years. That's the latest time for this ancestor. That's the last universal common ancestor, Luca. So, that's the first organism. But keep in mind, we use what we refer to as phylogenetics, these trees, tree of lives. Obviously, there is no tree of life. It's our romanticized view of life that we collect everything. We draw off trees and we imagine everyone. You're telling me there's no tree of life? It's a thing. Tell me that. But it helps. I like trees of life. I just like metaphors.

43:19Who take that from me? I will take it. And I study trees. I will leave this room with the tree. You are cold-blooded, man. You are cold-blooded. I'll take it. I would like you to read me a bedtime story. Where does the tree of life analogy fail? Because it doesn't really factor into the genetic exchange between organisms. And I think it creates this understanding. It implies a certain purity of path.

43:50Exactly. Yes, it gives this direction again. Time, time arrow, time's arrow. Then it is likely more web, network, rather than past tomorrow and Wednesday. I'll give you that. So it's more of a web than a tree. Absolutely. But it helps us, of course, because we understand time. We need to. But it is important that we acknowledge that we made that up. We just use that as a way to make sense of it. Make it easier to understand. Exactly. That's all. So I want to bring some physics into this, if I may.

44:23So... Uh-oh. You made him uncomfortable. You were just like, there's too much day in biology. We've got to get back to something. Let's bring some physics into this. I mean, if you made a pie chart of this show, it's probably like, what's the biology percentage? No, we try to get some good biology on here, but we do. We don't mind. We can have some physics, Neil. Okay, let me just... Go for it. Let me stir some physics into this. Okay, go ahead. If we were to define life in some way that might also apply on another planet, one of the concepts is metabolism, that the life absorbs, by whatever means, energy from its

44:59environment and uses that for its own survival and possibly reproduction. So how much do you guys think about metabolism when you think about life? Oh, all the time. All the time. It's the engine. We take metabolism. I mean, it's just... Okay, here's something else we think about. If an entire system is exactly at the same temperature, then you can't have a process take place because a process takes energy over here and puts it over there. And in order for that to be the case, it's got to be like hotter over here than over there

45:33or things have to be moving over here more than they're moving over here. So when biologists explore the world and think about life, do you also think about energy gradients from one section of an environment to another? For sure. So first of all, I mean, I'm a weird biologist because I'm interested in astrobiology. No, that's the best kind of biologist. Go on. But that still makes it weird. That doesn't get in a way. But so I think about the planet all the time. But for sure, biologists think about the ladder in which donor and an acceptor and how they

46:07relate to one another. What gives, what takes and what kind of voltage can be generated in exchange of electrons or materials in terms of like electrons, I guess, between the two ends of the optimum. So absolutely. Because as I said, life is an electron looking for a place to rest. And it is all about precise channelization of these electrons. Right. Because if all electrons are already resting, nothing happens. Exactly. So you need a receiver. You need that push and pull. And you need that tension. And you need that fight between these systems so that you create energy and you channel that.

46:40And you basically channelize that energy across enzymes or whatever is in the cell so that they bounce and push and pull and do their thing. Okay. Because we're looking now, we have a mission going to Europa. It's a, it's a, a ice penetrating radar mission that will orbit. So Europa has this ice sheet on top and we're quite certain that there is a highly confident, there's an ocean of liquid water. It's kept liquid from the tidal stresses of Jupiter itself. If it's just an ocean underneath ice, I guess it's kept warm because of the tidal stress.

47:17And maybe that's the source of energy. That's the source of energy. That's the source of energy for it. Right. Because without it, you would have no energy source. I mean, even if, if it is dormant, we will still be able to find it if it is there. You know, because we have like fermenters on this planet that are also quite lazy. Like what the, the, the, the voltage between the giver and receiver is pretty minimum. They're really weird. Fermenters? I mean, it is basically, if you're thinking about the ladder between the, like the donor and the acceptor, fermenters, we want the ladder to be the, if we draw a line between the donor and receiver, we want that line to be as steep as possible.

47:49But when it comes to fermenters, you're getting almost a flat line. It's the equal footing, but it still works. So, so even though thermodynamically. Is there any slope at all? Yeah, hardly any. I had not thought about that. Even though, you know, it is not, by looking at it, it's not energetically favorable, like maybe a carbon fixture might be, or a photosynthesis might be doing. It is still doing its thing. So what I'm saying is that dormancy or this kind of slow process, we'll not get in the way. We will take what we got. Let me get to Europe. Whatever the slope is. Whatever the slope is. It's a bunny slope, but we're taking it. But yes, metabolism, absolutely important.

48:20It's the energy. It's the, it's the engine. It's all about the battery, right? When it comes to life on this planet. So we have to think about that. Those two, I'm happy as being the only criterion for life, but need to speak to a pure biologist, not an astrobiologist. They start adding other things, has to be susceptible to evolution, has to be able to reproduce, has to. And I'm thinking, really? Really? You think so? And how do you feel about these other criteria? Absolutely. I mean, you cannot just have a battery that's just sitting there, right? The battery needs to produce another battery somehow.

48:51Why? Well, then it's not life. It's just sort of a battery. Why can't it just be a battery that lives a billion years? But then it's not life though. What do you mean? How is it going to live? He's, well, it lives slowly. I was going to say, it lives until it runs out of juice. It likely can assemble, but in order for at least our understanding of life, that memory of the information that assembled that metabolism per se, it has to continue. So you're saying a bunch of logs laying in a pile is not a house. You got to actually have a house in order for it to be.

49:21Not a house I want to live in.