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Ard Louis | Symmetry, Function & Predictability

Ard Louis discusses why symmetry and function show up more than one might predict in a purely random process.


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Crystal Hemoglobin Structure

Ard Louis discusses why symmetry and function show up more than one might predict in a purely random process.

Description

There are many biological structures in our bodies, things like proteins, DNA and RNA, and they do amazing things. How these structures came to self-assemble is somewhat of a mystery, but Ard Louis has been studying just that question and his works has shown that qualities like symmetry and function tend to show up quite a lot, more than a purely random process might predict. Ard helps us understand what this means for science and then discusses what it might mean for theology, while being careful to realize that our value does not come from describing our origins but from our being made and loved by God.

  • Originally aired on September 29, 2022
  • With 
    Jim Stump

Transcript

Ard:

One of the problems with this whole discussion about where do we come from, is that people think that where we came from determines who we are, and what our value is, and what our purpose is. For Christians, we believe that our value and purpose comes from the fact that we were made and loved by God, not by our origin. And that’s a very fundamental Christian belief. It doesn’t matter whether we’re rich or poor, black or white, came from high class or from low class, we’re all equally valuable in God’s sight. And so it’s important for Christians to remember that’s a deep theological principle that also holds for our physical origins. So whether we came about by God giving inevitable humans how he set the process or whether we came about because God tweaked the process at some point in evolutionary history doesn’t determine anything about us that’s important in terms of value. It’s a genuinely interesting question, a scientific question, but it’s not clear to me how much it tells us theologically.

I’m Ard Louis and I’m professor of Theoretical Physics here in the University of Oxford.

Hoogerwerf:

Welcome to Language of God. I’m Colin Hoogerwerf, your host while Jim Stump is away on sabbatical. But don’t worry, before Jim left, he recorded several interviews, and I have one of those for you here. 

We met Ard Louis in the new state-of-the-art physics building on the campus of the university of Oxford, where he walked us to the main floor staircase where we could look down 50 feet to see where the labs were that were built with advanced vibration dampening systems for sensitive experimental physics research. We didn’t go down though, but up, to where the theoretical physicists work, which consisted mostly of warm offices and cozy sitting areas where groups were working with equations on huge chalkboards. 

Ard Louis is one of those theoretical physicists. He’s also been deeply involved in the science and religion conversation. He’s an associate with the Faraday Institute for Science and Religion a member of the international society for science and religion and he served on the BioLogos Board of Directors for 9 years.

Ard’s recent science interest, which we spend much of the episode discussing, focuses on explaining why, out of the seemingly infinite possible outcomes, we tend to find biological structures that are symmetrical and functional. If you haven’t spent a lot of time thinking about the symmetry of biological structures or how they self assemble, that’s ok, Ard does a great job of explaining the science and why it’s interesting and important and also the limits of the science to explain some of our biggest questions. 

Let’s get to the conversation. 

Interview Part One

Stump:

Well Ard Louis, welcome to the podcast.

Louis:

Thank you. It’s a pleasure to be here.

Stump:

Thanks for talking to us, especially on your home territory here, which we need to hear a story about, because you are a Dutchman, who grew up in Africa, now living in Oxford. 

Louis:

That’s right. 

Stump:

Unpack a little bit of that. How did that all happen?

Louis:

Well, the reason I’m living in Oxford is just because they offered me a job. That’s basically it.

Stump:

It’s good work if you can get it.

Louis:

Exactly. So I originally did my undergraduate degree in Utrecht in the Netherlands. So I grew up in Gabon, Central Africa, then went back to the Netherlands, did an undergraduate degree, did a PhD in the US, theoretical physics at Cornell University. then I went to Cambridge. I worked there in theoretical chemistry. And then I got offered a job here. So I moved over.

Stump:

What year did you move to Oxford? 

Louis:

2006.

Stump:

Okay, so go back a little bit more. You grew up in Gabon. To missionary parents?

Louis:

Yes, Kind of. They went there to work in a school, the mission school, run by the Gabonese church in the middle of the jungle, then they made a transition to other kinds of work. My father is a botanist. So he started the herbarium in Gabon, which is, a herbarium is like a library for plants, you have a copy of every plant. And back then, when he was starting to work, the idea was that tropical forests were relatively boring, or the African one. The idea was that the South American was very diverse, the African wasn’t. But Gabon, and for example, they have a transect,it’s a fancy name for this piece of land on which you, like a certain fixed size of land, where you count the species. And they counted the second highest number per hectare ever.

Stump:

Like, what’s that number like?

Louis:

I think, I forget the exact number on the order of several 100. Well, and so Gabon, I know Gabon has 1000s of species, quite a bit more than say, a country like France, even though it’s all rainforest. So what’s interesting with the rainforest, and I’ve learned that from my father, that as you look at it, you know, it obviously looks green at first. But if you look more carefully, then you get different kinds of rainforest. So the early forests, so when you first cut something down on relativity on a small number of species, but then over time, as they get what they call primary forest, where there’s older forest, it’s incredibly rich, ao it’s an incredibly diverse set of plant species that all live together. It’s something very beautiful.

Stump:

So there must be something in there that’s part of the story that drew you to science, to observation of nature, at least.

Louis:

Yeah, I think so. I’m sure that did. I mean, it’s hard to know. I mean, I loved science, I was actually loved physics so apparently, my parents tell me—I don’t remember the story—but they tell me that at some point in my teenage years, I sat them down and said, “you know, Mom and Dad, I have something to say that’s gonna very disappoint you.” I think you know this, obviously, if you have a parent of a teenager, you worry, you sit down. I told them that was gonna be a physicist, not a biologist. 

Stump:

Oh, was that disappointing? 

Louis:

I don’t think they— They were very gracious. And they’re both biologists. And so I remember for example, they, you know, they would classically be walking somewhere, they suddenly stop, bend down, because they saw some plant. And you know be talking about it. And my sister and I would discreetly walk away and pretend we didn’t know these people.

Stump:

How old were you those years that you lived in Gabon?

Louis:

Teenage years. So I lived there from when I was just after I was born until I was 16. 

Stump:

And you were as well— 

Louis:

My parents still live there. They still they 

Stump:

They still live there, do they? 

Louis:

I was just there in July. And a lot of friends there. I really like that.

Stump:

So there’s some connection to the church in Gabon too What’s your religious tradition growing up?

Louis:

So I grew up there in an evangelical Christian church, and was very heavily impacted by that. So local Gabonese church network that my parents are part of. And that was very influential for me and still is.

Stump:

And there were never any conflicts between the scientific work that they were doing in the church community they were part or is that just an American hang up that we seem to have?

Louis:

It’s not just an American hang up. This is a Francophone country. So the French have a very strong sense of secularity. So this idea of secularism, like the Americans have a strong sense of secularism. The French have even stronger. So you definitely, the idea that science—and then they don’t mean just natural sciences, but actually a bit more like what the Germans, wissenschaft. Like the Germans took all kinds of thinking, philosophy. So for example, you take philosophy in secondary school, in high school, basically is very important. And the idea is that learning and faith are something completely different. So in that context, there’s definitely a strong sense of faith versus science. Obviously, in the African context, it’s different because people are, by nature, very deeply religious. It’s very much part of the culture. And so atheism doesn’t have the same ring to it. And even science, I think people will study it and see it as a different category. So I didn’t really grow up with very much this kind of conflict grounds. I did go to a school run by American missionaries. And so I was introduced to young earth creationism there. It was taught at the school. My parents just, they said, “this is one of the strange things that Americans do. Don’t pay too much attention to it.”

Stump:

[laughs] Our greatest export, I’m afraid.

Louis:  

Yeah. Well, I mean, it’s interesting. So for me, it just, they’re also very much into kind of end times things. Some of them were I mean. There’s obviously always a wide diversity of people. I think even on this question of creation, evolution has a wide diversity, there are definitely people that were very much on young earth sides. So I remember, they had a book called the handy dandy evolutionary future. I remember it mainly because the title was so interesting. And they were also very interested in this kind of end times, you know, Tim Lahaye, Left Behind. So my father used to call it Christian Science Fiction. And so I think, in my mind, these things all kind of fell into the same eccentricities of the Americans, which didn’t take that seriously. I think it’s more when I went to the Netherlands that I felt the conflict more strongly. And I think the conflict, I often think the conflict isn’t really as much with science as it is with this idea of scientism. So the idea that science or something like it can explain everything that’s important. In the kind of context that would be broader than just natural sciences that would include philosophy and psychology. And somehow, there’s an inbuilt idea that this will explain everything and if it hasn’t done yet, it will. And I think if you then go to university, and you have a Christian faith, and these two kind of worldviews collide a little bit, and partially because they’re presented as a kind of false dichotomy. So I think I definitely experienced that as a student. Obviously, I think if you grew up in a place like Gabon, where faith is so strong, it also seems odd when people completely don’t believe in God. It’s like a strange thing. So I also found it strange. So like the Netherlands is, in certain ways, a very secular country. So that kind of secularity, I found strange, but it was definitely something I had to work through intellectually.

Stump:

And well, we might come back and our conversation to some of those kinds of questions in a little bit, but let’s hear first about some of the science that you’re doing here now. So here we are sitting up in the top, what you said was the theoretical section of the physics building here in Oxford. Tell us about your work here.

Louis:

So this we’re in the—theory basically means that we don’t do experiments. So you look around. You can’t see us on the podcast, but you just see desks and blackboards. We had to fight quite hard to get blackboards and real chalk because nowadays, everyone’s whiteboards, but I still prefer–

Stump:

Why is that?

Louis:

Yeah, just when you’re writing equations it’s just easier with a chalk. In fact, we have, if you look around, you have this very famous hagoromo chalk, which is the chalk that originally came from Japan. And now it’s made in Korea. But it doesn’t, it’s not dusty. So at some point, when the Japanese company couldn’t find an heir to take over. This stuff started selling for $100 each on eBay. Now a Korean company took over or Korean family took it over. So now it’s coming back again. So we love this. So basically, I work with pen and paper, chalk, or computers. And then I’m mainly interested in biological physics these days. So I started out doing kind of more traditional things like quantum theory. But now I’ve moved into trying to use ideas from physics to understand questions in biology. And one of the things I’m most interested in is self assembly. So your body is full of things that make themselves, little machines that can walk on tracks or little motors that can spin around and around and around and they’re really extraordinary. If I show you one that you could hold in your hand and just see with your eyes, it would be made in a factory. So some large assembly line would make something much more complicated than the thing itself. But these things make themselves, by which I mean, they float around in the cell. And the proteins, which are little molecules which they’re made just kind of spontaneously stick together in exactly the right space. It’s the equivalent of taking Lego blocks, adding some glue, putting it in a box, shaking a little bit, because the small things get shaken up by thermal fluctuations. And let’s say I put that into a box, I shook it, and out came a fully formed train. That’s practically what nature does. It’s really extraordinary. Because if I put glue on these things, I put glue on my Legos and I shake them, I just get junk. And every time I get a slightly different piece of junk, because the number of ways to make not-train is much, much bigger than the ways to make train, which is basically a few ways. 

So the really interesting question is how does that work? Yeah, and actually, it was probably 15 years ago that I started thinking about this. I just thought, well, how does that happen? That’s so strange. Because there must be something very interesting about the physics of it or the maths of it right? So you’ve got this many possibilities that are not the thing you want, and only a few that are the ones you want, and how do you find them? It is like, you have a needle in a haystack, how do you put your hand out and find a needle each time? So I got very interested in that. And then I’ve been interested more recently in the evolution of these systems, because we think these came about by evolutionary processes. So rather than me coming in and saying, “okay, I want to have a little train, I’m going to put some glue here, and glue there and glue there,” these glues just kind of randomly appear on things. And yet they form these really well defined assembling structures. So it’s kind of cool. And amazing, so I’ve been interested in this question like, how on earth would you get something like that?

Stump: 

So how much of this can you explain to a general audience on a podcast without using equations and your fancy chalk here of how this actually works? Because this is one of the criticisms that we at BioLogos hear from people who are objecting to evolution in some sense, of how could this just happen this way? How in the world are there natural explanations for how these tiny little particles assemble into meaningful structures as opposed to what you’re saying, there are many, many, many more ways that it could go wrong, then it could actually work. How does it work then? What have you found out these last 15 years?

Louis:

Well, I think it’s a super interesting question to ask how does it work? It clearly does work because we see it. And so then the question is how? And so what I got interested in is thinking about what is evolution really doing when it’s searching for new patterns. And so the important thing is to think about evolution searching in a space of algorithms. That sounds very fancy, but algorithm is just a computer program. So when I have a bunch of particles together in a box with various ways of sticking into each other, I can change the way that they stick as I’m changing the program that makes them do something. And then what I’m now claiming is that if you think about theories of algorithms, that you can show that on certain kinds of shapes or shapes that have short algorithms are easier to make than shapes that have long algorithms, because I’m more likely to find a short algorithm than a long algorithm. And that should be reflected in the kinds of shapes that we find. So one example, one different way of thinking about this, it’s not actually self assembly, but it’s maybe a little easier to visualize is, I think about tree shapes. So trees have different shapes. And you might think, Oh, yes, because in the DNA of the tree is some kind of blueprints, that looks like an architectural drawing. And that tells me exactly where every leaf goes, and every branch goes. But that’s not how a tree does it. It has a little stochastic algorithms or random algorithm that says, make a branch with certain probability, make a leaf a certain probability. And if you do one kind, you get something that looks like an oak tree. And if you do another one that might look like a weeping willow. They look quite different although they have slightly different algorithms. In fact, if you took that oak DNA and replanted it, it would make an oak tree again, which would look slightly different from the way it grew before, even though has exactly the same DNA because there’s some randomness and how it makes things. But it still would be distinguishibly an oak. So now imagine that the environment changes, and the oak tree needs to become more willow tree like. So when you think about that, it’s very different if I have a blueprint of an oak tree, and I need to change it to look like the blueprint of a willow tree, rather than an algorithm that makes leaves and branches with a certain probability. And I want to go to a willow tree shape, it might be really easy to do so. It might be just one or two tweaks. And suddenly, the whole thing looks like a willow. Does that make sense?

Stump:

So just for the sake of our audience, understanding where these tweaks are happening in the DNA itself, so some mutation of one genetic base, that could have a fairly significant effect on not, I think too often we think there’s this direct relationship between that DNA and what it ends up looking like, the phenotype, but there’s something a little more complex going on there that— 

Louis:

Exactly. The DNA is really more—so I’m talking about this blueprint analogy to say that’s not the right way of thinking about it. It’s maybe more like thinking like a recipe and a dish. So the DNA is like the recipe and you could tweak the recipe a little bit and the dish might look really different. And so, the important thing to remember is that you are not your DNA, just like the recipe is not the dish. And so the recipe is like the set rules that are used. And so I can write the recipe out, that’s like the DNA. But actually, I have to interpret that. If the recipe says, put in one spoon of sugar, or put in one cup of sugar, there’s two very different things, the meal might taste very differently. But there’s only a few letters that have changed. And so the idea is that you can think about the way evolution works in these kind of pattern formations as a kind of recipe that says make a branch, make a leaf. And so I might say, make a branch quickly, or make a branch slowly. And that might make a very different shape. So that once you think about it that way, you realize, oh, okay, so evolution is really searching in this kind of more abstract space of shapes. And then if I get back to my self assembling proteins, then well, what’s easy to make? Well, if I I want to make a big structure, it’s much easier to say, take this unit, and repeat it 10 times, for example, then to tell you where every single one of the 10 units has to go.

Stump:

So this is why you’re saying the shorter ones–

Louis:

–are more likely to appear–

Stump:

–are more likely going to happen. And then we just keep connecting that same thing over and over again. So this is now to your work related to symmetry. 

Louis:

Right, exactly. So one of the consequences of that is that if you see, if I make something with a short, I have a short description of it, that is likely to be more symmetric, because I say I have to repeat something N times that’s going to have some symmetry to it. So we’ve just written a paper where we claim that we can explain a lot of the symmetries seen in these structures in our bodies, just from this argument about algorithms, that short algorithms are more likely to happen. And so we have to make a prediction about how often you should see certain types of symmetries. And then we look in nature, and we can more or less predict what you see. And that’s interesting, because I think it tells us that, on the one hand, something really cool, like symmetric structures naturally appear from this algorithmic way of thinking about evolution. It’s also interesting, because it’s a non—it’s a fancy word—a non-adaptive explanation. So I’m not talking about natural selection at all, I’m just saying there’s something about the structure of the way the world works that makes you more likely to get symmetric structures than structures that are not symmetric.

Stump:

So if you were just to survey all the things out here, naturally occurring, there would be more symmetrical objects, more symmetrical shapes than we would otherwise think would happen just randomly.

Louis:

Yeah and so not just a few more, but like exponentially more. 

Stump:

So when we’re talking about our bodies, we have an ear on each side of our head and an eye here and here. And so arms on each side, and lots of things work this way, because it’s more efficient for the DNA to produce body types like that.

Louis:

I should be careful and say our theory hasn’t, we haven’t used our theories on bodies yet. It’s a much more complicated story. But I think something like this must be true. So this principle, I think, the way you explain it is almost certainly true, although I’ve only shown it for the self assembling structures and not for brains or bodies or anything big like that.

Stump:

And is there some kind of direct relationship between symmetrical DNA and then the phenotype that comes out symmetrical looking? 

Louis:

I don’t think so. 

Stump:

You don’t think so?

Louis:

I don’t think DNA needs to be symmetric at all but just needs to encode things efficiently. That’s the theory. So the reason you’re asking me what I’m interested in, this is what I’m interested in. You should be careful when you ask a scientist, what are you working on because he’ll start talking about it for a long time. You know, I will say to people, one of the great things about being a scientist is that you get paid to work on things you find interesting. By definition, if I wasn’t interested in what I was working on, I should change to something else. And I was very fortunate that I got paid, in this case for the British taxpayers with taxpayer money. You might wonder why that sounds a bit frivolous to pay me to work on what I’m interested in. But historically, many of the greatest scientific discoveries have come from this kind of curiosity driven research from someone say. “hey, that’s strange, I wonder why that works.” And then they start working on it. And so we have a tradition of this kind of research where basically, we’re allowed to work on what we think is interesting, in the hope that something useful will come out.

Stump:

Okay, so I have a few follow up questions on this work. One, how do you discover it just using your paper and pencil and chalkboards? How do you, I mean, there has to be some empirical content that you’re taking in that you’re working on and trying to figure out, right?

Louis:

Yeah, exactly. So what we’ve done in this particular case is part of it are some mathematical theories about how a search would look if you searched an algorithm space and then we spent quite a bit of time adapting those theories so they would work for genetic systems. And so the thing to remember is, the way change happens in our bodies or in evolutionary, in nature is that you have random mutations at the level of DNA which are to first order pretty much random but those are then translated by some process that turns them into phenotypes, which is basically, for ourselves, what turns into bodies. And so that second step is quite complicated. It’s basically what takes the recipe and turns it into the dish. And so when you think about that, then there’s random changing the genotypes is a little bit like typing random into a computer program, the program has to be then processed. 

And so a simple example would be if I randomly type onto my laptop, and I type into a computer program, I might type something like, print 01 500 times. That’s a very short program. 21 characters. But then you would see 500 01’s. 1000 long sequence, with a nice pattern to it. And so if you were just looking at the outputs of my typing, and you didn’t know what I was typing, you will still know that I was typing into a computer program, because you notice that sometimes you get really long sequences coming out with patterns to them. Now, the interesting thing is, is that there’s a whole mathematical theory behind those, that tells us, for example, that most patterns have no short code. So if you saw long patterns, all the long patterns you see should have some kind of short description. So that would be a kind of abstract way of thinking about it. So part of is this has been mathematized, that is well understood. And then of course, we make predictions about for specific maps from DNA to phenotype. So like, the DNA, that changes that makes the little proteins have sticky patches at different places, we can work out how that works, then look at what kind of shapes you find. And then you can look in nature, people have— There’s 34,000 of those structures that we looked at, that other people have found and put into a database, a huge amount, you know, 1000s and 1000s of man years of work to characterize these things, they’re all in a big database, you can go and search that database, and then say, well, how much symmetry is in there. So I’ve got a bunch of collaborators that are specialized in that part of the work, which are really biologists that understand really in detail what these things mean, and how to understand the symmetries. And so they looked at this and analyzed it and said, this is what the symmetries look like. And then I made predictions where I think they should look like and then they agreed, and then we got excited and published it. So it could have been that I made these theories and, you know, I made these predictions, they went and looked at all the data and then they didn’t agree. Another beautiful theory killed by some ugly facts. It happens all the time. 

[musical interlude]

BioLogos:

Hey Language of God listeners. If you enjoy the conversations you hear on the podcast, we just wanted to let you know about our website, biologos.org, which has articles, videos, personal stories, and curated resources for pastors, students, and educators. And we’ve recently launched a new animated video series called insights. These short videos tell stories and explore many of the questions at the heart of the faith and science conversation. You can find them at biologos dot org slash insights or there’s a link in the shownotes. All right, back to the show!

Interview Part Two

Stump:

So one of your co-authors in the article in The New York Times about this paper that you published, one of your co-authors said, “it’s like we found a new law of nature.” So explain that a little bit. Because I think we have this cartoon understanding of evolution sometimes that here’s the genetic code, there’s a random mutation, if that produces something that survives better and produces more offspring, that’s what goes on. And so we just have, in our mind, this random process of producing variations, and then the natural selection, that the best, most fittest ones produce more of their own kind. But there’s something else going on in here, is this what were saying? 

Louis:

I mean, ‘law of nature’ is a bit of a hyperbole. But that’s, you know, journalists like this kind of stuff. And I think what we’re saying is, I think the way you explained is very helpful, because the way evolution is often popularized is as a random process. And that metaphor, in people’s minds,quickly turns into a purposeless process, kind of random and if you’re lucky, you get something that is slightly more fit then that will survive. But what we’re saying is, it may be true that the mutations are random, but because they’re being processed, just like my random typing into my computer program is processed, certain things are much more likely to happen than others. So their outputs are a lot less random than you might think. So the new law of nature that my collaborator was trying to talk about is really the idea that the things that this random process throws up are much less random than you might think, much more predictable than you might think. So it’s something interesting that we think that nature is actually much more structured in the kinds of potential things that it can produce, that natural selection can then work on. So natural selection can only work with those things that have been thrown up in the first place. Secondly, it’s called variation. So you’ve got mutations that generate variation. So for example, your kids might be slightly taller than you, might be slightly shorter than you and if that’s better than—and better strictly means something very simple, just means you have more offspring, or more viable offspring than you, that over time that will dominate in a population. I mean natural selection is a kind of truism, right? So, if for example, let’s say that there’s a Louis gene which are mine, there’s Stump genes which are yours, if yours are such that you have four kids, on average, and I have two that survive, and your kids keep that, and they’ve got four again, then after one generation will be four Stumps and two Louis, two generations will be 16 Stumps and foor Louis, after three generations be 32 Stumps, and only eight Louis. After a while there’ll be only Stumps. 

Stump:

What a world.  What a picture you’ve painted for us. 

Louis:

And that’s natural selection, basically, is all it’s saying.

Stump:

So let me see if I understand this. So let’s, instead of taking a human person, take some other kind of organism that we can talk about varying in different ways. So you talked about height, we could, we might say, size, color, consistency there, you know, all of these different possibilities, that we kind of have in our mind this cartoon version where all of those possibilities are equally likely to exist in reality, and then the ones that are the most fit, produce more of their kind and go on. But am I understanding, you say, no, not all of those are going to appear with the same probability.

Louis:

I am. I mean, I should qualify that you think for properties like height and size, this might not be a bad approximation. But for many other properties like this, the self assembling structures or RNA structures, this is patently not true at all. Certain structures are exponentially more likely to appear than others. And I think that you give you a good summary of it. I’ll give you another example, which I think is interesting, because it has some links to the kinds of critiques that people from the intelligent design community make. So we looked at another molecule, which is called RNA. So you probably remember from high school biology that you have got DNA and RNA and proteins, and the main thing you learned is that the RNA makes a copy of the DNA, gets transcribed into DNA, and then the RNA gets translated into proteins as messenger RNA. But there’s another kind of RNA called functional RNA, which can do stuff, like it can be a catalyst, or it can be structural. And so it actually is active in your—it’s not trying to translate a message. 

Stump:

It’s making proteins?

Louis:

No, it’s not making proteins, it’s actually behaving like a protein. 

Stump:

It is, oh, it’s not a protein but it does the same thing. 

Louis:

It’s called functional. An3d this is one of the reasons why sometimes people think maybe early life was RNA based, because RNA can both carry information and it can do catalysis, which is what you need from metabolism. So basically, RNA can behave like a protein. It’s very cool. So people have looked at these functional RNAs and they’re like long, it’s a long string that folds into a really well defined structure. Think about a little string that you roll up into like a little ball. And it’s got to have a very specific shape for it to do the job that it does. So if it’s part of a structure, it needs to have the right shape or the structure is going to be different each time. So that’s a good example of why you would need to have the exact same structure. So we studied these structures, there are lots and lots of possibilities. And I’ll, for the podcasters, definitely ignore the details of this. But you can characterize these structures, by the patterns of who binds to whom. And we did this for example, for different length structures. 

So I’ll give you a fun little fact to think about. The RNA is made up of this long sequence of four different nucleotides. And so at each point in the sequence, you can have four different ones. So how fast does that grow? Well, I have four at the first place, then four at the second one, so I got four times four possibilities, 16 ways of making just two. Times four again, and it grows really, really quickly. So quickly, that by the time I get to length 79. If I made every string of length 79, and I weighed them, they’d weigh more than the Earth. And if I made every string of length 126, they would weigh more than the observable universe. So let’s ignore dark matter, like just the universe you can see. That’s kind of wild when you think about it. So I call that a hyper-astronomical number, because the first length is larger than the universe. So you might think, okay, if I have that many possible strings of length 126, right, and I randomly searched them, I’m never going to get the same thing more than once. Because I can only search an unfathomably small fraction of them on earth because you don’t have enough mass to make them. So we looked at structures of length 126. And with this particular method we used, we think there’s actually about a trillion structures that you could make out of length126. And then we looked at the ones that are found in nature, and we found there’s only 68 there. So a very small fraction of them. Okay, fine. But the interesting thing is if I just randomly pick sequences and predict what structures I’m going to find with most likelihoods then I more or less can predict which 68, I’ll find. And those are the ones that I see in nature. So we can predict them based on just about a million random sequences, we can find all the structures that nature uses of that length to make all the biological diversity that RNA is used for. So it’s really interesting that you can quite quickly search through the space. And the reason for that is because the space doesn’t use all 10 to a trillion sequences. It only uses a really small fraction of them. And those are all the ones that actually turn out to have shortcodes to make, to fold. So those ones that have shortcodes to make structures are the ones that you find. So there’s a kind of a counterpoint, because on the one hand, the searching algorithms seems a bit abstract, but it actually allows you to find things really quickly. And it turns out that you’re, for reasons that we don’t understand, you’re finding good ones really quickly. So one of the big issues and I think it’s a genuine question that you’ll see people that are skeptical of evolution, they’ll say, “well, the sequence space is so big, it’s unsearchably big, so you could never find anything in it. So therefore, there must have been either, you know, God must have done something or there must be something miraculous.” Or if you’re an atheist, you’d say, “this tells us that we’re just here by a random fluke of accident, and there’s no purpose to us, because had the world been slightly different, we wouldn’t be here.”

Stump:

So make sure I understand the critique coming from intelligent design or whomever, that the possibility space is so enormously large, that we’d never just by random chance, get the ones, those 68, out of the trillion that actually work to produce life. So they’re saying there’s not enough time in the evolutionary development to find just those? And your response to that is, no, these aren’t  all equally probable, in terms of which of those variants we get?

Louis:

Exactly, I think you’ve explained it extremely well. So that’s exactly right. So what I’m saying, some of them are much more probable than others. And it’s kind of interesting, because this, I think, really legitimate question of how could you find function in this extremely large space of possibilities, seems really hard until you realize that there might be other principles at work, which is one that we think we described, that says that you could find it, that you keep finding the same things. And they turned out to be quite functional. So what I have not explained is why the ones that are easy to find are also so easily functionalized. That we don’t know. It’s completely mysterious. But what I have explained is why you see the ones that you see. And I’ve also explained that they’re actually really easy to find. And that’s kind of cool. I think it’s really cool. And in fairness to the intelligent design, my friends in the intelligent design community for whom I profoundly disagree, it was talking to them and them pointing out to me that this is a real problem that got me thinking about this. I thought well that is kind of interesting, because actually, that is a good question. That space is very big. How on earth does that work? And so then I started thinking, well, how does it work? I spent a lot, probably 15 years ago is when I first started thinking about this. And then I started thinking, you know, how should I think about that? And then I slowly but surely, came upon this way of thinking about algorithms.

Stump:

So related question, a few episodes back maybe 10 or 12 episodes back on the podcast, we talked to Simon Conway Morris, down the road in Cambridge, that other little town out here, right? And who’s become very well known for convergence, evolutionary convergence, which also drastically narrows down the possibility space of the kinds of things. Are these two related in some way? 

Louis:

So I think they are. So I think that the reason why you see convergences in like RNA structures is precisely because the ones that are easy to find are going to appear again and again and again. I got an interesting story with Simon. Simon is one of the reasons I got interested in evolution. So the way evolution is often kind of popularized is as just a random process. Kind of one damn thing after another, and that’s fine. But it’s not interesting for physicists, because we want to find patterns in there. So I kind of thought, well, kind of interesting but just being a random process, and I’m not, that doesn’t sound interesting. Then I came across Simon and his book Life’s Solution, where he has this incredible list of convergences, everything from a camera eye, or my favorite one, which is the Anteater. So there’s anteaters, there’s Africa, North America and in Australia, for example, they’re all anteaters, which are very strange animals. They’ve got a long snout. They’ve got incredibly big salivary glands because ants don’t like to be eaten. They’ve got an incredibly rugged stomach because the ants don’t like to eaten and are poisonous. And so you might think that would’ve only evolved once.

Stump:

Two came off the ark and went to all the different continents.

Louis:

Exactly, and there and you know, and in Gabon where I grew up there’s one called the pangolin, which has scales.

Stump:

The pangolin, isn’t that in Asia as well?

Louis:

In Asia is a different kind of pangolin.

Stump:

Connected and connected to SARS coV2 virus wasn’t it?

Louis:

This was one of the theories about SARS exactly. But the Pangolin is the one that I grew up with, and that is in Gabon. But like the spiny anteater in Australia is actually most close, is a marsupial. It’s linked to the platypus. It’s completely different kind of—so it’s an egg laying mammal, like a platypus. It’s a completely different kind of animal. And so you see, these are, they’ve all evolved independently. So I remember reading about that and thinking that’s just strange, that evolution keeps doing this, there must be patterns there. And so then I got excited. And I talked a lot to Simon at the time, who said to me, why don’t you find a theory for convergence, like some kind of mathematical equation that would explain it? I haven’t gotten there yet. But this is, I think, one part of a much more complicated puzzle. And there’s a deeper point, which is that I think the way evolution is often popularized is as a completely random process with random outcomes. I think that’s an unfortunate use of words. Because when we hear random, we often think of something that has no purpose. And so for me, it was interesting, because when I read about Simon’s work, I realized there is some pattern there. So this space of possibility is so constrained, I’m gonna try to figure out what that is, and maybe my physics thinking can shed some light on that. Whereas if it was just a truly random process, I wouldn’t really be able to do so. 

But actually, in another way, another thing I’m getting at is, what makes this interesting is that it suggests that our evolutionary history is a lot more predictable than we might have thought. And that makes it, I think, interesting and more fun to think about. It also tells us something about metaphor. So I just mentioned, I think I’ve mentioned a few times, that the metaphors that we—there are other levels of meaning that we give to the word random, which tend to become quite negative ones. Whereas there’s actually a technical word in the scientific procedure for something that we can’t predict very well, but we can predict maybe it’s average or something, we call it stochastic. So if we said instead, evolution is stochastic process, then nobody would, or people would be less likely to think that somehow it has some kind of metaphysical meaning to it, just a stochastic process. In fact, stochastic processes are all around us. You can, in fact, prove that a lot of high dimensional optimization problems are much more efficiently solved by stochastic processes than they are by non-stochastic processes. And so if you were a god, and you wanted to make a world that could make itself, then a stochastic process is probably the most efficient way of doing it. But when I say random process, it sounds like there’s nothing happening. It’s just completely unpredictable. But that’s not true if you think about it in a more technical sense.

Stump:

Okay, so let’s bring this back to God, trying to decide how to make a world that can make itself, because the sort of first level of, at least my understanding of your work, is showing people who were trying to inject God’s direct action into processes because they didn’t think they were explainable by natural means. And you’re saying, no, it turns out, it really does look like this is explainable from the laws of physics and whatever, you know, we’re understanding by those. But there’s a second level to this, that starts to make us think, at least, to bring back into conversation, those of us who are interested in these kinds of questions at the intersections of science and religion, that maybe there is something deeper here that isn’t a knockdown, drag out proof, but at least is highly resonant with those of us who think God may have had something to do with all of this. Is that fair to say?

Louis:

Maybe. Yeah, I think it is. I think these kinds of natural theological arguments are often very hard to run well, because but for sure, this picture of evolution is a lot less random in its outcomes, then the traditional way you might have been taught in school. I think that is, for many people, at the very least, it makes evolution feel much less like a metaphysical anti-God kind of theory.

Stump:

Right, right. So for instance, when we were talking with Simon, I brought up the fact that many Christians interested in his work have tried to leverage it as a new kind of fine tuning argument. So the subtitle of his book was ‘Inevitable Humans’ right? So that it sounds like people can take this idea and say, “oh, God knew that humans were going to come out of this evolutionary process at the end, it must have been designed that way from the beginning.” And I asked Simon about that in particular and he does not like that interpretation very well. Is there any? Again, we’re not looking for a mathematical proof of God’s existence in that sense, as much as trying to find ways that these can, that science and theology might be fruitfully at least brought into conversation with each other.

Louis:

Maybe. I think I share Simon’s concerns about running with these things to fast. Because the interesting point is if you take Simon’s point of view, which is much more a meta theory than mine, right, where he says, you know, something like humans are inevitable. My theories don’t tell us that this is true. But you know, Simon, has kind of, he says, let’s assume that’s true. You can contrast that with the kind of Stephen Jay Gould very famously wrote about on rerunning tape of life and if you run the tape of life you wouldn’t get anything like humans because of these little random steps that push you one way or the other. And sometimes in the back of that kind of contingency thinking is the idea that the possibility space is very big, and you start somewhere else, you start in a different part of the possibility space, and so you end up somewhere different. That’s effectively what’s happening, I think, with people like Gould. Now, interestingly, if you’re a theist or a Christian, you might say, well, either one of them could be God’s. If God just does a little tweak to the direction of life, and suddenly there’s like, humans appear, that might be also more nice for theism because God doesn’t have to be continually intervening, he just has to do a small tweak, and we appear, because possibilities be so big, he just has to start at the right place. So there’s so when you start thinking about this way, it’s not obvious necessarily which of the two is the most congenial to theism. 

I think what’s really interesting about it is that you can see that the science can give you very different metaphors for how you think about where humans come from. I think one of the problems with this whole discussion about where do we come from, is that people think that where we came from determines who we are, and what our value is, and our purpose is. For Christians, we believe that our value and purpose comes from the fact that we were made and loved by God, not by our origin. And that’s a very fundamental Christian belief. It doesn’t matter whether we’re rich, or poor, black or white, came from high class or from low class, we’re all equally valuable in God’s sight. And so it’s important for Christians to remember that’s a deep theological principle that also holds for our physical origins. So whether we came about by God giving inevitable humans, how he set the process or whether he came about because God tweaked the process at some point in evolutionary history doesn’t determine anything about us that’s important in terms of value. It’s a genuinely interesting question, a scientific question, but it’s not clear to me how much it tells us theologically. And I can turn this around and say, I think one of the reasons, and I think I understand this reason, why people of faith are often suspicious of evolution is because a lot of people who don’t believe in God, atheists, use evolution to try to prove that there is no God, in one way or the other. And you can see that in many, many examples. Richard Dawkins is a good example. But there’s many others that do that. And so if you are an average person on the street, you hear this, and you think, well, if evolution tells me there’s no God, so much the worse for evolution. But interestingly, I think people like Dawkins, are also natural theologians, they look at the natural world, they look at their particular interpretation of it. And then they say, “ah, this tells me that there is nothing here. There’s this world that we’re looking at there’s no good, no evil, nothing but blind, pitiless indifference,” in one of his Dawkins famous lines, where he basically looks at the world and says, “there’s randomness there, ergo, there’s no God involved, or there’s no meaning or purpose.” That’s a kind of theology as well.

Stump:

He’s deriving theological conclusions from empirical evidence himself.

Louis:

So he’s a, you might call it, you know, a natural a-theologian, right? But that’s effectively what he’s doing. So I–

Stump:

The process is the same. 

Louis:

The process is the same. So I think Christians and non Christians often fall into this trap, where they think that meaning and purpose derives from these particular mechanisms of the natural world, whereas I just gave you example of whether the evolution is contingent or predictable, either way is consistent, could be consistent, with God acting, or not acting, it doesn’t really matter that much.

Stump:

Okay, so we are running out of time here. Can you speak a little more personally to some of these questions? If we don’t want to have our theology and science so intricately entwined that we think we can derive theological conclusions from science. Are these running on separate tracks for you? Or are there points of contact between science and theology in your own mind that you think are fruitful at least.

Louis:

So I think, at the very least, looking at this from—so I think what you might be able to say with something like this, on the one hand, so if scientists have been influenced by a certain atheistic worldview that might close them off to certain ways of thinking about science, and maybe a theological worldview will give you some interesting new ideas. So that’s one way that this could interact. I think that has been true for some aspects of evolutionary theory that a particular worldview that was based on a kind of contingency resonated with people’s sense of a-theology and so they kind of ran with that longer than they maybe should have. That’s one way of thinking about it to be fruitful. I think that Christians are called by God to take care of this earth and to also, I think, investigate it. So that’s another way to understand it. So I think understanding gives us a sense of God’s grandeur. And I think it can be a glorious calling to do. So that’s another way that these things interact. And I think, as the more we understand about these processes, the more beautiful they typically become. So I think my own instinct is, the more I understand about evolution, the more intricate and beautiful it will become. And so that’s a theological kind of instinct that I have. And I think that is also a motivating factor. But do I think that the details of how the science works are going to affect the details of my theology? I don’t think that’s, I think it’s unlikely.

Stump:

Or the other direction? Do the details of your theology affect at all, how you can even interpret the scientific details?

Louis:

I don’t think so. I don’t think they do, I think these things are—it’s not like they’re running separate tracks. I think it’s the wrong way of thinking about it. I think a better way of thinking about it is to say, you know, I have a big circle of everything that can be knowable. And that circle is, would be maybe a theological circle, everything about God, and et cetera. And a sub-circle of that is science. That’s one way of thinking about the world. But it’s not the only way of thinking about the world. And science is extremely powerful. It’s probably the greatest thing that humans have ever invented. On the other hand, it doesn’t answer our most important questions like, what does it mean to be human? Or why are we here? Or what’s the purpose of my life? Those are questions that science and I don’t think neither science nor any conceivable advance of science could answer. That doesn’t minimize science. It’s just a different way of thinking about the world. So these really important questions like, what does it mean to be human? What’s the value of human being? How should I live? These are questions that we answer on religious grounds, for example. And if you’re not religious, then you have to find some other metaphysical type of argument to derive these ideas from. Science doesn’t give you those answers. So I’m not saying they’re running on different tracks. I’m just saying science is a subset of a bigger set of ideas about the world. And those include questions of meaning and purpose. And certainly, as a Christian, I think I find those questions, those things answered in revelation in the Bible, in the Incarnation, that God came to earth in human form. Those are really profound things that tell me something about my role. I believe that humans have intrinsic value, because they’re made and loved by God. That’s something I believe is absolutely true. You may believe that humans have intrinsic value for some other reason. Which is great. But I’m telling you the reason why I believe that’s true.

Stump:

Good. Well, what questions do you hope get answered before your career here at the Oxford physics building is done?

Louis:

What questions in science? Well, here in this building, we talk about lots of other things. So one of the biggest questions is finding a quantum theory of gravity, which my colleagues here on this floor are working on. I’d love to see that answered. That’d be pretty cool. And I think, you know, a more unified theory of evolution that takes into account these biases and how the possibility spaces are searched. I think that’s that’s a big, that’s a grand goal, that I’d love to see answered in some way or another. 

Stump:

And then any theological questions you’d like to see answered before your time here on earth has done.

Louis:

I think that theology often brings more questions and answers. And good science does the same. It brings more questions than answers. So hopefully you have these things that we’ll answer and they’ll raise new interesting questions. So I can’t think of theological questions that I’d like answered. But I’ve got lots of theological interests that I’d like to explore further, but that’s maybe for a different time. 

Stump:

We like to end these interviews now by asking you what books have you been reading lately?

Louis:

That’s a good question. I have been reading a lot of children’s books to my children. In other words, I’ve just been reading a very interesting book. by an American biologist called Arnold Stoltzfus, which is about mutations and evolution, so it’s rather boringly very closely linked to my research topic. That’s been the books I’ve been reading.

Stump:

Very good. Thanks for talking to us Ard. 

Lous:

Thanks. 

Credits

BIoLogos:

Language of God is produced by BioLogos. It has been funded in part by the Fetzer Institute, the John Templeton Foundation, and by individual donors who contribute to BioLogos. Language of God is produced and mixed by Colin Hoogerwerf. That’s me. Nate Mulder is our assistant producer. Our theme song is by Breakmaster Cylinder. 

BioLogos offices are located in Grand Rapids, Michigan in the Grand River watershed. If you have questions or want to join in a conversation about this episode find a link in the show notes for the BioLogos forum or visit our website, biologos.org, where you will find articles, videos and other resources on faith and science. Thanks for listening. 


Featured guest

Ard Louis

Ard Louis

Ard A. Louis is a Professor of Theoretical Physics at the University of Oxford, where he leads an interdisciplinary research group studying problems on the border between chemistry, physics and biology, and is also director of graduate studies in theoretical physics. From 2002 to 2010 he was a Royal Society University Research Fellow at the University of Cambridge and the University of Oxford. He is also an associate of the Faraday Institute for Science and Religion. He has written for BioLogos and served on the Board of Directors from 2011 to 2020. He engages in molecular gastronomy. Prior to his post at Oxford he taught Theoretical Chemistry at Cambridge University where he was also director of studies in Natural Sciences at Hughes Hall. He was born in the Netherlands, was raised in Gabon and received his first degree from the University of Utrecht and his Ph.D. in theoretical physics from Cornell University.

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