GEOFFREY BRIAN WEST
(photo, Santa Fe Institute, courtesy GB West)
I spoke with Santa Fe Institute physicist Geoffrey West at home in Santa Fe in between unpacking his suitcase from a visit to Singapore in March, where he was lecturing about cities, and packing for an April trip to London (weekend in Paris squeezed in), where he teaches math at Imperial College London and business at Oxford University. Part 2 of our conversation on life, evolution, and US Presidential politics follows.
Suzan Mazur: Do zoologists own the evolution discussion?
Geoffrey West: To a large extent the answer is yes they do own it, and they have to some extent cornered the market. They believe, perhaps rightly so, that they have all of the expertise. But clearly, other areas of biology, and also other sciences such as physics, chemistry and computer science should be an integral part of the conversation. The upcoming Royal Society meeting on evolution that you've been writing about, which has eminent biologists and philosophers represented, basically has almost no scientists from the hard sciences, which is where some of the important answers and insights are potentially going to come from.
A major conceptual challenge is the question of the origins of complexity in the universe that we need to understand before we can truly understand the origins and laws of life:
How does something so simple as the laws of physics produce something so complex? How does that happen? What are the mechanisms that give rise to that?
Most importantly, what are the underlying principles that augment, whether you believe in it or not, the principle of natural selection? Those are questions where having a dialogue with physicists -- especially physicists who have thought about complex adaptive systems -- could be quite productive.
Suzan Mazur: Do you have any plans to attend the Royal Society evolution meeting?
Geoffrey West: I don't. And I haven't seen the official list of speakers, but I'm disappointed that physicists, or chemists and computer scientists, aren't represented. I like the idea that there are philosophers speaking though because hopefully they would have thought deeply about some of the questions of evolution.
I actually came late to biology, from high energy physics -- quarks, gluons and dark matter, string theory, Higgs particles and all the rest of that wonderful stuff -- fundamental questions in physics that are conceptually at the opposite end of the kinds of questions asked in biology.
Suzan Mazur: Do you have your own concise definitions for evolution and for life?
Geoffrey West: In physics, of course, we think about evolution in terms of questions such as the evolution of the universe from the Big Bang.
What we mean by the evolution of a system is simply what is its time development and what are the new states of the system when they go through phase transition or tipping points. And the universe obviously did.
It started out as a bunch of energy maybe in the form of strings. It then progressively cooled as it expanded, and out of that soup condensed elementary particles, radiation, atoms and molecules followed by galaxies, planets, and eventually life and so forth. That's an example of what we mean by evolution.
Suzan Mazur: And what do you consider life?
Geoffrey West: I consider life from the perspective of the physical sciences, the conceptual principles, the equations, so to speak, and the particles and the basic forces.
The potential for life is somehow encoded in the emergent properties of the elementary constituents of matter at whatever scale you want to look at -- quarks and gluons, protons and neutrons, or molecules.
We know that because we're here. I can look out the window and see it all. That's a belief, of course. Those trying to understand the origins of life and those trying to artificially create life implicitly believe it.
Suzan Mazur: You referred to natural selection earlier, and in a couple of your papers on allometric scaling published in recent years you refer to natural selection. In light of the debate over the last decade regarding the metaphorical aspect of the term natural selection -- and citing Denis Noble and Richard Lewontin that natural selection was never meant to be taken literally by generations of scientists -- has your perspective changed at all regarding use of the term natural selection in science?
Geoffrey West: Yes. Let me back up a little bit. I came to biology indirectly, serendipitously in a way. I had no more than a very superficial understanding of what evolution and natural selection meant. One of the things I discovered as I entered into the culture of biology, and one of the many surprises, was that the kind of Darwinian notion of natural selection somehow was raised to some God-like principle, without it being carefully defined and quantified. That was the thing that bothered me. It was because I'm a physicist, because we try to make precise definitions that can be put into a mathematical framework, which may not be appropriate for biology.
So I had problems with some of the things I was learning in biology. But in particular -- and this may be tangential -- when I first saw these scaling curves, these extraordinary scaling curves that, roughly speaking, say that at the 80 - 90% level an elephant is a scaled-up mouse in terms of almost anything you can measure about its physiology and life history and that all of life scales accordingly, from cells to ecosystems. Ultimately, in terms of the work that I did to understand where these universal laws of biology came from mathematically, and the physics and principles underlying them, it gave me a very different view of natural selection.
I was quite surprised that implicit and sometimes quite explicit in discussions of natural selection there is the idea that what happens in terms of the evolutionary process is essentially random.
I have a great view from my window here in Santa Fe and if I look across at the extraordinary diversity, it is overwhelming in some ways. The concepts of diversity and natural selection sort of go hand-in-glove. But what also goes hand-in-glove is that everything is unique and has a unique evolutionary history.
Every organism and every part of that organism has its own unique history, every cell, every genome is historically contingent. But the scaling laws and the principles and mathematics underlying the theory that explains them show that this is at best only partially true -- after all, as I said, at the 80% plus level much of physiology and life history is predictable.
Suzan Mazur: Your work is about the "simplicity underlying complexity."
Geoffrey West: That's right. That's the point, it is not entirely random.
Suzan Mazur: To what extent do you think biology can be mathematized?
Geoffrey West: That's part of the quest I'm on, exactly, so I don't know the answer to that. But the question is, how much can it be. And by extension, how much can questions in the social sciences be mathematized, like the sustainability of communities, institutions, companies, etc.?
One of the things I often say is that because these are complex adaptive systems, there won't be Newton's laws of biology. There won't be three or four principles by which you can calculate, so to speak, everything about life. That's crazy.
Unfortunately, much of biology seems to take the view that you can't even ask the question. I advocate an in between view, and that's what my work is about.
It's not like Newton's laws, which means that I can calculate in principle everything to any degree of accuracy. Even with quantum mechanics, which is probabilistic, there is the idea that you follow this paradigm and can calculate everything and it's been enormously successful. That's not true in biology, but what I might believe to be true is that much of biology can be calculated in a kind of averaged coarse-grained way, which is what the scaling work is about.
If you tell me the size of any mammal or almost any organism, I can tell you almost everything about it, on the average, to 80 - 90% accuracy. I can tell you the length of the fourth branch of the arterial system, I can tell you how many children it will have, I can tell you how long it will live, I can tell you details about the diffusion of oxygen across the membrane, how long it takes to grow, and so forth. I can calculate those in an average coarse-grained sense, but only to 85% - 90%. How far you can push that is the question.
Suzan Mazur: Thank you. Antonio Lima-de-Faria noted some years ago in his book Evolution Without Selection that life is a dynamic process -- he calls it autoevolution -- but that there is also a biological periodicity. He says complexity is not a prerequisite for periodicity to emerge.
Geoffrey West: What is periodicity?
Suzan Mazur: The frequency with which certain forms and functions occur over time in diverse organisms. Lima-de-Faria has made a periodic table of some of these forms and functions. The examples of periodicity he cites are the placenta, which he says is already well developed in 550 million year old onychophorans, in flowering plants, some reptiles, some fish as well as humans. Other examples he's charted include, the appearance of high mental ability, vision, bioluminescence, the capacity to fly, appearance of the penis -- evident in flatworms, barnacles, humans and other organisms. So he's saying it doesn't have to do with complexity.
Geoffrey West: It's true that the eye, for example, has evolved several times presumably in response to external stimuli, and for want of a better word, greater survivability. But the eye is itself complex. The forms and functions you cite are already complex.
Suzan Mazur: Lima-de-Faria is saying the canalization was framed by the patterns of atoms but at the same time a certain plasticity exists, that the biology rests on prior evolutions, including the mineral.
Geoffrey West:
Much of what happens in biology is encoded in the physics.
For example, you might think that a whale, which is a hundred million times heavier than a shrew, is much more complex. They're both mammals, of course, but the complexity is essentially the same. You didn't need complexity, in that sense, to get to a whale, but you did need a principle that says something about getting bigger has consequences. Those consequences, it's hard to believe, don't depend on the environment for much of their physiology and life history -- after all the whale is in the ocean, that already says something -- although the physics determines the basis of the whale as a scaled-up shrew, which it is. The fact that a whale has to swim rather than walk obviously is hugely consequential for the whale but from a big picture viewpoint this is secondary to its essential mammalian character. In that loose sense it's deterministic. The physics determined much of what happened from the shrew to the whale. We don't need to code for it, it's in the equations already.
Suzan Mazur: What is your thinking about how form arises?
Geoffrey West: Ah form. Yes. That's a very tough question. You mean why does the elephant have a trunk. Why does it look the way it does
Suzan Mazur: From egg to embryo to adult.
Geoffrey West: How does that happen.
Suzan Mazur: Do you have any thoughts about that?
Geoffrey West: I have nothing very insightful to say other than I can calculate the growth curve of any organism. It's kind of curious that you can calculate that but it doesn't tell you about its specific form --
Let me raise a slightly different question. If biology were a science the way I think of science, so that it was quantitative, analytical, and things were predictive and calculable, and the theory of Darwinian natural selection were a complete theory rather than more of a narrative -- then what you'd like to be able to do was predict there were human beings. That would be what an ultimate theory is, if you predict a human being that would have the form that we have it would answer the question you asked -- how does that form emerge from an embryo up. How does that happen? I don't know the answer to that. And I believe it's impossible to do so precisely because these are complex adaptive systems.
Suzan Mazur: Your colleagues at Santa Fe Institute, Varn & Crutchfield, have been exploring this idea -- which is a bit along the lines of Lima-de-Faria -- with their recent research on chaotic crystallography that is now a Royal Society paper. Do you have any thoughts about the concept of stacking, the packing of materials -- crystals like ice -- and the layer disorder that lets in new information? How useful a tool might chaotic crystallography be for quantifying biology?
Geoffrey West: I'm familiar with that idea, but I'm not such a fan of it. I'm much more a fan of something more conservative and traditional, which is that much of form, and in fact just like those allometric relationships and the structure of all the networks that keep us alive, including those intracellularly, is driven by an approximate form of an optimization principle.
The form that we have in some average way is a response to optimizing something, usually it's energy.
Energy could even be in the form of minimizing heat loss, but energy because -- and this is where I do try to connect with traditional Darwinian theory. For example, the circulatory system, in fact all the systems that we have are approximately optimized so that we use the minimum amount of energy to stay alive. Our circulatory system has evolved so that the heart expends a minimum amount of metabolic energy in order to maximize the energy allocated for use in sex and reproduction and so forth and therefore maximize fitness. So it is, I speculate, with much of what we see regarding form.
A significant part of form has to do with externality. It is in response to whatever some environmental condition is in order to maximize fitness. For example, the form of a tree is the way it is -- a fractal network -- because it is maximizing the amount of radiation energy it can catch for photosynthesis.
Suzan Mazur: Are you familiar with Adrian Bejan's view of this, his constructal law? He sees the network as facilitating the flow of moisture from the earth via the roots seeking release into the atmosphere.
Geoffrey West: Yes, I'm familiar with his work. Adrian and I sort of agree conceptually. If we disagree -- I'm not even sure there's a fundamental disagreement -- but the difference is that I try to calculate everything, make predictions and compare them with data and experiments, very traditional scientific methodology based on underlying principles and a parsimonious framework. But I suspect that conceptually he and I are quite close. I haven't talked to him for a long time.
Suzan Mazur: I think he has a new book coming out next month, The Physics of Life.
Geoffrey West: I'm trying to finish a popular book that I'm writing.
Suzan Mazur: Can you say what it's about?
Geoffrey West: It's about many of these things we've been talking about in biology, from cells to ecosystems including sleep, aging, mortality, cancer and so on. There's a lot of physics in it, but it's all the biology stuff and much more. My work on cities and companies and global sustainability. The origins of the universe and so on, elementary particles. Showing that there's a unified framework for dealing with all of them, namely the concept and the way of seeing are pretty much the same whether it's thinking about the structure of the heavens, the structure of life or the structure of cities and companies.
Suzan Mazur: You've said "all life is controlled by networks." Have you been thinking at all about how viruses and microbes factor into and change the equation? Do you have any thoughts about how viruses, which operate consortially, are 10% or so of the human genome?
Geoffrey West: Unfortunately, the problem in dealing with the question of viruses and bacteria that are integral to an organism--
Suzan Mazur: My understanding is the thinking now is that animals, plants and fungi "live within the context of" the virome and microbiome.
Geoffrey West: Because this is relatively new, this kind of work, there isn't the kind of data and there isn't the kind of extensive look across many different animals or even plants to really start to properly reformulate evolutionary theory.
Suzan Mazur: I think it's interesting, and your colleagues mention in their Royal Society paper on chaotic crystallography as Luis Villareal and Lima-de-Faria have also noted, that viruses can exist in a crystal state. Villarreal thinks they were possibly at the start of life because viruses have the ability to transition from the chemical to living world.
Geoffrey West: Yes, we're discovering that there's much more to viruses than ever thought. It's not even clear what role they play. I've talked to a lot of people about it but I'm not an expert.
It's kind of interesting that it took so long for biologists to refocus their attention on this question.
Suzan Mazur: Did you once say cities don't die?
Geoffrey West: It's a scale question again. Of course, cities have died but they're all mostly ancient ones.
Suzan Mazur: And even some of those -- like Aphrodisias and Çatalhöyük -- are once again trafficked, now by archaeologists and tourists.
Geoffrey West: Of the millions of cities that have been formed on this planet, almost all of them are still with us. Very few on the grand scale have died. Most of them that have died have died because of war and famine. But once cities get above a certain threshold, it's very hard to kill off a city. Look at New Orleans, but much more dramatically, despite the horrible act of dropping atom bombs on cities, they've survived and now thrive.
Suzan Mazur: In the New York Times article about your thinking about cities, you mention the work of Jane Jacobs, author of The Death and Life of Great American Cities, who was a resident of Manhattan's West Village, where I am actually. It's mentioned that Jacobs saw the neighborhood interactions as a ballet and that the city itself was a dance. Do you still say there's a math to that dance?
Geoffrey West: Yes, there is. That's what's amazing and it's due to the fractal nature of that dance, the kind of social behavior that gets reflected in social relationships, networks and interactions. And out of social relationships comes the life blood of cities. The multiplicative enhancement arising from increased social interaction in a large city like New York is the origin of innovation, it's what creates ideas, wealth and so forth, but also crime and disease.
Suzan Mazur: I, of course, remember a much more bohemian West Village going back to the early 1970s, where there was an ongoing parade of lovers and various large hunting dogs. That dance has clearly lost its oomph. The last remaining Russian wolfhound in the West Village can now be rented for a dollar a minute for therapeutic petting purposes. Surveillance cameras have obviously taken their toll as well. But the emphasis on money has particularly diminished the human experience in New York.
Geoffrey West: All true.
Suzan Mazur: Could a city like New York fade into history?
Geoffrey West: I don't think as a city it can fade. It can certainly change, go from being this exciting place with a buzz with lots of diversity and lots of crazy people walking the street and dogs and all the rest -- the things that have made New York a great city. It could go from that to being just a great big Cleveland or whatever. That's certainly possible.
I just came back from Singapore. New York could end up looking like Singapore.
Suzan Mazur: Can you speculate on what presidential candidate would be the best one to ensure that our cities continue to thrive? You said that the action is increasingly in the cities.
Geoffrey West: Yes, there's no question that cities are where the action is and cities are to a large extent going to determine the fate of this planet or at least the fate of the socioeconomics of human beings of this planet. In fact, one of the concerns I have about all of the candidates, besides some of the obvious things, is two things they never talk about -- I haven't heard any conversation about -- one is science. Science and technology determine a great deal about how we live. The second is that none of them have talked about cities and urbanization and what that means. So it's very hard to answer your question.
Suzan Mazur: Of course Donald Trump has been very successful at building hotels and luxury buildings in Manhattan.
Geoffrey West: But that's a tiny, teeny bit of the city.
Suzan Mazur: Craig Ferguson once presented a map on his late night comedy show that divided all Manhattan into two parts: Trumpistan and DeNiroland.
Geoffrey West: [Laughter] Off the top of my head, I would say it could be that Hillary would be good -- this is regarding New York, anyway -- because rightly or wrongly she has been a supporter of open global trade and New York is part of a global urban system. That's important for New York. But whether she'd be good for the economy in the rest of the country -- I don't know.
Suzan Mazur: And her husband, Bill, awarded Lynn Margulis the Presidential Medal for Science. So there's some science interest in the family.
Geoffrey West: I know, that's amazing. I think that had more to do with Al Gore rather than Bill Clinton. I don't think Bill Clinton has any interest in, or knowledge of science, and I suspect Hillary is the same. It's likely anything significant that happened during the Clinton era regarding science was because of Al Gore. Al Gore somehow got the science and technology bits, primarily becoming interested in the whole global climate change issue very much before us now.