On stage at TEDGlobal 2011, Geoffrey West talked about the universal mathematics that govern cities and corporations. Knowing only the population of a city, he can predict the number of patents, the crime rate, the average walking speed and many other features of a city.
Before the conference, TED’s Ben Lillie reached him in his office at the Santa Fe Institute, in New Mexico, to talk about how this is connected to his previous research in biology, and how it might be extended to corporations, and even conferences.
You’ve done a lot of work on finding universal laws in biology and other subjects. Should I be surprised that there are such universal laws?
Yes, I think you should. After all, we believe in natural selection and the Darwinian process. That means that each organism, each component of an organism, each organ of a mammal, even each cell type, each mitochondria and each gene has evolved with its own unique history and its own environmental niche so to speak. Therefore what results is historically contingent and that’s one of the major points of natural selection. So if you look at any kind of physiological variable, from the classic ones like metabolic rate or the rate at which oxygen diffuses across a cell, or any life history event like how long do you live, how long does an organism take to mature, etc.. You would expect these, if you looked at them across a spectrum of sizes, it would be all over the map. You wouldn’t expect very significant regularities if you took the view that everything was determined purely by some kind of random interactive process. Quite the contrary, what you see is an extraordinary regularity, which implies that there are a whole bunch of constraints that are in play during natural selection.
Interesting, so this shows us that natural selection is operating within a set of constraints and maybe those constraints are stronger than we previously thought?
Yes, I think that’s true. If you go back and read The Origin of the Species, Darwin makes remarks to this effect at a couple of points. He doesn’t talk about what they are, but he just simply says it’s not totally random – there are all kinds of other things that are at play implying that there’s physics and chemistry and all these other things that are at work. I think the viewpoint that I take, anyway, is that in some ways an emerging property from natural selection that there would be these kind of constraints. Some of them are external, but they really come out of natural selection because they are, at least in the work I’ve been involved in, the constraints are the properties. These regularities are reflection of the network systems that sustain life at all scales, whether intracellularly or within you and me or in ecosystems or within a city for that matter. You could not have evolved a complex system like a city or an organism – with an enormous number of components – without the emergence of laws that constrain their behavior in order for them to be resilient. This is a very important point: if you want long term sustainability, susceptibility, resilience, and yet have adaptation and evolvability laws kind of have to emerge for that to happen. And so it isn’t all just random, it’s not arbitrary. From our viewpoint the natural construct for that are networks. If you have a million citizens in a city or if you have 1014 cells in your body, they have to be networked together in some optimal way for that system to function, to adapt, to grow, to mitigate, and to be long term resilient. Life is extraordinarily resilient. It’s been around for over billion years.
That ties in with a fascinating observation of yours: when you look at cities, very few cities failed or really gone away. That’s somehow an even stronger form of resilience than an individual organism.
Yes! The two questions that motivate me in this part of the work are “Are cities and companies, for that matter, just an extension of biology?” Are they biological – is New York a great big elephant? Microsoft a big anthill? We use those because, we can laugh at it, and we do, but the fact of the matter is biological metaphors are continually used in socioeconomic situations – the DNA of a company, the metabolism of a city. The question is, is that just a metaphor or is there something substantive about it? In what way do cities and companies behave as if they are all organisms? And in what way is there some new kind of dynamic, new kind of system evolved after man and woman started talking to one another, developed language. But then a subsidiary question to that is the one that you raised – if that’s the case, how come cities never seem to die? It’s very hard to kill [a city], we know classic cases of course, but of the millions of communities that have grown on the planet, almost all of them are still with us. My classic example is that you can drop an atom bomb on a city and 30-40 years later it’s thriving. It’s unbelievable. If you drop the equivalent of an atom bomb on Google and it will be dead, for sure. So to understand what is the underlying mechanism and what are the principles that are governing these kinds of phenomenon.
You base a lot of this work on the analysis of networks and the behavior of networks, is this something you can apply to just about anything that’s networked, say large international conferences or something like that?
Oh you could, absolutely. The worked I’ve been involved in, of course, has been biology and from intracellular levels up to ecosystems – you know, forests, and so on – and now cities and that’s clearly networked. It is networked in a much more subtle way. There’s the obvious networks of the roads and electrical lines and all the rest. But really what’s driving a city is the virtual network: the social interactions, the way individuals interact in clusters and interact with each other. So it’s kind of a network system. But you could expand that it to things like NGOs or conferences or TED. Or, not TED, what it would really be are things like TED – all the various gatherings like this. It would be very interesting to note are there any kind of commonalities and regularities as you look at the different scales at these kinds of events. I’ve wondered a little bit, if you go to Davos, TED, Techonomy, and these various conferences, they’re very different scales. But if you hang out it’s clear there are commonalities even though each one is different and has it’s own quite distinct character. It’s obvious there are a bunch of common features because they are a network of people. There are people interacting and there’s universality to the way people interact – no matter where you are in the world. That’s really where we are at the moment. It’s developing the conceptual framework and trying to put that stuff into a mathematical framework, which we did in biology, and is turning out to be more challenging.
Your background is in physics, and you attacked this from a very physics perspective. Clearly that’s one reason why this was new research and the people working in biology hadn’t done it before. Do you have thoughts on other reasons why?
Very long story short, one of the main reasons I got interested in this was the demise of the SSC [the Superconducting Super Collider]. I got kind of angry at the whole thing, the way in which physics was somehow being sidelined. The great adulation of biology, I thought, was certainly correct in terms of it being the science of the 21st century. My concern was that it didn’t look very much like science to me, for a physics perspective. It wasn’t quantitative – I mean areas of course are – but a lot of it wasn’t.
I was also getting interested in the question of aging. What motivated this work originally was — I said to myself as an arrogant high energy physicist — if biology were a real science you would be able to predict, or at least understand, not just the mechanism of aging, but where in the hell does a 100 years for the lifespan of a human being come from? Why isn’t it a 1,000 years or a billion years or six months? We believe everything is molecular whether its genes or respiratory complexes or whatever, but those have molecular time scales. How the hell do those things build up to 100 years? What upset me is that I would read in the gerontological literature at that time they would say that lifespan is genetically controlled. I would say that’s an explanation of nothing. In fact, the great mystery of health is how the molecules know a 100-years. And not only that how do the same molecules, if they’re in a mouse, know its 2-3 years?
And so then in just thinking about that and doing a little bit of literature search, I came across these scaling laws [such as the fact that an organism’s lifetime is determined by it’s size. Bigger animals live longer according to a very accurate mathematical relationship]. When I first saw them I was astounded because they were so good. I started looking at it, and no one had done anything; all they had done was collect this marvelous data. In fact it had been quite an active field up until the 50’s by many of the famous biologists. Then of course the molecular revolution took over, so it was kind of forgotten. There were people that did recognize that there was something remarkable about scaling laws, but then it kind of devolved into just being a curiosity. It amazed me that biologists weren’t struck by the fact that this is potentially an extraordinary window into underlying principles – which is what it is in physics. Scaling has played a critical role in physics, certainly did in the development of high energy physics.
So, I started to think about it and that’s what got me involved and I realized the tremendous difference of a physicist looking at the problem versus a traditional biologist. I started working on this, a skeleton of a theoretical framework, but I was extremely fortunate in coming together with my colleague, Jim Brown, who is a very distinguished ecologist who had been thinking about these things from an ecological viewpoint. This guy is a traditional biologist in the sense that he does a lot of fieldwork and has a huge number of students and post docs and he’s very well known in his field. He is totally mathematically changed, but he has amazing intuition. We were brought together through the Santa Fe Institute and that’s how I really started getting connected with him. He was very traditional, but at the same time he had a non-traditional mind that was incredibly important in terms of me being able to kind of put it all together.
I must say that just as a physicist coming into that field in a rather informal way, I was struck, not just by those scaling laws, but by the fact that biologists had not appreciated how extraordinary they were. That this was saying something very general and I actually believe quite deep about biology. A lot of biologists have bought into that, and a lot don’t get it or are threatened by it. One of the interesting things about this has been this cultural difference between biology and physics in terms of what constitutes scientific explanation, what do you focus on. Roughly speaking, I now make a total cartoon of it, biologists don’t believe in theory and they don’t believe that there are any general principles other than natural selection, nothing else. I just find that bizarre, actually. I still do. I mean, many of the best ones don’t feel that at all.
Moving into the social sciences, it’s been interesting there because the analogy to the problem with biologists has been the problem with some economists. (Not all, Paul Romer, an economist at Stanford has been a big admirer, which is very nice.) Many have a similar kind of funny reaction that some biologists do, but the thing that has been really encouraging and really delightful is that urban geographers, urban designers, urban planners, architects — people who are doing it have been extremely positive. That has been very encouraging.