Question Center

A Talk with Armand Leroi

ARMAND LEROI is a Professor of Evolutionary Developmental Biology at Imperial College London, and the author of Mutants: On Genetic Variatey and The Human Body

[click for large high resolution image]

An 1817 British Admiralty map of Kolpos Kallonis, the lagoon in Greece where Aristotle began the study of the biological world. Aristotle proposed that organisms were formed and maintained by their "souls," by which he meant the topography of their metabolic and regulatory networks. Superimposed within the lagoon, therefore, is a map of the regulatory network of a yeast cell: Aristotle’s vision realized in the 21st C.


[ARMAND LEROI:] So who is the greatest biologist of all time? Good question. For most people it's got to be Darwin. I mean, Darwin is top dog, numero uno. He told us about evolution, he convinced us that evolution happened, and he gave us an explanation for it. I mean, there just wouldn't seem to be any competition. Okay, fine, well you might then say: Mendel. Mendel discovers transmission genetics, and that was pretty good. And I suppose then you have to go pretty far down the list to come to people like Watson and Crick, who just discovered the structure of DNA, which is just a bit of structural biology, really, a bit of biochemistry.

Okay, but who is the real top dog? For me, the answer is absolutely clear. It's Aristotle. And it's a surprising answer because even though I suppose some biologists might know, should they happen to remember their first year textbooks, that Aristotle was the Father of Biology, they would still say, “well, yes, but he got everything wrong." And that, I think, is a canard. The thing about Aristotle - and this is why I love him - is that his thought was is so systematic, so penetrating, so vast, so strange – and yet he's undeniably a scientist.

Aristotle was a student of Plato's.  Around the year 347/8 BC, when he was in his late 30s, he left Athens and went to the Island of Lesvos. He scooted a bit along the Aegean Coast, and as he did so picked up a wife. We believe that she was 18 years old. We don't entirely know that for sure. We know her name was Pythias. We think she was very young because he says the best age for a man to marry is 37, the best age for a woman to marry is 18, and given that we know that Aristotle was 37 when he married, we infer that his wife was 18. He was a great man for rationalizing things.

In any event, he's 37, he's left Athens.  He’s done this, incidentally, after Plato's death, and one explanation for why he left was that he’s the brightest guy in the academy, clearly a candidate for the top job, the head of the academy, but he doesn’t get it, so he up sticks and leaves. He arrives in Lesvos, the Island in the Eastern Aegean, around 345 BC.

He's got his young wife, he's thinking about biology, and he goes down to the shore, and he picks up some snails, and he picks up some fish from the local fish market, and he begins to dissect them, and he writes the results down.  And that's when biology is born, in those few years. I think of Lesvos, and the place that he worked, which was a lagoon, a magical lagoon, a beautiful piece of water that bisects the island, as Aristotle's Galapagos, his Down House, his Andes. It was to him what all those places were to Darwin, and to Humboldt, and all the other great biologists, each of whom seem to have some place, some location, that inspired them. And for me, that I think is what Lesvos was. What he did there was lay the foundations of biology.

We don't know the order in which he wrote his books. We can take a bit of a stab at it. Probably the first book that he wrote, though some scholars dispute this, it's not really very important, was Historia Animalium, which you can roughly call a natural history of animals. It's not really a natural history, it's certainly not a systematic treatise, rather what it is, it's a comparative anatomy. He goes through digestive systems, and hearts, and circulatory systems, and so on, and so on, and so on, and he shows how they differ between different creatures. He goes through their behavior, and he does a lot of dissections.

We've lost his book of dissections, but he refers to the dissections in there, and it's all astonishingly modern. He said, "As you can see in the picture, to the left, the part labeled "alpha" is this, and the part labeled "gamma" is that, and the part labeled "zeta" is that", and so you infer that he's got an anatomical diagram complete with labels that looks exactly like that, which you'd find in any modern textbook. Fine. So that's Historia Animalium.

Then he writes a book about the parts of animals, which is his functional anatomy. Then he writes a book about locomotion, on the movement of animals, and he writes one about sleep, and he writes another one about aging. He gives a very coherent and articulate theory of aging, which has had enormous amounts of influence right through the history of life. Indeed, it still forms part of the modern theory of aging. He writes, in fact, two books about that, and of course, he writes on generation, which is his great book about the development of animals, the generation of animals, and it's here that he does one of his great and most wonderful observations, and it's such a simple one, but it's so beautiful, and it has been so immensely influential.  He takes a chicken egg, which has just been newly laid, and he opens it up, and he sees the chick embryo lying there with his little beating heart, and he watches how the chick embryo develops over the course of days.  And that is the foundation of developmental biology, the science of how we make ourselves during ontogeny. And it is still to this day that chicken is used by thousands of developmental biologists.

Every generation has to reinterpret Aristotle, because the thing about him is he's so vast. His works, his biological works, would span, in small print, a shelf of books – something like that, thousands of pages. However good modern biologists may believe they are, they're nothing compared to Aristotle.  No-one can compare to him in just the sheer force and scope of his thought. And that is what makes reading him so wonderful. It's a whole system of biology which bears some resemblance to our own, but is yet sort of strangely skewed by comparison because it's kind of like our biology, and yet its premises are in some ways so strange and so very different.

And that's actually what makes reading him so exciting because it causes you to look at the natural world in a way that frees you from the assumptions of modern science. You see things afresh, and you say, "Well, actually, couldn't he have a point here?" But as I said, every generation needs to read Aristotle afresh, precisely because he is so vast, and every generation finds in him the things that they are looking for. In the 19th century the big thing in science was systematic biology, it was sorting out and cataloguing the natural world. People looked at Aristotle, and they found the systematic biologist, a taxonomist. I don't know if he really was.  Many scholars dispute that he was much of a classifier, and I think that's actually right. I don't think it was a primary concern of his.

So what do I find when I look at Aristotle? Well, for me the thing that fascinates me about Aristotle is his discussion of the soul. Now, I know that's a strange thing to say because when we talk about souls, we immediately think of the Judeo-Christian conception of the soul which is some strange non-physical entity that hangs above your head, or something, and survives you after death. That's not what Aristotle meant, not at all.

Aristotle thought that soul was central to life. And there's nothing vitalist about it, there is nothing metaphysical about it. It's hard to get a grip on what he meant, but it's a resolutely empirical kind of concept. What he meant was something like this: he says all living things have a soul, and when they die, the soul disappears. So none of that nonsense about the immortality of the soul. Plato thought souls were immortal, many people believed that souls were immortal, but Aristotle is clearly using soul in a very special, and technical, and new sense. It's the moving principle of life.

Okay, but what is it made of? The answer is it's not made of stuff, it's not made of matter. Well, that's a bit strange. So how can it exist if it's not made of matter? You think about that, and you think about that quite a lot, and you read Aristotle, and then you sort of see what he's getting at. What he's getting at is that the soul is not matter itself, it's the way that matter is organized. It's the relationship between the parts. It's the system. And, in fact, many Aristotelian scholars reaching for metaphors to explain what Aristotle is getting at, they use words like "system", and "cybernetic", and so on, depending on exactly when they were writing. You know, when cybernetics was cybernetics, well, they used that. And I think that's basically right.

If we understand what Aristotle is getting at, we can show, and you can find this in his text, is that he's interested in explaining how creatures take stuff from the environment, food, how they partition it, how they distribute it to the various ends that they need, and how all that is regulated by a very elaborate homeostatic system. Again homeostasis. This is cybernetics systems talk, a system that he actually tells us about in some detail. One that is deeply wrong, but then, again, his fundamental chemistry is completely barking mad by modern standards, since it’s based upon four elements. But given all that, the logic of his explanation is very clear.  And it’s very beautiful.

On Armand Leroi's "Who Is The Greatest Biologist of All Time?"

Introduction by John Brockman, George Dyson, Stewart Brand, Richard Dawkins

by John Brockman

One of the problems with the Darwin lovefest of a year ago is that it overwhelmed both the recent and ancient history of biology. Most EDGE readers have at least some familiarity with the high points of modern physics in the past one hundred years or so: Einstein's Special theory of relativity (1905); Eddington's expedition to observe the Solar eclipse that provided one of the earliest confirmations of relativity (1919); Bohr, Heisenberg and Quantum Mechanics (1920s); the work of Gell-Mann and Feynman (1960s); the unified field theory Glashow, Weinberg, and Saalam; and more recently, areas such as string theory, the inflationary universe, the multiverse, etc.

The same cannot be said for the field of biology. Physicist don't talk about "Newtonism", but biologists can't shut up about "Darwinism". Enough is enough; and more than enough is too much.

This aspect of our science culture is, in my opinion, a show-stopper. I believe it contributes to the problem of how biology and evolution are treated as political footballs in debates over school curricula in America.

It's time for biology to get up to date, to credit people other than Darwin for their contributions to biology and to present these achievements to the educated public.

I would like to hear about the relationship of Darwin's ideas to those of Jean- Baptiste Lamarck. What about the the work done by Mendel in 1900 and how the the gene, though its exact nature was unknown at the time, became a player in "the modern synthesis" of Mendel and Darwin. This synthesis, which reconciled genetics per se with Darwin's vision of natural selection, was carried out in the early 1930s by R.A. Fisher, J.B.S. Haldane, and Sewall Wright, and augmented a few years later by the work of the paleontologist George Gaylord Simpson, the biologist Ernst Mayr, and the geneticist Theodosius Dobzhansky, who expanded on this neo-Darwinian paradigm.

How many readers of Edge are familiar with the biological developments of the 1960s and 1970s led by George C. Williams, William Hamilton, and John Maynard Smith. Williams, for example, was the first to emphasize that it was the gene on which natural selection acted. In this regard, he precedes Richard Dawkins, with whom he shares a great many ideas, and he was in a different camp from Stephen Jay Gould, who had a hierarchical theory of selection processes, of which the gene is only one level. Williams' book Adaptation and Natural Selection, published in 1966, described the gene as having a "codical" as well as a physical character — that is, he views the gene as a package of information, not an object.

And that just brings us up to the 1970s when Robert Trivers, while a post-doc at Harvard, wrote five seminal papers that created a new scientific field: the scientific study of human nature. A seminal moment in that decade was the publication of Dawkins's The Selfish Gene (with an introduction to the first edition by Trivers) in which he presented many of the ideas of Williams, Hamilton, Maynard-Smith, and Trivers along with his own original thinking on the subject. All the while, the mainstream media in America were misrepresenting Stephen Jay Gould as the authority on evolutionary biology, when Gould himself said this his role was that of a critic, of the mainstream researchers in the field.

There is still discord in the ranks of evolutionary biologists. The principal debates are concerned with the mechanism of speciation; whether natural selection operates at the level of the gene, the organism, or the species, or all three; and also with the relative importance of other factors, such as natural catastrophes. This is evident in the strong reactions to a controversial paper recently p published in Nature by Martin Nowak, Corina Tarnita and Edward O. Wilson ("The Evolution of Eusociality", 26 August 2010).

And so it goes. The conversation in biology since Darwin is interesting, it's important, and it's something the general public should know about. To the extent the Edge community can present it in a coherent manner, it will be a wonderful public service.


Science Historian; Author Baidarka; Project Orion; and Darwin Among the Machines.

In his Edge conversation "Who is the greatest biologist of all time?", Armand Leroi asks, and unequivocally answers the question. What can anyone add?

The only question left is "Who is the greatest biologist since Aristotle?" Now, in general, "who is the greatest" questions are dangerous, but, if Edge is going to ask one, you have to ask that. And most people are going to answer, "Darwin!" and we just had a full year of that.

So, let's move on to the next question:


Now that's an interesting question....

Founder, The Whole Earth Catalog; Cofounder, Chairman, The Long Now Foundation; Author, Whole Earth Discipline: An Ecopragmatist Manifesto

Indeed, Leroi has written a lovely piece, full of news for me. And I like George Dyson's question, as he has framed it above.

Evolutionary Zoologist, University of Oxford. Author, The Blind Watchmaker; The Greatest Show on Earth

I've listened to Armand Leroi's talk: beautifully delivered (apart from his infuriating use of the historic present), but his nomination of Aristotle is obviously just contrarian for the sake of it. He is simply bending over backwards to contrive a way of answering the question with a name other than Darwin. And that's a hopeless cause! I prefer to answer the question straight, making no attempt to be contrarian or 'interesting'. Darwin, of course, is the greatest biologist ever.

Who is the greatest biologist since Darwin? That's far less obvious, and no doubt many good candidates will be put forward. My own nominee would be Ronald Fisher. Not only was he the most original and constructive of the architects of the neo-Darwinian synthesis. Fisher also was the father of modern statistics and experimental design. He therefore could be said to have provided researchers in biology and medicine with their most important research tools, as well as with the modern version of biology's central theorem.

John Brockman, Editor and Publisher
Russell Weinberger, Associate Publisher

contact: [email protected]
Copyright © 2011 By Edge Foundation, Inc
All Rights Reserved.