ERNST MAYR: WHAT EVOLUTION IS

EDGE: To what extent has the study of evolutionary biology been the study of ideas about evolutionary biology? Is evolution the evolution of ideas, or is it a fact?

ERNST MAYR: That's a very good question. Because of the historically entrenched resistance to the thought of evolution, documented by modern-day creationism, evolutionists have been forced into defending evolution and trying to prove that it is a fact and not a theory. Certainly the explanation of evolution and the search for its underlying ideas has been somewhat neglected, and my new book, the title of which is What Evolution Is, is precisely attempting to rectify that situation. It attempts to explain evolution. As I say in the first section of the book, I don't need to prove it again, evolution is so clearly a fact that you need to be committed to something like a belief in the supernatural if you are at all in disagreement with evolution. It is a fact and we don't need to prove it anymore. Nonetheless we must explain why it happened and how it happens.

One of the surprising things that I discovered in my work on the philosophy of biology is that when it comes to the physical sciences, any new theory is based on a law, on a natural law. Yet as several leading philosophers have stated, and I agree with them, there are no laws in biology like those of physics. Biologists often use the word law, but for something to be a law, it has to have no exceptions. A law must be beyond space and time, and therefore it cannot be specific. Every general truth in biology though is specific. Biological "laws" are restricted to certain parts of the living world, or certain localized situations, and they are restricted in time. So we can say that their are no laws in biology, except in functional biology which, as I claim, is much closer to the physical sciences, than the historical science of evolution.

EDGE: Let's call this Mayr's Law.

MAYR: Well in that case, I've produced a number of them. Anyhow the question is, if scientific theories are based on laws and there aren't any laws in biology, well then how can you say you have theories, and how do you know that your theories are any good? That's a perfectly legitimate question. Of course our theories are based on something solid, which are concepts. If you go through the theories of evolutionary biology you find that they are all based on concepts such as natural selection, competition, the struggle for existence, female choice, male dominance, etc. There are hundreds of such concepts. In fact, ecology consists almost entirely of such basic concepts. Once again you can ask, how do you know they're true? The answer is that you can know this only provisionally by continuous testing and you have to go back to historical narratives and other non-physicalist methods to determine whether your concept and the consequences that arise from it can be confirmed.

EDGE: Is biology a narrative based of our times and how we look at the world?

MAYR: It depends entirely on when in the given age of the intellectual world you ask these questions. For instance when Darwin published The Origin of Species, the leading Cambridge University geologist was Sedgwick, and Sedgwick wrote a critique of Darwin's Origin that asked how Darwin could be so unscientific as to use chance in some of his arguments, when everyone knew that God controlled the world? Now who was more scientific, Darwin or Sedgwick? This was in 1860 and now, 140 years later, we recognize how much this critique was colored by the beliefs of that time. The choice of historical narratives is also very time-bound. Once you recognize this, you cease to question their usefulness. There are a number of such narratives that are as ordinary as proverbs and yet still work.

EDGE: Darwin is bigger than ever. Why?

MAYR: One of my themes is that Darwin changed the foundations of Western thought. He challenged certain ideas that had been accepted by everyone, and we now agree that he was right and his contemporaries were wrong. Let me just illuminate some of them. One such idea goes back to Plato who claimed that there were a limited number of classes of objects and each class of objects had a fixed definition. Any variation between entities in the same class was only accidental and the reality was an underlying realm of absolutes.