Preface to Paperback Edition of NO FREE LUNCH
My book NO FREE LUNCH is now, five years after its publication, appearing in paperback. I was asked to write a new preface to the paperback edition. Here is an excerpt:
… Ironically, the very sketchiness of mathematical details that Wolpert claims prevents one from properly assessing the book does not prevent him from offering just such an assessment. In his review, he writes: “Neo-Darwinian evolution of ecosystems does not involve a set of genomes all searching the same, fixed fitness function, the situation considered by the NFL theorems. Rather it is a co-evolutionary process. Roughly speaking, as each genome changes from one generation to the next, it modifies the surfaces that the other genomes are searching. And recent results indicate that NFL results do not hold in co-evolution.” Since one of my main claims in this book is that NFL results do apply to co-evolution, it would seem that, coming from the inventor of the NFL theorems, this criticism should be devastating. But it is not. In Wolpert’s 2005 paper with William Macready titled “Coevolutionary Free Lunches” (IEEE Transactions on Evolutionary Computation), the authors acknowledge, in both the abstract and the conclusion, that “in the typical coevolutionary scenarios encountered in biology, where there is no champion, the NFL theorems still hold.” I highlight this contradiction not to gloat but simply to point up that the issues raised in this book remain very much alive and under discussion, and that the key players are still quite far from reaching a consensus….
