Until this summer, I had only a vague idea of who Nikolai Vavilov was. I knew he had been Dobzhansky's mentor, and that like all Russian biologists, he had suffered at the hands of Lysenko. Otherwise, I had heard of Vavilov only in connection to an obscure quote from the introduction of Maynard Smith's Evolution and the Theory of Games:
Suppose for example, that only two kinds of wings could ever develop -- rectangular and triangular. Natural selection would probably favor the former in vultures and the latter in falcons. But if one asked 'Why are birds' wings the shapes they are?', the answer would have to be couched primarily in terms of developmental constraints. If, on the other hand, almost any shape of wing can develop, then the actual shape, down to its finest details, may be explicable in selective terms.
Biologists differ about which of these pictures is nearer the truth. My own position is intermediate. Clearly, not all variations are equally likely for a given species. This fact was well understood by Darwin, and was familiar to me when I was an undergraduate under the term 'Vavilov's law of homologous variation' (Maynard Smith 1982:7).
Well, so much the more for mystery. A historical footnote to be remembered in an argument with Stephen Jay Gould. So I filed it in the back of my mind, since this kind of developmental constraint hypothesis has become more and more important in human evolution during the past few years. It turns out that the traits that differentiate some hominid species are in many cases the same traits that have the most variation within species.
Anyway, it was enough to get my interest when Peter Pringle's new book, The Murder of Nikolai Vavilov, showed up in the local bookstore.
