2009 celebrates the 150th anniversary of “The Origin of Species”, we all know that too well. But are there any other memorable 1xx9 year for evolutionary biology? In 1979, 120 years after the “origin of species”, two major papers were published and revisited the concept of constraint in evolutionary biology.
On one side, the “romantic” view of constraints, with Lewontin and Gould who wrote a paper entitled "The Spandrels of San Marco and the Panglossian Paradigm" (Proceedings) which introduced the architectural term spandrel into evolutionary biology. A spandrel is the space that exists between arches. When visiting Venice, Gould noted that the spandrels of the San Marco cathedral, while quite beautiful, were not planned, but rather resulted from the arches the architects deliberately designed. Gould and Lewontin thus defined the word "spandrel" in evolutionary biology as a coincidental character, which does not directly result from selection but from contingency, although which may eventually increase fitness. This would later on lead Gould to further investigate the issue of exaptation and preadaptation, which had been introduced already in 1859 by Darwin. So far this paper has been cited 2536 times according to Google scholar, and remains one of the most studied papers in evolutionary biology by undergraduate students, at least in France.
On the other side, the more “pragmatic” view, with Lande, who wrote another very much cited paper (843 times), and in certain fields of evolutionary biology, even more influential: “Quantitative genetic analysis of multivariate evolution, applied to brain: body size allometry” (Evolution). This was the first study to really assess the constraining effects of genetic covariation between traits. By using data from selection experiments on brain and body size, Lande hypothesized that in certain mammalian groups such as primates, reduced covariation between these two characters might have enabled encephalization through direct selection. However, the real reason why this paper has had a profound effect on evolutionary biology is because it has (re-)introduced multivariate quantitative genetics methods to study phenotypic evolution. After this, studies on the constraining role of the genetic variance-covariance matrix during phenotypic evolution have flourished.
The reason why I wrote this post is because I think it might be interesting to discuss these two classic papers with the aim of addressing the influence they have had so far on our own work, if any, or on the current agenda of evolutionary biology. However, I am quite tied up right now with my parental leave, so it won’t be any time soon for me, but maybe we could plan something in April for one of our Wednesday meetings. In the mean time, you guys are free to react on that and maybe to propose other key papers published in 1979 that I might have forgotten.