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.
Fabrice Eroukhmanoff.
Interesting post Fabrice!
ReplyDeleteI agree, these two papers should be discussed together. Few have realized how much influence Gould & Lewontin (1979) had on Lande & Arnold (1983). Those who criticize Gould & Lewontin for there views (sometimes too extreme, in my opinion), should reflect over the fact that they stimulated Lande and others to develop statistically rigorous methods to study selection, and not rely on verbal arguments and "Just-so stories".
This is a nice example of dialectics, by the way: "thesis-antithesis-synthesis".
Very nice analysis Fabrice!!! It is interesting that Lande and Gould & Lewontin were published in the same year, because the work Lande was doing would turn out to be a powerful response to the criticisms of Gould and Lewontin. For example, Lande and Arnold ('83), which of course builds on Lande ('79), responds directly (and rather negatively) to Gould and Lewontin. I had my students read Gould and Lewontin when I taught evolution in Santa Cruz, though I remain undecided about the value of the paper (today I like it, tomorrow I hate it...). I thought it would promote lively discussion at least, but the students all pretty much thought it was retarded.... which may not be good. Perhaps we've all be too successful at selling the power of adaptation. Of course, my papers that deal with adaptation are extremely adaptationist, so I'm not sure I am in a good position to lecture people on this....
ReplyDeleteMy favorite year for Evolutionary Biology is 1966 -- perhaps I'll detail this in another post, but for now I need to get back to work.
Erik, you scooped me!!!!! You posted as I was writing my response, and I didn't see it until I posted..... Well, as "they" say, great minds think alike! =p
ReplyDeleteI agree with you guys, i thought about mentioning the 1983 paper in my post but wanted to stick with 1979... However, it would be a nice tradition for this blog to once in a while go through the good"millesimes" of evolutionary biology, 1966 being the next one!!!
ReplyDeleteComcerning the spandrels paper, i agree that it is far from perfect, but every time i read it again, i find something new in it... although, ow that i realize it, i haven't read it in a couple of years... shame on me...
I think that Shawn's and mine independent responses illustrate that "great minds think alike" :)
ReplyDeleteWell, the Gould & Lewontin-paper and all that might be criticized with it (they are quite extreme in some paragraphs) have also done a lot of good to evolutionary biology. The main point is that we should focus on science AS A PROCESS (=ongoing discussion) not as a finished PRODUCT (=paper that represents the final word). In that sense, what happened in 1979 is how science should ideally proceed: a controversial paper comes out which stimulates further discussions and forces people to sharpen their arguments and become more convincing.
Such great papers as the Gould ’79 paper have an artistic feel, i.e they have a subjective quality about them, especially as they are critiqued to the point where every sentence is taken to mean something. For me, this paper awoke me from my need as a budding evolutionary biologist (not that I’ve flowered or anything) to find the adaptive explanation to every trait we see. I took their message to be that of a warning, simply finding a trait that serves a purpose does not mean it was adapted for it, it is unlikely that the elephants trunk evolved to scratch its arse (not that I’m suggesting it arose as a byproduct to something else). And I don’t see how Lande & Arnolds 83 paper changed that. Showing selection is currently occurring on a trait, doesn’t mean that it is the cause of its origin, just as the spandrels of san marco were not constructed specifically for the art that adorns them.
ReplyDeleteAs for your students Shawn, just shows what they know. Every time Gould blew his nose he produced something more worth while than they will in their combined lifetimes. Not that I hate opinionated students or anything.
Of course it was a while ago that I read it and it is late here and I can’t sleep, not that I’m getting my excuses in.