Evolution and "Laws of Form"
Post of the Month: September 1997
Copyright © 1997 by John Wilkins
arry Moran has challenged me on the claim that Stephen Jay Gould represents, or at least flirts with, a tradition known as the "laws of form" tradition dating back to Oken and the Naturphilosophen movement of the late 18th and early 19th centuries, mainly in German-speaking countries, with Goethe as its intellectual stem species. It's time I put up or shut up. Not being one to shut up, here is my best shot.
First the salient points of the tradition that derives from Oken. The references here are secondary, as I do not speak enough German to read the originals. The refs are Mayr 1982, Depew and Weber 1995, Panchen 1992, and Dennett 1995, but I could given many other source histories (eg, Nšrdenskiold 1928) that avoid the claim of neo-Darwinian bias.
Beginning with Oken, the Naturphilosophen movement tried to understand homology in terms of morphological affinity - of what in German are called BauplŠne (roughly, "blueprints"), following Goethe's attempt to see all parts of plants other than the stems as modified leaves. Geoffroy attempted to specify a "prototype" for each of the main kingdoms, stating that "every animal is either outside or inside his vertebral column". Cuvier demolished this view, since Geoffroy hadn't distinguished between homologies due to relationship and those due to function, and his claim was vulnerable to evidence, but the view did not die then. Owen, who coined the term homology, attempted to synthesise the Cuvierian and Geoffroyan views (respectively, Cuvier's "embranchements" and Geoffroy's "connections"), and Agassiz famously viewed each of Cuvier's embranchements as a special "plan of structure" that determined the form of each species (Lurie 1960:205).
The tradition was revitalised during the so-called "eclipse of Darwinism" period (Bowler 1983), mainly by D'Arcy Thompson (1917), to which Gould often refers. Thompson's view was that the "laws of growth" are more in control of phylogenetic change than selection.
All of these descendents of Oken have one thing in common - that morphological change is (entirely or mainly) the result of inherent, or endogenous, properties of the organisms. In the evolutionary version, Bauplans (let us now give the word an English plural) constrain and even direct the changes that occur over phylogenetic times. This is the modern version of the "function or form" debate that goes back to Cuvier's debate with Geoffroy.
The implication in modern terms is that change is not (necessarily) adaptive, and that selection is not therefore the major cause of what some are pleased to call "macroevolution", evolution at or above the species level.
We come to Gould, and his coworkers Lewontin, Stanley, Vrba, Valentine and Eldredge, who, though not exactly forming a school like the "Oxford School" of adaptionists in England, are some sort of cohort. In the "Spandrels" paper, Gould and Lewontin (1979) make a good case against the profligate adaptive stories that were mere speculation without evidence, and that point was well-made. But they also make a number of other points. The very idea of a spandrel in evolution implies that some features of biological organisms are just architectural, and that they are not adaptive. This was never in doubt in Darwinism - indeed Darwin made some similar comments in the Origin, that
There are many unknown laws of correlation of growth, which when one part of the organisation is modified through variation, and the modifications are accumulated by natural selection for the good of the being, will cause other modifications, often of the most unexpected nature.
But this is not what Gould and Lewontin are claiming, at least implicitly. They are claiming that there are changes not due to selection at all. They are claiming that some changes are due to the developmental Bauplan. As they say in the abstract:
[We] attempt to reassert a competing notion (long popular in continental Europe) that organisms must be analysed as integrated wholes, with BauplŠne so constrained by phyletic heritage, pathways of development and general architecture that the constraints themselves become more interesting and more important in delimiting pathways of change than the selective force that may mediate change when it occurs.
Now this is clearly in the tradition of Oken and his successors, but with a minor role for selection, and with transmutation of species permitted. Compare this with Darwin's statement that selection is the "main but not sole" cause of evolution. So I consider that the major claim I made - that Gould is flirting with views derived from Oken has been demonstrated just from this quote.
In recent years Gould seems to have downplayed this a bit. First off, Maynard Smith and other "hyper-Darwinians" have admitted the general validity of their main thesis that adaptive stories must be at best only speculation for further investigation (refs in Dennett 1995). Secondly, Gould has responded to the misconstrual of evolutionist and creationist alike by writing a number of pieces extolling the centrality of selection to Darwinian thinking (eg, Gould 1980). Whether or not one thinks that Dennett is correct in his analysis of Gould's and his cohort's views that, in the words of GE Moore when assessing a thesis submitted to him, they are both original and interesting, but where original, not interesting, and where interesting, not original, Gould et al. represent the continuing influence of a tradition that arose in the Naturphilosophen, and which influenced such diverse thinkers as those I listed in the third and fourth paragraphs above.
I know this won't convince Larry, but at least I have shown some primary grounds for my belief.
Bowler, Peter J, The Eclipse of Darwinism, Anti-Darwinian Evolution Theories in the Decades around 1900, John Hopkins University Press, Baltimore and London, 1983
Dennett, Daniel, Darwin's Dangerous Idea, Evolution and the Meanings of Life, Allen Lane The Penguin Press, Harmondsworth UK, 1995
Depew, DJ and BH Weber, Darwinism Evolving, Systems Dynamics and the Genealogy of Natural Selection, A Bradford Book; MIT Press, Cambridge MA, 1995
Gould, SJ, The Panda's Thumb: More Reflections in Natural History, Penguin Press, Harmondsworth UK, 1980
Gould, SJ and Lewontin, RC, The spandrels of San Marco and the Panglossion paradigm: a critique of the adaptationist programme, _Proc R Soc Lond B 205, 581-598, 1979
Lurie, Edward, Louis Agassiz, A Life in Science, Johns Hopkins University Press, Baltimore and London, 1988 (reprint of the 1960 University of Chicago Press edition)
Mayr Ernst, The Growth of Biological Thought: Diversity, Evolution, and Inheritance, The Belknap Press of Harvard University Press, Cambridge MA, 1982
Nšrdenskiold, Erik, The History of Biology, Knopf, New York NY, 1928
Panchen, Alec L, Classification, Evolution, and the Nature of Biology, Cambridge University Press, Cambridge UK and New York, 1992
Thompson, D'Arcy, On Growth and Form, Cambridge University Press, Cambridge UK, 1917
Article originally posted September 28, 1997
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