Evolving Thoughts

Evolution, culture, philosophy and chocolate! John Wilkins' continuing struggle to come to terms with impermanence... "Humanus sum, nihil humanum a me alienum puto" - Terence

Wednesday, June 01, 2005

Embryos and evolution

This is a short review of a book I will do a proper review of for Philosophy in Review.

Amundson, Ron. 2005. The changing rule of the embryo in evolutionary biology: structure and synthesis, Cambridge studies in philosophy and biology. New York: Cambridge University Press.

AU - Amundson, R.
PY - 2005
BT - The changing rule of the embryo in evolutionary biology: structure and
CY - New York
PB - Cambridge University Press
SN - 0521806992 (alk. paper)
KW - Evolution (Biology) Philosophy.
Developmental biology Philosophy.
Embryology Philosophy.

Ron Amundson, Professor of Philosophy at the University of Hawai'i, has long had an interest in the history of biological thought. Here, he enters into a revision of the nature of biology before Darwin, attacking what he calls the "Synthesis Historiography" (SH). I call it the Received View, and others have their own names for it, but basically it's the view you'll find in Ernst Mayr's Growth of Biological Thought.

It has long been known that the standard view, whatever it is called, is a rhetorical device used by scientists and philosophers to affirm the novelty of the new science. Scientists do this in every science - from astronomy to geology, science is a Whig Historian, finding precursors to the present everywhere, and chronicling the triumph of the "right" view. Mayr and other evolutionists did this too. The difficulty, for a historian of science, is to figure out what interests this served, and to work out what of the past is really like it is portrayed in the textbook views.

And Amundson shows some things that may surprise readers who only know the textbook accounts. For a start, the idea that species were fixed is a mid-17th century invention. Amundson fingers Linnaeus, but I think it's John Ray or a bit earlier. Older accounts of species had them able to change through hybridism or in ways that had to do with the nature of generation.

Moreover, essentialism, one of Mayr's bĂȘte noirs, doesn't make an appearance in biological systematics until Hugh Strickland, in the 1830s. And oddly, Darwin is an enabler here - the Strickland Rules were something he was crucial in getting adopted. Amundson points out that these were not essentialist in the way Mayr wrongly thinks preceded Darwin, that species were composed of their causal essence, but only in a formal, nomenclatural and diagnostic sense - species had better have a name and a definition or else we couldn't tell what we were referring to when we used a species name. That is pretty harmless.

Worse, the Mayrian claim that ideal morphology was a creationist view, or an example of the "idealist version of the argument from design", is historically false. The ideal morphologists associated with Goethe and Oken, and present in Britain in the person of Richard Owen, were neither statists (that is, opposed to temporal change of form) nor creationists. Instead, they expected that form could change over time, and were more interested in developmental sequences than evolution in the broader sense (for "evolution" originally meant development).

He presents in detail Owen's ideas and influence on the subsequent debate, as well as that of Cuvier, Martin Barry, and others on Darwin himself. Then, in part II, he addresses the invention of heredity in science, and the neo-Darwinian accounts of evolution, in a new and fresh way. In particular he deals with the "eclipse" of Darwin, so named by Huxley and dealt with by historian Peter Bowler in a book by that name, following Jean Gayon, who argued that the reason Darwin was eclipsed from 1890 to 1930 was reasonably simple - natural selection hadn't run up the scientific credentials. By 1930, it had.

I won't go into detail with Amundson's telling of the story - it is worth reading itself, and I urge those interested to do so. One thing that Amundson does is retrieve the "hidden" history of 20th century biology - that of developmental biology, which has been itself eclipsed until quite recently. Now, with the new field known as "evo-devo", the evolution of developmental cycles has become the hot new field as it integrates into genetics and the ecological aspects of biology.

I have few criticisms of the book. Its worst sin is pretty much a pecadillo - the naming of positions as "-isms" such as structuralism, essentialism, adaptationism, and so on. I recommend it to those worried that the neo-Darwinian view is all-conquering. I recommend it also to those who think this is a good thing.

There is no comfort for creationists here, of course. The history is in fact quite inimical to creationism although there is no intention to be. It's just a side effect of re-examining the history - creationism, and species fixism, were only minor players, and aren't even traditional accounts of species.

Strongly recommended.