DISCLAIMER: I used to read, close a book and forget about it. To improve my writing and also my critical analysis, I started writing pseudo-reviews about books I enjoyed reading.
Essays in the history of embryology and biology, by Jane M. Oppenheimer
(Or an essay about the usefulness of reading historical papers and books when starting a new scientific project).
I believe that transfuges between fields get to experience child-like enthusiasm more often than seasoned researchers, which might be the best perk of working at the interface. On top of being freshly enthusiastic, transfuges are unorthodox: without initial training, no dogma has been integrated yet and they have additional degrees of freedom for creative thinking. However, naive ideas are usually good ones only if they are backed by insights from previous training/other disciplines.
It is possible to watch an embryo grow, and be ecstatic and feel privileged, but every time I think I am getting the idea of the century regarding its development I have to remember that everything that could be witnessed by eye has been described somewhere else by generations of committed scientists. Even if it is in an extinct foreign zoological publication about fish breeding. One has to weed out all the naivety through targeted reading – and I found out that old literature is more powerful than recent publications for that specific purpose.
The importance of reading (and understanding) old literature to produce good science is at the core of Essays in the history of embryology and biology, and Jane Oppenheimer is its author. She used to be an embryologist, a philosopher and a writer and I discovered her out of pure luck. The library shelves of my institution do not carry indicative labels for sections and harbor only the cryptic classification known as « Library of Congress ». I was lucky enough Oppenheimer’s book was close to the one I initially intended to track down using a small grocery shopping list with these infamous numbers scribbled down.
There is a lot of German in the Oppenheimer book. Some classical musicians say that if you practice enough pieces, you will slowly learn Italian – at least enough to order your pasta presto or andante. It seems likewise that getting a foot in the history of developmental biology requires an advanced German level.
Ist denn das Studium von Klemmen wirklich die einzige Aufgabe des Biologen?
I thought this would only decorate the first page of the book, to enforce seriousness and gravitas on the reader, but Jane Oppenheimer gives us many more German interludes throughout the book, probably to preserve the initial philosophical meaning and avoid translative distorsions. There are also huge quotes in an older version of English, as she describes Sir Thomas Browne’s contribution to experimental sciences. Oppenheimer’s own prose itself is beautiful and poetic:
To formulate a romantic analogy, the 19th century might have intimated that the germ layers are the phrases in which the embryo composes its melodies.
In her book, Oppenheimer rehabilitates many ideas and experiments from the 19th century, drawing “ontogenies rather than phylogenies” to hammer her point: be more creative by understanding how our ideas evolve rather than establishing who was the first. She introduces us to the three patron saints of classical embryology – Roux, Driesch and Boveri – to expose how their ideas are still investigated today. I could name a few here and paraphrase her – developmental rhythms (Driesch), immuno-embryology (Roux) and polarity (Boveri). Thanks to the explosion in microscopic and spectroscopic expertises, we now have many more techniques to experimentally interrogate these concepts, and many more levels of observation and perturbation than what these guys initially had. We are however far from building a « whole-embryo description » that would be based on the understanding of its individual components – we have not even reached this level of integration for a single cell yet1. It seems thus that increasing the depth of our observations from the nanoscale to the millimeter scale has generated infinite ways of interrogating these old questions.
There is another dimension to this emergent complexity that does not come from technological breakthroughs, but from the way our thinking is structured. Embryological concepts defined with a vocabulary borrowed from psychism2 have to be decomposed into analytical frameworks inherited from material sciences and modern biology. At this language junction, there are a multitude of possible translations and each one of us is operating its own deconstruction based on the logics predominant to its initial scientific community. Thus, translating becomes a problem of impedance adaptation.
Parents of Modern Embryology had probably a more transverse knowledge than the one we have today3 and were looking for unifying scientific concepts, allowing someone like Driesch to draw this analogy:
If there could be a dynamic geology that studies the forces by which the earth has been brought to its present state, could there not also be a dynamical biology, a science of the forces bringing about the configuration of the organisms ?
Referring to Darwin and Mendel, Oppenheimer reminds us that intellectual rather than technological innovations bring great scientific advances, but that experimental design is constrained by technology. No matter how perfect this technology is, one cannot measure – not even look at – without introducing perturbations. There is no such thing as studies of wild-type embryonic development. We investigate instead bench embryonic development. Some of these experimentally-introduced artifacts can strongly bias our conclusions, and Jane Oppenheimer gives us the following example as food for thought. Roux initially validated mosaicism by killing one or two blastomeres from the early frog embryo and getting a half blastula. McLendon showed later that this process was not removing the influence of the dead blastomere and that proper separation would instead yield whole embryos4. History thus teaches us that we should carefully trust technology, and that part of the normal scientific process is to get wrong conclusions even with the right experimental design. Short-comings of successively developed techniques can require additional time to be exposed, often through contradictory experiments that attempt to establish or invalid the same theory. Which is probably the right definition of what constitutes a good control …
I am always astonished by the speed at which deep philosophical ideas are reached in embryologists conversations. Jane Oppenheimer’s book is no exception to that. She analyzes the morphogenesis of scientific ideas, addresses the dichotomy between “the qualitative” and the “quantitative”5, between synthetic and analytic models and uses the historical and philosophical analysis of past embryology to demonstrate her thesis, that one cannot develop accurate ideas and methodology without a culture of what our ancestors have achieved.
NB: A better book review than the one above can be found there: https://mitpress.mit.edu/contributors/jane-oppenheimer. There is a profile of Jane Oppenheimer on the Embryo Project Page: https://embryo.asu.edu/pages/jane-marion-oppenheimer-1911-1966
NB2: I could not resist but quote here my favorite parts of the book that did not fit in the essay above.
Roux to Emperor Franz Josef: « Your Majesty, you must first have a question in mind and then look for an appropriate means of extorting an unequivocal answer to it ».
Schwalb to Roux « Never write so philosophical a book again or you will never be appointed to a professorship in anatomy ».
Oppenheimer about critical thinking: « 1) familiarize oneself with former ideas and their basement 2) think critically about these theories 3) free oneself from these theories by challenging the old dogmas. » Three laws of Scientific Behavior, in chronological order.
1 https://www.newyorker.com/magazine/2022/03/07/a-journey-to-the-center-of-our-cells
2 Oppenheimer reminds us that the lexical field induction, determination, etc… comes from psychism.
3 Aka the holistic Da Vinci scientist
4 Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. The Developmental Mechanics of Cell Specification.
5 Oppenheimer refers to Malicious Philosophies of Science by Nagel (1954), but see also the last addition to the debate https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(21)00284-6)