Gavin de Beer : My lifelong mentor and idol (2006.4.4[Tue])

 

It seems we've already reached the sixth installment of this series, making this the first anniversary issue of the Ex Libris series. To mark that occasion, I'd like to dedicate this essay to The Development of the Vertebrate Skull (1937) by Gavin R. de Beer, a book that was one of the first and greatest influences on my own research. My very first scientific interests were in the morphology of the mammalian skull, and had it not been for this book, I wonder if I would ever have found my calling - I am certain at least that my mentors would've had a tough time giving direction to that eager young student of morphology.

 This book focuses entirely on the cranial development of various vertebrate groups, what would today be called a systematic approach, with extensive referencing, annotation and interpretation bringing both evolutionary and comparative morphology to bear. For me, this is a morphological treasure trove, a brimming crucible of knowledge spiced with mouth-watering jargon. This is where I finally found what I had been seeking; or, to be more correct, this is the book that showed me what I didn't know I wanted to seek.

 The first thing that strikes you when you enter the book is the dedication on the frontispiece, which reads like a Who's Who of the scholarship of the day. De Beer devoted his work to Thomas Henry Huxley (the 19th century British champion of the theory of evolution, a giant who needs no further introduction here); William Kitchen Parker (who co-authored with Bettany the first monograph on vertebrate skull development); Ernst Gaupp (a well-known German comparative embryologist, who had validated Reichert's theories on the ossicles of the ear and known for his exegeses of mammalian head development); and Jan Willem van Wijhe (A Dutch scientist who offered a new appraisal of the mesodermal coelom discovered by Francis Balfour (see the previous article), and who remains one of the most influential figures in the history of the study of vertebrate head segmentation). That's quite a list! If nothing else, it sheds light on the book's scientific provenance and shows the intensity of de Beer's commitment to this work.

 As I understand it, the seminal Studies on the Structure and Development of Vertebrates authored in 1930 by E. S. Goodrich, a fellow Oxford morphologist several years de Beer's senior, inspired him to draft his own work. I should mention that the Goodrich book is also among my longtime companions; I've read it four times already. Goodrich openly recognized that his was not an exhaustive treatment, and that he had paid relatively more attention to some structures and organ systems than others. That bias was only amplified by de Beer (a specialist nonpareil, who may only have been exceeded in specificity by Gregory's recherche monograph Fish Skulls). Turn to any page and you find skulls, skulls and more skulls. This is a pure and conclusive validation of the ideals of descriptive embryology in the German mode, informed by a consciousness of the history of research into vertebrate head development all the way back to Goethe, and seeking to follow that clew as far as it could lead him in his pursuit of the questions of skull formation and developmental patterning. Johann Wolfgang von Goethe, the very founder of morphology ( Morphologie ), once wrote something to the effect that he could never rest until his understanding had led him to an archetype, a sentiment which seems to have been shared by de Beer in his meticulous compilation. Of course, there can be no pat and all-encompassing explication for such a broad diversity, and there is a kind of nobility in the uncompromised and uncompromising simplicity of his approach, which recognizes that complex things require complex explanations. It's an arrangement that works on many levels, examining how evolutionary continuities and divergences could have given rise the so great a number of variations on the single theme of the head, which appears as both leitmotiv and cadenza in a mysterious score realized as an orchestration of cartilage and bone. To the uninitiated, I'm sure the book stands as no more than an impenetrable monument. But the field in its complexity and inherent difficulty is a demanding one, and students will find that the insights gained from a struggle toward understanding are a remedy to any pains taken to gain them.

 I think it's safe to say that until the 1970s, de Beer's book languished in obscurity in both the zoology community and indeed among Japanese researchers in general, little more than an archaic and undecipherable cryptogram. The sheer volume of alien and untranslatable morphological terms must have been intimidating, and then to find them as labels attached to unrecognizable structures presented in the pictorial atlas at the back of the book... Almost like a modern art objet... Certainly, the images vaguely allude to the development of head structures, but it's hard to work out or even to imagine what the bones and cartilages might mean, how they would fit together, or what any of the elements might eventually give rise to. The turning point in our understanding came only after dyes like alizarin red and alcian blue came into common use. For the field's pioneers, who made shift by modeling the head in fragments, the sudden ability to reconstruct the entire cartilaginous structure by staining must have been like a dream come true. then, as the 20th century drew to a close, molecular biology finally began to reveal the close and evident involvement of genetic developmental programs in the morphological principles first set forth by the German school.

 It's no exaggeration to say that most students of developmental biology have seen the cartilage of the mouse head visualized. And musty old terms that were in the lexicons of only a handful of fanatical devotees just a few decades ago, are now becoming commonplace in 21st century molecular biology labs, where it would not seem unusual to hear an exchange like,See how this Meckel cartilage is shortened?Part of the ala temporalis seems to be missing too.

 Professor de Beer, I think you'd agree that biologists nowadays rarely revisit classical textbooks. But even if you're not here to enjoy it, make no mistake, your work is enjoying a renaissance.

Reference :” The Development of the Vertebrate Skull”