13 March 2015

Delayed Discourse on Diplodocine Discontinuation

Dippy the Diplodocus
The Natural History Museum
It's been another cold, dark winter both literally and, as far as this blog is concerned, figuratively.  I've just returned to Iowa following Cornell's Spring Break and as the snow is melting, the flowers are sprouting, and the weather is warming, I thought it was high time to wake the Mammoth Prairie from its hibernation.
While the winter has been a quiet one in regards to my writing (or at least my writing here; there's been plenty of application and manuscript prep), as per usual paleontology has been making headlines.  There's not much in addressing most of these after the fact, but there was one story that hit a nerve both personally and professionally that I felt was worth revisiting.  I'm betting that the majority of what's left of my audience knows that back in January London's Natural History Museum announced that Dippy, the Diplodocus skeleton that's been the centerpiece of their main hall for nearly four decades is going to be replaced by a blue whale skeleton as part of the museum's renovation project.  I've written before about the personal significance of Dippy to my own development as a paleontologist (the brief synopsis is that he was the key figure in my origin story) and so, like a whole generation of paleontologists, my first reaction was one of dismay.  However, approaching things from a museological standpoint, it's not too hard to come up with a whole list of reasons why a blue whale makes for a better centerpiece.  It's bigger, first of all; bigger, in fact, than any dinosaur or any other vertebrate that has ever lived (unless you buy the upper limits of the mass estimates for some sauropod species, of which it is wise to be extremely skeptical given the scrappiness of the material and the corresponding degree of extrapolation necessary in most cases).  This may sound trivial, but the NHM's central hall was clearly envisioned by its founder Richard Owen and architect Alfred Waterhouse to evoke the style of Europe's great cathedrals, and it has stood the test of time as one of the most spectacular examples of monumental museum architecture in the world.  Diplodocus was undeniably a big animal, but was quite svelte for its size, meaning that Dippy has always been dwarfed by his surroundings; architectural sketches seem to suggest that the whale will fill the space better.  Also, Dippy hails from Wyoming, while the blue whale was found beached in Ireland, meaning that while the star of the museum's show still won't be English, it will at least be from the British Isles.  Dippy, for all his fame, is a cast of a specimen housed in Pittsburgh, while the whale will be the genuine article.  Even the argument that Dippy should be retained because he is the museum's traditional centerpiece don't hold water, as a whale skeleton occupied the space well before the dinosaur made its debut.  And so, despite my personal attachment to Dippy, from pretty much practical and educational standpoint, the whale makes much more sense.
Illustration of the NHM Blue Whale
The Natural History Museum
Professionally, though, there is one aspect of the NHM's plans that troubles me more than it probably should.  The museum has stated that part of its motivation for bringing in the blue whale is to emphasize their focus on the ecology and conservation of modern ecosystems.  Without a doubt, studying and mitigating the impacts of human activity on the natural world is the most important goal of natural science, and in that sense the museum's motivation is laudable.  However, it doesn't necessarily follow that an emphasis on ecology and conservation should displace displays of fossils.  Paleontology suffers from a widespread and misguided perception of obsolescence.  The word dinosaur has, after all (and, again, misguidedly), come to mean something outmoded and inferior and even recently extinct organisms have come to be synonymous with being outdated (see 'gone the way of the dodo').  I don't for a moment suppose that the exhibit designers involved have an anti-paleontology agenda, nor does the displacement of one dinosaur by one whale mean that one of the world's largest fossil repositories will be subbing in pandas, insects, and sea turtles for their ground sloths, ammonites, and plesiosaurs.  However, one cannot help but worry that this will only help reinforce the artificial line between "practical" neobiology and "impractical" paleobiology when in fact, paleontology is (or at least should be) an integral part of ecology, evolutionary biology, and even conservation biology.  I could selfishly point to a paper on which I was a co-author that came out during my blogging hiatus that shows how important paleoecology can be in formulating and testing models of the effects of future environmental change, but for the sake of argument lets stick to whales.  Cetacean paleobiology is a flourishing branch of paleontology, and with good reason.  Between heavy bones, wide distributions, and living in a top-notch preservational environment, whales have a magnificent fossil record that, more clearly than in any other organism, tracks the evolution of land-living animals into marine taxa.  This is most famously illustrated by Phil Gingerich's work on Eocene cetaceans from Pakistan and Egypt, where a spectrum of fossils lying between fully terrestrial cetaceans to seagoing whales with vestigial hind legs have been found.  Elsewhere in the world (my Northwest pride compels me to note that this encompasses the Washington and Oregon coasts) other major transitions, such as the evolution of baleen or the bizarre morphology of river dolphins, are clearly documented by cetacean fossils.  Just as fossils demonstrate how whales have evolved, so too do they reveal how whales have shaped and been shaped by the organisms and environments with which they interact.  Whale paleocology is perhaps best illustrated by the study of whale fall communities, long one of the most important deep-sea ecosystems.  This field of study has yielded myriad papers by researchers from across the globe, one of which (Pyenson & Haasl 2007) is one of the neatest examples out there of how ecology profits when both paleoecological and neoecological data are considered.  So how is this exceptional fossil record relevant to whales now and in the future?  First of all, it shows us how the diversity and ecology of modern whales came to be, putting modern forms in their proper evolutionary context.  Beyond this, understanding when and in which groups major evolutionary or ecological changes occurred allows us to approach the question of which forces have driven whale diversification and extinction and how these changes have affected other organisms, a field of study that has been most prominently (but by no means exclusively) explored by Ewan Fordyce.  Understanding the forces that have shaped whale evolution, particularly during periods of time that differ climatically from today, could in turn play a huge role in predicting the effects that warming oceans, fluctuating food supplies, and interactions with human activity may have on whales and on the organisms and environments with which they interact.  A blue whale, then, is a fantastic choice for conveying the magnificence and precariousness of life on Earth today, but is also just one player in a vast evolutionary saga that can only be fully told by including fossil data.  Put in the proper context, the NHM blue whale could become the world's most prominent illustration of how the big questions about life on Earth both today and in the future are best answered by integrative science that incorporates data from neontologists, paleontologists, climatologists, geologists, and many, many others.  Displayed out of context, it could further reinforce the harmful impression that science operates within compartmentalized disciplines, some of which are more "valuable" than others.  Here's hoping they do the right thing.