Of the Songs of Dinosaurs

They were terribly large and not particularly intelligent and they stomped around emitting fearsome roars and have now been extinct from the earth for 65 million years. Anyone who talks dinosaurs in this way with Julia Clarke will be recipient of a professorial furrowed brow and a look that contains both a rebuke and mild understanding for those whose head is filled with such Jurassic Park images – for there is virtually no truth in them. Not only were dinosaurs often quite small but they probably didn’t roar either. And they are not extinct but still live among us in woods and jungles and parks, on the coasts of the world’s oceans, they delight us with their merry song, they are intelligent, and these creatures are called birds, who are neither relatives of the dinosaurs but in fact dinosaurs themselves! Julia Clarke has played no small role in making us aware of this salient fact.

Julia Clarke is a professor for vertebrate paleontology in the Jackson School of Geosciences at the University of Texas, Austin, where she holds the Katherine G. Jackson Chair in Geobiology. Within this College, she is part of the Department of Earth and Planetary Sciences, and even if that sounds like very distant time horizons and even if Julia Clarke has spent many years excavating dinosaurs all over the world, her actual research interest is birds, which are not so very old from a geological perspective – a mere 150 million years ago, they took flight.

In 1992 on an island at the edge of Antarctica, a bird fossil was discovered that Julia Clarke’s team, thirteen years later, through the application of analytical methods such as X-ray computed tomography, could identify as the 67 million-year-old bones of Vegavis iaai. During its existence at end of the Cretaceous period, this duck-size bird had to be careful of its mighty contemporaries. Perhaps these birds could loudly warn each other about other dinosaurs, for Vegavis already shared something with its present-day relatives – namely a syrinx, the sound-forming organ to which birds owe their voice, in contrast to the larynx of other vertebrates. The syrinx is a very inconspicuous organ, not much more than thin, vibratory membranes that lie between mineralized cartilage rings at the branching of the bronchi. Paleontologists felt there was almost no chance of something like that being preserved in fossils from the Cretaceous period; the only described fossilized parts of the syrinx were from the Pleistocene and Holocene epochs, i.e. no more than 2.5 million years old.

But then Julia Clarke and her team took a closer look at the Antarctic fossil – which is perhaps one of the special talents of this scientist: seeing differently than others and finding the undiscovered in whatever object. In this case her discovery was tiny rings, just a centimeter in size and only visible through computer tomography. But as a paleontologist you needn’t take part in that typical race to find the biggest dinosaur that ever walked the earth. Julia Clarke herself has excavated such giants, but photos of her numerous expeditions tend to show her with a brush and hand lens. Of course the skeleton of Vegavis cannot compete in the view of many with that of T-rex, for which private buyers now pay millions of dollars, so that they can keep the dinosaur in their homes? Julia Clarke laughs at this idea – is her interlocutor suggesting that the T-rex might be the new badge of excentricity for the super rich? 

Her findings are small by comparison, but that delicate organ of Vegavis proved those early birds of the Cretaceous period already had their new vocal organ. They could presumably quack with it, perhaps like present-day ducks. This was hardly the melodic strains of a nightingale or lark, but it was still a critical piece of the fossil puzzle in reconstructing the evolution of birdsong. The challenge of this type of paleontology, as Julia Clarke practices it, lies precisely in this search not simply for bones but clues to functions and abilities, i.e. the capacity to produce sounds or fly in the air or under water as penguins do. One could call her research a kind of excavation of the evolutionary achievements of living beings, of complex biological systems, that one doesn’t just stumble over in the wastelands of Patagonia like the bones of another Titanosaurus recently discovered there. The images of gigantic and terrifying creatures help secure a place for this kind of paleontology in the scientific myths of our present day – but how does one come to research the deep history of song and of dinosaurs? 

There is hardly an economist, constitutional expert or church historian (all colleagues of Julia Clarke here at the Wissenschaftskolleg) who will tell you with a gleam in their eye: That’s what I wanted to be when I was a kid! But in Julia Clarke’s case this early certainty is one of the established myths of a discipline that is almost archetypal in humankind’s discovery of the scientific method; searching and finding that which has hitherto been hidden deep in the darkness of the soil is exemplary of research itself. The fact that this seeking out and disclosure of the unknown is thus rooted in the very nature of the human spirit, that we are born researchers and in the course of our lives we never lose this curiosity and sense of wonder – this too is a research topic in Julia Clarke’s discipline – in other words, the evolution of the human mind, of cognitive abilities and therefore of culture. That is one aspect of the story. The other is that science, despite the human-center quality of its endeavor, is permanently confronted with the question: Why do you do it? What’s so interesting about it, why is it so important, what’s the point of it all? Can it be harnessed economically? Can you earn money with it?

If people only funded those things whose immediate utility could be ascertained in advance, then most scientific projects would never be pursued at all. It is happily the case, Julia Clarke notes, that Co-Fellows are curious and open to all kinds of research, she says, while adding, “That’s the spirit of the Wissenschaftskolleg.” She explains that she has much time to read, that she sits together a lot with the other Fellows, who also read and write a great deal, then they talk about it. Julia Clarke read countless books already as a child. And she traveled a lot with her parents. “All I really wanted to do,” she says, “was be out there in the world, travel to extraordinary places with a purpose.” Reading, traveling, discovering strange and unfamiliar things. And Julia Clarke is doing precisely that same thing today, although it wasn’t dinosaurs she wanted to find. “Originally, I wanted to be an archeologist. I was always fascinated by the stories within objects – the stories, the things, their forms, their beauty.” So she first studied art, she studied comparative literature and archeology, and finally geobiology. From the very start this led her to the some of the most remote places on earth, where Julia Clarke has been doing research ever since. In reports on these expeditions – to South America, Asia, the Antarctic – you see her sitting in the dust somewhere, digging, examining, collecting. And going for a month without a shower, she adds laughingly. But she loves working in the field, and ultimately that’s what everyone thinks a paleontologist does, right? Nope. Many of her colleagues do not do fieldwork but focus on lab-based inquiry. Of course Julia Clarke has also spent much time in labs. Her early research was on the evolution of flight, then the evolution of underwater diving in penguins. When still a student, she discovered new extinct species including one called Apsaravis. She described the first fossil of a penguin with feathers. Then came her discovery of the vocal organ of Vegavis.

Julia Clarke has a remarkable talent for unearthing those things that others have overlooked. In her case, however, this is not just a talent but based on enormous interdisciplinary knowledge and the ability to put together teams that themselves work in an interdisciplinary fashion. Her pathbreaking findings on the evolution of birdsong would have been impossible without this multidisciplinary aspect of her research. She says that today anyone can do experiments and examine just how the syrinx functions. But she wanted to know why this organ exists in birds, where it comes from, for in the evolutionary past of birds there was already an organ with which their ancestors made sounds. But it was entirely different. Why does evolution “invent” a new organ? It’s absolutely puzzling, says Clarke, “it blows your mind!” But first you have to see it, she says, because if you can’t see something then you’ll never find it.

One can tell that Julia Clarke finds it difficult to be in just one place for a protracted length of time, but now she is in Berlin at the Wissenschaftskolleg – meaning: she has time for all that thinking which she has postponed for so long, finding answers to those open or thorny questions that have amassed in thirty years of intensive research and travel. She has time to work on a book examining just what we can learn about the “evolutionary innovation of biological systems” – in other words the particular insights into the evolution of faculties such as vision and the development of brains and intelligence that come from the study of dinosaurs. Such a book does not yet exist, and perhaps Julia Clarke is the only one in her field who could write it. If we speak of what’s new in evolution, life and time produces newness. But what traits can tell us something new about evolution itself? And is it an important but understudied case of biological evolution that new organs will emerge for “old” preexisting abilities? The transition from the vocal organ of their ancestors to the new vocal organ of birds must have given them a selective advantage, but the reason for this transition still remains unknown. And Clarke says there are no indications that this new organ was somehow better at producing sounds than the old one. So then why this particular arc in the evolution of birds and their organic abilities? Were there other advantages to these new structures, such as parallel developments in the neural evolution of birds’ brains?

In answering these questions, she has an enormous amount of material because of a wealth of new discoveries in bird evolution (to which she herself has made no small contribution) that she wants to process during her time at the Wissenschaftskolleg and “somehow” work up into a synthesis. After over 140 journal articles, why now a book? Julia Clarke admits that in a discipline where nobody actually writes books anymore, this poses something of a challenge. But when one sees the tenacity that she has brought to bear in overcoming the manifold challenges she has faced in her scientific career, one has little doubt that she will master this latest one as well.