#5 In conversation with: Dr. Advait Jukar

Dusting away sediment from dinosaur egg shells in southern India, during the first formal field expedition with Dr. Greg Wilson and his team in 2010 (Photo Dr. Advait Jukar)

Dr. Advait Jukar is a vertebrate paleontologist and science educator, whose work focuses on global change and the evolution and biogeography of large herbivores. He was a Deep Time-Peter Buck Postdoctoral Fellow at the National Museum of Natural History, Smithsonian Institution, and is currently a Gaylord Donnelly Postdoctoral Associate at the Yale Institute for Biospheric Studies, where he studies the impact of hunting and climate change on the megafaunal extinction in India.

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AB: Children are often fascinated by dinosaurs and fossils, but not many end up working with them when they grow up. How did you become a paleontologist and how do people react when you tell them what your job is?

AJ: I have been fascinated by the natural world from a very young age. I would collect everything from rocks to stamps, so in many ways, I was destined to work in museums. My path to paleontology though was convoluted. My first real foray into fossils was when an Advanced Placement biology teacher told me of fossils he had found in Kutch, in the western Indian state of Gujarat. It was almost too good to be true, because my mother had been going to that part of India for ophthalmological camps conducted by one of the hospitals she practiced medicine at. She found out about some places where you could find fossil shells and ammonites, and so the two of us went out for my first fossil collecting trip back in 2006, I think. I went back to Kutch twice more after that trip, while I was in college, and found a number of ammonites and other invertebrate fossils. I was hooked.

I went to Reed College in Portland Oregon, and majored in biology and worked with a professor, Robert Kaplan, who studied frogs. I naturally jumped at the opportunity to study whole animals; I wasn’t as interested in genetics or molecular biology. While at Reed, I took a couple of seminars on reptilian and invertebrate paleontology, and the professor, Steve Black, who interestingly was a developmental biologist, encouraged me to pursue paleontology in graduate school. I was also encouraged by my colleague Gene Hunt, the assistant biology stockroom manager, to pursue paleo. I applied to a number of paleo Ph.D. programs and even went to the field in India with Dr. Greg Wilson from the University of Washington as a pre-admission interview. That was my first experience on a proper field expedition. I didn’t get into a Ph.D. program, but got into a masters program at Marshall University studying under Dr. F. Robin O’Keefe.

Unfortunately, Marshall wasn’t the best fit for me, and by that time, I had become disillusioned with paleo as a career choice because of the lack of jobs, so I decided to transfer to George Mason University in Virginia to study environmental science and ecology with Dr. Thomas Lovejoy. I worked on coral reef ecosystems in the Caribbean for my masters. Before I came to George Mason, I had visited the Smithsonian with Dr. O’Keefe and we stayed with his grad school friend, the curator of Dinosauria, Dr. Matt Carrano. I asked Matt if I could volunteer in his lab, and after I came to Virginia, he got me in touch with the Paleobiology Fossilab coordinator Dr. Abby Telfer, who took me on as a paleo volunteer where I did projects on late Cretaceous microvertabrate fossils for Matt. At around the same time, I got in touch with Dr. Mark Uhen at George Mason. Mark is a whale paleontologist. Because I was still interested in paleontology, he invited me to prep fossils in his lab on campus.

I think working with Mark and Matt helped me come back to paleo, but this time, I had a lot more focus and wanted to understand long-term ecological dynamics, and the best way to do that was using the fossil record. I decided to enroll in the PhD program at Mason and worked with Mark Uhen as my PhD advisor. Because I was in the paleobiology department at the Smithsonian, I was able to interact with paleoecologists Dr. Kate Lyons and Dr. Kay Behrensmeyer, who both encouraged my research in paleoecology (Kate would later co-advise my dissertation, and Kay inspired my work in India). This is basically how I got interested in mammalian paleontology.

My first project on Indian mammals was to try to unravel the story of the megafaunal extinction in the region. That project took me to the Natural History Museum (London), which has one of the finest collections of late Pleistocene mammals from India. While I was there, I also got the opportunity to look at the Siwalik collections. It was that trip in 2015 that really cemented my interest in Indian mammalian paleontology. I made two more trips to London to study the Siwalik collections there, and then went to the American Museum of Natural History, Academy of Natural Sciences in Philadelphia, Panjab University Museum, the Wadia Institute of Himalayan Geology and the Indian Museum in Kolkata to study Indian Mammals. While at the Smithsonian, I had the opportunity to work on the Deep Time Fossil Halls, which opened in June 2019, and was later awarded the Deep Time Peter Buck Postdoctoral Fellowship at the museum to work with Matt Carrano and also be a museum educator and science communicator. At the end of the day, though, I wouldn’t have been able to make it as a paleontologist had it not been for my parents, whose enduring support and encouragement allowed me to pursue a very unusual field for an Indian.

I think most people respond with awe or amazement when I tell them I’m a paleontologist. I also get the comment “like Ross from Friends” all the time. I do get questions from people in India about what I’m going to do with paleontology though, which speaks to a larger lack of appreciation or understanding of these more pure sciences. But they do have a point; there aren’t a lot of jobs in the field.

AB: How does one train to become a paleontologist? How important is international experience in this process? It seems to be a discipline predicated on circulation, more so than other sciences like mathematics—the circulation of people for fieldwork, of fossil specimens from one part of the world to the other. Which also brings me to the inevitable question: how has the current pandemic impacted your work?

AJ: Paleontology is an interdisciplinary field. We’re both biologists and geologists, some more of the former, others more of the latter. I approach paleontology from a biological and ecological lens. In general though, paleontologists need a solid understanding in organismal biology and some kind of sedimentary geology (fossils preserve in sedimentary environments). We also do a lot of math, especially with the advent of big-data paleo, so a strong understanding of statistics is also important.

International experience is not crucial. I decided to work on India because 1) I’m from India, and 2) it’s been largely understudied despite its importance in the story of life on earth. North American paleontologists often focus only on North America largely because of the abundance of fossils there. You don’t even have to go to the field. People have been collecting fossils for close to 200 years now, and many of those collections are still in museum drawers waiting to be studied. This is precisely what I do with the Indian fossil collections. I don’t go to the field to find new fossils; I work on historical collections because there is still so much left to discover there.

Matthew Carrano, Advait Jukar, Michelle Pinsdorf, Matthew Miller at a late Cretaceous (ca. ~75 million years) field site in Montana (Photo Dr. Advait Jukar)

I did have field work planned in India (not for my research per se, but for a dinosaur expedition in Kutch), but that had to be cancelled because of the pandemic. My own research requires international travel, and the pandemic has made that impossible. I still have a lot of old data I can work with, and database-based projects, or literature searches to create new datasets, but I’m going to be stuck in front of a computer for a while because of Covid-19.

AB: I recently watched with utter fascination—I am a converted paleobiologist now!—your episode on “Forgotten Elephants of Deep Time” for the Smithsonian Science Show. Has your work focused mostly on elephants? If so, why? Why is it important to study extinct animals in today’s world?

AJ: I like to describe myself as a vertebrate paleontologist interested in global change and the evolution and biogeography of large herbivores. To that end, I have been involved in projects on mammalian extinctions, mammalian community change, the size structure of mammalian and dinosaurian herbivores, and the taxonomy and biogeography of large mammals like elephants and horses.

I stumbled upon elephants by accident. When I was studying Siwalik mammals, I wanted to understand how the structure of the mammalian community has changed through time. One way to understand this is to investigate how the distribution of body sizes has changed through time. From modern mammal communities, we know that larger mammals are found in more open environments so a shift in the distribution of body sizes can tell us about how the environment is driving community change.

The fossil record of Siwalik mammals from the last 4 million years primarily consists of even toed ungulates (artiodactyls) like buffalo, camels, giraffes, and hippos; odd toed ungulates (perissodactyls) like rhinos and horses; and elephants and their relatives (proboscideans). It’s fairly easy to estimate the weight of extinct artiodactyls and perissodactyls from their teeth; there are strong linear relationships between molar dimensions and body weight in living members of these groups. It’s a bit more complicated for elephants. The best estimators for elephant body weight are shoulder height or the length and circumference of the long limb bones. To get at the shoulder height of an extinct elephant, you need the entire limb bone, and isolated elephant limb bones are hard to assign to a species especially if there are multiple species in a given place and complete skeletons are not known for these species.

Siwalik elephants are best represented by teeth and skulls, but elephant teeth are poor predictors of body weight. I decided to figure out if I could find a way to estimate body weight from skull measurements. That project really got me hooked on elephants, because I had to read a lot about fossil elephants, their evolutionary history, their proportions, etc., and I also realized that there are so many problems associated with fossil elephant diversity in the Indian Subcontinent. I teamed up with Dr. Adrian Lister at the Natural History Museum (London) to try and solve some of these problems. He showed me how to properly measure elephant teeth, and we’re currently working on a project to try to distinguish species of fossil Indian elephants from their teeth.

Measuring the third molar of a Siwalik elephant called Elephas hysudricus at the Wadia Institute of Himalayan Geology (Photo Dr. Advait Jukar)

I have also been involved in other fossil proboscidean projects, for example, describing the first specimen of Deinotherium indicum from Kutch, and am also describing a new species of mastodon from Idaho.

I think it’s important to study extinct animals, especially animals that have recently gone extinct because it helps us understand the role of these animals in ecosystems. We can compare ecosystems with large animals to those where they have recently gone extinct to understand how the structure and functions of the ecosystem have changed. This has implications for how we manage our wild lands, and potentially re-wild them in the future.

AB: To follow up on the previous question, there seems to be a strong public engagement component in your work. The episode you produced as part of the Smithsonian Science Show, if I understood correctly, is a tool for distance learning aimed at students from grades 3 to 8. In translating our work for a broader audience, we are confronted with certain choices, e.g. to showcase those aspects that are more likely to interest a lay audience, engage directly with contemporary problems or have a higher entertainment factor. Isn’t there a danger that this also misrepresents the work we are doing, for example by glossing over the less glamourous aspects of it, such as job insecurity, dangerous fieldwork sites, etc.?

AJ: I think it is very important for scientists to engage with the public, but to do that we are forced to come up with creative ways of showcasing what we do. For example, it’s very hard to talk to the public about long term trends in diversity, or about the paleoecology of mammals. But it is a lot easier to engage with people with large, charismatic objects like elephant fossils, or dinosaurs. We are in a sense glossing over less glamorous aspects of our work, but I think what these charismatic objects do is tell the story of life on earth pretty effectively. My outreach efforts are more geared towards inspiring that sense of wonder in people, many of whom have had no interaction with the natural world, past or present. I don’t want to necessarily make more paleontologists; I just want people to be more scientifically literate, and fossils are a great tool to do that.

Engaging visitors at the Smithsonian’s National Museum of Natural History for a Fossil Family Day (Photo Dr. Advait Jukar)

In venues like podcasts or longer interviews, I do make it a point to stress that paleontology is a difficult field to enter. I think we’re doing a disservice to students when we tell them to pursue a field without discussing all the hardships and sacrifices that come along with them. Paleo is a satisfying career, but there are next to no jobs, and I try to stress the point that paleontologists don’t actually spend all of their time outside digging up bones. We’re not actually like Indiana Jones. We spend a good chuck of our day teaching/researching/writing. At the end of the day, my message depends on the audience I am talking to, and I try my very best to select narratives and objects carefully to achieve those goals.

Matthew Carrano and I dissected this alligator for a public program at the Smithsonian’s National Museum of Natural History called “Dissecting the Tree of Life” (Photo Dr. Advait Jukar)

AB: You have already mentioned that paleontology is an interdisciplinary field. Indeed, while doing preliminary research for this conversation, I realized that in order to do your job well you need to wear many hats: as you pointed out, you are a biologist, a geologist, a mathematician, but also a historian. For your work on South Asian mammals, you are reading nineteenth-century catalogues of fossils like those of Richard Lydekker, who was employed with the Geological Survey of India. But this also made me think of the strange relationship academics often have with interdisciplinarity—on one hand, we put it on job ads and present it as something that is highly desirable, on the other hand, there are plenty of contexts when we tend to be quite territorial about our particular disciplines. Are all paleontologists historians as well? How do the methods of the historian differ from those of the paleontologist?

AJ: I think paleontologists need to start thinking more like historians. I was forced to be one because the fossil record that I work on has only been extensively studied in the 19th century. I have thoroughly enjoyed that process. What I enjoy most is learning about the socio-cultural contexts in which the fossils I study were found in, and how they’ve been interpreted through time. For instance, many of the Siwalik fossil species have been given Indian species names (Stegodon ganesa, Vishnutherium, etc), and understanding why British explorers decided to forego the classic Greek or Latin names for local names is really interesting. Turns out Falconer was more enlightened than most, and wanted to pay homage to local Indian culture.

While I do not necessarily use the methods historians use (I am not a formally trained historian), I do historical research to understand the taxonomy of different specimens, and to look for evidence of where they were found (many early explorers kept very poor field notes). To this end, I consider myself a “historian” of Indian mammalian paleontology.

The reason I think more paleontologists should think like historians is because many of the fossils we work on were excavated from land that did not belong to the people who found them, and it is extremely important to understand how these specimens were collected and how native populations were engaged with in these exploration efforts. For example, O.C. Marsh, of Yale Peabody and Bone Wars fame, used to carry arms with him when he went out West in the US to ward off Native Americans because they were collecting on Native American land. The British collectors in India also employed a number of native Indians to find fossils, and some of the first “discoveries” were fossils given to them by local Indian rajas. Understanding how native populations thought about fossils is really crucial to an understanding of how different cultures view the natural world.

I think paleontologists are inherently interdisciplinary. We often study anatomy, geochemistry, and geology at the same time to understand the “what”, “how”, and “when” these animals lived in Deep Time. But we seldom engage with the humanities. I think I was heavily influenced by my mentor Dr. Matthew Carrano, who is also very interested in the history of paleontology and has written about the history of dinosaur discoveries in India. These historical accounts are not only interesting for paleontologists but also for Indians trying to understand their past.

AB: If you were to pick a tool that is indispensable to your “trade,” what would that be and how do you use it? For context, a lot of my research is concerned with the ways in which humans have used technologies historically, ranging from fields like transport and communication to medical care and education. I often feel that the actual technologies of research tend to be relegated to the background and do not receive sufficient attention in histories of science, which is why I am interested to hear stories about the tools of science making and communication and how people improvise, innovate, adapt or change them to better suit their purposes.

AJ: There are a few tools. In the museum, I use calipers. They are essential for getting any kind of morphological data from specimens. It’s a very simple tool that’s been used for centuries. More broadly, I think meticulous note taking and photography is probably more important. It’s so easy to see something at a museum, think you are going to remember it, but then you forget it by the time you get home. Or, if you’re in the field, it’s so important to write down exactly where and in what context you found a fossil. Fossils without context are about as good as pretty rocks. This is actually why I do so much historical research; I want to find more provenance data on these historical collections.

Measuring a lower molar from a Siwalik Stegodon using a pair of digital calipers at the Natural History Museum, London (Photo Dr. Advait Jukar)

AB: One of your goals is to reassess the taxonomy of fossil mammals from the Indian subcontinent. Can you tell us more about this project, the rationale behind it and why do you think India has attracted so little attention from paleontologists in the past, despite yielding such a rich fossil record?

AJ: Taxonomy is a really interesting discipline where we name species. Unless we know who all the players are in a given system, we can’t determine how diversity has changed through time, how species’ ranges have shifted with climate change, and how evolutionary processes have worked in a particular place. Many of the mammal species we know of from the Indian Subcontinent were named in the 1800s when the science of paleontology was still developing. Scientists then did not have access to vast comparative collections, and many similarly aged fossil deposits from neighbouring regions were not known until much later. They also did not have easy access to comparative literature. Other regions had the same issues. Because of these problems, regional paleontologists oftentimes gave the same species different names based on where they were found.

Now that we have a better understanding of the variation in species and better resolved fossil records in parts of Eurasia and Africa, we can start re-investigating some of the taxonomic decisions that were made in the 19th century. There’s still a lot of hidden diversity, and at the same time, a lot of taxonomic inflation that has taken place. For example, my re-assessment of fossil three-toed horses from India has shown that a horse called “Hippotherium” antelopinum is likely a wastebasket taxon that actually included multiple species. I have identified for the first time, Chinese and African lineages of horses in the Indian Subcontinent. This alters how we think about patterns of extinction and community change in the fossil record of the region, and how we think about provinciality of species. There are lots of hypotheses discussing the breakup of an Afro-Eurasia savannah biome, but new studies like mine are showing greater connections across the continents than we previously thought existed.

Despite a very rich fossil record, India has systemic problems that have prevented an in depth study of its fossils. For instance, paleontology is not a lucrative field in India, even less so than it is elsewhere, so it is hard to get trained to be a paleontologist. Universities and museums also lack the resources to fund expeditions and purchase expensive equipment for geochemical and paleomagnetic dating methods. Another reason Indian fossils have received little attention is that the record has largely been forgotten by Western researchers. It’s a lot easier to study the extensive fossil deposits in North America or Europe, and without local interest and support, paleontology has declined quite dramatically in India. There were a series of Western expeditions to British India between 1919 and 1938, but after Independence, much of the large-scale paleontological work has been carried out in Pakistan where the Geological Survey was more amenable to collaborations, or in small pockets in Northern and Western India.

AB: For a historian, your description of the taxonomic “mess” that surrounds the two species of stegodon excavated from the Siwalik Hills, for which you pointed the finger at the Scottish geologist Hugh Falconer and American paleontologist Henry Fairfield Osborne, was absolutely fascinating. This story strikes at the heart of one of the most enduring myths of British colonialism in South Asia, namely that the science of the colonizers was orderly, objective, rigorous, reliable. I am assuming that revisiting the methods of one’s predecessors is not an exceptional occurrence in paleontology (in fact, correct me if I am wrong, it might as well be the norm?). Why, then, has it taken so long to revisit and “tidy up” Falconer’s work?

AJ: I think the main reason it’s taken so long to tidy up Falconer’s work on Stegodon taxonomy is that we would have to essentially start from scratch. Falconer in many ways was an amateur. He didn’t keep good field notes and never got the chance to publish everything he wanted to before he died. His notes were compiled and published by Charles Murchison in 1868, but even there, his descriptions are very brief, and largely uninformative. This is to be expected though, from a surgeon/botanist-turned-paleontologist, and not uncommon for 19th century British explorers in India. This wasn’t uncommon for late 19th century American paleontologists like O.C. Marsh and E.D. Cope either. Many of their descriptions were lacking and they are also guilty of creating taxonomic problems. So it is VERY common for modern paleontologists to revisit the methods and conclusions of our predecessors.

I think Osborn is probably more guilty of perpetuating the mess than Falconer. Osborn was a bonified paleontologist and an expert on fossil elephants. He really should not have accepted Falconer’s erroneous conclusion that Stegodon insignis and S. ganesa are female and male of the same species, AND then unify the names in the form of a hyphenated specific epithet. If Osborn truly believed that they were the same species, then he should have assigned S. ganesa as the junior synonym of S. insignis.

Studying the skull of Stegodon ganesa, which was collected by W.E. Baker in the Siwaliks in the 1830s. The tusks are about 12 feet in length. (Photo Dr. Advait Jukar)

Because Osborn was such an authority on fossil proboscideans, subsequent paleontologists blindly accepted his nomenclature and hypothesis and the problem continued, including Lydekker, who in 1876 published on a potential “female” skull of S. ganesa. What modern proboscidean paleontologists have done is accept that S. ganesa and S. insignis are separate cranial types, or species that can be identified from their skulls. But so much more work has yet to be done. For example, because of this nomenclatural mess, every Stegodon molar found irrespective of where it came from in the stratigraphic section has been called either S. insignis, S. ganesa, or S. insignis-ganesa. This complicates our understanding of where these species occurred in space-time.

What would have really helped solve this new problem was if Falconer (and the other explorers) had kept detailed records of where they found the fossils. This is the greatest tragedy of 19th century paleontology and British science in India. Without good geographic and stratigraphic information, we cannot now determine whether or not these two species lived together in space and time. Of course, they did not really understand the importance of this because geology, stratigraphy, paleontology, and zoology in the modern sense were all in their infancy. So, yes, you are correct when you say that the science of the colonizers was orderly, objective, rigorous, reliable is a myth. Modern paleontologists are burdened with the taxonomic sins of our predecessors.

If you want to actually solve this problem today, you need to do fresh field surveys and detailed museum work, all of which takes a lot of time, money and man power. In museum collections, we would have to do a detailed study of isolated Stegodon molars (the most common part preserved and found), and then compare these teeth with teeth that are still embedded in skulls that we can identify as either S. insignis, S. ganesa, or S. pinjorensis to get a sense of what kind of morphological variation exists in the teeth of these three species found in the Siwaliks. Then, in the field, we need to do careful field surveys for these teeth, noting the exact locality and stratigraphic interval, and then try to date these localities. Once we have all of this information, we can see exactly where in space-time these species occurred.

AB: How do your experiences of practicing paleontology in India compare to the US or other countries where you have worked? Are there any challenges that you would say are specific to Indian paleontology? One of the things that crossed my mind after watching the Smithsonian episode was the issue of storage. For historians, this is a vexing problem and I would imagine that it is only compounded in your case, considering the size and shape of the “records” you handle.

AJ: In general, I would say, that it’s a lot easier to do paleontology in the US and the UK. There is a longer, more sustained, and more populous record of paleontology in these places compared to India. There are established educational programs, world-class museums and collections, and many opportunities for field work. Paleontology in India is still in its infancy, so it is harder to get into the discipline, and to do research there. Having said that, I have to add that I’ve had very good luck in India. I have some great colleagues at University Museums at Panjab University (Dr. Rajeev Patnaik), and Deccan College (Dr. Vijay Sathe), and at the Wadia Institute for Himalayan Geology (Dr. A. C. Nanda and Dr. R. K. Sehgal) who have given me access to their collections. Academicians are eager to collaborate, and I have had many fruitful collaborations with my colleagues at these aforementioned institutions.

It was a lot harder for me to get access to the government administered collections at the Geological Survey of India, and I think that stems from woefully slow government bureaucracy, a lack of expertise when it comes to proper curation practices, and the high turnover of government curators and geologists who administer the collections. However, when I did finally get permission, everyone was eager to help, and I had some great conversations with folk at the GSI in Kolkata. The collections need better cataloguing and storage, and many haven’t been curated properly since 1885.

Storage is a huge issue in paleontology. We can’t possibly collect everything from the field. What I think Indian institutions need to focus on is training in fossil preparation and on better long-term storage practices that will allow collections to be stored for future generations. I’ve heard many horror stories of fossils being thrown away after professors leave institutions, or specimen labels falling off, making the fossils essentially useless. Repository management is critically lacking in India, and it’s only once we figure this out will we be able to make large scale advancements in the field. We have museums; they just need more care, more professionally trained staff, and better management.

AB: This last question is usually aimed at women in science, but this is precisely why I would like to hear a variety of perspectives on this issue: What are your experiences of gender bias, for example in the institutions of education where you studied or, more generally, the profession you are practicing?

AJ: I’ve been lucky in the sense that many of my undergraduate, graduate, and postdoctoral cohorts have been pretty well balanced in terms of gender. I think the gender bias is way more apparent in the faculty and curators. For example, Dr. Kay Behrensmeyer was the only full-time female paleontology curator at the Smithsonian, and I believe the first female curator in the department, and she’s been there for close to 40 years. We recently hired a new female curator at the Smithsonian, but the department is still extremely heavily biased towards men. I think the leaky pipeline is graduate school, and after. Paleontology is not an easy field and demands way too many unreasonable sacrifices. It seems to disproportionately affect women and other underrepresented groups. It’s hard to bounce around from post doc or temporary faculty position and not have anything permanent until you are 40. It’s taking longer every year to find a permanent position in a place you’d want to live. It’s hard for a lot of people to move to parts of the country where they are discriminated upon based on how they look, or places where women’s healthcare isn’t prioritized, or even available.

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