Dr. Devapriya Chattopadhyay is a paleobiologist whose work investigates the evolution of molluscs and the factors that drive their evolutionary trajectory. Educated at the University of Jadavpur and IIT Bombay, she received her PhD in Geological Sciences (Paleontology) from the University of Michigan and is currently an Associate Professor in Earth and Climate Science at the Indian Institute of Science Education and Research in Pune.
AB: Your educational trajectory seems to follow a fairly straightforward path that many of us can only be envious of: you have a B.Sc. in Geology from Jadavpur University, a M.Sc. in Applied Geology from IIT Bombay and a Ph.D. in Geology, with a focus on Paleontology, from the University of Michigan. Did you always know you wanted to study geology? How much support did you receive once you decided that you wanted to pursue a career in this field?
DC: While growing up, I often followed my father into the forests in my hometown in North Bengal. While he painted landscapes, as a little girl, I would stroll around, watching nature at play. I was pretty curious about nature early on but did not know the exact educational stream that would give me the correct exposure. The exposure came as a chance event. As part of my school activity during senior years, I took part in a science presentation competition where I chose the topic of fossil fuels. Preparing and researching for the presentation, I came to know about Geology for the first time. After finishing my 12th level examination, I decided to take Geology as a major. It surprised my parents and teachers because it is different from engineering, medicine, or physics—a common career choice among science graduates. My parents, although surprised, were supportive.
A career in active research in any discipline is quite demanding. Mine is no different; in addition to the standard requirements of an academic’s life, I travel to unfamiliar territories quite often and for days. Although my parents were quite supportive throughout, they are still quite astonished to see what it takes to build a career in scientific research. My family, including my parents, in-laws, and husband, never stood against any career decision I made. But the society, in general, is not very supportive of a woman’s choice to pursue an active research career. I understand this even more now, as the mother of a five-year-old. Motherhood for me is a superbly gratifying experience; however, it is another equally demanding role in a society like ours where it indirectly forces women to choose between career and family.
AB: As someone who has studied geology both in India and the US, what would you say are some of the main differences and similarities between geological education in these two countries? What makes the US an attractive destination for Indian students who wish to pursue a PhD in geology?
DC: My US experience taught me first to develop good questions and then address them with the best quantitative approach, not the other way around. The five-year Ph.D. program of the US universities aims to provide a broad education through course work and focused emphasis on the candidate’s research area. Because of the well-structured Ph.D. program, the mandatory requirement of advanced courses, and a rigorous qualifying examination, the candidates are forced to expand their knowledge beyond their comfort zone and evolve as mature academicians. The Ph.D. candidates are expected to develop their thesis questions independently and defend their work in several national/international conferences throughout their Ph.D. tenure. This practice transforms them from promising students who can carry out research tasks as instructed to independent researchers capable of designing their research trajectory. These opportunities make the US an attractive destination for Indian students who wish to pursue a Ph.D. in geology. Many of these aspects have recently been adopted in some Indian institutes/universities, and students often choose these places. However, the fact that graduate research fellowship in India is highly irregular (often a student has to survive without any fellowship for more than six months) has a detrimental effect on potential students planning to pursue a Ph.D. in India.
AB: Your work investigates marine faunas, both those of deep time and the present, and you seem to focus particularly on molluscan communities. Why is it important to study them? How do you study them? How are these two sides of your work—the one that focuses on the deep past and the one that focuses on the present—connected?
DC: I try to understand how marine organisms respond to their physical and biological environment in the ecological and evolutionary time scales. I partly use shelled molluscs as a model system because of their impressive fossil record, ubiquitous presence in the recent ecosystem, and relatively complex trophic structure. Their durable carbonate shells can be used as geochemical proxies for reconstructing past environments.
In addition to studying fossils in the field, we work on modern organisms using underwater observations, conduct laboratory experiments in aquariums and use statistical modeling. Once I develop a testable hypothesis about molluscan response either to biological triggers (predation, competition) or physical triggers (change in temperature, salinity, productivity, etc.), I try to test it in a controlled setup salt-water aquarium. Once verified, I move on to the ecological data and test it using time-averaged dead shells. Finally, the same is tested using an appropriate fossil record. With every step, we go closer towards the actual natural system, but the uncertainty increases because of the involvement of unknown variables. The present is in a continuum of the record of the deep past, and I try to utilize the entire spectrum. A popular article based on one of our papers on cannibalism using this approach can be accessed here: ‘It’s a snail eat snail kind of world!‘.
AB: Studying Indian coastal faunas seems like a timely and incredibly relevant topic of research, yet I learned from your work that it has also been an overlooked area of investigation. Why is that so? What are some of the challenges that such research encounters in India?
DC: The detailed identification of coastal fauna is made primarily by the Zoological Survey of India (ZSI). That is always the first step to understand the distribution of fauna. However, there is often a disconnect between biologists and paleontologists in India and abroad. Consequently, the knowledge transfer is limited, and the full potential of collected samples is not reached. I am interested in the recent molluscan distribution along the Indian coast and what drives this distribution. For this, I need detailed bulk samples from along the coast. Although ZSI collection has documented fauna from various sites, it is often not a bulk collection. Hence, we can only have the presence/absence of a species in a given locality. Quantitative ecology requires other information that can only be derived if we know the number of individuals for each species.
Moreover, we need associated environmental data to evaluate their role to guide distribution, and this data is often not available with ZSI collection. We, therefore, collect our sample and build the research based on the detailed identification work of ZSI. The other issue is a lack of funds for research related to taxonomic and ecological analyses. As a result, the number of taxonomists is decreasing every day, and very few people are joining the discipline.
AB: Where do you usually conduct fieldwork and how does a day in the field look like for you?
DC: In India, I primarily conduct my fieldwork in Gujarat (Kutch) and Andaman. The typical day in a field trip to Kutch, where we look at fossil assemblages, differs from a day in Andaman, where we collect recent marine fauna. In Andaman, we stay in government guesthouses or private establishments and travel by car to the locations next to the sea. We primarily use small fishing boats to collect specimens from the sea. We are fortunate to have excellent collaborators who worked in Andaman ecology and biodiversity over decades, and they help us address all logistical challenges.
In Kutch, it is often difficult to find a decent hotel close to the fossil localities. We usually end up staying in smaller inns and Dharamshala—a humble resting place for the pilgrims. We start our mornings with available breakfast and leave for the day in a rented car to go to the nearest road to our desired locality. Many potential localities are within dried river channels because the river action exposes the older strata and hence, we cannot access it by car. We try to start our traverse before 8AM to maximize the time; it often takes more than two hours to find a place with substantial fossil collection. If we are lucky, we find retrievable fossils. After locating such a place, we start documenting the area using photographs, GPS measurements, and detailed notes; next, we take samples of the rocks for further analyses. Finally, we try to retrieve the fossils with hammer and chisel after detailed photographic documentation. If some fossils are impossible to recover, we try to make a cast using quick-drying casting materials.
It isn’t easy to work between 2-3PM because of the extreme heat of Kutch that often goes beyond 40C. Our humble lunch usually consists of bread, fruits, nuts, and water (anything else is hard to come by in the morning and adds to the load we have to carry). We resume our work again after an hour and try to push it till 5PM. Then comes the most tedious part. We distribute the collection among ourselves and carry it back to the car. On a successful day, each of us carry more than 20kg of fossil for about 10km. Once we are back at our hotel/Dharamshala, we freshen up and finish our dinner. After that, some of us write the day’s journal compiling all the data from the field notes; others carefully pack the fossils with proper notes and make them ready for shipment. On a regular day, that’s when it ends. On unusual days and in unfriendly places, we wake up at night with bangs on the door by curious strangers, and the saga continues.
AB: How important is teamwork in your field? In relation to this, how important are international collaborations?
DC: Teamwork is of absolute importance, and students in my group also learn to work together as a team. To address critical questions, a multidisciplinary approach with various subject experts is necessary. However, the amount of collaboration between researchers is not always as typical as one would expect.
International collaborations for Paleontological research in India are not always encouraged. However, they are of paramount importance for paleontologists like me because of the following reasons:
1. Many of the fossils retrieved during the British colonial era reside in museums outside India, primarily in Europe and America. These museums are reluctant about the repatriation of fossils or loaning them. It gets more complicated because of a lack of a national fossil repository in India. Moreover, Indian funding agencies generally do not offer to fund international travel to work on these collections. The only way to work on those specimens is to collaborate with international colleagues and write joint projects funded by international agencies.
2. Many Indian paleontologists, including me, are interested in addressing questions related to specific time intervals. Often the best fossil exposures of those time intervals are outside India. The Indian funding agencies do not fund such research. Again, to carry out such research, we need to collaborate and depend on funding sources outside India.
AB: If you were asked to pick one scientific instrument you work with and introduce it to a non-specialist audience, what would it be and why? How would you describe it?
DC: I am only a user of multiple instruments; I am not a specialist in running any instrument.
AB: Does your work engage with the history of geology? To put it differently, what other records of the past do you use besides the fossil record? I am also interested in this connection to history because, as historians, we are usually trained to look at what happens on land, much less at what happens underwater. But apart from its more general relevance to environmental histories, marine life also featured quite prominently in histories of telecommunications, e.g. nineteenth-century accounts of submarine telegraphy often make mention of barnacles that grew on underwater cables causing them to snap.
DC: Certain aspects of recent human history create interesting scenarios to test organismal response to changes in the environment. The development of the Suez Canal helps us to test the effect of changing seaway configuration. Paleontologists, experts of historical ecology, in particular, are exploring this aspect.
Another important aspect is the effect of human history in the preservation/interpretation of fossil data. The fossil record is incomplete and uneven, with strong biases towards certain global regions such as North America and Europe. These spatial biases are not exclusively due to physical factors but also to historical and socio-economic factors related to colonialism. In recent collaborative work, we explored how scientific colonialism and socio-economic factors (e.g. GDP, education, security, and English proficiency) affect the global distribution of fossil data and distort our understanding of deep-time biodiversity. That work is available as a paper here: ‘Colonial history and global economics distort our understanding of deep-time biodiversity’.