Post Doc

Michaela Falkenroth, Sedimentologist

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The image is a selfie of a girl in a black jumper. She has a green toothbrush sticking out of her mouth and an amused look on her face. The background is a backbeach area with reddish sand and a couple of thorny shrubs. You can make out tire tracks and footsteps on the sand. The sky is whitish blue and the lighting shows that the sun is just rising.
When you are a field geologist that studies beaches, chances are you have to work at the beach, sleep at the beach, eat at the beach and brush your teeth there, too.

Hey there! My name is Michaela and I am a cat-lady, sci-fi-nerd and hobby illustrator, who gets paid to hang out on tropical beaches a lot – how is that possible, you ask? Well… I got lucky.

The first time I got lucky was when I was eight years old and announced to my flabbergasted parents that I had decided to become a paleontologist like my hero at the time: Dr Alan Grant (also known as “guy with the cool hat in Jurassic Park”). My parents, who did not have the opportunity to go to university themselves and had never heard of paleontology, would have been perfectly justified to believe that my career goals were nothing to be taken seriously and move on, but they did not. Instead, they bought piles of dinosaur books, spent countless hours in museums and corrected everyone who confused paleontology with archeology with admirable patience. I was still set on becoming a paleontologist 11 years later, when I first set foot in the geoscience department of University Bonn. It is certainly not my parents’ fault that I didn’t.

The image shows a broad river flowing through a deep valley with high but not very steep, rocky walls. A bright blue sky in the background, no vegetation except for some palm trees by the water and bright sunlight indicate a desert environment. The water is calm, completely clear and shallow, the ground is covered in light grey gravel. A girl is standing knee deep in the water looking at a smoothened cliff that is twice as tall as she and boarders the river. The cliff is almost white and consists of well-rounded gravel in different sizes that is held together by a white matrix. The girl wears long, green pants, a dark T-Shirt and a cap that casts a shadow over her face. She points at something on the cliff to show it to a guy standing a few meters behind her.
Sedimentology is the study of rocks that were broken down into smaller pieces and transported on the surface of the planet by wind, gravity, and water. Here, I look at a river sediment in Oman that was turned into hard rock by a natural cement.

The second time I got lucky has to do with the fact that becoming a paleontologist in Germany requires you to become a geologist first. It only took a couple of rock identification classes for me to realize that yes, dinosaurs are amazing, but evolution is only one of the natural processes that shape our planet, and the others are even more fascinating to me. I had never thought about mountains being crumbled into tiny pieces by weather and time, these pieces then being transported by wind and rivers into the ocean, while being reshaped again and again, before they come to rest somewhere along the way. As a sedimentologist you look at the pieces of rock that are shuffled around on the planet’s surface and make them your own personal window through time. Sedimentary rocks let you study rivers that rushed by millions of years ago or watch coral reefs grow and die and regrow in a millennial cycle. By the time I finished my bachelor’s degree I was hooked. I still have a cool dinosaur model on my desk, but sedimentary rocks are what is on my mind, what pays my bills (sometimes) and what got me into another field of science with a very relevant application: sea level research.

A strongly fractured, uneven surface of brown and crumbly-looking rock fills most of the image that was taken from a heightened position. On top of the rock stands a smiling girl in fieldwork attire. She has her hair in a ponytail, arms akimbo and a broad grin on her face. One corner of the background shows a rough, blueish-green ocean with big waves breaking on a rocky platform in white foam.
Me on a beach in South Africa, happy about a freaky beachrock that I just discovered. The rocks that I am standing on formed within the last 77 years, before that it was just a sandy beach.

This brings me to the third time I got lucky. This one really did not feel like luck at the time. In 2016, I got rejected for three possible projects for a master thesis and thus one day stumbled into the office of the new professor at the department, who had nothing to do with sedimentology. I stood in the doorframe a little desperate and ready to take whatever the man would offer. This professor, who would later become my PhD supervisor and close friend, offered me an opportunity to study sea level change at the coastline of Oman – turns out you can squeeze sedimentology into any project.

Sea-level and coastal research became the focus of my scientific journey and Oman somewhat of a second home. For my masters and PhD, I studied beachrock. That is essentially beach sand that turned into hard rock, because a natural cement forms in between the individual grains of sand. Think of it as a bunch of sand and gravel glued together by carbonate, the white stuff that forms in your kettle or washing machine. Beachrocks are not only very cool, but also useful when we are trying to understand how sea level changed in the past and make assumptions on how it is going to change in the future. Climate driven global sea level rise might be something you are familiar with, but that is only part of the story. Yes, global sea level is rising, but the land might move as well. In some areas it is sinking, making global sea level rise an even bigger problem, in other areas the land is uplifting, mitigating the effects of global sea level rise. Beachrocks can help to understand what is happening on one individual stretch of coastline, giving coastal communities the chance to adapt and me the chance to hang out on tropical beaches a lot. While on the beach, I study the sedimentological characteristics of the beachrock and take samples. The samples are then taken to the lab – either to determine their age or to use a microscope to look at the cement between the grains.

The photograph shows a magnified image of four sand grains and the empty space between them. A scale in the corner shows that the grains are between 200 and 400 microns in diameter. The grains have smoothed surfaces and show different colors: transparent pale blue, transparent pale green or black with a grainy texture. The empty space between the grains is black. A 50 to 100 microns thick rim surrounds the grains. It has a greyish color and looks like a palisade fence with pointy tips reaching into the empty pore space. The individual grains do not touch but their rims overlap, holding them together.
Beachrock under the microscope. The empty space between the sand grains is filled by a natural cement that first forms as a rim around each grain and will later fill up the entire pore space turning loose sand into hard rock within years.

Right now, I am (sadly) neither at a beach nor in a lab, but at a desk in Germany preparing for my PhD defense and applying for postdoc positions – a tedious task that involves a lot of rejection. I don’t think there is a career in science without tedious tasks, be it repetitive lab work, marking piles of exams or never-ending application forms to fill out. Nevertheless, science allows me to keep my inner child alive, it allows me to follow my curiosity, all while making a contribution that helps coastal communities deal with the threat of sea level rise. I don’t know if I’ll get lucky one more time and be allowed to do this for a few more years, but I certainly hope so. One thing that I wish I had known from the beginning is that people are more important than the academic disciplines they belong to – looking back I would always choose a mentor outside my specialty with whom I have a great connection over the greatest expert in my field who does not care about me.

Update: By the time this is posted, I successfully defended my PhD thesis and started a Postdoc position in Heidelberg, Germany, where I get to teach sedimentology (yay) and work on a grant proposal for studying the incorporation of trash into beachrock on the Bahamas (even bigger yay)!!

The image shows four smiling people in fieldwork attire standing next to a one-humped camel. All four are wearing sandals and scarves wrapped around their heads. Three of them are girls and one is a bearded man, who is slightly older than the others. One of the girls is stroking the camel’s neck. The scarves and loose hairs of the girls are flapping in the wind, which seems to be quite strong. The background is a desert landscape with high dunes and a couple of fences but no vegetation. The sand is bright red. The sky is grey with dust, indicating a mild sandstorm.
Me, two other PhD-students from our lab and my supervisor Gösta at a field trip in the Wahiba Sands in Oman. Pro tip for everyone pursuing a career in science: choose your lab based on the people not on the prestige, the lab gear or the expertise… you can get all of these elsewhere. A good relationship with the PI is irreplaceable.

Abdur Rahman, Biogeochemist

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Hi everyone! I am a postdoctoral candidate at the Geosciences Division, Physical Research Laboratory, Ahmedabad, India. I have recently submitted my thesis and am now waiting for the final defense/viva. My primary research interest is in the field of biogeochemistry in different ecosystems (terrestrial and aquatic) using stable isotopes.

Man and girl in a lab with a yellow wall, looking at vials.
Trying to explain what we do in our lab to a 6th grade student on National Science Day (NSD) in GeoSIL, Physical Research Laboratory. (We were posing for the pic.)

My current research revolves around the biogeochemical study of the early ocean during the late Neoproterozoic-Cambrian transition period. I obtained limestone rock samples from Marwar Supergroup (Rajasthan, India) and am extracting the remnant of ocean life (organic matter) from those rock samples for stable isotope analysis. I will use carbon, nitrogen, and sulfur isotopes of organic matter to address the outstanding questions about the early Earth’s biology and associated biogeochemical processes. I am a curiosity driven early career researcher, always motivated to learn new techniques/methods and gain knowledge that would help develop a better understanding of the Earth’s environment. To expand my expertise, I am also involved in various parallel works. In one of my ongoing projects, I am using black carbon in Himalayan lake sediments (produced during the partial combustion of biomasses) to decipher the paleofire events and vegetation history of the region. I am also involved in the establishment of the clumped isotope measurement of carbonate (speleothems) in our lab. Clumped isotopes are a newly introduced technique to reconstruct the temperature of the water body in which carbonate precipitates.

Man walking in a shallow lake holding a tube, with cloudy sky in the background.
Taking a break to pose for photographs during sample collection for the biogeochemical study.

During my Ph.D., I have focused on the reconstruction of the Himalayan environment and lake biogeochemical evolution using stable isotopes in live- and paleo- lake sediments. My Ph.D. work has covered the last 45 ka of Himalayan environmental history and highlighted various extreme cold periods in the region. In one of the studied western Himalayan lakes, the carbon isotopes of occluded organic matter within diatom frustules have shown the influence of catchment geology on the lake carbon-biogeochemical cycle during 45-29 ka. The nitrogen isotopes of bulk sediments and carbon isotopes of authigenic carbonate and diatom in the western Himalayan lake sediments (Manasbal Lake, Kashmir, India) have shown the influence of climate on the lake stratification and associated biogeochemical cycles. Apart from the impact of natural stress, my Ph.D. also focused on the impact of the increasing human population and associated urbanization on the biogeochemistry of Garud Lake, Nainital, Uttrakhand during the last 70 years. This study has been performed using the stable carbon isotopes of organic matter and black carbon along with the nitrogen isotope of bulk sediments.

What is your favorite part about being a scientist, and how did you get interested in science?

After receiving my high school degree, like any other kid from my village, I was told to go for an early job and get settled. But the rebel child under the guidance of a few wise cousins ended up enrolling for a Bachelor’s degree in Geology at a reputed Central University. Being an avid reader, I connected with the subject in no time. Geology turned out to be more than a mere paper, it took me back to my early village days where I would take several breaks from school to roam around the banks of Ghaghra River (A major tributary of the Ganges, that flows through Uttar Pradesh, India), along with my friends. The little observations made out of sheer curiosity, the colored rocks, the ripples on the sands, the meandering river, all of those childhood observations, all of those many questions and crazy theories made sense then. The time spent in the university and the several departmental field trips brought me a bit closer to nature. Looking at things, sedimentary structures to predict the dip and strikes, it was a fun journey of learning and falling in love with the subject.

Three men in a lake, with their heads just above the blue water, with a blue, clear sky in the background.
Getting relaxed and enjoying the lake with my lab colleague after completing the sample collection.

I eventually followed the course and joined the Masters of Science with Geology as the major. Me and my batchmates were now quite familiar with academia. Like in several other Indian hostel dorms, famous for heated debates and loud late-night discussions we would often end up talking about the career ahead. I still remember that after several long hours, we did manage to agree on a single point, that the most beautiful element a career in research would constantly provide, was the uncertainty in the knowledge acquired and the constant pursuit for truth. For me, pursuing a scientific career means to be a curious student forever in the class of nature.

What advice do you have for up and coming scientists?

Based on my personal experience, I would encourage you to be patient, have faith in yourself, be bold and fierce, and always inspire yourself. In this profession, setting a major goal for a long period of time can be frustrating, so I propose defining small objectives for a day or a week and ticking them off as you move ahead. When you reach your objective, you will feel inspired and happy, which is necessary in our field. Another point I’d want to make is that you should be open to criticism, suggestions, and comments from people both inside and beyond your field of expertise. It aids us in our professional development.

Learn more about Abdur by following him on Instagram, Twitter (@shant_admi), and Facebook!

Paolo Abondio, Research Fellow, Molecular Anthropology & Population Genomics

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The “masked scientist” in front of the Institute of Anthropology entrance at the University of Bologna, where he performs his bioinformatic magic with human genetic data.

What kind of scientist are you and what do you do? I currently am a Research Fellow at the University of Bologna, where I participate in several projects pertaining human evolution and environmental, as well as biocultural, adaptation. My main occupation is developing and implementing computational, analytical, and statistical methods for large-scale genetic datasets, in order to infer population composition, relationships, dynamics and instances of adaptation due to natural selection. I mainly handle data produced from modern human groups, but also integrate ancient DNA to provide a temporal framework and disentangle episodes of adaptive introgression, where the genetic elements providing evolutionary advantage have been acquired through admixing events with the cousin populations of Homo sapiens (Neanderthals and Denisovans). As part of a team in the highly interdisciplinary field of anthropology, we are trying to answer human-related questions from several viewpoints, integrating molecular expertise with socio-cultural perspectives, as well as geo-archeological and linguistic data. The methodology that we employ is very flexible and can be easily applied to any other living (or extinct) population, provided that reasonably good quality DNA can be recovered.

What is your favorite part about being a scientist, and how did you get interested in science? I have been interested in science since middle school, where biology and maths were my favourite subjects. I actually started a degree in Physics, but later realized that I wanted to study something more real, concrete and “dirty”, so I switched to Biological Sciences and graduated with a thesis in Biophysics. During my undergraduate degree, I have been particularly fascinated by two courses, Anthropology, and Introductory Bioinformatics (an emerging discipline in Italy at that time). I decided to enroll in an International Master’s Degree in Bioinformatics (something only two Italian universities were offering), where I graduated with a thesis in Molecular Anthropology, studying the differential composition of the Italian population in terms of ancestry and possible adaptive pressures. I then pursued a PhD in Earth, Life and Environmental Sciences, again focusing on human evolution and adaptation to changing environments, dietary influences, socio-cultural and linguistic isolation, as well as the evolution of cultural and behavioral traits in the context of genetic variation. Lately, I am broadening my academic interests towards issues that are close to my heart: neurodegeneration, science education/communication, conservation biology and public health in minority groups. And this is what I love about being a scientist: being able to blur disciplinary boundaries while working at the cusp of knowledge, towards novel fields of study.

The “masked scientist” in front of the poster he is presenting at the XVI National Congress of the Italian Society of Neurology for Dementias. Here, population genomic methods have been applied to contextualize and estimate the age of a rare mutation causing Alzheimer’s disease in Southern Italian families.

What advice do you have for up and coming scientists? Based on personal experience, my advice for the new generation of scientists it would be this: if you want to pursue a career in any field, you must believe in yourself, be fierce and fearless, and know that there are no limits to what you can do. Be patient and open-minded: you will have to deal with despicable people, but also with the greatest and most generous minds you will ever meet. The future of science (and of all other academic fields) is interdisciplinary and transdisciplinary, so think big, be bold and try to stretch your brain and the boundaries of knowledge as far as you can.

Agathe Toumoulin, PhD, Paleoclimatoecologist

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Me, animating a climate modeling workshop with middle school students for a Science day in the lab (CEREGE, Aix-en-Provence, France).

How did you get interested in science in general? To some degree, my family probably played a role by cultivating my curiosity. My dad, by making some electricity home experiments from time to time (I think his favorite, and more impressive to us was: putting a light on from a potato!), my mom by loving plants and growing flowers everywhere, my aunts by occasionally brining my sister and I to zoos and museums. However, I don’t think any of my family and friends would have predict I would work in the science field. Until my 20’s I was more on the road to become stage director, art or theater critic, or even visual artist. After studying theater, languages, philosophy and literature in high school, I decided to start medical studies with the motivation to learn about the human machine functioning. After a few months, I realized it was hard but not exciting at all. Therefore, I decided to move to another discipline and while I was hesitating between art history and biology, I choose the second option. And this was the good one. I will always remember how my BSc botany and zoology classes were captivating. It was like learning about so many aspects of our world I never questioned before: what muscles make an earthworm move? How does a clam breath? What processes enable plants to move? How many lichens are there on the trees around? Without mentioning field trip on country side identifying plants and fungi, or on an island, collecting algae for herbarium… All these experiences really change the way you apprehend your environment! A tipping point in my formation was my first research internship in paleontology, during this experience I measured a hundred of belemnites (an extinct group of marine cephalopods) but more importantly, I realized I wanted to become a researcher. Of course, I feel really lucky that our public education system is (for the moment) not expensive, as compared to most other countries’. This enabled me to test for different branches and find my own. 

Late Eocene Eotrigonobalanus furcinervis fossil leaf (Museum für Mineralogie und Geologie, Dresden, Germany).

In laymen’s terms, what do you do? My work aims at reconstructing deep-time (i.e., millions of years old) environment and climate characteristics using fossil plants (wood and leaves) and Earth System Models. 

An Earth System Model is a numerical tool that calculates the earth’s climate according to a number of parameters. It is often used to predict how the climate will be in the future. It allows us, for example, to estimate how much the earth should warm up for a given increase in greenhouse gases concentration in the atmosphere. For the past, climate models allow us to assess the effects on paleoclimates of big changes, often suggested by fossils, such as changes in continent position, relief, volcanic activity, sea-level, or greenhouse gases concentration.

Fossil plants enable the reconstruction of past local to regional environment conditions. We can use fossil plants in different ways: (1) by identifying them and looking for their current closest cousins (called nearest living relatives). As we know in what conditions these live, we can then hypothesize the related fossil species had close preferences (in terms of temperature, need for water, nutrients); (2) – this is what I prefer by far – by looking at the size and shape (called physiognomy) of the fossil leaves. We know, thanks to numerous measurements of global modern vegetation, that leaf size and shape change according to the conditions in which the plant develops. For example, leaf size changes with the amount of rainfall: leaves are larger in wet areas, where plants are not likely to dry out. 

Examples of results from different climate simulations made with the French Earth System Model (IPSL-CM5A2). Hundreds of parameters can be analyzed! Our experiments use a middle Eocene paleogeography, which explains some differences in continent location!

Here is an example of my work to better illustrate the use of these tools. My MSc internship and PhD were focused on the Eocene climate (between ~56 and 34 Myr ago). We know from several indicators, notably because fossil plants close to extant tropical vegetation and crocodilian bones were found at very high latitudes, near the Arctic Ocean, that this period was globally warmer. Despite on average higher temperatures, this period is particularly known for a long-term climate cooling, responsible for the Antarctic ice-sheet growth! By studying the evolution of leaf shape of a fossil beech leaf assemblage, I tried to see if this cooling was visible in Germany. Then, using climate models, I tried to understand which parameters were responsible for this change. In the different modelling experiments, we tried to understand how the major changes described at that time: changes in paleogeography (more precisely, the Drake Passage opening), drop atmospheric concentration in CO2, Antarctic ice-sheet expansion, and the associated drop in sea level (the growth of continental ice-sheet result in sea-level lowering), may have affected the Eocene climate and if some of these parameters could explain the global cooling!

How does your research/goals/outreach contribute to the understanding of climate change, evolution, paleontology, or to the betterment of society in general? My research aim at better reconstructing the evolution of Earth climate and environment through life history, but we always learn from knowing our past. Eocene temperatures correspond to those predicted for 2300 following the worst climate change scenario (RCP8.5). Studying this period of time may provide some information on the manner a globally warmer climate works. It also constitute the opportunity to test the validity of climate model predictions for the future: paleoclimate modeled can be compared to climate estimates obtained from proxy-data. However, Eocene and modern world aren’t fully comparable, there are important differences, notably in the continent location (ex. North and South America were not connected during the Eocene). This means that we cannot necessarily apply our knowledge of the Eocene to the future. For my part, I find that my research is important for its historical significance, to understand how global biodiversity got here. 

Jurassic coniferous fossil wood from Antarctica, University of Kansas, Paleobotany Collection

What methods do you use to engage your community/audiences? What have you found to be the best way to communicate science?  During my BSc I get a half time job, as a guide at the Museum of Natural History of Toulouse. It was a great experience that really made me want to connect people to science. Since then, I designed and animated some workshops around biodiversity and climate for children. I am not a professional in Sci Comm, but for me, communicating science starts by establishing an equal relationship between researchers and the general public. We all know things. I like to instill confidence in people, by making them participate, and then share original anecdotes on a given topic. These anecdotes are not necessary complex mechanisms, nor the most recent scientific discoveries, but stimulate curiosity and raise interest, and I think it’s the first step for people to get into science. 

Me, looking for Permian fossil plants in the Lodève Basin (France) during a field trip organized by the association Agora Paleobotanica.

What is your favorite part about being a scientist ? There are different aspect of working in science I really like: 

To marvel and play – To me being a scientist in paleo- is like a game, there are some clues around (and not always your favorite) and you must get some information from that to picture how the environment was millions of years ago. For now, I’ve been working on 35 to 180 Myr old periods which differs through many aspects of our everyday life context. To me working on these ancient landscapes is somehow like traveling (I guess that fiction authors may also feel this way). 

Being part of something bigger – Although, we sometime feel like being in a very specific research niche, there are at least dozens of people working on similar/complementary questions around: you are part of one community! This network structure really opens up research questions that can be addressed. I like contacting people from other country asking for their expertise and exchange.  

Being free – One of the big advantages of research is also that you are relatively free in the work you do and the way you do it. It certainly depends on the labs and teams you’re part of, but in general you manage your time and projects, being your own boss in a way and this is something I really like. I’m currently writing my first postdoctoral research project and I really feel like I can build something that fits me 100%.

What advice do you have for aspiring scientists?

  • Do as many internships as you can: these experiences will help you define your interests and what you want to do, and meet inspiring people.   
  • Do not hesitate to contact / talk to people! Although everybody is busy, people generally like you being interested in their work and may provide you help (e.g. on special methods) or advice (including for your career!). 
  • Do not censor / limit yourself: just because you never worked in a given field/with some methods doesn’t mean you won’t be able to succeed. Believe in yourself and work hard enough to explore research areas that interest you.

Follow Agathe’s updates on her website and Twitter!