Scavenging the fossil record for clues to Earth's climate and life
Meet the Scientist
The goal of this page is to introduce you to how diverse science is by exploring what individual scientists do! We hope that you will learn how many different avenues you can take to explore the natural world around us. Each guest scientist will also explain what type of data they use, why they enjoy science, and share some advice for young future scientists. Other similar blogs include Fossil Guy’s paleontologist interviews, The Female Scientist portraits, and Rock-Head Sciences.
I am a paleoceanographer. Basically, I study how the ocean changed in the past, in order to understand how it might change in the future. To do this, I primarily use foraminifera, which are sand-sized plankton that have a hard shell that is easily preserved in ancient sediments. In fact, in many places far from land the sea floor is entirely made of foraminifera and other microfossils (fossils so tiny, you need a microscope to see them properly or at all). To get the microfossils, I often go in the field or to sea. I do a lot of work with core samples of both ancient and modern sediments from the deep sea and on the continental shelf, and also collect samples from outcrop on land where the sea used to be.
My research touches on a number of societally relevant topics, although if I’m honest my main motivation is just to better understand how the world works. I like when my work addresses specific problems like declining oxygen in the oceans, but there is value in all kinds of science, and you never know what discoveries might lead to an important insight into processes that are significant today. That being said, much of my work focuses on how anoxia (i.e., no dissolved oxygen in the water) develops in the ocean, and how marine life responded to it in the past.
A combination of warming water due to climate change and plankton blooms due to increased nutrient runoff from agriculture on land has led to a recent decline in the amount of oxygen in the oceans. In turn, this had led to an expansion of deadzones (places in the ocean where marine life cannot live) on continental shelves and in bays and estuaries. The modern ocean is losing oxygen at a similar rate to the just before major anoxic events in the Cretaceous Period about 90 million years ago. These past oceanic anoxic events are useful partial analogs to understand deoxygenation in our oceans and its effect on marine life (the short version is it drives a lot of extinction).
I also study how life recovers after major mass extinction events, particularly the End Cretaceous mass extinction that killed the dinosaurs and 75% of life on Earth. That mass extinction was caused by an asteroid impact in the Gulf of Mexico. The impact caused particles to fly into the atmosphere, blocking the sun. Because of this, photosynthesis crashed, and everything went extinct in just a few years. This is probably the only major event in Earth history that happened faster than modern climate change, so it’s a useful analog to understand how ecosystems rebound after a rapid extinction event. We are not (yet) experiencing a sixth mass extinction today, but rates of extinction are undeniably high because of human activity. How the biosphere (the plants, animals, and various other life forms on Earth) will recovery once human disruption finally stops is an important thing to understand. Unfortunately, results from the past suggest that life will take millions of years to bounce back.
The best part of being a scientist, in my opinion, is working to solve problems that I find interesting (this is my main advice to aspiring scientists, too, find something that you think is interesting and that will hold your attention. There are lots of important things we don’t know and you don’t have to pick the highest profile one). The other best part of being a scientist is the opportunity to work in the field and go to sea and work with friends from all over the world to solve a problem. I got into geology because I wanted a job where I could be outside at least part of the time, but the chances to travel have surpassed all of my expectations.
Chris is currently a Research Associate at the University of Texas Institute for Geophysics. He was a member of a drilling expedition that recovered a core from the Chicxulub crater, where the asteroid that killed the dinosaurs hit. Chris and his team were featured in the NOVA documentary ‘Day the Dinosaurs Died’, which is freely available online here. To learn more about Chris and his science, you can follow him on Twitter @clowery806.
What is your favorite part about being a scientist, and how did you get interested in science in general? I’ve been interested in science for as long as I can remember. My dad was working on his Master’s of Science in Biology when I was a kid and I loved going to class with him to look at cells under the microscope and helping him collect insects in the field behind our house. I got into paleontology specifically when I learned how common it was to find mastodon fossils in fields near my house. I wanted to find one of those mastodons! I love that as a scientist I still get to do these things that I loved as a kid.
What do you do? In undergrad I said that I majored in hugging trees and minored in playing in the dirt. I would say that’s still true. I use the size and shape of leaves to figure out the ancient temperature and precipitation (paleoclimate). I do this by studying modern plants and applying what I learn to fossil plants. Specifically, I use the size and shape of tropical African leaves to study the paleoclimate and environment in Kenya during the evolution of our early ancestors.
How does your research contribute to the understanding of climate change and evolution? I like to say that I am the context. As a paleobotanist, I study the ancient temperature, precipitation, and environment.What was the world like when our early ancestors were evolving. Was it hot or cold? Was it wet or dry? Was the landscape open or forested? Was there water nearby? Understanding this can help us understand the context of human evolution.
What are your data and how do you obtain them? Because I study both modern and fossil plants, I get data from a couple of different places. For modern leaves, I primarily use existing collections from herbaria. A herbarium is like a library of plants. For hundreds of years people have been pressing leaves, collecting seeds, and drying fruits and I can use these collections to understand the range of size and shape of leaves from tropical Africa. In addition, I study both previously collected fossil leaves as well as fossils I collected myself. This means that I’ve been lucky enough to spend a few months studying collections in the National Museum of Kenya as well as doing my own fieldwork.
What advice would you give to young aspiring scientists? It’s okay to ask questions. Very often other people have the same question but are too afraid to ask.
It’s okay to ask for help. Asking for help is not a sign of weakness; it’s a sign of strength. Knowing what you don’t understand or can’t do alone shows that you understand what it takes. It’s okay to reach out to scientists that you admire. Scientists tend to be very excited to talk about their research and are happy to hear that people are interested! Scientists are humans too.
Today I’m a consultant investigating and cleaning up soil and groundwater contamination (click here for more information); I also have a podcast called That’s So Second Millennium where I talk about science, geology and physics in particular, as well as religion and philosophy.
As far as how I got into geoscience in the first place… I was always that little boy who was really interested in math, and that expanded to include chemistry and minerals in high school. Over time the elements came to have personalities for me. I love color, so minerals were natural things for me to love as well. Years later, when I taught mineralogy, I assigned lists of elements – oxidation states – colors for quizzes. Unfortunately, it seems that students never enjoy anything as much when they’re going to be tested over it as I did when I was reading it for fun.
Hopefully you’re reading this blog post for fun, though, so let’s give it another go.
Elements, color, and minerals
You may have picked up in high school or college chemistry that the periodic table has the shape that it does because of the quantum behavior of electrons. They sort themselves out into shells and subshells. The elements in each row of the periodic table have their outermost electrons (in ground state, the lowest energy configuration) in a given shell: 1 in the first row, H and He, 2 in the second row, Li to Ne, and so on. Each shell has one or more subshells–those are those s, p, d, f letters you learn about.
How does that translate to light and color? Well, light comes to us as little bits of energy called photons. The whole electron structure business is about energy, and the jumps in energy electrons need if they are going to jump from one subshell to another. Visible light is made up of photons with a particular range of energies. Those energies happen to be about the right size to coax electrons to jump around inside the d subshells of atoms big enough to HAVE d subshells, but not completely full ones. The elements that fit that description are down there in the low spot in the middle of the periodic table, the transition elements, or you might nowadays call it the “d-block.” The rare earths, or lanthanides and actinides, or “f-block” elements also work.
If you run your eyes along the top line of the d-block, you see all in a row chromium, manganese, iron, cobalt, nickel, and copper. All of those are important elements in geochemistry and in industry, iron of course being a major element and the most abundant. They also all happen to be “willing” to lose variable numbers of electrons, go into different oxidation states, and exhibit different colors:
As you can see with cobalt and nickel, the oxidation state is not the only thing that controls the color. The ligands – molecules or ions – bonded to the metal change the behavior of the electrons and produce a whole spectrum of colors. Thus, this table is only an attempt to note some of the most common colors. You can explore the subject in a number of different directions, for an example click here.
Meanwhile, most compounds of non-transition elements, especially the “s-block” elements to the left of the periodic table like sodium and calcium, are colorless or white. It takes more energy to jerk around s and p electrons, and those energies correspond to ultraviolet photons.
Having d or f-block elements is not the only way for a mineral to wind up colored, by any stretch, but it is very common. Here are some of my favorite colored minerals and the elements that make them so, along with mugshots from mindat.org:
Uranium and nuclear waste
My criteria for choice of dissertation topic and therefore advisor and graduate school essentially came down to this. When I ran into Peter Burns (yes, Simpsons fans, I learned about uranium from Dr. Burns, go figure) at Notre Dame, and found out that I could work at the lunatic fringe of the periodic table, I decided to go for it. I’d recommend broadening the thought process beyond just the subject matter if you’re choosing a graduate program, but I can definitely report that uranium geochemistry is not boring.
At that time, 15 years ago, this place called Yucca Mountain in Nevada was in the news as the one place under consideration for storing the U.S. high level nuclear waste from power plants. I can’t possibly go into all the issues surrounding high level nuclear waste – weapons work generates different wastes than power plants, there’s the whole reprocessing question, the security problem so that waste doesn’t get stolen and made into dirty bombs, it goes on and on.
Let’s focus on a few key issues. Whether it was the best idea or not, nations around the world built quite a few nuclear power plants. We have dozens here in the U.S., and NONE of their high level waste has ever been permanently disposed of.
Although nuclear waste is nasty stuff to deal with, nuclear power has one big advantage today: it gives you juice without having to burn fossil fuels. Wait, let me make that two advantages: unlike renewable energy from solar and wind, nuclear power plants provide baseline power regardless of the weather. So it might not be the best solution to move completely away from nuclear power just yet.
(Really, they need to get fusion plants working so that we can stop dealing with uranium, but we’ve been waiting an awful long time for that. We may have working Star Trek transporter beams before we have fusion reactors at this rate.)
So we really, really need places to put all this high level waste safely. That means we need to understand how uranium geochemistry works well enough to put together reliable models. That means we need to know what uranium species are in solution at particular geochemical conditions.
Uranium is a weird element – I did not call it the lunatic fringe of the periodic table for nothing. Uranium(VI), the oxidation state of uranium when it’s in equilibrium with all this nasty oxygen stuff we have in Earth’s atmosphere, is nearly always in the form of a weird complex cation called the uranyl ion, UO22+. Those two oxygens stick off into space to make this sort of three-ball dumbbell.
You may be aware that there are a lot of carbonate minerals… most metal carbonates are insoluble in water. Not the uranyl ion. Uranyl carbonate is mad soluble. There are also uranyl hydroxide ions in water solution at a variety of pH conditions. All this was known reasonably well from studies dating way back, some in geology (especially related to ore deposits of uranium) and some from chemical engineering. So in the run up to deciding on whether to do the Yucca Mountain repository or not, these existing studies were used to model the geochemistry and how long it would take the uranium to escape and how far it would go. Like all engineers and bureaucrats, the people involved were pretty confident about their answers.
For a trace element, uranium forms a lot of distinct minerals. That tends to happen when your chemistry is weird and you don’t fit into the sites of other elements in ordinary minerals. There were and are many of these minerals whose structures are not yet known. At the time, my research group (not me personally) was interested in a weird pair of minerals called studtite and metastudtite. Their structures weren’t known. Their bulk chemistry seemed to indicate peroxide ions, which would be very strange; there aren’t any other peroxide minerals, because the peroxide ion is really unstable. As I recall, Peter didn’t think they were really peroxides once they were crystalline, although he might remember it differently.
In any case, as it turns out, you can use peroxide to synthesize studtite and it is, in fact, a peroxide. The peroxide must be generated by radioactivity chewing up water molecules to make peroxide in the intense environment around other uranium minerals.
But as it turns out, on the way to making studtite, the real science happened.
If you jack uranium and peroxide into solution at certain pH conditions, you get crystals of studtite. At other conditions… well, you get a solution, and if you evaporate it down, depending on the counter ion (you need some cations like sodium, lithium, etc. for charge balance) you get something delightfully frightening:
Nobody knew these things existed. They’re actually pretty stable in solution. In a nuclear waste repository, like oh say Yucca Mountain, with MAD amounts of radiation from not just uranium but a whole bunch of hot, hot fission products, there could be oceans of peroxide and the conditions could be just right for making these things, which would traipse off into the Nevada groundwater and do things those previous geochemical models did not suspect.
Yucca Mountain died because of politics, not because of these studies. It may be just as well. Maybe we dodged a bullet there. In any case, we need to do something else with all that waste, and there may be some more craziness lurking out here on the lunatic fringe that we’d better put into our models before we pull the trigger.
For my first postdoc, I studied the interaction between clay minerals and high-pressure carbon dioxide. This research was funded by Shell in the Netherlands and was aimed at discovering whether carbon sequestration in deep aquifers is a viable option. An aquifer is a permeable rock with water in it, and deep aquifers have caps of less permeable rock called aquitards. Clays tend to be the dominant minerals in these aquitards. Many clays have the ability to expand or contract their crystal lattice and are called swelling clays.
Carbon sequestration involves scavenging carbon dioxide from power plant emissions and compressing it into a liquid or supercritical fluid. Carbon dioxide below the critical point liquifies at around 60 atmospheres, not a very high pressure. It’s actually very easy to make supercritical carbon dioxide, as the critical point is only around 30 C.
This fluid is then injected into a deep aquifer to get it away from the atmosphere. By the time it gets into that aquifer, it will be warm enough to be supercritical even if it was not at the surface. The supercritical fluid is lighter than water, so it rises, and the caprock will have to hold it in place if the sequestration effort is to work.
When we started the experiments, we were concerned that the carbon dioxide would suck water right out of the clay and cause the caprock to shrink and crack. Remarkably, the opposite was what we mostly observed. If anything, carbon dioxide entered the clay and swelled it. This is mostly good news: although swelling could also destabilize the caprock, a modest amount of swelling will actually close cracks and make the caprock better at holding in the carbon dioxide.
The best advice I could give to young scientists is to ask questions. Ask all kinds of questions and just talk to people. Get specific about what you can expect from a career in academia, in environmental consulting, in mining, in geotechnical, in whatever industry. Make friends and be a friend. Tell people about the things that light you up and also the things that make you sad or afraid, and be a welcoming person when other people respond in kind. This was immensely hard for me when I was in college: I was definitely a loner and pretty depressed most of the time. I had to learn eventually that I had to talk to people whether I felt up to it or not.
At the same time, be gentle on yourself. You’ve got plenty to offer the world, whatever your problems or family issues or your relationship status.
I am currently a PhD student at the University of Leeds, UK. My research looks at the role of mass extinctions in driving long-term trends in ecology and evolution. I do this by analysing large volumes of data from the fossil record, which requires statistical programming, an approach often termed computational paleobiology.
I’ve always enjoyed the problem-solving nature of science; it can be frustrating at times but really satisfying when all of the pieces of the puzzle fit together. As an undergrad, I studied Biology and Earth Sciences at Durham University, UK, before going on to complete a Masters in Palaeobiology at the University of Bristol, UK. Both of these courses helped to cultivate my passion for evolutionary biology, and equipped me with the scientific approaches and data analysis skills I needed to tackle “big data” questions in paleontology.
My PhD project is focused on comparing large-scale spatial patterns of biodiversity (=the variety of life in an area or on a global scale) before, during and after the Permian-Triassic mass extinction event (~250 million years ago), the most severe mass extinction event in Earth history. During this time, up to 95% of marine species became extinct. Widespread volcanic activity drove extreme global warming, leading to ‘hothouse’ conditions which prevented ecosystems (=a community of animals and how they react with the environment around them) from fully recovering for several million years. Understanding how global warming has affected the biosphere in the past is important for making accurate predictions of how global warming will affect animals and plants in the future.
Most of my data comes from the Paleobiology Database, a global database of fossil occurrences compiled by paleontologists, which is freely accessible to everyone (you can explore the data using the Navigator app). As one of the data enterers, I spend a lot of my time looking for information on fossils published in journals and books and adding them to the database. Once I’m happy with my occurrence data, I analyse them using R, a programming language and environment designed specifically for statistics. It enables me to carry out complex calculations across big data sets relatively quickly, to establish what the fossils are telling us about large-scale evolutionary patterns.
I also really enjoy outreach. Alongside my PhD, I work part-time delivering environmentally-themed school sessions, building on the experience I gained doing outreach with the Bristol Dinosaur Project during my Masters. At present, I’m particularly involved in delivering ‘Fossil Hunt’ sessions, visiting local schools to give 7-11 year olds the opportunity to handle fossils and learn about paleontology. It’s great to be able to show the children what ‘real’ scientists look like, and I always leave refreshed by their enthusiasm.
I love my research because it strikes the perfect balance between being something I’m really interested in (evolutionary biology) and requiring something I’m good at (data science). My advice to aspiring scientists would be to find this crossover in your own skills and interests – science takes perseverance, and that’s much easier when you’re making the most of your talents and are passionate about what you’re doing!
What do you do?
As an undergraduate at the University of South Florida I am in the process of undergoing the absorption of the necessary geologic common knowledge about Earth processes to become a geologist. In addition, I’m also learning the approaches and disciplines necessary to perform scientific observations and investigations that are required to do research and field work for my future endeavors in geology.
What is your data and how do you obtain your data? In other words, is there a certain proxy you work with, a specific fossil group, preexisting datasets, etc.?
I haven’t yet been afforded the opportunity to plan my own research or collect my own data. I have, however, taken a deep interest into volcanology, geochemistry, and petrology while assisting a graduate student and a research volcanologist with their investigations of the evolution of magma bodies. This has allowed me to use their geochemical analysis data retrieved from rock samples. During this time, I have applied calculus and statistics to the geochemical analysis data to form a geochemical model that describe the degree of crystallization that would result in those rock formations. The data sets for these rock samples were collected via electron microscopy.
How does your research contribute to climate change, our understanding of evolution, or to the betterment of society in general?
The research I have assisted with could help in both economical and societal benefits by helping understand how and where mineral deposits may form. In addition, it helps describe the geologic history (via rock formation) of an area or region which is of benefit to all.
What is your favorite part about being a scientist?
My favorite part about being a scientist is the opportunity that it provides to get out and question the how and why of things in the natural world. There are so many stories to be told about time (both deep and recent) that haven’t been told yet. Being a scientist offers the opportunity to contribute to both the scientific and non-scientific community by offering the possibility to help spread more understanding of the Earth’s natural processes. In my opinion, this is part of what helps keep alive the awe-inspiring wonder and “magic” about the Earth.
What advice would you give to aspiring scientists?
Even though I am 36 I would still be considered a “young” scientist myself in the sense that I am new to the field of geology. However, I can give the advice that if you have the desire to seek out to become a geologist, or any discipline for that matter, don’t hesitate to go for it. Furthermore, don’t be afraid to ask for help and guidance from your peers and fellows. The amount of support and guidance I have been given so far in my journey by professors and fellow students has helped guide and inspire me. In my experience, most individuals in the wide umbrella of geoscience are more than willing to help if they are capable.
What are your experiences with returning to school at a later age and what were the driving forces behind this decision?
My reasons for returning to school were quite simple. I made some foolish life choices as young student graduating high school and ultimately lacked direction in my life for many years. After spending more than a decade in the landscaping industry I couldn’t escape the feeling of being wholly unsatisfied with my career. I finally reached a point where I was not excited about what my career path was. Three years ago, I set out to seek a new direction. I asked myself the question, “What is the thing that I enjoy doing the most in life?” and followed that question with another; “Is it possible to find a career that would place you directly in that activity or surroundings. My answers were, without a doubt, that I felt most at home while being out in the natural world as I am a hiker and backpacker who has always loved exploring the beautiful environments and monoliths you can find across the globe; and that as a geologist I could choose a focus that would provide me an opportunity to both be placed in the outdoors and to help expand knowledge and understanding of these places I loved so much. So, the choice was clear. Three years ago, I re-enrolled into community college and finished AA before transferring to USF to seek my BS in geology. The experience has extremely gratifying while also very challenging. Being a now 36-year-old adult meant that I had a many more personal responsibilities and bills than most of my fellow students. It can be a challenge to find enough time to fit in all my duties as an employee, as a son, and as friend while continuing to uphold my studies. Regardless, I always try to keep the end goal in mind and remind myself that this is all a part of the process. The greatest benefit I have received from returning to school is the gift of being able to stay focused on my goals. Since I have already experienced the oft confusing timespan of young adulthood, it is much easier for me to not get off course due to the perceived necessity of over indulgence in social gatherings in which I see many young students struggle with. I’m here to trust the process and enjoy the ride.
Follow Luke’s geology experiences by checking out his blog: click here!
What is your favorite part about being a scientist, and how did you become interested in science?
Throughout my time in middle school, my favourite lessons at school were always biology, chemistry and physics. I also really enjoyed physical geography, and my teachers at school were always enthusiastic, engaging and were more than happy to support my interest in geology. They pointed me in the right direction with careers when I was in high school, and without their guidance I probably wouldn’t have studied geology at university. I also volunteered at the Natural History Museum in London from the beginning of my third year of undergrad with an EU funded research project called Throughflow (as part of the V Factor Volunteer Scheme). The researchers who I volunteered with were also incredibly encouraging and supportive, and great mentors too.
I enjoy being a scientist because:
I get to look at microfossil specimens that no one has looked at before. Foraminifera are so pretty, and I still can’t believe that these single celled organisms manage to create these ornate skeletons which record climate during their lifetime! Understanding the stories they have locked up inside is sometimes a little difficult, but I enjoy the challenge that this presents.
Lab work is fun. I love learning different chemical techniques.
I get to meet lots of awesome people from a variety of backgrounds and geological disciplines and talk science with them.
I get to communicate my science to public audiences and inspire new generations of scientists.
What do you do?
I use the chemistry of fossil plankton called foraminifera to understand more about their ecologies and what the climate was like millions of years ago.
How does your research contribute to the understanding of climate change, evolution, or to the betterment of society in general?
We use chemical data from foraminifera shells to reconstruct past climate. However, we don’t fully understand all aspects of foraminiferal ecology i.e. exactly what their lifestyles were like- did they all live with algae? Did they migrate or change in size because oceans became harder for them to live in? Ecology affects shell chemistry. Thus, before we put together long term climate records to understand how the earth’s climate has changed through time using chemical signals from foram skeletons, it is important to understand the controls on the signals that we use. This is particularly pertinent to geological periods that we use as future climate analogues such as the Eocene (~47-33 million years ago).
What are your data and how do you obtain them?
Planktonic foraminifera are single celled plankton which have a skeleton made from calcium carbonate. Some species choose to live in the surface waters of the ocean, whilst others choose to live in the thermocline. Some even live together with algae! All forams are beautiful, and they come in all sorts of shapes and sizes. Foraminifera are really awesome too, because in the same way human hair records our diet, their skeletons record the environmental conditions around them in the ocean. By the analysis of one shell, we can understand the climate in the location and the time that the foram lived, including how hot the oceans were and even how much ice there was on land!
When foraminifera die, their skeletons sink to the sea floor and build up in layers, creating an extensive fossil record more importantly an extensive climate record too! The same signals we use to infer climate in the past can tell us how they used to live too i.e. their ecology.
To understand foraminiferal ecology, I use several geochemical proxies. Proxies are chemical signatures which are an indirect way of understanding an environmental parameter. I primarily use oxygen isotopes, carbon isotopes and the amounts of magnesium (Mg), strontium (Sr) and boron (B) (ratioed to calcium, Ca) in foraminiferal shells. If these elements are unfamiliar to you, you might not have realized you’ve seen them before. White fireworks have Mg, green fireworks have B and red fireworks have Sr! I gather these data using different machines called mass spectrometers and electron microprobes. One of the mass spectrometers I use is hooked up to a laser, which is super cool. I use the laser to drill through foram shells to understand how Mg, B and Sr vary through the shell wall. Mg/Ca, Sr/Ca, B/Ca, δ18O and δ13C signatures are specific to certain species. For example, a surface dwelling species will have greater Mg/Ca and a more negative δ18O signature. Therefore if I collected these type of data from a species with an unknown ecology, I would infer that it was a surface dweller.
What advice do you have for aspiring scientists?
Always be curious.
Ask as many questions as you can – no question is stupid. If someone tells you your question is stupid – they’re wrong.
Talk with lots of people who might be able to help you gain more of an insight into the world of science. You never know who might be able to give you work experience/research internships/jobs (both academic and non academic).
If things go wrong academically early in your career, don’t let that stop you from progressing later on. Work hard, learn from your mistakes, and you can do anything you’d like to (I speak from experience with this one…)
Have mentors and a support network. I wouldn’t have survived the final stages of my PhD without mine.
Look after yourself – no science is worth you burning out over. As a friend once told me – the forams will still be there and waiting for you to look at them in the morning… (they’re not wrong).
For those studying for exams (including PhDs): Don’t lose your enthusiasm and don’t give up if things get tough. You set out to learn/research something cool, and if you’ve made it this far, you can totally do it!
Learn more about Rehemat’s research and follow her on Twitter @rehemat_
First, let me introduce myself. I am a Colombian PhD student at the National University of La Plata, Argentina. My research is focused on the evolution of xenartrans, mammals that include armadillos, sloths, and anteaters.
Since I was a child, I have had a strong fascination to learn about nature. For that reason, I loved (and I still do love) reading a lot and watching documentaries about science, wildlife, meteorological phenomena, the history of the Earth, the history of the Universe, astrophysical theories and hypotheses, and other similar topics. Science has an amazing explanatory power, and that has always been what I like most about it. Science allows us to know our place in the Universe.
Following my vocation, I studied biology in college. Although during my undergrad there were many disciplines that caught my attention, the only one that enamored me was the study of extinct life forms, i.e. paleobiology. At first glance, it is not easy to explain why I wanted to be a paleobiologist, since there are very few Colombian paleobiologists and institutions that teach paleobiology and/or develop paleobiological research in my home country. However, studying the unique history of evolution of living beings seemed not only a noble, respectable activity, but it also became a passion that I believe will always accompany me as long as I live. Paleobiology has formed the basis of my life in the professional field, and also in a personal, philosophical sense.
To perform research in paleobiology in a country located in the intertropical belt of the planet (near the equator) and characterized as one of the most biologically diverse areas on Earth poses great challenges and opportunities. On the one hand, there is little or no state support to study paleobiology as a consequence of socio-historical development. In addition, there are limitations related to logistics in regions that are difficult to access due their geographic location and/or security features. We also face scarcity of continuous outcrops of sedimentary rocks where fossils can be found. Often, as a result of climatic factors and abundant vegetation (plant life), fossils are poorly preserved (however, sometimes, they are exquisitely preserved!). But these limitations are largely compensated by huge opportunities. Fossils from the tropics are exceptionally valuable. They document innumerable evolutionary stories that can help explain one of the most disturbing questions for many biologists: why is there a tendency in different groups of living organisms to present greater diversity in the intertropical zone compared to other regions on Earth, such as in higher latitudes?
Paleobiology in the tropics is very necessary because of the generalized geographic bias in research of many extinct organisms and periods of Earth’s history. Namely, most research on these topics has been conducted in Europe and North America. In Colombia, paleontological field expeditions and studies have yielded surprising findings, including, of course, our flagship fossil organism (in my opinion): Titanoboa (Titanoboa cerrejonensis). For all those who do not know it, this snake lived approximately 60 million years ago in the extreme north of Colombia (Guajira peninsula), and its most surprising feature is its size and body mass. Titanoboa measured about 13 meters in length and could exceed one metric ton in weight. That makes it the largest known snake of all time!
I contribute to tropical paleobiology by studying fossil xenartrans (armadillos, sloths, and anteaters), particularly those that lived in northern South America and southern Central America. I seek to clarify questions on evolutionary/phylogenetic relationships between extinct representatives of these charismatic mammals and, at the same time, to reconstruct historic changes in their geographical distributions (where they lived through time).
Why is it important to study extinct armadillos, sloths, and anteaters? There are many reasons, but my favorite is that they are animals whose origin and evolution are closely related to great-magnitude abiotic (non-biological) events and processes (such as climate changes and tectonic events). Through tens of millions of years, abiotic factors shaped their biology and ecology to configure the xenartrans in one of the most peculiar mammals that existed during the Cenozoic (the last 65 million years). Have you seen how strange some armadillos look when they roll into a ball, or the very slow movements of a three-toed sloth, or the long tubular snout of a giant anteater? If you have not seen this, you should check out the videos linked in the previous sentence. But in the fossil record we know even more bizarre features of xenartrans than we see in living species. For example, several species of giant sloths used to swim (yes, you read it right, ‘swim’) in littoral zones (areas close to the beach) of western South America around 5 million years ago! Is that not mind-bending?
Xenartrans constitute an outstanding study model on how Earth and life evolve together, from their evolutionary differentiation ~98 million years ago, possibly triggered by the geographic separation of Africa and South America, until their colonization of North America during the last 9 million years in the environmental framework of the Panama Isthmus uplift and the Last Great Glaciation. This makes xenartrans interesting organisms to study evolutionary patterns and processes of high complexity in the tropics.
I am particularly interested on the evolutionary implications (diversification) of dispersal (or movement) events of xenartrans from northern South America to North America (including its ancient Central American peninsula) during geologic intervals which immediately precede the definitive formation of the Isthmus of Panama. Long distance dispersal through a shallow sea, like that which existed between southern Central America and northwestern South America before the complete isthmus emergence, is one of the least understood biogeographic phenomena. The explanatory mechanism of long-distance dispersal allows for disjunct distributions and for us to more comprehensively understand the subtle interaction between distinctive faunas of contiguous areas.
In order to fulfill my general research objective, it is necessary to work hard in determining identities and affinities of Middle-Miocene to Pliocene (15-2 million years old) xenartrans of the aforementioned regions, including not only previously collected fossils, but also new findings. In a complementary way, it is required to put identifications in geographic context through faunal similarity/dissimilarity methods. I also use probabilistic biogeographic models (models that use statistics) to infer major distributional patterns and processes of several subgroups of xenartrans, so that we could understand in an analytic, non-strictly traditional narrative way, the changes of their occurrences in space. Finally, long distance dispersal events through poorly suitable environments for most xenartrans, like shallow seas, are approached through locomotive reconstructions to estimate dispersal capacity (vagility).
I want to end this post by giving an important advice to all those who aspire to be scientists. The path to work in science may be, to a greater or lesser extent, long and complex. However, if you remain true to your convictions and strive under a regime of self-discipline, you will not only be a scientist, but also one of the most prominent researchers in your field. Question everything, do not firmly hold onto hypothesis that have little associated evidence. And, above all, write, write to clarify in your mind many issues related to your research.
I am a paleoclimatologist, and I study the ecological and environmental effects of climate change using the fossil record. Specifically, I research how the Ross Ice Shelf in West Antarctica responded to temperature and atmospheric CO2 concentrations slightly higher than what Earth will experience in the next several decades. The Ross Ice Shelf is currently the largest mass of floating ice in the world, and West Antarctica is currently melting faster than the rest of the Antarctic Ice Sheet–what’s going to happen when this much ice melts into the ocean? How will melting affect regional plankton communities, the base of marine food webs? When that much freshwater is added to the ocean, what happens to ocean currents and circulation? I’m interested in answering these questions and using research outcomes to improve environmental policies and climate change mitigation strategies.
I’m also an educator! I spent the last two years in the classroom teaching 5th and 6th grade STEM (Science, Technology, Engineering, Mathematics) classes, and I informally teach when I participate in STEM outreach events and programs. I plan to use my research as a model to teach the next generation of voters and environmental stewards about their planet’s historical and future climate change, and inspire the next generations of diverse, innovative STEM professionals. As an educator, I have seen how disparities in access to educational opportunities disproportionately affect low-income communities, communities of color, immigrants and non-native English speakers, and other traditionally oppressed and disadvantaged groups. As a member of these communities, I see a lack of representation and inclusion in STEM professions, and a gap in scientific literacy in our policymakers, so I want to use STEM education to affect greater social and political change.
What do you love about being a scientist?
I love learning about the Earth’s past–being the first person ever to see a fossil since its deposition, using clues in the fossil record to understand and imagine what the Earth looked like millions of years ago, and making connections to predict what our world will look like in the future. However, my favorite part of the job is telling other people about what I do! I can see folks light up when I mention I study fossils, and it’s cool to see how many people grew up wanting to become a paleontologist, just like me! I think most people believe paleontology doesn’t have any real-world applications but in reality, paleontology offers a unique perspective to understanding the modern environment. When I tell students, I see them get excited about science and all its possibilities: I remember when I judged the MA State Middle School Science Fair once year, a participant was amazed that you can use fossils to study climate change, and she asked what else can we study using fossils? It is exciting to share my career with youths, especially those who look like me, because their idea of what a paleontologist looks like and does changes when they meet me.
Describe your path to becoming a scientist.
As a kid I loved dinosaurs and exploring outside, so I knew I wanted to be a paleontologist from an early age, but I wasn’t sure if I’d ever get here. Growing up as a child of undocumented immigrants, our family faced housing, food, and financial insecurities, so college seemed beyond our means. However, I received the Carolina Covenant Scholarship to become the first person in my family to attend college, and I studied Biology at the University of North Carolina at Chapel Hill (Fun Fact: Time Scavengers Collaborator Sarah Sheffield was my teaching assistant for Prehistoric Life class!). I completed a B.S. in Biology, and minors in Geological Science, Archaeology, and Chemistry.
While I was an undergraduate at a large research institution, I didn’t have a dedicated mentor or the cultural capital to know I should pursue undergraduate research as a stepping-stone to getting into graduate school. After graduation, I pursued research opportunities with the National Park Service in Colorado and the Smithsonian Tropical Research Institute in Panama, where I got the chance to conduct independent research projects, help excavate and catalog fossils, and teach local people about their community’s paleontological history. While in Panama, I became fluent in Spanish and wondered how I could use my new experiences and skills to communicate complex STEM concepts to broader audiences. I transitioned to teaching middle school for the next two years; I taught hands-on STEM classes to 5th and 6th graders in the largely immigrant community of Chelsea, Massachusetts. I enjoyed giving my students educational opportunities that will help them in the future, and the challenges my family faced in my childhood prepared me as an educator to understand how my students’ personal lives affected their learning in my classroom.
The experiences I pursued after my undergraduate career gave me the skills and clarity needed to develop and pursue a graduate research degree. I’m currently working on my Master’s/Doctoral joint degree in Geosciences at the University of Massachusetts at Amherst.
How do you communicate science? How does your science contribute to understanding climate change?
For my graduate research, I’m studying how warmer-than-present paleoclimates affected Antarctic ice cover and the paleoecology of the surrounding ocean. Specifically, I study the Miocene Climatic Optimum, when global temperatures and atmospheric carbon dioxide concentrations were slightly higher than they are today, and close to what we expect to see at the end of the century. Studying the deep sea records of this time period reveals how microfaunal communities (i.e. foraminifera) reacted to a rapidly warming global climate, and how changes in Antarctic ice cover impacted sea level and ocean circulation; this can be applied to improve climate models and future environmental policies.
I want to bring my research to public audiences through in-person, multilingual outreach at museums, schools, and other educational institutions, and through online media to make climate science accessible and improve scientific literacy. Using multimedia, interactive, and open-access platforms to communicate science not only reaches more people, but also fits the needs of many different learning populations; this is why I believe STEM disciplines need to move away from the traditional format of communicating findings in paid science journals and articles.
What is your advice for aspiring scientists?
Mistakes are the first steps to being awesome at something.
Try as many new experiences as possible.
Identify what skills you need to do the job you want, then identify opportunities that will give you those skills.
Find a career that you enjoy, you are good at, that helps others, and hopefully makes you some money along the way.
What is your favorite part about being a scientist, and how did you become interested in science?
From my earliest memories I have always had an interest in dinosaurs and fossils. I grew up in Bellbrook, Ohio, where I spent many a day playing in the creeks in Magee Park and the Sugarcreek Reserve. Both were loaded with fossils from the famous Cincinnatian series of the Ordovician. While collecting fossils is my absolute favorite, I’ve always been fascinated by science and nature in general, with interests in biology, geology, minerals, astronomy, engineering and physics, as well as art, cooking and photography.
What do you do?
I have a degree in Landscape Architecture, but I work as a mechanical designer in the aerospace industry. Currently, I design tools that are used to build jet engines. I create the 3D models and drawings, which are used to make the tools.
While I haven’t as yet spent much time doing my own research, I’ve been blessed to help the professionals with numerous papers based on specimens I collected. I love and collect all fossils, so I’ve not concentrated on any particular group or type. I feel this has been advantageous, as it gives me more opportunities to work with the various scientists who do have areas of specialty. Lately, I’ve been working with Dr. Alycia Stigall on brachiopods. In the past I worked with Dr. Roger Cuffey on bryozoans, and Dr.’s Carlton Brett and David Meyer on Godzillus. As a member of the Dry Dredgers, the oldest fossil club in North America, I get to contribute regularly. I take meeting photos for the website, bring in specimens for others to examine, and occasionally write something for the newsletter or website. I also volunteer, and am an exhibitor, at Geofair every year, and occasionally play fossil tour guide at local parks or give presentations with my portable fossil display.
How does your research contribute to the understanding of climate change, evolution, or to the betterment of society in general?
I have a talent for finding rare, unusual or exceptional fossils. I bring these specimens to the attention of the professionals so that they can be properly studied, and sometimes, they are used to write a scientific paper and are deposited in a museum or university collection for future scientists to study. Godzillus has been my best effort so far. It actually became very famous! I collect everything prodigiously. The quality specimens are made available to professionals for research projects, and the rest is given to the Dry Dredgers to make the fossil kits that fund club activities, or given to school kids.
What advice do you have for aspiring scientists?
Your life will be far richer if you pursue your interests. Find others who share your passions, join a club, volunteer. You won’t regret it!
My curiosity about the natural world started on family camping trips. One regular destination was the shores of the Sea or Cortez, where the extreme tidal range (up to 9m!) produced incredible tide pools full of stingrays, octopi, brittle stars, and more. My fascination with nature and true love of being outside eventually led me to pursue job opportunities (and later a master’s degree) in environmental education. Environmental education aims to help people understand, appreciate, and think critically about their interactions with all aspects of the natural world. This can be accomplished through outdoor experiences, laboratory activities, live animal encounters, and more. My work days have included leading students on forest hikes, taking families seining at the beach, and educating public visitors at rehabilitated sea turtle releases. While many of these experiences are short-lived, they often spark enduring curiosity, positive feelings about nature, and sometimes positive behavior change among participants. Not every interaction makes a difference, but when they do the results can be quite powerful.
To remain effective, environmental education must adapt to our changing world, and in the 21st century this means branching out into virtual education. In my current position as coordinator for the FOSSIL Project, I get the opportunity to engage with audiences through online interactions on social media and our website (www.myfossil.org). FOSSIL (Fostering Opportunities for Synergistic STEM with Informal Learners) is an NSF-funded initiative that supports a community of amateur (avocational) and professional paleontologists with the goal of shared learning. Utilizing online platforms has allowed us to build a diverse and widespread community of learners, but also a community of educators. Each of our participants brings knowledge to the table, and the online space makes it easy and comfortable for them to share their experiences. This fall, we hope to further expand our community with the introduction of an accompanying mobile app. This tool will allow users to document and share their paleontological experiences directly from the field. I never thought I would contribute to an app, but I am now so excited to see the learning opportunities that will result from this new technology.
One of the great joys of working as an environmental educator is seeing how excited people get when they learn something new, especially people who may be discovering their passion for science for the first time. For those thinking about a future in science, I hope you will consider the many career paths available to you. If you like technology or inventing, you can help develop the tools scientists use to make new discoveries. If your passion is writing, you can pursue science journalism or help edit science publications. You can conduct investigations as a researcher, teach others as a formal or informal science educator, pursue art as a science illustrator, or help shape policy as an environmental lawyer. In its own way, each job makes an important contribution to science, and society needs curious science enthusiasts in many different roles!