If I had a dime for every time I heard this sentence…well, let’s just say I’d probably be free of student loans by this point! I teach hundreds of introductory geology and the large majority (95% or so) are not science majors. So, suffice to say, I teach students with a range in interest and self-assumed ability in science. But after three semesters of teaching full time and nearly 1,000 students, I’m putting a ban on this phrase in my classes and I’ll tell you why.
I want to talk about what it does to your ability to learn when you come into a classroom with the idea that you’re bad at something. You come in with a mental block that will stay with you for the duration of the class. If you struggle with the material, you’ll only give yourself a confirmation bias (see? I don’t get this stuff. I must be bad at science/math/French/whatever it is). How are you supposed to learn with that attitude? You can’t! And before you say “it’s easy for you to say-you’re a scientist with a Ph.D. You weren’t bad at science”. This simply isn’t true.
I struggled with learning math and science through middle school, high school, and through college. I’d sit down to study-I’d feel overwhelmed instantly. I’d tell myself “you’re not good at this stuff” so much that no matter how hard I’d study, I’d second guess myself on just about every problem, leading to even worse self esteem (and not surprisingly, worse grades on assignments). By the time I got to classes like Calculus and Physics in college, I had only made this even worse for myself. I told my professors when I went for help “I’m bad at math” or “I’m bad at chemistry”. Finally, a professor looked at me in my final math class (Calculus II) and said, “Sarah, you know you’re actually quite good at math. You just need to give yourself a little more time to learn it. And you need to be kind to yourself”. That idea stayed with me for a very long time- it freed me to be patient with myself. And to let me love learning without the fear of grades a little bit more. I made my highest grade on a college math exam that semester (a B-!) and you know what-I was (and still am) proud of myself for that exam grade-I even hung it on my apartment fridge for the entire rest of the semester so I could celebrate it every day. Achievement isn’t always measured by A’s!
Many of us (myself included) automatically assume that what we’re good at and what comes easily to us is one in the same. On the flip side, we assume that we’re bad at things we’re not automatically good at, especially in the world of academics. This simply isn’t true. To take an easy example, one that you’re familiar with if you’re reading this blog, is learning to read. Learning to read is incredibly complex! It took you months to years just to master your alphabet- learning to recognize each individual letter. Then, it took you even longer to figure out how to string bizarre patterns of these letters together to form words, sentences, and paragraphs. No became good at reading overnight-it’s a skill that you worked on for years. And, just like reading, none of us were born to learn science instantly! It takes time to learn how to learn science, just like you learn anything else.
So how can you boost your confidence in science? I’m glad you asked! If you’re taking a high school or college course, ask for help. Visit your professors and ask them to help you! We can explain concepts to you in different ways, help you relate the knowledge to something you’re more familiar with, or just assure you that you’re on the right track. Many times, my students have asked questions that have forced me to learn how to make a concept clearer (so professors actually really appreciate it when you tell us what you’re struggling with). Also, seek out cool articles or blogs or even popular science books in the subject you’re learning about! It can really help to boost your enthusiasm about a concept, which can help your confidence, too.
So give yourself permission to be patient with yourself. Science may not come easily you to-it’s never come easily to me. I worked hard to pass chemistry and even geology classes (looking at you, structure and tectonics!). It’s OK to love something that takes you more time to learn. And it’s also OK to pick a major or to take classes in something that you might need a little more help with. Science is a wide and complex field that takes dedication to master. It can take years to learn how to learn science to the point where you feel confident enough to proclaim, “I’m good at science!”- so why do so many of us automatically label ourselves bad at science? Just like learning to read, learning science isn’t easy! It takes time!
So here’s my warning to my students starting this semester-I’m no longer going to let you say that you’re bad at science in my class (and I don’t want to hear it from people reading this blog, either!). Your science education is a work in progress- and we’re going to work together to help you love science.
Antarctic ice sheet sensitivity to atmospheric CO2 variations in the early to mid-Miocene
Richard Levy, David Harwood, Fabio Florindo, Francesca Sangiorgi, Robert Tripati, Hilmar von Eynatten, Edward Gasson, Gerhard Kuhn, Aradhna Tripati, Robert DeConto, Christopher Fielding, Brad Field, Nicholas Golledge, Robert McKay, Timothy Naish, Matthew Olney, David Pollard, Stefan Schouten, Franco Talarico, Sophie Warny, Veronica Willmott, Gary Acton, Kurt Panter, Timothy Paulsen, Marco Taviani, and SMS Science Team
The Problem: The early to mid-Miocene (23 to 14 million years ago) is an interval of geologic time where atmospheric carbon dioxide (CO2) concentrations (about 280 to 500 parts per million) were similar to those that are projected for the coming decades under human-induced climate change. Thus, this interval of time is interesting for geologists because we can use the geologic record from this time to interpret how our oceans, atmosphere, and ice sheets ‘behave’ under warming scenarios. Understanding the extent to which the Earth will warm, weather patterns will change, and sea levels will rise in the coming decades can help scientists, the public, and policy makers prepare for our future. Related to sea level rises is understanding how much continental ice sheets, such as those on Greenland and Antarctica, will melt.
In this study, geologists use several methods to determine how sensitive Antarctic ice sheets are to increases in atmospheric CO2 concentrations 23 to 14 million years ago. The results from this study are useful in that we can determine how much Antarctic ice may melt in the coming decades, which would add to sea level rise.
Methods: To interpret how sensitive Antarctic ice is to atmospheric warming (or increased average global warming), the scientists use sediments obtained in a drilled core from the coastal margin of Antarctica (an ideal location to study the melting and growth of ice sheets). The core was drilled in 2006 and 2007 as part of the ANDRILL (ANtarctic DRILLing Project) scientific drilling project from the McMurdo sector of Antarctica. The core is approximately 1,138 meters long, and contain sediments that are dated at over 20 million years old!
This study is very unique and fun because the scientists use several proxies (or naturally-occurring records) to interpret what the margin of Antarctica looked like through time. The presence and abundance (or numbers) of plankton (such as foraminifera) and pollen grains indicate when the margin of Antarctica was warmer, and ice sheets had melted back. For example, when the ice around Antarctica melted back, this allowed more room and soil for plants to grow. The lithology, or general characteristics of the sediments and rocks collected in the ANDRILL core, was also used as a clue to the changing environment of Antarctica through the study interval. Just knowing the different sediment types through time is a very powerful proxy itself!
Results: Using all the different methods and proxies, the geologists were able to interpret how Antarctic ice sheets melted and re-grew through the Miocene interval. They determined that several times from 23 to 14 million years ago, ice grew and retreated inland. They found that Antarctic ice becomes very sensitive to small changes in the amount of carbon dioxide in the atmosphere.
To best illustrate their findings, the authors of this study created four ‘environmental motifs’. These are images of what the scientists think the Antarctic margin looked like through time. Note that there are only four motifs; these just capture the major environments that the scientists inferred from their data. There were likely other ‘in-between’ environments. But notice how dynamic the ice sheet around the Antarctic margin were: the ice melted and then re-grew quite a bit in response to warming and cooling events through the Miocene!
Why is this study important? This study highlights and solidifies the hypothesis that Antarctic ice sheets were very sensitive to changes in atmospheric carbon dioxide concentrations during the Miocene. The findings of the study also indicate that Antarctic ice will behave similarly under increased warming predicted for Earth’s future. Melting ice will have a huge impact on sea level, which will make living on coastal lands hard or impossible due to flooding.
Citation: Levy, R. H., Harwood, D., Florindo, F., Sangiorgio, F., Tripati, R., von Eynatten, H., Gasson, E., Kuhn, G., Tripati, A., DeConto, R., Fielding, C., Field, B., Golledge, N., McKay, R.,, Naish, T., Olney, M., Pollard, D., Schouten, S., Talarico, F., Warny, S., Willmott, V., Acton, G., Panter, K., Paulsen, T., Taviani, M., and the SMS Science Team, 2016. Antarctic ice sheet sensitivity to atmospheric CO2 variations in the early to mid-Miocene. PNAS 113(13), 3453-3458. doi: 10.1073/pnas.1516030113.
Not long ago I was invited to visit Dr. Gordon Hubbell’s personal collection and museum of modern and fossil sharks. Dr. Hubbell is a retired veterinarian who is a renowned shark expert. He has been on fossil collecting expeditions across the world. I’ve been fortunate to know many collectors with vast personal collections but Dr. Hubbell’s was on another level. He had a special room that was devoted to his specimens, preparation, and photography.
There are curated specimens in display cases, that were designed specifically for Gordon’s fossil collection. The display cases each hold miniature exhibits on different aspects of sharks. For a non-shark expert, or even enthusiast, this was absolutely overwhelming. I like sharks, I think they are fascinating but I haven’t spent much time learning about them or exploring their fossil record.
The group that I visited the museum with included a graduate student researching some of the fossil specimens in Gordon’s collection. Another phenomenal aspect about Gordon – he understands the utility of his collection in active scientific research. In this case, the student and his assistant were photographic a complete set of shark teeth – by complete I mean a set from the top and lower jaw of the animal. Gordon had many complete sets of fossil teeth, which is incredibly rare.
I learned an incredible amount about sharks from their morphology (whole and just teeth), sexual dimorphism, geographic distribution, and some of the weird mutations that can occur in their teeth. But I think what was the largest takeaway is that Gordon wanted his visitors to learn and be excited about sharks. He didn’t have to make all of these incredible displays, he could have just pulled out specimens and I still would have learned a lot. But allowing the visitor to learn and ask questions about the content is much more effective and kept me engaged for a long time.
In addition to having one of the largest collection of shark remains, Gordon is also an artist. He sculpts animal life – modern and ancient. Some of these models were present in his collection and were so fun and lifelike that they really added to both my exploration of sharks and the exhibits. He even offers souvenirs on your way out – I got to take home an extinct mackerel shark tooth from Morocco that lived about 60 million years ago.
Take a virtual tour of his collection and museum here. Read more in the news about Gordon’s expertise and collection 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_
Every Semester, the University of Massachusetts Amherst Department of Geosciences offers the class Introduction to Geology. The course is designed for undergraduate students who need science credits for their degree, but it is also a required course for our geoscience undergraduate majors. The course has a lab that complements and expands on topics that are covered in lecture, such as plate tectonics, igneous, metamorphic, and sedimentary rocks, river dynamics, topography, and the history of how the Connecticut river valley was formed. The labs are run by four to five teaching assistants, graduate students who are pursuing their master’s or PhD degrees. We take the students on two field trips as part of their labs: the first trip is to look at geologic features in the valley leftover from the glaciers, and the second to look at the major rock formations in the valley.
This post is about the glaciation that ended around 20,000 years ago, and the imprint the ice and ice melt left on this area of western Massachusetts. This time of huge ice sheets that covered northern North America, Europe, and Asia is referred to as the Last Glacial Maximum. In North America, the glaciation is referred to as the Wisconsin Glaciation. The glaciers that covered North America reached their maximum southern extent about 26,000 years ago, after which the ice began to melt and retreat back to the north. At the glacier’s maximum extent, Massachusetts was totally covered by ice. Estimates based on how thick the ice was range from 1 to 2 kilometers (0.62-1.24 miles)! That’s a ton of ice! Because ice is very heavy, it depressed the Earth’s crust below it. In southern New England, the ice is estimated to have depressed the Earth’s crust down by about 50 meters (~165 feet; Oakley and Boothroyd, 2012). Once the ice melted, the crust of the Earth began to pop back up. This phenomenon is called isostatic rebound. Satellites that measure the rate of isostatic rebound indicate that parts of Greenland and Canada, where the ice was thickest, are still popping back up today.
Back at a more local scale, there are several features around UMass Amherst that we, the graduate students that teach the Introduction to Geology labs, can identify that were created as a direct result of the glaciers in this area. I’m going to take you on our glacial field trip virtually, so that you, too, can get a first-hand look at the types of geologic features the glaciers left behind! First, a fun aside: There are several large boulders all over campus that, at first glance, look like they were placed in specific locations for an aesthetic affect. Upon closer inspection, the boulders are made from a certain rock type that occurs in our valley. Glaciers, and ice, act as bulldozers, and have no problem picking up and carrying huge chunks of rocks. These boulders, then, were picked up from the nearby hills and deposited all over the valley, with some ending up on our campus! These boulders aren’t part of our field trip, but are neat nonetheless.
The first stop on our field trip is right on campus, behind our football stadium. Here, there is a small creek with about 5 feet of the upper part of the soil profile exposed. But there’s something special about the soil here: it is unlike anything found in other places of the world: varves! Varves are alternating bands of dark and light-colored clay layers that made up the bottom of a lake that used to cover the valley. The lake was created once the glaciers began to melt, leaving more parts of Massachusetts exposed. The meltwater from the glaciers flowed via river into the Connecticut River Valley, and became dammed here. This created Glacial Lake Hitchcock. The varves are remnants of the sediment that collected on the bottom of this lake. Varves are awesome because they record climate changes on a seasonal basis! The dark bands contain finer clay particles, and are deposited during the winter months when there is less sediment being brought into the lake by the river (during the winter months, there is less glacial melt, and thus less water flowing in the rivers). Lighter varve bands are usually made of coarser (or larger) grains and are deposited during the spring and summer months when glacial melting increases, bringing more water and thus sediments into the lake. By counting the pairs of dark and light varves, scientists can estimate how old Glacial Lake Hitchcock was. Varves from the lake were counted by scientists at UMass Amherst, and they found that the lake was around for at least 4,000 years, from 17,5000 to 13,5000 year ago (Rittenour et al., 2000)!
After checking out the varves, our second stop is a kettle hole a few miles from campus. A kettle hole is a depression in the Earth formed from a chunk of ice that broke off from the retreating glacier. The ice chunks become buried by glacial outwash, or the mix of water and sediment that spreads across the land as the glacier melts. Thus, the ice chunk is completely buried by sediments. After some time, the chunk also melts, which then creates the kettle hole. These features are prominent throughout New England, and are usually small in size.
The third stop on our glacial field trip is to the Sunderland Delta. A delta is a place where a river meets a larger body of water, like a large lake, ocean, or sea. Some rivers flow fast, and some flow slower. In general, the faster a river flows, the more sediment it can move and carry. I mentioned earlier that the glacier began to melt back, and that melt water was transported by a river into Glacial Lake Hitchcock. The river was quite large, and had the ability to move sand-sized sediment. But where the river met the calm waters of the lake, it lost its velocity, and thus its ability to carry sediment. The sediment was then ‘dropped’ at the mouth of the river where it emptied into Glacial Lake Hitchcock. This dropped sediment formed a delta, or an area where fine-grained sand was deposited. This sand accumulated over thousands of years. Today, these sand deposits that make up the delta are mined by humans for use in concrete and manufacturing. There are several open mining pits around the university, but one in particular preserves the features of the delta, namely topset and foreset beds of sand. When the river gets close to the larger body of water, it begins to slow down. The loss of velocity leads to the river dropping some of its sediment it is transporting. This sediment is laid down in thin sheets that lie flat. These sediments form topset beds. Where the river meets the body of water, it is slowed even more, and the rest of the sediment it carries is dropped. These particles form a slope down into the lake, and make up the sloping foreset beds.
Once the students understand how the Sunderland Delta was formed, we then move downhill to our fourth stop: a trout hatchery right down the road. This, by far, is the coolest stop, as it contains a unique geologic feature: a natural spring! At our first stop, you saw that the base of Lake Hitchcock was composed of very fine sediment called clay and silt. Clay and silt grains are flat, and when they are compressed over time, they don’t allow water to pass through very quickly. In the introduction paragraphs of this post, I also explained how the Earth’s crust underneath New England, including Massachusetts, popped back up, or rebounded, after the overlying weight of the glaciers was gone. When the land began to rebound, that caused the clay layers of the lake to crack. When this happened, the groundwater that was stored deep in the sediment under the clay was able to come to the surface. Here, at the trout hatchery, is one of the places the groundwater is able to come to the surface via cracks and conduits in the thick clay layers! It can be seen bubbling to the surface continually throughout the year. The video below shows the spring in action:
The water stays a constant temperature year round because it originates from so deep within the sediment. The constant temperature and clarity of the water is great for raising trout, because the water rarely, if ever, freezes during the winter and is never too hot during summer months! The trout that are raised at the hatchery are released into local streams and rivers so that fishers do not over-fish the local populations. This stop is one of my favorites, as it is an excellent example of how geology and biology go hand-in-hand, and how the geologic processes of the past are relevant and useful today.
Our fifth and final stop is just down the road from the trout hatchery. The feature here is not as impressive or obvious after the large delta feature and the natural spring, but it records an important phenomenon related to the retreat of the glaciers nonetheless. On the side of the road is a small hill that most local folks pass by probably everyday. This hill is covered in trees and vegetation, and one might totally overlook it quite easily. But if you stop and dig down 4-5 inches through the roots and topsoil, you’ll hit sand! This small hill is, in fact, a sand dune that was formed from winds towards the end of the Last Glacial Maximum.
When the glacier that covered Massachusetts began to melt back, the Earth was beginning to warm up. The area to the south of Massachusetts was becoming warmer, but on top of the glacier to the north, the air temperature was still very cold. This difference in air temperature, or temperature gradient, created strong winds that blew from the warmer regions towards the colder regions. This phenomenon happens today at the beach: during the day, the wind blows towards the ocean from the hot land; but at night, the wind direction changes as the land cools down until it is cooler than the ocean water. The beach is also characterized by sand dunes,which are the products of these strong winds depositing small sand grains behind the beach. Just like at the beach, the strong winds moving towards the glacier picked up small sand grains and deposited in the valley near UMass, where they are still visible today!
The features that we show our undergraduate students and that are explained here are just a few features in our valley that are leftover from the massive glaciers that once covered the land. All around New England, there is evidence of the heavy ice that was once here not too long ago: exposed rock where the glaciers scraped away soil; glacial striations, or scratches, in the exposed rocks from the glaciers moving over them; and potholes in the bedrock near the rivers, where melted water mixed with larger pebbles and boulders under the ice to carve out rounded holes in the rocks. If you’re ever in New England, keep your eyes peeled for evidence of the glaciers; it’s literally everywhere!
Oakley, B. A., and Boothroyd, J. C., 2012. Reconstructed topography of Southern New England prior to isostatic rebound with implications of total isostatic depression and relative sea level. Quaternary Research 79, 110-118.
Rittenour, T. M., Brigham-Grette, J., and Mann, M., 2000. El-Nino Like Teleconnections in New England during the Late Pleistocene. Science 288, 1039-1042.
One of my favorite parts of being a scientist is constantly learning about new ways to answer research questions that I have. I am a paleontologist, but in recent years, I have become very interested in how I can use geochemistry (looking at stable isotopes and trace elements) to address paleontological questions. Since this is a relatively new interest of mine, I have been taking classes in geochemistry, and this past semester I took an analytical geochemistry class to learn different methods that I can use to answer my own research questions. I want to share some of what that class was like because WOW, I’m still processing how awesome it was!
Two years ago now, my department (Department of Earth and Planetary Sciences, University of Tennessee) moved into a new building that has not only lab space for faculty and graduate students, but has a research lab designated for undergraduate research. This lab has many different instruments (ion chromatograph, gas chromatograph, inductively-coupled plasma optical emission spectrometer) as well as equipment for bench experiments that is intended to provide undergraduates with research experience through classes and working with faculty members and graduate students. The class that I was a part of did consist of graduate students, but we got to be a part of the process of launching the use of this lab and continued to prepare this space for use by undergraduates. This lab space in and of itself is a unique space for undergraduates to explore the geosciences, but my experience using the lab and learning the methodology of the instrumentation available in the lab was very beneficial.
Class Set Up
My favorite part of this class was how it was set up because it was so interactive. We spent the first half of the semester getting acquainted with the lab itself and learning the processes that are involved with setting up a lab like this and preparing for a safety inspection. We completed a chemical inventory, worked on developing a chemical hygiene plan, and discussed budgeting (everything from how much DI water costs to the basics of how much each standard is). While this seems pretty mundane, it was an interesting process to complete and to see how detailed the process of setting up a lab is.
The second half of the semester, each student in the class chose a method to research and teach the class to use. This was a two day lesson that we were each in charge of, the first day spent teaching the theory behind the method and how the equipment works, the second day was spent using that method to look at a quick in class experiment. This meant that not only did we each become the in-class expert on a method, but we had to be able to think about timing to stage each step of the process to using that method. Some of the methods we learned about include gas chromatography, ion chromatography, and inductively-coupled plasma optical emission spectrometry (ICP-OES).
In addition to learning the process of setting up a lab and learning all different methods, budgeting was also emphasized in this class. Our professor was very transparent with us about how much money was spent to set up the lab as well as how much our science cost to do. With every method, every student leader included a question for us to figure out how much it would cost to run a certain number of samples using that method. This really impressed upon all of us in the class that science does cost money and more importantly, time, and how that all needs to be thought about well before wanting to do any analyses.
The set up of this class ensured that not only did we learn how to use different methods, but that we learned how to run our own labs and understand the work that goes into the different analyses that we write about wanting to complete. Not only did I walk out of the lab this semester being able to complete many different geochemical analyses on my own, but with some idea of the complexities of running a lab!
I mentioned above that part of this class was to see the breadth of projects that could be completed using the equipment that already exists in the lab. The four other people who took this class with me and myself all have VERY different areas of research and our class projects reflected that. One person was looking at fluid inclusions in granites, someone else was looking at toxins in microbes, and I was looking at trace elements in different skeletal elements of sea urchins. Almost all of us used the ICP-OES because we were interested in trace elements, but for several of us, our samples required other methods that we discussed in class to prepare the samples to be run through the ICP-OES.
All of us in the class completed all of the prep work and ran our own samples regardless of the method that we chose. Yes, we had guidance from our professor and lab manager, but the project work was all very hands on and completed by us. This gave us each a chance to apply what we had learned in class, see just how long some of these methods take, and gave us an appreciation for juggling multiple people’s lab schedules! At the end of the day though, all of us walked out of the lab with useable data to complete our chosen research projects. And, for several of us, the work done for this class project either directly helps with the completion of analyses for our theses and dissertations or helped inform us if the method we used is useful for the question we want to address.
I am going to be really honest here, at points this class was incredibly overwhelming to me-I don’t have a strong geochemistry background and I really didn’t know what I was expecting to see in the results of my research project. But I’m really glad that I took a chance on it because I did learn so much more than I thought I would. I feel more confident in my abilities to complete geochemical analyses on my own, I learned the capabilities of several different instruments and have ideas of how to use them in future research projects, and overcame some personal lab fears-using acid to break down solids into liquids is a little scary the first time you do it! But beyond the methods, this class really emphasized the process of setting up a lab for the first time and understanding how time and monetary budgets fit in to building labs and getting analyses run. I am glad that I challenged myself to learn new methods this semester and I encourage you all to step outside your comfort zone to see where you can stretch your research to!
A re-interpretation of the ambulacral system of Eumorphocystis (Blastozoa, Echinodermata) and its bearing on the evolution of early crinoids
by: Sarah L. Sheffield and Colin D. Sumrall Summarized by Sarah Sheffield
What data were used? New echinoderm fossils found in Oklahoma, USA, along with other fossil species of echinoderms. The new fossils had unusual features preserved.
Methods: This study used an evolutionary (phylogenetic) analysis of a range of echinoderm species, to determine evolutionary relationships of large groups of echinoderms.
Results:Eumorphocystis is a fossil echinoderm (the group that contains sea stars) that belongs to the Blastozoa group within Echinodermata. However, it has unusual features that make it unlike any other known blastozoan: it has arms that extend off of the body, which is something we see in another group of echinoderms, called crinoids. Further, these arms have a very similar type of arrangement to the crinoids: the arms have three distinct pieces to them (see figure). Researchers placed data concerning the features of these arms, and the rest of the fossils’ features, into computer programs and determined likely evolutionary relationships from the data. The results indicate that Eumorphocystis is closely related to crinoids and could indicate that crinoids share common ancestry with blastozoans.
Why is this study important? This study indicates that our understanding of the big relationships within Echinodermata need to be revised. Without an accurate understanding of these evolutionary relationships, we can’t begin to understand how these organisms actually changed through time-what patterns they showed moving across the world, how these organisms responded to climate change through time, or even why these organisms eventually went extinct.
The big picture: This study shows that crinoids could actually belong within Blastozoa, which could change a lot of what we currently understand about the echinoderm tree of life. Overall, this study could help us understand how different body plan evolved in Echinodermata and how these large groups within Echinodermata are actually related to one another. Data from this study can be used in the future to start to understand evolutionary trends in echinoderms.
Citation: Sheffield, S.L., Sumrall, C.D., 2018, A re-interpretation of the ambulacral system of Eumorphocystis (Blastozoa, Echinodermata) and its bearing on the evolution of early crinoids: Palaeontology, p. 1-11. https://doi.org/10.1111/pala.12396
To read more about Diploporitans please click here to read a recent post by Sarah on Palaeontology[online].
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.
At the University of Tennessee in Knoxville, we have a natural history museum on campus called the McClung Museum of Natural History and Culture. Every year they do a family fun day event called Can You Dig It? where scientists from different departments on campus come and set up various activities to engage families. The Earth and Planetary Sciences department always shows up with several fun activities for families and kids of all ages. This year we had quite a few things going on.
Outside we had two tables of planetary activities. One table was talking about volcanoes and how to tell the difference between rocks formed by volcanic eruptions and rocks formed by meteorite impacts. We had real meteorites and impact deposits, as well as some volcanic rocks, so the kids could hold them all and really see the difference.
I was at the other planetary table, where we had some more meteorites and 3D-printed models of actual impact craters on the moon and Mars. We used these to explain how the shape of impact craters change depending on the size of a meteorite and the speed at which it impacts. We also had a tub of flour with a thin layer of cocoa powder on top. There were several marbles and small balls, and kids could hold one above the tub and drop it to make their very own impact crater. The layering using cocoa powder allowed us to show them how ejecta blankets work at real impact craters. An ejecta blanket is made of rocks from the impact site being blown up and out of the crater and landing to form a “blanket” surrounding the crater. In the tub, you could see flour on top of the cocoa powder after the impact, showing how buried layers get exposed at the surface surrounding impact craters.
Inside the museum, we had a table where people could bring in rocks or fossils they had collected and geologists or paleontologists would help identify them. This is a really popular thing, and some people bring loads of rocks they’ve been collecting all year.
If you have a local museum, make sure to go check them out. Local museums are often cheap or free and also host fun events like this one!
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.