Iris Arndt, Geoscientist

Tell us a bit about yourself
Hi everyone, my name is Iris. Besides science, I enjoy spending time outdoors. I love hiking and (relaxing) bike rides (preferably combined with a bit of regional geology). I also enjoy playing board games and pen and paper role-playing games with friends. It is important to me to volunteer and get involved in my surrounding, such as in early career networks and university boards.

What kind of scientist are you, and what do you do?
I am a PhD student in geosciences working on geochemical analysis of tropical bivalve shells. I analyze geochemical parameters (element ratios e.g. Mg/Ca, Sr/Ca, Ba/Ca and stable isotopes δ18O and δ13C) recorded during growth within the shell, with the goal of reconstructing the paleoenvironmental conditions (such as temperature, salinity, and primary productivity) that prevailed in the reef where the organism grew. I also look at more recent shells to evaluate the structure and geochemistry of shells grown under known environmental conditions.

What is your favorite part about being a scientist, and how did you get interested in science?
I think I was always a curious person. As a child I loved going to natural history and science museums, especially those with interactive elements. My grandfather encouraged my scientific interest a lot and provided me with toys like crystal growing sets and chemistry kits. Ironically, I was particularly interested in extraterrestrial topics. I started studying geosciences because it seemed like an interesting field that combined chemistry, physics, and biology, and because I thought it would be really cool to go on field trips. My enthusiasm for geosciences grew over the course of the first semester, and after my first field trip, I was absolutely certain that geoscience was what I wanted to do. With paleoclimate reconstruction, I found a field that I personally think is important to advance and interesting to work in.

For me, the best thing about being a (geo)scientist is that you get to work on something you really care about and that you have the opportunity to contribute to the understanding of some of the important processes that shape this wonderful planet we live on. I also appreciate being able to work creatively and come up with new ideas and approaches, building on decades of remarkable research. Plus, it’s fantastic to be surrounded by so many cool, open-minded, talented, and nerdy people to share and discuss exciting new findings and approaches with.

How does your work contribute to the betterment of society in general?
The Earth is a very complex system, and modelers are making remarkable progress in predicting its response to climate change. Models are often tested against paleoclimate data and are not (yet) always able to reproduce the parameters identified in paleoclimate studies. Providing paleoclimate data and understanding how Earth’s climate has changed in the past can help to better predict future changes. My work focuses on obtaining high-resolution (up to daily) paleoenvironmental data from shells. These high-resolution climate snapshots can provide insights into short-term climate aspects such as seasonality and frequency of extreme weather events. I believe that climate-related changes in seasonality and extreme weather events are more tangible than, for example, long-term changes in average temperature over decades. Therefore, I hope that continued research in the field of high-resolution paleoclimate reconstruction will provide a basis for making the relevance and effects of upcoming climate change in daily life more apparent to everyone.

What advice do you have for aspiring scientists?
Don’t be afraid to ask questions; the more you ask, the more you learn.

Dare to find your own interpretations and discuss your ideas with colleagues, even if they seem crazy. Maybe you missed something, in which case your interpretation can be adjusted, or maybe you found something super cool that others overlooked.

Stay curious and adventurous. Don’t get discouraged if things don’t turn out as planned. Unexpected results can lead you into the unknown, where new findings are waiting to be discovered.

Using Female Antlers to Understand Caribou Landscape Use

Historical Landscape Use of Migratory Caribou: New Insights From Old Antlers

Joshua H. Miller, Brooke E. Crowley, Clément P. Bataille, Eric J. Wald, Abigail Kelly, Madison Gaetano, Volker Bahn, and Patrick Druckenmille

Summarized by Claudia Johnson, who is a geology major at the University of South Florida. She is currently a senior who will be graduating in Fall 2021. She is interested in environmental geology and may like to work in the National Park Service after graduation. In her free time, she enjoys biking and reading.

What data were used? Caribou are a type of deer where both the males and females shed their antlers, contrary to most other deer where only males exhibit this behavior. The female caribou typically shed their antlers after they calve (i.e., give birth). Due to this timing, these antlers can give insight about the seasonal travels of the caribou. These herds have been living on this land for over 700 years but have only recently started being studied. By analyzing past antlers shed, a fuller picture of their history can be put together. This study looked at two herds in the Arctic National Wildlife Refuge of Alaska: the Central Arctic Herd on the Western Coastal Plain, and the Porcupine Caribou Herd on the Central and Eastern Coastal Plains. Their seasonal ranges are shown in Figure 1.

Methods: These antlers were collected from Alaska and analyzed for a number of variables. First, each antler was categorized based on degree of physical weathering by observing how much of the original bone texture was preserved. The antlers were separated into either recent (post-1980) or historical (pre-1980). Next, rubidium–strontium dating, a type of radiometric dating was performed. When a particular isotope of rubidium decays, it slowly decays into stable (i.e., non-decaying) strontium at an extremely consistent rate. So, by measuring the amount of strontium (⁸⁷Sr/⁸⁶Sr) in the bone, they will be able to determine the age of the antler. This analysis was also used to try to determine differences in herds and location by comparing it to available ⁸⁷Sr/⁸⁶Sr in the environment.

Results: A question posed by the researchers was whether the ⁸⁷Sr/⁸⁶Sr of the antlers would be enough to differentiate the two herds from each other in both recent and historical times. This study was able to do so. Comparing the recent and historic female antlers, no difference was found in the ⁸⁷Sr/⁸⁶Sr of the Porcupine Caribou Herd. However, the Central Arctic Herd had many differences, including an increase in variation and ⁸⁷Sr/⁸⁶Sr from historical to recent antlers. These differences in ⁸⁷Sr/⁸⁶Sr are used to understand landscape use, and these findings coincide with existing biomonitoring records, meaning that this is an accurate way to realize historic landscape use. 

Why is this study important? This study was able to provide data on caribou patterns further into history than had been done before in this area. By being able to analyze antlers hundreds of years old, as well as present-day age, the caribou’s response to environmental changes is clear. This study was able to occur because the Arctic provides excellent conditions for the preservation of antlers. The Arctic also provides a valuable setting to study the effects of climate change due to the acute effects of it that occur there. Only the Central Arctic Herd changed landscape use during the interval of change studied here, which researchers concluded was likely due to development for oil exploration, including roads and pipelines that became intrusive to the herd’s ranges in the 1970s.

The big picture: The Central Arctic Herd’s landscape use was shown to be affected by human influence. This solidifies the knowledge that human alteration of land does indeed affect organisms living in the area. In the ranges of this herd specifically, development for oil exploration has been occurring since the 1960s. It was around this time that the pregnant females had to change their old routes to avoid this infrastructure. These principals can be applied to animals elsewhere to better recognize how infrastructural development is affecting the way they live and could be harming them because they must seek out new places to live. 

Citation: Miller, Joshua H., et al. “Historical Landscape Use of Migratory Caribou: New Insights From Old Antlers.” Frontiers in Ecology and Evolution, vol. 8, 22 Jan. 2021, doi:10.3389/fevo.2020.590837.

Macroparasites and their megamammal hosts: Pleistocene-Holocene sloths

Macroparasites of megamammals: The case of a Pleistocene-Holocene extinct ground sloth from northwestern Patagonia, Argentina

by: María Ornela Beltrame, Victoria Cañal, Carina Llano, Ramiro Barberena

Summarized by Ariel Telesford, a geology major with a minor in G.I.S at the University of South Florida and is currently a senior. He plans to work within the structural geology field, whether it be in mining, construction or the oil and gas industry. He plans to complete his master’s degree in London, England in the near future. Outside of academics, he is an avid gym-goer and plays multiple sports, mainly soccer and volleyball. 

What data were used? Feces extracted from a cave in Patagonia, Argentina was examined for parasites and other variables to determine environmental factors and diet of these sloths. The samples of feces used for this study were a part of a stratigraphic unit that dated between 16,600 and 13,600 calendar years before present (B.P.). This falls within the Pleistocene Epoch that spans from 2.58 million years ago to 11,700 years ago. 

Methods: Optical microscopy at 100x and 400x was utilized to identify and study the parasites found in the feces, as well as the diet of the sloth. Pollen analysis of the feces was conducted to determine environmental factors during that time, as the types of pollen present can inform researchers about a number of environmental factors, like temperature or moisture in the area. Pollen found within these species were compared to the known pollen record.

Results: The pollen analysis revealed that the climate was generally colder than what it is today and were found to belong to a specific shrub steppe. This supports what we already know concerning a cooler climate during the Pleistocene. The microscopic work done revealed that the sloths’ diet consisted mainly of shrub and grass, due to woody fragments and herbaceous matter found. This was consistent with the type of parasites (Nematoda family, also known as roundworms) that were found within the feces, since these worms usually inhabit grassy environments. These parasites also had researchers considering the various health impacts that parasites could have had on these sloths. The species of parasites found in the feces were also found in modern-day herbivores, indicating that co-extinction did not occur along with the extinction of these sloths during the mega-mammal extinction event of the Pleistocene. These results led researchers to hypothesize that host-switching (i.e., finding a new host) likely occurred for these parasites to survive.

Figure showing the parasitic eggs found in 8 out of the 21 samples of feces. Most of these eggs belong to the nematode (roundworm) family, specifically Strongylida species.

Why is this study important? When looking at extinction events throughout geological time, a lot of focus is placed on the organisms that are directly impacted by the event. However, we know that nature is super connected and intertwined and thus we must consider the effects these extinction events have on the organisms that are extremely dependent on those that were wiped out. 

The big picture:  The research done here shows the importance of considering even the smallest organisms when we try to understand the ecology of prehistoric times. This study should improve our understanding of the relationship that organisms have with each other (parasite-host in this case). Further work in paleoparasitological studies will help us understand host-switching, co-extinction, and the domino effect of extinction events on dependent species, especially when trying to recreate prehistoric environments. 

Citation: María Ornela Beltrame, Victoria Cañal, Carina Llano, Ramiro Barberena. Macroparasites of megamammals: The case of a Pleistocene-Holocene extinct ground sloth from northwestern Patagonia, Argentina, Quaternary International, Volume 568, 2020. Pages 36-42. ISSN 1040-6182. Retrieved from (

Mahmoud El-Saadi, M.Sc Candidate, Environmental Physiologist

Hello! My name is Mahmoud, a master’s student at Carleton University in Ottawa, Canada. After completing my undergrad at Carleton, I stayed to pursue an M.Sc in Biology in Dr. Heath MacMillan’s lab.

What is your favorite part about being a scientist and how did you get interested in science in general?
I would say my favorite part of being a scientist is the constant excitement of asking questions and having the freedom to try things out. In a constantly changing world, new evidence is always popping up which can occasionally change the way we look at pre-existing theories and data. I really enjoy meeting other scientists and bouncing ideas off of them, as well as communicating science to people.   

As for my interest in insects, it started with an upper-year biology course on insects which involved going out and collecting different species of insects. I was hooked after the course, in large part due to simply appreciating how diverse these animals are in their biology. The world of insects is massive!

What is your research about?
My research is currently looking at how insects are injured by low temperatures, and if there is any connection to their gut. The majority of insects, such as flies, locusts, crickets, and bees to name a few, do not do very well at low temperatures, and this can result in them becoming injured or dying. The exact driving forces behind these injuries are not exactly known, but they are thought to be driven by water and ion balance becoming dysregulated due to the insect’s gut losing most of its ability to control water and ion flow between the inside and outside of the gut. However, similar to us, insects also have a diverse community of bacteria in their gut! This leads me to my main question: if insects suffer injuries at low temperatures, is that partly because gut bacteria are finding their way outside and into tissues? If that is the case, then the resulting infection could be another factor behind the tissue damage which would provide better insight as to why most insects cannot handle the cold very well.

What are your data, and how do you obtain them?
To see if low temperatures lead to bacterial leak from the gut, I am feeding a fluorescent strain of E. coli bacteria to locusts, my model insect of choice. After they eat the bacteria, I expose them to a low temperature and extract a sample of their hemolymph, or “blood”. I then place the hemolymph in agar gel plates that allow any bacteria to grow overnight. I would then confirm the presence of the fluorescent bacteria by shining a UV lamp on the plates, which would show a strong yellow fluorescence. If bacteria are finding their way out of the gut, then I would see the fluorescent bacteria in the plates.

A unique strain of bacteria that emits a yellow glow under an ultraviolet lamp.

How does your research contribute to the bigger picture?
When it comes to the spread of insects across the globe, their ability to handle low temperatures is a very strong predictor for their survival and distribution. In other words, insects that are better able to survive cold environments are more likely to spread further than insects that are less able to survive the cold. This is particularly important when it comes to the issue of climate change, as greater and more frequent extremes in temperatures can expose many insect species to a different environment than what they are normally used to. In the context of pests that may damage agricultural crops, trees in forests, and pose a risk to our health, knowing how insects are physiologically affected by the cold can provide valuable information that we can use to predict their movement and future distribution. I would say that my work is just a small piece of the much grander puzzle of why insects do not like the cold!

What advice do you have for aspiring scientists?
The advice I always give aspiring scientists is to never be afraid to ask questions. In a way, asking questions is what defines us! If you are an undergraduate student in STEM who is interested in research, try to take the first step to email a professor if you are interested in their work, because that first step can definitely go a long way. No matter your research background or experience, there is a field out there for everyone. Embrace your passion for science and go forth!

Origins of nocturnal habits in modern-day birds: how did modern birds become both diurnal and nocturnal creatures?

Evolutionary Origin of Nocturnality in Birds

by Yonghua Wu

Summarized by: Ana Jimenez Bustos is a geology undergraduate student at the University of South Florida. She plans to attend graduate school in a field related to volcanology, possibly planetary geology. Once she has her degree, she would like to teach and continue to do research in volcanology or planetary geology. Outside of school, she enjoys eclectic, noisy music, her dog Miranda, and loves reading and learning about birds and parrots. 

What data were used? This study compiled data from scientific literature that analyzed genomes, physical characteristics such as eye sizes, ear structure, and anatomy of fossils of ancient and modern birds. Molecular, genetic, morphologic, and evolutionary data was used to determine whether the origin of these nocturnal habits (or the habit of being active at night) was based on a common ancestor or if it evolved along the way. The active and inactive genes (genes that are ‘turned on’ or ‘turned off’ in creatures’ bodies) of eyes involved in light reception and transport were used to try to understand when birds began to live, hunt, and forage in the dark. The study analyzed the compilation of these articles’ conclusions to try to determine whether nocturnality in birds was a trait inherited from a common ancestor or if it evolved side by side in different bird species.

Methods: This study used an array of existing scientific literature to study the evolutionary origin of nocturnality in extant bird species. By analyzing existing scientific literature, the study drew conclusions regarding ancient and modern bird habits.  

Results: It is likely that the nocturnal habits of birds evolved from a common ancestor, representing some of the earliest birds. This hypothesis is supported by the morphology of existing birds, such as large eye to body ratio when compared to other vertebrates because larger eyes allow more light into the retina for clearer nocturnal vision. In addition, these birds have a relatively advanced hearing apparatus that could have evolved from the need to communicate in the dark. The lack of certain organs like the parietal eye in crocodilians and birds (today found only in lizards), which is a light sensitive organ connected to the part of the brain responsible for hormone regulation, suggests that birds had a nocturnal origin, as this organ would have been rendered useless in the dark; the ancestors of birds lost this organ millions of years ago. 

In addition, certain genes that are related to detecting movement (specifically, GRK1 and SLC24A1) are thought to have been present in the common ancestor of birds. These genes would have helped to avoid predation in low-light conditions and support the hypothesis that their ancestor was at the very least both diurnal and nocturnal. 

Activity of birds and phylogeny based on reviewed and published studies. Taxa in red present species with true nocturnality, while taxa in green contain species with occasional nocturnal habits.

Specific adaptations to nocturnal life present in modern birds likely evolved independently from each other. Owls’ asymmetric ears, for example, evolved to precisely locate prey in the dark. This trait was likely not preset in the owls’ ancestors. The deactivation of specific genes related to color vision in nocturnal birds was also likely an evolutionary adaptation to the lack of need for color vision in birds that hunt and forage in the dark. This mutation is present in owls, kiwis, and nocturnal parrots. Some modern birds such as nightjars (Caprimulgiformes) have also evolved a tapetum, which is an extra layer in the back of the eye that reflects light back into the retina. This structure often gives eyes a “shiny” look when flashed with bright lights and can help to give animal clearer vision at night. 

Genetic and morphological evidence suggests that it is possible that birds evolved nocturnal habits in parallel to each other, but it is still possible that the common ancestor of all modern birds was both diurnal and nocturnal. Since the activity patterns of modern birds’ ancestors are still mostly unknown more analysis is needed to understand the habits of ancestral birds. 

Why is the study important? Nocturnality of mammalian creatures is largely understood to have evolved to avoid competition and predation from creatures that lurked during the day, but the origin of nocturnality in birds is not so well understood. Did ancient avian (bird) ancestors also have diurnal and nocturnal habits or was it a trait that was picked up along the evolutionary road? Did this nocturnality evolve in several different species or was it inherited from a single ancestor? Studying extant nocturnal birds and birds that have a combination of diurnal and nocturnal habits may help shed light on the evolutionary history of these behaviors. Understanding these behaviors in birds (or avian dinosaurs) can also help understand the behavior of non-avian dinosaurs like other theropods such as Tyrannosaurus rex the distant past. 

The big picture: This study addresses the origins of nocturnal behavior in birds. It suggests that these habits were present in extremely distant relationships going all the way back to the time of the non-avian dinosaurs. Understanding the habits of modern-day bird ancestors can help understand how ancient birds, and even dinosaurs like Tyrannosaurus or Velociraptor, lived in the past. Previous studies have been absolutist in their approach by classifying ancient birds and their ancestors as either nocturnal or fully diurnal, but the complete story may be significantly more complex and requires more studies to fully understand. Analyzing molecular, morphological, and phylogenetic relationships together can provide a better picture of the origin of these behaviors.  

Citation: Wu, Y. (2020). Evolutionary origin of nocturnality in birds. ELS, 483-489. doi:10.1002/9780470015902.a0029073

Oldest preserved DNA gives new insight on mammoth evolution and speciation

Million-year-old DNA sheds light on the genomic history of mammoths.

By: Tom van der Valk, Patrícia Pečnerová, David Díez-del-Molino

Summarized by: Amanda Gaskins, a senior at the University of South Florida studying geology and astronomy. After she graduates, she plans on continuing her education and obtaining her master’s degree in Geological Oceanography, where she hopes to find ways to combat the effect of global warming on coral reefs. In her free time, she loves to spend time in nature and read mystery novels.

What data were used? A team of scientists made paleogenetic (i.e., studying the DNA preserved in fossils) history by extracting what turned out to be the oldest genome data from the molar teeth belonging to three different mammoth species. 

Methods: To reveal the age and makeup of the mammoth’s genetic data, the authors isolated the DNA from molars found in the Siberian permafrost. Fortunately, the cold temperatures of Siberia reduced the effects of DNA break down throughout time. From there, they used methods that maximized the restoration of short fragments of DNA. The authors utilized biostratigraphy, a branch of stratigraphy that involves correlating and assigning the relative ages of rock strata by using the fossil fauna captured within them, in order to gain an idea of when the mammoths lived. They did this by correlating the fossil remains found at the Siberian site with fossils at locations where absolute dates are available. Moreover, in order to observe how these species of mammoths adapted to their cold environment in Siberia, the authors compared the genomes of the woolly mammoth descendants with those of the ancient specimens. 

Results: Through their experiments, the authors were able obtain ages for each of the three mammoths under speculation; each mammoth specimen is discussed here using a nickname given to them by researchers. The youngest of the mammoth group, nicknamed Chukochya, lived approximately 680,000 years ago. By examining the nuclear DNA that is contained within every cell nucleus of a eukaryotic organism, the team was able to construct a phylogenetic (evolutionary) tree (Figure 1) and discovered that Chukochya actually shares a common ancestor with the wooly mammoth. This confirms the hypothesis that Chukochya was a representative of an early form of the woolly mammoth. Adycha is the second-oldest mammoth of the group, whose life span aged back 1.34 million years ago amidst the early Pleistocene. It lived before Chukochya but is an ancestor to the woolly mammoths. The oldest mammoth of the bunch was dubbed Krestovka, with mitochondrial genome (DNA found only in the mitochondria in the cell) dating confirming that it roamed the earth 1.65 Mya in the early Pleistocene.

Figure 1. This figure is a visual of mammoth evolution throughout time. The three points on the timeline represent the three species of mammoths (represented here by their nicknames) that the authors have sequenced the DNA from.

Why is this study important?: This study provides an excellent example of the potential that ancient paleogenomics have to help uncover the mysteries of evolutionary processes like speciation, in which populations evolve and develop into distinct species. Not much research has been done on deep-time paleogenomics with respect to speciation, as it would require a sample with a long range of genome time sequences, ranging at least a million years old, which the vast majority of fossils do not preserve. The previous oldest genomic data on record was recovered from a horse specimen dating back only 780-560 thousand years ago. The experiment also gives insight on the potential of utilizing DNA as a component of biostratigraphy to help correlate the ages of the rocks and fossils contained within them.

The big picture: Overall, this study shed light on the evolution of mammoths while breaking records in paleogenomic history by uncovering the most ancient DNA sample ever analyzed, pushing our knowledge of genomics all the way back into the Ice Age. The ideas and methods displayed in this experiment will be beneficial in future studies regarding temporal data.

Citation: van der Valk, T., Pečnerová, P., Díez-del-Molino, D. et al. Million-year-old DNA sheds light on the genomic history of mammoths. Nature 591, 265–269 (2021).

Ymke Temmerman, Ing. Water manager/ Aquatic ecotechnologist and MSc student Aquaculture and Marine Resources Management.

Ymke during a field trip to Texel where she just did some field work at The Slutter

What is your favorite part about being a scientist and how did you get interested in science in general?
From a young age, I was always very curious, wanting to learn as much as possible about everything related to the ocean. I always tried to learn more and continue to look for new things to discover. I grew up close to the coast in the Netherlands and till this very day, I still enjoy the nature there and it always feels like coming home. Part of the reason I got so interested in the ocean is the mystery that is part of it, the fact that on the beaches and along the coast, we only see a glimpse of the life beneath the surface. So when the time came to make a decision about what I wanted to study, the choice for water management/aquatic ecotechnology at a university located close to the coast was one that was directly related to my passion for the coasts. During my studies, the passion and enthusiasm for science only grew. The contrast between theory, lab work and boots in the mud is something I enjoyed and still do. During my first internships at the research institutes NIOZ (Royal Netherlands Institute for Sea Research) and Wageningen Marine Research, I really got to experience doing research. These were amazing experiences, with fieldwork, experiments and a lot of new knowledge which ranged from small worms at the bottom of the North Sea to invasive species in industrial harbors. During these periods, I learned that the part I love about science is the continuous exploration of what seems like endless topics. And that with doing research, you contribute to knowledge. Because science to me is exploring new things of which the stories should be shared not only among scientist but with as many people as possible, especially the next generations that will need it to do better.

Ymke on a mudflat on Texel taking samples during an excursion

What do you do?
At the moment, I am finishing up my Masters in Aquaculture and Marine Resources Management. Within this program I am focusing on ecology and marine resources. The marine resources part is mainly about the services provided to us by the ocean (e.g. fish, coastal protection) and how to use these services in a sustainable way. For example, how fishing could be sustainable or how oyster reefs can be used for coastal protection. The ecological aspect is more about how these coastal and marine systems work and how different species contribute to keeping them healthy. Before my adventure at the university started, I did a Bachelors in Water Management in the middle of the Southwestern Delta of the Netherlands. During this study, I focused on ecology from rivers to oceans, learning about how to work together with nature to protect us against flooding. Other topics included climate change and the importance of water, where some countries have too much, others don’t have enough.

In addition to my studies, I am also active as an ambassador for the Dutch Wavemakers. This organization aims to educate the next generation worldwide about sufficient and clean water but also about water safety. We want to achieve this by collaborating with water athletes and students, hoping to make young people enthusiastic about water sports and water studies.  Next to this, we also hope to motivate the young generation to take action and be the change they like to see.

Ymke in Shanghai on a trip for the Dutch Wavemakers to participate in the Wetskills challenge 2019

What are your data and how do you obtain them?
We, as Dutch Wavemakers, communicate these important topics of water safety and scarcity with a positive attitude. We are convinced that it is not fruitful to keep pointing fingers at each other, since solutions are not often born from conflict. Instead we have a solution oriented approach in which we, of course, also talk about the problems but instead of focusing on doom scenarios we try to set out a positive future perspective. From experience, I know that this is way more effective in the long run when it comes to activating people. If they see the type of positive impact they can have as an individual, and if they spread the word with the same positivity as we do, this small action might become a big movement, leading to a real change in mindset.

How does your research contribute to the understanding of climate change, and the betterment of society in general?
As a Dutch Wavemaker, but also as someone with passion for the ocean, I hope to contribute to a positive change in which we start to see the ocean as a companion instead of an enemy or endless resource. As an ambassador I am involved in multiple projects that aim to create awareness for problems like plastic pollution, changing ecosystems and of course, the effects of climate change on our oceans and coastal zones. One of them is the SDG 14 alliance, which focuses on achieving the United Nations’ sustainable development goal 14: Life below water. Here we hope to create more awareness about pollution, sustainable fisheries, increasing biodiversity and protection of the oceans, with the focus on the younger generations. Next to these projects, we also visit all different types of events where we teach the younger generations about the impacts of too much water, but also about the importance of having enough water. We do this with the help of fun little activities in which the children can participate. In this way, children learn about large scale problems like too much water in cities because of the lack of green spaces.

Measuring temperature for an experiment during Ymke’s Bachelors thesis

What advice do you have for aspiring scientists?
Stay curious! As long as you remain curious and eager to learn new things, there is always a way for you to get there. Don’t be afraid to ask questions, there are always people in your surroundings that would be happy to answer them for you. Especially if it is something that you are really passionate about! And remember you will never be too old to learn new things, because a world without new things to discover would be a bit boring, if you ask me!

Was it possible for trilobites to live in brackish water?

Were all trilobites fully marine? Trilobite expansion into brackish water during the early Palaeozoic

By: M. Gabriela Mángano , Luis A. Buatois, Beatriz G. Waisfeld, Diego F. Muñoz, N. Emilio Vaccari and Ricardo A. Astini

Summarized by: Abby McAleer, a senior at the University of South Florida.  She is majoring in geology with a minor in geographic informational systems. After graduation she plans to get a job in conservation or become an elementary school science teacher. In her free time, Abby loves to hike and travel with her friends. 

What data were used? Trilobite trace fossils (meaning, the marks left behind by an organism, separate from a body fossil) from the early Paleozoic were used along with stratigraphic sections from four ancient estuary (an area where fresh and sea water mix) sites. The specimens were found in sediment structures located in Northwest Argentina.  

Methods: The methods used in this study were a combination of ancient estuary outcrop identification, analysis of the different sediment types from these outcrops, and an analysis of the tracks, burrows, and trace fossils of the trilobites to compare fully marine trilobite fossils to fossils of trilobites found in brackish waters. The ancient estuary sediments were identified by dividing the valley systems of the Paleozoic Northwest Argentina Basin into 3 estuary zones; inner fluvio-estuarine (closer to the river), middle estuarine, and outer estuarine (closer to the ocean). The ancient estuary sediments were examined in a stratigraphic log, which describes the vertical changes of sediments from bottom to top in a particular area. Additionally, an analysis of how the fossil record of trilobites was altered by sedimentary processes was preformed to create a connection between paleobiology and the stratigraphic layers of the outcrops. Lastly, body fossil analysis was preformed on the trilobites to compare characteristics of offshore and onshore assemblages (deeper and shallower water, respectively). 

Results: The presence of trilobite fossils in ancient estuary environments supports the hypothesis that trilobites could handle a change of salinity and still survive. Although the presence of these fossils in the ancient estuary fossil record does not mean that the trilobites permanently inhabited these regions, it leads us to believe that trilobites migrated to these areas for food and possibly a safe place to nest and spawn. It is likely that the realization that tidal influenced estuaries were not fully marine environments helped us come to this conclusion. Figure 1 illustrates the 4 stratigraphic logs that were taken from the ancient estuaries. In this figure, we can see the expansion of the trilobites from marine to brackish water. 

Figure 1. This diagram represents the four stratigraphic logs of the ancient estuaries. In this figure, we can see the expansion of the trilobites from marine to brackish water through the column.

Why is this study important? This study helps us understand that trilobites made evolutionary changes to be able to handle the salinity change to survive, unlike other strictly marine invertebrates, like echinoderms. We can use the findings of this study to better understand the lifestyles of other marine organisms that lived during this time. 

The big picture: Previously, it was believed that trilobites could not handle salinity changes.  After this study, it has been indicated that trilobites were able to migrate to areas with fluctuating salinity for evolutionary advantages. This has helped scientist understand that assumptions of an organism’s tolerance for salinity may need to be reevaluated to limit future biases in paleontological studies.  

Citation: Mángano MG, Buatois LA, Waisfeld BG, Muñoz DF, Vaccari NE, Astini RA. 2021 Were all trilobites fully marine? Trilobite expansion into brackish water during the early Palaeozoic. Proc. R. Soc. B 288: 20202263.

Molecular phylogeny of an elephant-like species

A molecular phylogeny of the extinct South American gomphothere through collagen sequence analysis

By: Michael Buckley, Omar P. Recabarren, Craig Lawless, Nuria Garcia, Mario Pino

Summarized by: Stormie Gosdoski a student at the University of South Florida. She will be receiving her Bachelor of Science in Geology this December, 2020. After school she plans to join the scientific community and put her degree to good use. 

Data: Phylogenetic trees are created to determine the closest possible relationships between species, like a family tree. The phylogenetic tree containing gomphotheres, a group related to modern elephants, was created by analyzing molecular differences across species and determine the relationships between gomphotheres and true elephants and mammoths. One of the most informative ancient biomolecules that scientists can use for this type of study is collagen, which is the most abundant protein in bones and teeth. 

The scientists sampled four different gomphothere fossils belonging to a genus called Notiomastodon from South America. To reduce extraneous variables that could be present in the dataset, all the fossils were taken from the same location: the Pilauco Site in Osorno, Chile. They were also taken from the same layer of sediment. The layers of sediment on Earth can be read like a book, if no other geologic event has altered their positions. The ability to read each layer like a book gives scientists the ability to date the specimens; 13,650 ± 70 years ago to 12,372 ± 42 years ago. The fossils collected from this site included two root molars, a piece of rib, and a skull fragment.

Methods: The bones had fragments removed from them using a diamond-tip Dremel drill. They were then demineralized in hydrochloric acid (meaning, the scientists removed the minerals from the bones). The collagen was extracted from the solution. It was analyzed by a machine called a Matrix Assisted Laser Desorption Ionization Mass Spectrometry Time-of-Flight Mass Spectrometry (MALDI-ToF-MS). This type of equipment is used specifically to find the protein fingerprint of cells (which, just like our fingerprints, are unique to specific groups). The data collected from these methods were compared and searched for on the Swiss-Prot database for any potential matches to the primary protein sequences that are present in the collected data. This database is a protein sequence database. A potential match in the database would mean the species are more closely related. Once the analysis was complete, the scientists then performed a phylogenetic analysis of the data collected. Meaning, they compiled this information and ran the phylogenetic analysis using these new specimens and animals belonging to the closely related proboscideans, the group including elephants and mammoths, in the database as well, to determine relationships of the organisms in question.

Results: The protein fingerprint spectra of the four specimens collected in this study compared to the spectra of woolly mammoth and American mastodon was determined to differ from one another. The collagen fingerprints were similar, but there were three variations observed in the data (figure 1). At this point, using parsimony, Bayesian analysis, and maximum likelihood (the three methods of determining evolutionary relationships) a range of phylogenies was generated. This range compared three extinct proboscideans (Mammuthus, Mammut (the American mastodon), and Notiomastodon) and other closely related mammals. The results of these comparisons showed a closer relationship between Notiomastodon and Mammut. Meaning, the South American gomphothere has a close relationship to the American mastodon (figure 2).

Figure 1 This figure is the mass spectrometry of the three species. (Top to bottom) gomphothere (green), mastodon (blue), and woolly mammoth (red). This shows observed peak difference in the spectra between the three species.

Importance: This determination of the relationship between gomphotheres and mastodons can change how scientists interpret the relationships of other species in phylogenetic studies. Are there other relationships that need to be changed? How accurate can the scientific community get with the relationships of species? How does this affect our relationship to other species? How can we use this type of analysis to track our own evolution through time? This relationship is but one small portion of a larger question and we can use this to refine what we already know about ancient and present species.

The Big Picture: As scientists, we cannot rely on what our eyes are seeing to determine the relationships between species. Using molecular analyses can give a better idea of how closely related species are to one another. This type of analysis can also show how elephants have evolved and changed through history. This can give scientists a better understanding of the biology of elephants. Who knows- maybe it could lead to predictions of how the species will evolve in the future?

Figure 2 This is the phylogenetic tree that was generated from the analysis with ancient ancestor Paenungulata at the bottom (yellow) and the branch containing the common ancestor at the focus of the study, Proboscidea (pink). The South American gomphothere (green) is the sister taxon to the American mastodon (blue). It further shows the relationships of the other species. On the left is the geologic time scale, which shows when each species was alive.

Citation: Buckley, M., Recabarren, O. P., Lawless, C., García, N., & Pino, M. (2019). A molecular phylogeny of the extinct South American gomphothere through collagen sequence analysis. Quaternary Science Reviews, 224, 105882.

Jihan Al-Shdifat, Chemist / Organic Biogeochemistry Scientist In-Training

Processing samples after the dive.

What is your favorite part about being a scientist and how did you get interested in science in general? I got into science out of curiosity. Not many people I know are in the sciences which I think called out to me to explore what a scientist does, what do they look like aside from how they are portrayed in popular culture, or in general. I chose chemistry because understanding the universe from a molecular point of view appealed to me. Now, I am focused on oceanographic work employing biogeochemistry tools and techniques.

The best part about being a scientist is that you can allow your curious mind to think freely. There is always so much more to learn. When you’re out doing fieldwork, or simply processing samples in the lab, the thrill you get whenever you’re making a discovery is irreplaceable. This doesn’t mean obtaining purely positive results- insights and observations on negative results and failed experiments make you appreciate the scientific process more. Unlocking life skills in pursuit of science is a thing! I learned SCUBA diving, and programming, because these are requisites needed to tackle the research problem I am working on at the moment.

With my work, I hope to encourage more Filipinos to pursue a career in the sciences.

In laymen’s terms, what do you do? My research involves enumerating the lipids found in microbial mats, the water column and sediments in an area where groundwater bubbles out from the seafloor. These areas have very dynamic chemistries and my objective is to understand how micro- and macroorganisms thrive and adapt to these conditions.

Submarine groundwater discharge research group of the OASIS Lab, UP-MSI collecting biomass, sediment and gas samples.

How does your research/goals/outreach contribute to the understanding of climate change, evolution, paleontology, or to the betterment of society in general? Knowing the lipid composition gives us an understanding of the metabolic processes employed by microorganisms in adapting to their environment. Looking at the adaptation in areas affected by submarine groundwater discharge can very well contribute to assessing how organisms may behave in response to the changing oceans. The research also employs stable isotope measurements to go hand-in-hand with lipid studies. Another goal is to test how paleotemperature proxies behave in tropical climate as most studies are being done in temperate regions.

Leisure dive after sample collection: We make time to have a leisure dive after completing the sample collection dives to appreciate the rich biodiversity in Mabini, Batangas.

What are 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.? The data that my research uses are lipid mass spectrometry profiles as well as isotopic compositions from isotope-ratio mass spectrometry analysis. Isotopic data are both compound-specific and bulk analysis. We also perform the standard physico-chemical measurements of the study site, as well as obtain DNA data of the microbial mats we’ve collected from the field. The team is also exploring the use of imaging to profile the microorganisms across the water column.

Bubbles emanating from the seafloor.

What advice do you have for aspiring scientists? Scientists come in all shapes and sizes. As long as you have that curious mind to hold on to, there is no mold that you should follow on how to be one. Find an inspiration and follow it through with hard work and a lot of readings, and you’re good. More importantly, engage people on your work. Science is meant to be communicated to the larger population outside the scientific sphere and now more than ever is citizen science a force we definitely want to tap into.