Research Blog

Following the people and events that make up the research community at Duke

Applying the Ways of the Sea to Outer Space: A Conversation Hosted by Duke’s Space Diplomacy Lab

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Whether it was Marco Polo traversing the Silk Road (which was more like Silk Routes), Columbus sailing the ocean blue, or even Moana restoring the heart to Te Fiti; oceans have been integral to our way of life as humans for thousands and thousands of years.

The Silk Road, mapped
The (fictional) story of Moana draws from (true) Polynesian history and seafaring lore

But humans have always been bad at sharing – most wars are fought over territory, land especially. And as time has passed, the things we share as humans has evolved – from oceans and land to the Internet and outer space. So how do you keep things diplomatic? Last Friday, Duke’s Space Diplomacy Lab, co-chaired by Dr. Benjamin Schmitt of Harvard University and Duke’s own Dr. Giovanni Zanalda, hosted a webinar on what space diplomacy can learn from ocean diplomacy. Featuring Dr. Clare Fieseler of the Smithsonian Institution and Dr. Alex Kahl of the National Marine Fisheries Service, the conversation covered everything from zoning to equity to even the lessons we can learn from Indigenous communities.

Sharing data and sharing fish

There are multiple challenges to sharing the world’s waterways. Fieseler did not start out her career studying ocean diplomacy. Initially stationed in the Persian Gulf, building a marine mammal monitoring network, she noticed that the fraught state of politic affairs in the region made it hard to share data on the animals that were washing up on the shore.

Dr. Fieseler presenting

Meanwhile, Kahl, who works in Hawaii as the National Resources Manager at the National Marine Fisheries Service, runs into problems not in sharing data but primarily in sharing fish. “How do you focus on the shared exploitation of a natural resource?” he asked.

Two key themes arose in linking the sharing of the ocean to the sharing of outer space.

First, Fieseler pointed out that engaging scientists can help in transcending politics, something that ocean diplomacy does well. She pointed to efforts to establish a Marine Peace Park between North Korea and South Korea, and that if two of the worlds most polarized countries could come to an agreement in the name of science and human betterment, then “surely other countries can too.”

Second, Kahl remarked, unlike in the ocean, the primary resource in space is, well, space. You need fish to eat to survive – do you need space to survive?   

Centering equity

On the topic of whether we really need space in space to survive, Kahl pointed to the significance that many celestial bodies have in cultures here on Earth, such as in Hawaii and the Pacific Islands. Does interfering with these celestial bodies cross a red line for cultures on Earth? It’s worth noting that as Kahl said, with space exploration, “very few people are profiting,” so balancing the interests of people on Earth as well as in space is important.

Dr. Kahl presenting

Fieseler spoke to the need to build equity in space through some sort of formal agreement, similar to the Law of the Sea. But, she says, that might be skipping a few steps. Right now, “many developing countries can’t even afford to go to space.” How can you build equity in a region where not everyone even has a seat at the table? Kahl pointed out that this marginalization impedes discussions on how to share space – something that should be consensus-driven.

Zoning

As Fiesler remarked, zoning of the ocean has been key to a relatively peaceful sharing of this resource for the variety of uses that people have for the sea. A good example of this is the Antarctic Treaty, which zoned different places in Antarctica for scientific use.

Kahl spoke to being a beneficiary of the Antarctic Treaty – “it reduces bureaucratic burdens, and the collective benefits are also increased.” However, he made the point that the slicing and dicing of space, as with anything, could lead to initial tensions.

Science should have a seat at the table

A central theme that ran throughout the conversation was that, as Kahl put it, scientists “rely on each other to level-set the truth” – even in spaces where they might be in the minority, such as in a room of politicians engaging in diplomatic talks.

Fieseler pointed to how in environmental justice work, her Indigenous colleagues were good at taking the initiative – and finding the urgency – to demand a seat at the table. “As scientists, we sit around, thinking that one day the phone will ring and someone will invite me to be a part of the conversation – but that’s not how it works.” Diplomacy will always be a necessity as we aim to navigate sharing the vast resources at our disposal, but many scientists hope that we won’t forget to center the pursuit of the truth as we make decisions.

Post by Meghna Datta, Class of 2023

Do Snakes Have Tails? and Other Slithery Questions

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Dhruv Rungta, a member of the Wild Ones club, with a ring-necked snake during a herpetology walk with Dr. Nicki Cagle in the Duke Forest.
Upper left: Dr. Nicki Cagle holding a ring-necked snake. Photo by Montana Lee, another Wild Ones member.

On a sunny Friday in September, Dr. Nicki Cagle led a herpetology walk in the Duke Forest with the Wild Ones. The Wild Ones is an undergraduate club focused on increasing appreciation for the natural world through professor-led outings. Herpetology is the study of reptiles and amphibians.

Dr. Cagle is a senior lecturer in the Nicholas School of the Environment at Duke and the Associate Dean of Diversity, Equity, and Inclusion. Along with teaching courses on environmental education and natural history, she is also the science advisor for a citizen science project focused on reptiles and amphibians, or herpetofauna, in the Duke Forest. Volunteers monitor predetermined sites in the Duke Forest and collect data on the reptiles and amphibians they find.

“We get a sense of abundance, seasonality… and how the landscape is affecting what we’re seeing,” Dr. Cagle says. There is evidence that herp populations in the Duke Forest and elsewhere are decreasing.

Dr. Nicki Cagle flipping over a cover board with members of the Wild Ones. The cover boards are used to monitor reptiles and amphibians for a citizen science project in the Duke Forest.

The project relies on transects, “a sampling design… where you have a sampling spot at various intervals” along a line of a predetermined length. In this case, the sampling spots are “traps” meant to attract reptiles and amphibians without harming them. Each site has a large board lying on the ground. “Different herps are more likely to be found under different objects,” Dr. Cagle explains, so the project uses both wooden and metal cover boards.

But why would snakes and other herps want to hide under cover boards, anyway? Reptiles and amphibians are “cold-blooded” animals, or ectotherms. They can’t regulate their own body temperature, so they have to rely on their environment for thermoregulation. Snakes might sun themselves on a rock on cold days, for instance, or hide under a conveniently placed wooden board to escape the heat.

Salamanders that use the cover boards might be attracted to the moist environment, while “snakes will tend to go under cover boards either to hide — like if they’re about to molt and they’re more vulnerable — to look for prey, or just to maintain the proper temperature,” Dr. Cagle says.

Citizen scientists typically check the boards once a week and not more than twice a week. Volunteers have to avoid checking the traps too often because of a phenomenon called “trap shyness,” where animals might start avoiding the traps because they’ve learned to associate them with pesky humans flipping the boards over and exposing their otherwise cozy resting places. By checking the traps less frequently, scientists can reduce the likelihood of that and minimize disturbance to the animals they’re studying.

The first snake we saw was a worm snake, dark above with a pink stomach.

Dr. Cagle gave the Wild Ones a behind-the-scenes tour of some of the cover boards. Using a special, hooked tool conveniently stashed in a PVC pipe next to the first cover board, we flipped each board over and looked carefully underneath it for slithery movements. We didn’t find any under the first several cover boards.

But then, under a large sheet of metal, we saw a tiny snake squirming around in the leaf litter. There was a collective intake of breath and exclamations of “snake!”

Dr. Cagle captured it and held it carefully in her hands. Snakes, especially snakes as young as this one, can be all too easily crushed. We gathered around to look more closely at the baby snake, a species with the adorable name “worm snake.” It was dark above with a strikingly pink underside. The pink belly is a key field mark of worm snakes. Earth snakes are also found around here and look similar, but they tend to have tan bellies.

After a minute or two, the worm snake made a successful bid for freedom and wriggled back under the board, disappearing from sight almost immediately.

Crossing over a dry “intermittent stream,” which Dr. Cagle describes as “the running-water equivalent of a vernal pool.” A vernal pool is a temporary wetland that is dry for much of the year.

Some of the cover boards revealed other animals as well. We found a caterpillar chrysalis attached to one and several holes — probably made by small mammals — under another.

Whatever made the holes, we can safely assume it wasn’t a snake. According to Dr. Cagle, the term “snakehole” is misleading. Most snakes don’t make their own holes, though some of them do use existing holes made by other animals. One exception is the bull snake, which is known for digging.

We found a young five-lined skink sunning itself on top of one of the metal cover boards. (Thermoregulation!) Juvenile five-lined skinks are colloquially known as blue-tailed skinks, but the name is somewhat misleading — the adults don’t have blue tails at all.

The snakes we were looking for, meanwhile, were often elusive. Some vanished under the leaf litter before we could catch them. Sometimes it was hard to tell whether we were even looking at a snake at all.

“What are you?” Dr. Cagle muttered at one point, crouching down to get a better look at what was either a stick-esque snake or a snake-esque stick. “Are you an animal? Or are you just a wet something?” (Just a wet something, it turned out.)

The Duke Forest is a valuable community resource with a complicated history. “We know that slavery was practiced on at least four properties” in the Duke Forest, Dr. Cagle says, and the forest is located on the traditional hunting grounds of several indigenous peoples. The interpretive signs along the Shepherd Nature Trail, which we walked part of during our herpetology outing, were designed in collaboration with the Occaneechi Band of Saponi. Today, the Duke Forest is used for research, recreation, timber management, and wildlife management and conservation.

Later on, we found at least three young ring-necked snakes (Diadophis punctatus) under different cover boards. One of them was particularly cooperative, so we passed it around the group. (“All snakes can bite,” Dr. Cagle reminded us, but “some have the tendency to bite less,” and this species “has the tendency not to bite.”) Its small, lithe body was surprisingly strong. The little snake wrapped tightly around one of my fingers and seemed content to chill there. A living, breathing, reptilian ring. That was definitely a highlight of my day.

The faint, dark line on this ring-necked snake’s underside (on the bottom of the loop) is the anal vent. Everything below that point (farther from the head) is considered the official tail of a snake.

If you’ve ever wondered if snakes have tails, the answer is yes. The official cut-off point, Dr. Cagle says, is the anal vent. Everything below that is tail. In between flipping over cover boards and admiring young snakes, we learned about other herps. Near the beginning of our walk, someone asked what the difference is between a newt and a salamander.

“A newt is a type of salamander,” Dr. Cagle says, “but newts have an unusual life cycle where they spend part of their life cycle on land… and that is called their eft phase.” As adults, they return to the water to breed.

We learned that copperheads “tend to be fatter-bodied for their length” and that spotted salamanders cross forest roads in large numbers on warm, rainy nights in early spring when they return to wetlands to breed.

Students holding a ring-necked snake. Above: Kelsey Goldwein (left), Gurnoor Majhail (one of the co-presidents of the Wild Ones), and Simran Sokhi (background on right). Below: Emily Courson (left) and Barron Brothers.

Perhaps the most interesting herp fact of the day came near the end of our walk when one of the students asked how you can tell the sex of a snake. Apparently there are two ways. You can measure a snake’s tail (males usually have longer tails), or you can insert a metal probe, blunted at the end, into a snake’s anal vent. Scientists can determine the sex of the snake by how deep the probe goes. It goes farther into the anal vent if the snake is a male. Why is that? Because male snakes have hemipenes — not two penises, exactly, but “an analogous structure that allows the probe to slide between the two and go farther” than it would in a female snake. The more you know…

Looking for snakes on a herpetology outing with Dr. Cagle and the Wild Ones. Photograph by Gurnoor Majhail.

Disclaimer: Handling wild snakes may result in snake bites. It can also be stressful to the snakes. Furthermore, some snakes in this area are venomous, and it’s probably best to familiarize yourself with those before getting close to snakes rather than afterward. Snakes are amazing, but please observe wildlife safely and responsibly.

Bonus snake! I saw this adorable fellow on the Duke Campus and thought it was an earthworm at first. Dr. Cagle thinks it might be a rough earth snake. I did not check to see if it had a tan belly.
Post by Sophie Cox, Class of 2025

Meet New Blogger Kyla: Humans Grow up. Ideas Do, Too.

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If you asked my eight-year-old self what I wanted to be when I grew up, the answer would have been, resoundingly, “an inventor!” It was around this time that I also decided, with surprising assuredness for a shy second grader, that I would one day build a saltwater-powered car.

I must have heard the idea somewhere, although to this day I don’t quite recall where. Perhaps it was a story on the radio. NPR was a constant background noise in the basement where I spent countless hours playing and tinkering alongside my father in his hobby shop. Or maybe it was buried somewhere in a book or science magazine. They were often stacked in neat piles, filling bookcases in many corners of our house. It also could have floated across the dinner table in conversations between my parents and older siblings. Everyday talk of high school biology and current events seemed light years out of the grasp of my eight-year-old brain.

Kyla Hunter, Duke Engineering 2023.

Regardless of where it came from, the idea stuck. Before I knew what it meant to conduct research or study engineering, I found myself charmed by novel ideas and drawn to the possibility of discovery. For some reason, this “car that runs on salt water” took shelter in my mind and secured itself as the perfect idea: an ingenious invention that was good for the planet. At the time, of course, I never thought about how this whimsical, far-fetched idea was fundamentally tied to my core interests and values. Now, however, as a 21-year-old senior studying mechanical engineering, passionate about renewable energy technology and protecting the planet, it all makes perfect sense.

My interest in engineering is, at its core, a love for creativity, combined with a desire to solve problems. A fondness for physics certainly helps too, but that came much later. As a child, the desire to practice creativity manifested primarily as a love for art. Some of my earliest childhood memories are toiling away at my little table in the corner of the living room, carefully sorting the crayons in my tin Crayola box. Today, I practice creativity in my critical thinking, brainstorming, and implementation of the iterative design process.

At an elementary school science fair, I presented my model V8 engine and explained how it worked. I was drawn to many different interests before I settled on engineering, but it’s clear that the passion was always there.

The other facet that drew me towards engineering, the desire to solve problems, evolved from an early love for nature and a passion for environmentalism. I remember seeing my grandparents’ devastated home in the aftermath of Hurricane Sandy, and the noticeable decline in pollinators to my mother’s garden. In high school, when I heard the term “environmental engineering,” it was the first time I realized such a field existed. I immediately felt the various pieces of my interests and values click together. There are many ways to be creative and to solve problems, but for me, the combination led down a path towards pursuing engineering.

An entry from my second-grade journal, declaring my dearly held beliefs. In many ways, nothing has changed (including my ability to spell). 

Despite the way I’ve laid it out, this is not to say there was a linear path between latching onto an eccentric notion as an eight-year-old, and deciding to pursue my current career as a soon-to-be graduate. Looking back now, I can see the symbolism in this cornerstone of an idea. With hindsight, I recognize why it appealed to different facets of my just-blossoming identity, and the ways in which I returned to it over the next several years. However, this is what is bound to happen when you expose yourself to as many new ideas as possible: one (at least) will catch your attention. The point is not to latch onto the first idea you stumble upon and pursue it relentlessly. The point is to keep an open mind to all ideas – and pay careful attention to the ones that light up inside your brain. The ones that stick in the back of your mind, and continuously pop up at unsuspecting times. 

One of my favorite serendipitous moments in life is when, soon after learning something new, that newfound idea pops up somewhere else. It’s like receiving an unexpected gift in the form of previously inaccessible appreciation. Imagine turning over a stone and happening to uncover an insect that you just spent all night studying. It feels purely by chance, but it’s not quite.

The more you expose yourself to new ideas, the more they will appear. You never know when a story you stumble across by accident will move you to action, or lead to something bigger. A magazine I stumbled across by chance led to a research topic of an entire semester. A book I read in high school came up in an interview I had last week. An idea I heard at eight years old about an eco-friendly car perhaps started a life-long captivation with science that led me to become an engineer. Our life is made up of decisions that are based on millions of data points, determined by our history, background, and the types of ideas we surround ourselves with daily.

As a blogger for the Duke Research Blog, my goal is to make it easier for more people to have more exposure to more ideas. Each new idea has the potential to build bridges, whether expanding to new fields, or building upon an existing network of knowledge. Expanding our realm of understanding allows for challenging perspectives and broadening understandings. These are not ideas for the sake of ideas, but for the larger goal of enabling meaningful connections with others.

When more people have access to more ideas, everyone benefits. However, there’s no denying that much of the research going on at Duke is very high-level, usually going unread by much of the student body. Other fascinating content goes unnoticed simply due to the busy lives of Duke students, and the sheer volume of exciting events. (If only we could all be multiple places at once.)  My goal is to take ideas – whether overly intimidating or underappreciated—and present them in a way that is more accessible for anyone who is interested.

When I first heard of the idea of salt-water running cars, the idea was just that: an idea. The frenzy began in 2007 when John Kanzius, an American engineer, accidentally discovered how to “burn” salt water while attempting to research a cure for cancer. Today, the QUANT e-Sport Limousine is an all-electric sports car concept that uses an electrolyte flow cell, powered by salt water. It actually works, and was authorized for on-road testing in Germany a few years ago soon after its debut. It is many years from authorization, and it will likely be an even longer time before it is a viable option from an economic standpoint, but the progress is apparent.

Fifteen years since my infatuation with this idea, I can’t help but feel slightly emotionally connected to it. Humans grow up. Ideas do, too. I did not invent the first car that runs on salt water, but I am eternally grateful for every new idea that fuels my curiosity, shapes my values, and expands my current perspectives.

Post by Kyla Hunter, Class of 2023

Meet New Blogger Addie: A Recovering Advice Columnist

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“My name is Meg Stalter I’m 5’7 I’m living in LA and a fun fact about me is something bad happened to my cousin.”

As made evident by her Twitter profile, my favorite comedian, Megan (“Meg”) Stalter, knows how to make an introduction.  Stalter is best known (as far as I know) for her role in the HBO comedy “Hacks,” in which she plays Kayla (whoever that is). 

 I do not have a Twitter account and I have never seen the show.  While we are talking about me, I will explain that I do not really watch TV, with the one exception of West Wing.  

Since we are still talking about me, you should know that I fibbed.  There are two exceptions.  The other one is Grantchester, a Masterpiece Mystery about a hot priest who solves crime (but that was sort of a given, no?).  

I share Stalter’s bio for a few reasons.  For starters, it makes me smile, and sharing a smile is a tried-and-true way to score a friend (cha-ching!).  

Meg Stalter once again proved her knack for making a first impression at her Emmy’s debut

On top of that, it is a good example of someone who knows how to make a first impression.  I expect to have made a great impression by the time I finish this, but to ensure things got started on the right foot, hedging my bets if you will, I thought it best to leave the preamble to someone at the top of the trade.

Stalter’s bio also proves a simple point; it is not merely what you say that counts, but how you say it.  

I am something of a sub-par reader.  I love to read, it is just not my biggest strength (doesn’t mean it can’t be (growth mindset)! Just facing today’s facts).  I don’t think I read enough as a child, so now I am slow and I usually fall asleep.  

But I get by.  I power through my class readings, I keep a book on my bedside table, and I get my news through the radio (that and two free tickets to the Hoppin’ John’s Fiddler’s Convention–it pays to be tuned into WUNC on Saturday nights at 10. Cha-ching!).  

This relationship with reading influences my writing style.  When I write, I try to keep my readers awake. Not with what I write — I have full faith in the topic at hand’s capacity to speak for itself — but with the way I write it.

My past experience writing for a published paper was in high school, where I spent four years as co-editor of the “Hustle and Bustle” page. I authored a satirical advice column in which troubled high schoolers (me) could send their personal woes to someone who would publish them for the whole school to read (also me).  I like writing as a secondary form of chatting.   

My senior year, I retitled my column “Dear Addy,” after the well-known advice column “Dear Abby.”

And so it is with this laudable writing background that I report to you on the groundbreaking discoveries from one of the top research universities in the U.S.

Why write for a research blog?  Research is interesting. Research makes the world go round. Just ask a freshman. They all came here for the “research opportunities,” as did all the other freshmen at all the other universities.  

Before I sign off, I will let you know where you might catch me in my free time.  This is a key element of the standard student bio, and I am prone to severe FOMO, so let me get right to it.  

I am a sophomore from Hickory, North Carolina hoping to major in Public Policy and minor in Math. In my free time you might catch me listening to NPR, jogging, potting, singing to myself, making a smoothie, telling people about my smoothie, spamming my contacts for an ice cream date, or for the not-so-lucky, trying my best at Appalachian-style fiddle.

By Addie Geitner, Class of 2025

Meet New Blogger Alex: Pipetting Writer from Coastal SC

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When I write about myself, it always reads like a poorly crafted match.com zinger. Boring, awkward, and something along the lines of:

I’m Alex. Aquarius. Love dogs, classic rock, old NCIS episodes. $1 Goodwill paperback thrillers, marked with “Happiest 53rd Richard! All my love, Janet” and “8/17/2005, Saw this and thought of you!” And I like to ask myself why Steven King’s Carrie conjures up thoughts of said person? Who’s Richard? How’s Janet?

I also love coffee. And tea. Peppermint, of course. Irish breakfast, sure. Chamomile, why not. But I think I really just like collecting mugs — hearty ceramics, dainty porcelain, hand-painted, non-dishwashable, chipped, stained monstrosities. It might be a problem though (as I don’t have much shelf space).

Favorite genre of film? It’s got to be anything in the Meg Ryan romcom cinematic universe. Or the Brat Pack coming-of-age cannon. Breakfast Club, St. Elmo’s Fire, About Last Night, Pretty in Pink. Really just the Judd Nelson je ne sais quoi.

My dog and I celebrating her 11th birthday this summer!

I think my 2nd grade superlative was “Wormiest Bookworm,” whatever that means. That might’ve been the year I read every Nancy Drew book in the library and founded the neighborhood’s first and only detective business. I do wish I could say I’ve Jules Verne’d the world in 80 days — circumnavigating all five nebulous oceans, frozen Arctic plains, Swiss peaks, and continental slopes; Phileas Fogging my way through the Mediterranean, aperitivo in hand. But I’m a bit unworldly in the geographic sense. I’ve only been out of the country once to boat up next to Niagara Falls, wearing a thin, plastic poncho and an I <3 Canada tee (though I’ve possibly made it a second time to Canada after getting lost on the circumference of a lake in Vermont).

I’ve only ever lived in Charleston, SC, never straying too far from its labyrinth of intercostals and waterways, its Theseus-like shrimpers, gliding into port. At Duke, I spend half my time majoring in molecular/cellular biology and the other lamenting my landlockedness, missing Charleston’s temperate sea breeze.

Beach in the middle of winter

Growing up there was all briny inlet and Waffle House, midnight bacon, butter pats, cordgrass, molting blue crab, churches on every street corner and in every denomination, weak coffee and greasy hash brown breakfast, September hurricanes, salt, cicadas, farm stands packed with peaches, a once-in-a-hundred year 6-inch snowfall that closed school for two weeks.

On Saturdays, I sharktooth-hunted with my sisters in pluff mud plots now developed (strangers tend to find the smell of the marsh pungent, but I think it’s character building). Fished for red drum. Searched for pearls in half-mooned oyster mouths. Kayaked down creeks.

Charleston’s a literary city, or so I’ve always heard. I think Edgar Allen Poe’s ghost haunts a cobble-stoned alley downtown or something like that. And if not an alley then a quaint B&B, its porch bearing creaky rocking chairs and purple coneflower. I went to an arts-specialized middle and high school for creative writing, wrote some bad poetry in my formative years and a couple of questionable short films, then went to college and somehow fell into the field of cell bio and now I spend a decent chunk of my free time researching genetic heart disease in a campus lab. Feeding cardiomyocytes via gentle pipette like they’re sea monkeys.

I like to picture the act of writing and that of science as similar — fraternal twins or first cousins — and I don’t think it a coincidence that early philosophers were our first physicians, mathematicians, physicists, chemists, etc. Both fields challenge us to pose questions about our world, about its inhabitants, its oddities, its nuances. We just go about answering them differently.

For this reason, I’m incredibly excited to join Duke’s Research Blog, to write about science and innovation, to poeticize protein structures or to search for lyricism in neuronal action potentials the way a deep sea troller searches for the elusive giant squid. I just think there’s something so wonderful about learning new things, cradling little curiosities that often lead nowhere, and doing so through an accessible, enjoyable medium.

Post by Alex Clifford, Class of 2024

What Are Lichens, and Why Does Duke Have 160,000 of Them?

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Saxicolous lichens (lichens that grow on stones) from the Namib Desert, and finger lichen, Dactylina arctica (bottom left insert), common in the Arctic, on display in Dr. Jolanta Miadlikowska’s office. The orange color on some of the lichen comes from metabolites, or secondary chemicals produced by different lichen species. The finger lichen is hollow.

Lichens are everywhere—grayish-green patches on tree bark on the Duke campus, rough orange crusts on desert rocks, even in the Antarctic tundra. They are “pioneer species,” often the first living things to return to barren, desolate places after an extreme disturbance like a lava flow. They can withstand extreme conditions and survive where nearly nothing else can. But what exactly are lichens, and why does Duke have 160,000 of them in little envelopes? I reached out to Dr. Jolanta Miadlikowska and Dr. Scott LaGreca, two lichen researchers at Duke, to learn more.

Dr. Jolanta Miadlikowska looking at lichen specimens under a dissecting microscope. The pale, stringy lichen on the brown bag is whiteworm lichen (Thamnolia vermicularis), used to make “snow tea” in parts of China.

According to Miadlikowska, a senior researcher, lab manager, and lichenologist in the Lutzoni Lab (and one of the Instructors B for the Bio201 Gateway course) at Duke, lichens are “obligate symbiotic associations,” meaning they are composed of two or more organisms that need each other. All lichens represent a symbiotic relationship between a fungus (the “mycobiont”) and either an alga or a cyanobacterium or both (the “photobiont”). They aren’t just cohabiting; they rely on each other for survival. The mycobiont builds the thallus, which gives lichen its structure. The photobiont, on the other hand, isn’t visible—but it is important: it provides “food” for the lichen and can sometimes affect the lichen’s color. The name of a lichen species refers to its fungal partner, whereas the photobiont has its own name.

Lichen viewed through a dissecting microscope. The black speckles visible on some of the orange lichen lobes are a “lichenicolous” fungus that can grow on top of lichen. There are also “endolichenic fungi… very complex fungal communities that live inside lichen,” Miadlikowska says. “We don’t see them, but they are there. And they are very interesting.”

Unlike plants, fungi can’t perform photosynthesis, so they have to find other ways to feed themselves. Many fungi, like mushrooms and bread mold, are saprotrophs, meaning they get nutrients from organic matter in their environment. (The word “saprotroph” comes from Greek and literally means “rotten nourishment.”) But the fungi in lichens, Miadlikowska says, “found another way of getting the sugar—because it’s all about the sugar—by associating with an organism that can do photosynthesis.” More often than not, that organism is a type of green algae, but it can also be a photosynthetic bacterium (cyanobacteria, also called blue-green algae). It is still unclear how the mycobiont finds the matching photobiont if both partners are not dispersed together. Maybe the fungal spores (very small fungal reproductive unit) “will just sit and wait” until the right photobiont partner comes along. (How romantic.) Some mycobionts are specialists that “can only associate with a few or a single partner—a ‘species’ of Nostoc [a cyanobacterium; we still don’t know how many species of symbiotic and free-living Nostoc are out there and how to recognize them], for example,” but many are generalists with more flexible preferences. 

Two species of foliose (leaf-like) lichens from the genus Peltigera. In the species on the left (P. canina), the only photobiont is a cyanobacterium from the genus Nostoc, making it an example of bi-membered symbiosis. In the species on the right (P. aphthosa), on the other hand, the primary photobiont is a green alga (which is why the thallus is so green when wet). In this case, Nostoc is a secondary photobiont contained only in the cephalodia—the dark, wart-like structures on the surface. With two photobionts plus the mycobiont, this is an example of tri-membered symbiosis.

Lichens are classified based on their overall thallus shape. They can be foliose (leaf-like), fruticose (shrubby), or crustose (forming a crust on rocks or other surfaces). Lichens that grow on trees are epiphytic, while those that live on rocks are saxicolous; lichens that live on top of mosses are muscicolous, and ground-dwelling lichens are terricolous. Much of Miadlikowska’s research is on a group of cyanolichens (lichens with cyanobacteria partners) from the genus Peltigera. She works on the systematics and evolution of this group using morphology-, anatomy-, and chemistry-based methods and molecular phylogenetic tools. She is also part of a team exploring biodiversity, ecological rules, and biogeographical patterns in cryptic fungal communities associated with lichens and plants (endolichenic and endophytic fungi). She has been involved in multiple ongoing NSF-funded projects and also helping graduate students Ian, Carlos, Shannon, and Diego in their dissertation research. She spent last summer collecting lichens with Carlos and Shannon and collaborators in Alberta, Canada and Alaska. If you walk in the sub basement of the Bio Sciences building where Bio201 and Bio202 labs are located, check out the amazing photos of lichens (taken by Thomas Barlow, former Duke undergraduate) displayed along the walls! Notice Peltigera species, including some new to science, described by the Duke lichen team.

Lichens have value beyond the realm of research, too. “In traditional medicine, lichens have a lot of use,” Miadlikowska says. Aside from medicinal uses, they have also been used to dye fabric and kill wolves. Some are edible. Miadlikowska herself has eaten them several times. She had salad in China that was made with leafy lichens (the taste, she says, came mostly from soy sauce and rice vinegar, but “the texture was coming from the lichen.”). In Quebec, she drank tea made with native plants and lichens, and in Scandinavia, she tried candied Cetraria islandica lichen (she mostly tasted the sugar and a bit of bitterness, but once again, the lichen’s texture was apparent).

In today’s changing world, lichens have another use as well, as “bioindicators to monitor the quality of the air.” Most lichens can’t tolerate air pollution, which is why “in big cities… when you look at the trees, there are almost no lichens. The bark is just naked.” Lichen-covered trees, then, can be a very good sign, though the type of lichen matters, too. “The most sensitive lichens are the shrubby ones… like Usnea,” Miadlikowska says. Some lichens, on the other hand, “are able to survive in anthropogenic places, and they just take over.” Even on “artificial substrates like concrete, you often see lichens.” Along with being very sensitive to poor air quality, lichens also accumulate pollutants, which makes them useful for monitoring deposition of metals and radioactive materials in the environment.

Dr. Scott LaGreca with some of the 160,000 lichen specimens in Duke’s herbarium.

LaGreca, like Miadlikoska, is a lichenologist. His research primarily concerns systematics, evolution and chemistry of the genus Ramalina. He’s particularly interested in “species-level relationships.” While he specializes in lichens now, LaGreca was a botany major in college. He’d always been interested in plants, in part because they’re so different from animals—a whole different “way of being,” as he puts it. He used to take himself on botany walks in high school, and he never lost his passion for learning the names of different species. “Everything has a name,” he says. “Everything out there has a name.” Those names aren’t always well-known. “Some people are plant-blind, as they call it…. They don’t know maples from oaks.” In college he also became interested in other organisms traditionally studied by botanists—like fungi. When he took a class on fungi, he became intrigued by lichens he saw on field trips. His professor was more interested in mushrooms, but LaGreca wanted to learn more, so he specialized in lichens during grad school at Duke, and now lichens are central to his job. He researches them, offers help with identification to other scientists, and is the collections manager for the lichens in the W.L. and C.F. Culberson Lichen Herbarium—all 160,000 of them.

The Duke Herbarium was founded in 1921 by Dr. Hugo Blomquist. It contains more than 825,000 specimens of vascular and nonvascular plants, algae, fungi, and, of course, lichens. Some of those specimens are “type” specimens, meaning they represent species new to science. A type specimen essentially becomes the prototype for its species and “the ultimate arbiter of whether something is species X or not.” But how are lichens identified, anyway?

Lichenologists can consider morphology, habitat, and other traits, but thanks to Dr. Chicita Culberson, who was a chemist and adjunct professor at Duke before her retirement, they have another crucial tool available as well. Culbertson created a game-changing technique to identify lichens using their chemicals, or metabolites, which are often species-specific and thus diagnostic for identification purposes. That technique, still used over fifty years later, is a form of thin-layer chromatography. The process, as LaGreca explains, involves putting extracts from lichen specimens—both the specimens you’re trying to identify and “controls,” or known samples of probable species matches—on silica-backed glass plates. The plates are then immersed in solvents, and the chemicals in the lichens travel up the paper. After the plates have dried, you can look at them under UV light to see if any spots are fluorescing. Then you spray the plates with acid and “bake it for a couple hours.” By the end of the process, the spots of lichen chemicals should be visible even without UV light. If a lichen sample has traveled the same distance up the paper as the control specimen, and if it has a similar color, it’s a match. If not, you can repeat the process with other possible matches until you establish your specimen’s chemistry and, from there, its identity. Culberson’s method helped standardize lichen identification. Her husband also worked with lichens and was a director of the Duke Gardens.

Thin-layer chromatography plates in Dr. LaGreca’s office. The technique, created by Dr. Chicita Culberson, helps scientists identify lichens by comparing their chemical composition to samples of known identity. Each plate was spotted with extracts from different lichen specimens, and then each was immersed in a different solvent, after which the chemicals in the extracts travel up the plate . Each lichen chemical travels a characteristic distance (called the “Rf value”) in each solvent. Here, the sample in column 1 on the rightmost panel matches the control sample in column 2 in terms of distance traveled up the page, indicating that they’re the same species. The sample in column 4, on the other hand, didn’t travel as far as the one in column 5 and has a different color. Therefore, those chemicals (and species) do not match.

LaGreca shows me a workroom devoted to organisms that are cryptogamic, a word meaning “hidden gametes, or hidden sex.” It’s a catch-all term for non-flowering organisms that “zoologists didn’t want to study,” like non-flowering plants, algae, and fungi. It’s here that new lichen samples are processed. The walls of the workroom are adorned with brightly colored lichen posters, plus an ominous sign warning that “Unattended children will be given an espresso and a free puppy.” Tucked away on a shelf, hiding between binders of official-looking documents, is a thin science fiction novel called “Trouble with Lichen” by John Wyndham.

The Culberson Lichen Herbarium itself is a large room lined with rows of cabinets filled with stacks upon stacks of folders and boxes of meticulously organized lichen samples. A few shelves are devoted to lichen-themed books with titles like Lichens De France and Natural History of the Danish Lichens.

Each lichen specimen is stored in an archival (acid-free) paper packet, with a label that says who collected it, where, and on what date. (“They’re very forgiving,” says LaGreca. “You can put them in a paper bag in the field, and then prepare the specimen and its label years later.”) Each voucher is “a record of a particular species growing in a particular place at a particular time.” Information about each specimen is also uploaded to an online database, which makes Duke’s collection widely accessible. Sometimes, scientists from other institutions find themselves in need of physical specimens. They’re in luck, because Duke’s lichen collection is “like a library.” The herbarium fields loan requests and trades samples with herbaria at museums and universities across the globe. (“It’s kind of like exchanging Christmas presents,” says LaGreca. “The herbarium community is a very generous community.”)

Duke’s lichen collection functions like a library in some ways, loaning specimens to other scientists and trading specimens with institutions around the world.

Meticulous records of species, whether in databases of lichens or birds or “pickled fish,” are invaluable. They’re useful for investigating trends over time, like tracking the spread of invasive species or changes in species’ geographic distributions due to climate change. For example, some lichen species that were historically recorded on high peaks in North Carolina and elsewhere are “no longer there” thanks to global warming—mountain summits aren’t as cold as they used to be. Similarly, Henry David Thoreau collected flowering plants at Walden Pond more than 150 years ago, and his samples are still providing valuable information. By comparing them to present-day plants in the same location, scientists can see that flowering times have shifted earlier due to global warming. So why does Duke have tens of thousands of dried lichen samples? “It comes down to the reproducibility of science,” LaGreca says. “A big part of the scientific method is being able to reproduce another researcher’s results by following their methodology. By depositing voucher specimens generated from research projects in herbaria like ours, future workers can verify the results” of such research projects. For example, scientists at other institutions will sometimes borrow Duke’s herbarium specimens to verify that “the species identification is what the label says it is.” Online databases and physical species collections like the herbarium at Duke aren’t just useful for scientists today. They’re preserving data that will still be valuable hundreds of years from now.

Meet New Blogger Jakaiyah, an infectious disease enthusiast

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Hello, my name is Jakaiyah Franklin, and I am a sophomore here at Duke University. In terms of my major, I am undecided, but I do know my passion lies in biology, science communication, and environmental science.

Outside of classes, I am the treasurer for the Duke Chapter of the NAACP and LLC leader for the Stem Pathways for Inclusion, Readiness, and Excellence (SPIRE) program. Last year I was the stage manager for two Hoof n Horn productions.

This is the Rocky Horror Picture Show company after finishing our last show.

This year, I will start a research position along with this research blogging position.

In a more personal sense, I am the youngest of three and a proud aunt. Right now, I say I am from Texas, even though I have lived in Georgia, South Carolina, Germany, and presently North Carolina. If someone ever asked me, I would say that Germany holds my most memorable memories; however, I have grown into a better version of myself in each place I have lived. Other than school, I like to read and watch House of the Dragon and the earlier seasons of The Game of Thrones. I prefer to study outside or in a place where natural light is abundant. I also love learning new things pertaining to science, specifically infectious diseases.

My view of Muhuru Bay, Kenya, where I spent the summer after my first year at Duke. That’s Lake Victoria in the distance.

I find diseases fascinating, and I believe they are our natural predators. I want to be able to not only understand them, but also, I want to help prevent them. If one were to have a favorite type of disease to study, mine would be zoonotic diseases. They are interesting because the act of a virus being able to jump from a host like a rat to a human is captivating to me.

After graduating from Duke, I want to earn a master’s in public health or a Ph.D. in epidemiology, virology, or infectious disease to feed my curiosity about diseases. However, before I can even decide what Ph.D. or master’s I want to earn, my current goal is to decide on my major.

Jakaiyah Franklin

I do like to think ahead, so, for my very distant career, I know I want to be able to see infectious diseases in both the lab and in the places where they are infecting populations. I want my research to be digestible for the general population because, as seen with both COVID and Monkeypox, science can be easily misinterpreted if not delivered appropriately. I want to prevent this occurrence from happening to me by learning more about science communication and actively improving my communication skills.

I hope this blogging position will expose me to infectious disease research or general public health research. With this new understanding of the research, I hope this position will also educate me on how to inform others so that they can enjoy and understand the science.

Post by Jakaiyah Franklin, Class of 2025

Expanding the SCOPE of Medical Education

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It may be hard to put your finger on it, but Duke often allows students to connect their classes to something more personal.

The university’s emphasis on interdisciplinary education is a major initiative that colors students’ academic experiences. While there are many examples of these connections between people, classes, fields, and departments, few so tangibly represent those connections like The SCOPES Project, which connects arts and humanities to medical education at Duke.

Beneath the Surface by Mihir Patel, 2022. Image Courtesy of SCOPES.

Art and medicine can exist in entirely different worlds. They can appeal to different people and tell different stories. But why be simple when you can be, well… stunning? They can be integrated to form something powerful, and that’s precisely what SCOPES leadership members Isa DeLaura, Raluca Gosman, Mason Seely, David Stevens, and Lindsay Olson aimed to do. 

“It is encouraging as an upperclassman who previously participated in this program to see rising students continue the tradition of incorporating the humanities into medical practice,” Mason Seeley says. The generational aspect of the project seems to contribute to its personality; participants bring their own perspectives to their work only to walk away with dozens more. 

“Having a creative outlet has helped me process interactions with patients and the difficulties of the profession, and celebrate happy moments as well,” says Isa DeLaura.

“The goal is to give artists creative freedom to explore their relationships with their patients with whatever medium and in whatever style works best for them. As such, every year the feel is entirely based on the decisions of the artists.”

Isa DeLaura, MS3+

David Stevens insists that the artists “resist… forces of depersonalization in compelling and beautiful ways.”

The project is inspired and supported by yet another interdisciplinary Duke initiative called APPLE (Appreciating Patient Perspectives through Longitudinal Encounters), which connects medical students with patients living with chronic illnesses. The artists/medical students/empaths-in-training then attended multiple creative workshops and developed art pieces to reflect their patients’ personal experiences. But this year’s 6th annual SCOPES exhibition looks a bit different from past years’ (which are conveniently available online for your viewing pleasure).

Having attended many an art opening myself, I am unashamed to say that much of my enjoyment comes from the cheeseplates (and the excitement in the air, but that’s besides the point). Some exhibitions opt for a traditional charcuterie, some marked Kirkland Signature and others displayed on a handmade butcherblock. The point of fingerfoods is to encourage the attendees to stand up, walk around, and interact with the masses. But it also encourages attendees to “just stop by,” making the affair all the less intimate.

Following limitations on group gatherings Duke enforced during COVID, the SCOPES team decided to apply their newfangled interdisciplinary/revolutionary/innovative thinking to the art opening itself: They held a banquet. 

“I loved the way this turned out,” says DeLaura. “It was very personal and made for great discussion and comradery.” 

Fences, Rivers, Walls by Taylor Yoder, 2022. Image Courtesy of SCOPES.

“SCOPES has provided an opportunity to reflect on my experiences as a first-year medical student while also exploring new ways to combine various art forms to create my vision,” says Taylor Yoder, who created Fences, Rivers, Walls, pictured above. “I hope to continue shooting film throughout my medical education and career.”

I was particularly (although wrongfully) surprised about the variety in the exhibit. While the artists attended the same workshops and worked with patients through the same program, they took radically different approaches to their creations. Esme Trahair, a second-year medical student, was a humanities major in undergrad. Her piece combines historical perspectives with modern (although antiquated) mechanisms, emphasizing “the importance of remembering and learning from historical, outdated medical teachings.”

For the Record by Esme Trahair, 2022. Image Courtesy of SCOPES.

The work features a variety of perspectives, but also some clear motifs that could be key takeaways for future medical providers. Like Yoder, artist Kreager Taber explores the patient’s value of “home.” Exploring these motifs could allow for more personal, “upstream” healthcare. 

This year’s SCOPES exhibition is held in the Mars Gallery in the Duke University Hospital Concourse. It is an initiative of the Trent Center for Bioethics, Humanities & History of Medicine at the Duke University School of Medicine. It will be on display August 9-September 29, and available for viewing online at this link. 

P.S. If you are an MS1 student interested in participating in SCOPES, I have a link for you!

Post by Olivia Ares, Class of 2025

Predicting What Extinctions Could Mean for Lemurs and the Forests They Call Home

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New research shows that lemurs and their food trees are tightly linked in ecological networks, and that the extinction of lemurs will have cascading effects on ecosystem functions.

The Critically Endangered black-and-white ruffed lemur, Varecia variegata, is one of the lemurs that eats the most fruit. When they consume the fruit, they pass the whole far from the mother tree, effectively aiding in seed dispersal. Photo credit: Laura De Ara

Lemurs are the primates found only on Madagascar. They are unique in many ways, and like many organisms, they fit in complex ecological networks. These networks include interactions between lemurs and their food trees. Many interactions are beneficial, or mutualistic; for example, lemurs eat the fruits of trees and disperse their seeds, providing a critical service to the trees. If lemurs go extinct — 98% of species are threatened with extinction due to human activities — the links in the ecological network will be severed, with potentially negative impacts on the trees.

Research published in the Journal of Animal Ecology by Ph.D. student Camille DeSisto, of the Duke University Nicholas School of the Environment, and James Herrera, from the Duke Lemur Center, shows how tightly linked lemurs and trees are in their interaction networks, and the negative impacts of extinction on network resilience. If lemurs do in fact disappear, many trees will be left without a way to disperse their seeds, and may not be able to reproduce effectively.

DeSisto and Herrera used advanced techniques in social network analysis, including exponential random graph models, to test which traits of lemurs and trees predict their probability of interaction. The lemurs with the highest probability of interactions with trees were large, fruit-eating species with a short gestation length, occurring in arid habitats, and with a threat status of Least Concern. Closely related plants were more likely to interact with the same lemur species than distantly related plants, but closely related lemurs were not more likely to interact with the same plant genus.

Simulated lemur extinction tended to increase network structure in some properties, including connectance (% of realized interactions out of all possible interactions) and modularity (how many unique cliques or subcommunities form in the network), but decrease nestedness (the tendency for specialists which feed on only a few trees to be a subset of generalists which feed on many trees) and robustness (tolerance to future extinctions), compared to pre‐extinction networks. Networks were more tolerant to plant than lemur extinctions.

The silky sifaka, Propithecus candidus, is one of the most endangered primates in the world. Unlike some lemurs, the sifaka have antagonistic relationships with trees, eating leaves and prey on seeds, rather than pass them intact. Photo credit: Laura De Ara.

By simulating the loss of lemur and plant species, the authors could predict how network structure will erode over time if threatened lemurs and trees go extinct. The results showed that if the most well-connected lemurs in the network were to disappear, the percentage of trees with interactions would quickly decline, compared to scenarios in which lemurs were removed randomly or if the least-well connected lemurs went extinct. Given the threat status and geographic range size of lemurs, the percentage of trees that would lose their interacting lemurs would be greater than that expected if lemur extinctions were random.

The bamboo lemur, Hapalemur occidentalis, is a highly specialized species, eating mostly bamboo leaves. They do, however, occasionally eat fruits, and often spread the seeds effectively. Photo credit: Laura De Ara

Results also showed that if lemurs go extinct, the resilience of the networks to further disturbance would decrease. This indicates that the current links between lemurs and trees are critical to the stability of these complex ecological networks.

To prevent the loss of key ecosystem functions like seed dispersal, it is critically important to protect lemurs and trees, which depend so crucially on one another for survival. DeSisto is currently conducting field research in Madagascar, studying how well seeds germinate when eaten by lemurs. She created a tree nursery in the forest to grow the seeds obtained from lemur feces, and already has several species germinating. Interestingly, she is also showing how lemurs disperse the seeds of vines, which are an important yet understudied food source when tree fruits are not available. She will continue her research across multiple seasons, to determine how changes in plant phenology affect seed dispersal patterns.

Author Camille DeSisto and assistant Feno Telessy examine the seeds germinating from lemur feces.
Amazingly, seeds from lemur feces are already germinating after only one month. Some tree seeds take months or even a year before germinating.

Many conservation programs are currently striving to safeguard Madagascar forests and the diverse species found only in these natural habitats. The Duke Lemur Center has an active conservation program in the northeast, called the DLC-SAVA Conservation Initiative. This program takes a community-based approach to conservation, partnering closely with local stakeholders and actors to develop projects that address the needs of both lemurs and people. By co-creating projects that include alternative and sustainable livelihood strategies, both nature and people benefit from conservation. Natural ecosystems provide important services for people, including locally, such as protecting watersheds and pollinators, as well as globally, such as carbon sequestration. Without the native forests, and the lemurs that call those forests home, people would lose the valuable and irreplaceable services forests provide.

CITATION: “Drivers and Consequences of Structure in Plant–Lemur Ecological Networks,” Camille DeSisto and James Paul Herrera. Journal of Animal Ecology, July 15, 2022. DOI: 10.1111/1365-2656.13776.

Symposium Explores How People and Nature are Inextricably Entwined

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The massive Keeler Oak, a white oak (Quercus alba) in New Jersey.

An April symposium at Grainger Hall, People and Nature, brought a diverse set of speakers, both from Duke and other U.S. institutions, to examine the relationship between human culture and land and to discuss pressing issues such as environmental justice. The session was organized by PhD students Nicholas School of the Environment and the biology department.

Paul Manos of Duke Biology

Professor Paul Manos of Duke Biology told us  how oaks, ubiquitous tree species in temperate regions, can make people think about nature. A walk in the woods looking at the different oaks can result in a fascinating journey of natural history. For those who are curious enough, an inquiry into the lives of oaks will take them deep into topics such as evolutionary history, leaky species boundaries, plant-animal interactions, among others, Manos said. Keeping true to the theme of the symposium, Manos explored some hypotheses about the first time that humans had contact with oaks, and how this relationship unfolded ever since.

Orue Gaoue of Tennessee-Knoxville

Associate Professor Orou G. Gaoue of the University of Tennessee, Knoxville,  took us through a detailed case study of human and plant interactions with long-term data from the country of Benin, in Africa. He showed how the harvest of the African mahogany (Khaya senegalensis) affects human demography and even the marriage dynamics of the Fulani people, with many other insights into the intertwined relationship of the locals and their harvest.

Andrew Curley of Arizona

Central to the morning sessions were the rights of nature and the granting of personhood to non-humans, which is common in the cosmology of many indigenous cultures. For instance, Andrew Curley, assistant professor at the University of Arizona, mentioned in his talk that the O’odham people in the Sonoran Desert confer the Saguaro cactus personhood status. His talk exposed how colonial dynamics have created climate catastrophes and drought around the Colorado River, how indigenous peoples have to navigate these foreign systems, and how they understand their relationship with the land and water.

Michelle Carter, a first-year Masters of Environmental Management (MEM) student at Duke, examined the feasibility of the rights of nature in the US legal system. These rights allow certain natural features (e.g. rivers) to stand as a sole party in litigation and recover damages on their behalf. However, effective application and the enforcement of policy have been lacking.

The second part of the symposium focused on environmental justice. Duke Ph.D. student Maggie Swift presented a land acknowledgement which was divided into three parts: recognition of the violent history of the past; an understanding of the present with a celebration of the lives and achievements of current indigenous peoples; and a call to action so that participants were encouraged to financially support native-led organizations.  Links for donations and more information can be found on the symposium website. The land acknowledgement was followed by a brief presentation on the project Unearthing Duke Forest  that explores the human history surrounding Duke Forest.

Why is it important to jointly consider people and nature in your work? What insights do you gain in your work by taking this approach?

People & NAture
Christine Folch of Duke Cultural Anthropology

Assistant professor Christine Folch, from Duke’s Department of Cultural Anthropology provided an analysis of the discourse around climate change. At the center was the question “do you believe in climate change?” which has ingrained the element of doubt and the ability of the speaker to say “no, I don’t.”  

Associate professor Louie Rivers III, from NC State University,  gave a talk on perceived environmental risks and their influence on social justice. He pointed out that these questions  could be dismissed by certain groups such as black farmers, who are concerned and disproportionally affected by environmental issues but might not relate to how the question is addressed.

Sherri White-Williamson, Environmental Justice Policy director at NC Conservation Network, explained the concept of environmental justice and provided concrete examples of how certain policies (e.g. federal housing/lending policies or interstate highway systems) can create inequalities that leave communities of color to bear the exposure of environmental degradation. She also made us aware that this year is the 40th anniversary of the birth of the US environmental justice movement that started when an African-American community  in Warren County, North Carolina organized to fight a hazardous waste landfill.

No exploration of people and nature would be complete without including the seas. A team of three students at the Duke University Marine Lab, undergrad Maddie Paris, second-year MEM Claire Huang, and Ph.D. student Rebecca Horan, presented two case studies of social and ecological outcomes linked to education and outreach interventions conducted in tropical marine environments.

Their first case study was on turtle education in Grenada, West Indies. Here a 10-week summer program for local children ages 9-12 created an improved understanding of marine turtle biology and its connection to the health of the ocean and their communities. The second case study was a 4-week training course for fisher people and fisheries officers in Mtwara, Tanzania. These participants increased their skills in monitoring the local reefs and were better equipped to educate their communities on marine environmental issues.

The symposium ended with two open questions for the audience, which should be considerations for anyone doing environmental research:  Why is it important to jointly consider people and nature in your work? What insights do you gain in your work by taking this approach?

Guest post by Rubén Darío Palacio, Ph.D. 2022 in Conservation Biology from the Nicholas School of the Environment, and science director of conservation non-profit Fundacion Ecotonos in Colombia.

Lemur Gut Isn’t One Ecosystem, It’s Many

Lemurs like Ferdinand are leaf-eating machines, says Duke microbiome researcher Lydia Greene. Credit: Lydia Greene

DURHAM, N.C. — A jungle. A rainforest. A wetland. A wilderness. Researchers have used various metaphors to describe the complex, interconnected community of microbes (most of them bacteria) living inside your body, and all over it too.

If you were to count up all the trillions of cells inside and out, we are more bacteria than human. Fortunately, perhaps, the microbes that make a cozy home inside your nose, or clinging to your teeth, aren’t the same ones that are living behind your ear or busily multiplying in your belly button.

The same is true for our distant primate cousins the lemurs, particularly in their guts, say researchers Lydia Greene and Erin McKenney in a new study.

Lemurs rely on gut microbes to digest their leafy diets, explains Greene, a research scientist at the Duke Lemur Center. Microbes in lemurs’ GI tracts help ferment plant fiber, detoxify plant chemical defenses, and synthesize vitamins and nutrients that lemurs can’t make for themselves. Our own gut bugs do many of the same things for us.

Greene and McKenney study how lemur gut bacteria are shaped by what lemurs eat, how they evolved and the complexity of the route microbes travel through the body. They hope to better understand how these microorganisms keep lemurs healthy, or — when they’re out of balance — make them sick.

Researchers who do this kind of work spend a lot of time collecting poop. For good reasons, says McKenney, an assistant professor at North Carolina State University. Scientists can learn about lemurs by what they leave behind, and poop can be collected repeatedly without harming the animals. But for this study the team tried something different, made possible by a one-of-a-kind biobank:

When an animal dies at the Duke Lemur Center, veterinary staff determine the cause of death, and blood and tissue samples that might be important for research or education are collected and preserved.

Today, the collection holds thousands of samples, collected over decades from more than two dozen species of rare and endangered primates, which the center stores in super cold freezers in their headquarters in North Carolina. It’s a frozen ark maintained at up to minus 80 degrees Celsius, with redundant backup power.

In the event that any one of these species goes extinct, and the last living parts of them are gone, future generations will still be able to study the genetic and other information they left behind.

Using this bank, the team sampled several sites in the bowels of 52 deceased lemurs, including dwarf lemurs, aye-ayes, ruffed lemurs, bamboo lemurs, brown lemurs, ring-tailed lemurs and sifakas.

A trip through a lemur’s GI tract is a journey through a varied landscape. The long, twisting route from the stomach through the small intestine to the colon serves numerous functions, filtering, digesting, absorbing, detoxifying, fermenting.

Not all lemur guts work the same: Fruit-eaters, like ruffed lemurs, generally have short, simple guts. If you stretched them out, they’d be five times their body length — not much shorter than ours, relative to body size. Leaf-eaters like sifakas have more complex GI tracts with relatively longer colons and a leaf-fermentation pouch called a cecum. Their guts are the lemur champions — up to 16 times body length.

Having whole lemurs to study instead of just poo enabled the researchers to sample different regions of the gut to figure out what kinds of microbes were present in each spot. They used genetic sequencing technology to identify microbes and compare their relative abundance in different sites.

Sampling along the digestive tract, they found that different spots along this long, twisting pathway have their own communities of bacteria doing different kinds of jobs. The complex ecosystem lurking in a lemur’s small intestine, for example, isn’t the same as the microbial menagerie setting up camp in their colon.

Levels of biodiversity varied too. The stomach supports less microbial life because fewer species can tolerate its acidic digestive juices. But if the upper regions of the gut are a garden, the lower regions are more like a tropical rainforest. About two dozen types of bacteria were more abundant in the cecum and colon than elsewhere. Lemurs with relatively longer lower guts host the richest microbiomes, to better ferment high-fiber foods.

“We probably couldn’t have detected these relationships without such an extensive comparative dataset,” McKenney said.

“This kind of lemur research can really only be done at the Duke Lemur Center,” Greene said.

Rodelinda, a Coquerel’s sifaka lemur, munches on leaves at the Duke Lemur Center. Credit: Lydia Greene.

This research was supported by the National Science Foundation (DBI PRFB 1906416) and by a Duke Lemur Center Director’s fund.

CITATION: “Gut Site and Gut Morphology Predict Microbiome Structure and Function in Ecologically Diverse Lemurs,” Lydia K. Greene, Erin A. McKenney, William Gasper, Claudia Wrampelmeier, Shivdeep Hayer, Erin E. Ehmke, & Jonathan B. Clayton. Microbial Ecology, May 14, 2022. DOI: 10.1007/s00248-022-02034-4

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