Geer Cemetary in Durham is one of many burial grounds in America that hold the remains of thousands of Black Americans from the 19th century. There are no records of the people buried there. The process of researching grounds like these as a form of reparations to descendent communities was pioneered by Michael Blakey in the African Burial Ground Project in Lower Manhattan, New York. He is currently the Director of the Institute for Historical Biology at the College of William and Mary.
On April 4, Blakey visited Duke as a guest of the Franklin Institute of Humanities, the Department of Classical Studies, the Department of International Comparative Studies, and Trinity College. In attendance to his lecture were students of Classical Studies 144: Principles of Archaeology with Alicia Jimenez, International Comparative Studies 283: Death, Burial, and Justice in the Americas with Adam Rosenblatt, and several graduate students by invitation (and me). His presence was clearly highly anticipated.
I initially approached Dr. Jimenez with my interest in bioarchaeology in January as I was planning my Program II application. She invited me to this seminar, and to lunch with Blakey and the graduate students beforehand. I came prepped with questions on osteopenia and hypertrophy, as well as a map of Brightleaf Square so I wouldn’t get lost (I still got lost) and a few dollars cash for parking (they only took card).
For those of you who have ever loved the detective fiction heroine Temperance Brennan, Blakey’s work is for you. He is co-chair of the Commission for the Ethical Treatment of Human Remains through the American Anthropological Association. He was claiming the title of bioanthropologist before it was cool. He wrote a guide for the profession called Engaging Descendant Communities, or, more lovingly, The Rubric. Blakey encourages allowing those descendant communities to guide scientists’ research on human remains. He calls us Homo reminiscens, because what makes us “human” may be our affinity for memorializing our dead as much as it may be our large brains (á la Homo sapiens). “Burial is human dignity,” Blakey announced during the seminar, “Dignity is what we do.”
“Ethical code is not law. It is our greatest responsibility.”
After all, science has historically been used to justify the unjust. Bioarchaeology is a famous contributor to the field; the pseudoscience of phrenology was upheld until well into the 20th century, and was originally used as “scientific proof” that people of African descent were lesser than Europeans. It was also cited as a justification for displacing Native Americans from their lands.
During lunch, I was struck by Blakey’s cadence. He had a deep, slow voice and spoke with intention. He ordered the giant pretzel. I never asked my questions; instead, I was swept away by the group’s discussion on ethics–a topic I had no open Safari tabs on. I asked instead why a scientist would choose to guide themselves entirely by a non-expert opinion rather than scientific inquiry; would that not hinder discovery?
The scientific method, as you may recall, starts with asking a question. Rather than gracefully including descendent communities after the paper has been written, Blakey urges scientists to only pursue questions about remains that the descendants wish to answer. The science of death should never be self-serving, he noted. There is no purpose to publishing a paper if it is not in the service of the community that provided the subject. A critical reader may notice that The Rubric is not called The Gospel or The Constitution. Rather than a rule of law, it is a guideline. That’s because ethics is based on the respect of self, of craft, and of others. “Ethical code is not law,” Blakey reminds scientists. “It is our greatest responsibility.”
Geer Cemetary has been the subject of Duke research for years now, from a Story+ program to class field trips. Members of ICS, CLST, and FHHI have been in cooperation with Friends of Geer Cemetary to answer such questions about burial conditions–the attempt at dignity granted to Black residents of Durham by their descendants.
Edit: a previous version of this article had incorrectly stated that the Department of African and African American Studies sponsored Michael Blakey’s lecture.
I recently had the pleasure of attending Professor Janet Malek’s lecture: Only Mostly Dead? The Evolving Ethical Evaluation of Death by Neurologic Criteria, a lecture sponsored by the Trent Center for Bioethics, Humanities & History of Medicine.
Dr. Malek is an associate professor in the Duke Initiative for Science & Society, and at the Baylor College of Medicine Center for Medical Ethics and Health Policy.
We don’t often talk about death. On the surface, it seems like it would be a straight-forward concept. You’re either dead, or you’re not dead. Right? It turns out that clinically defining death is not so simple.
Popular media has some grasp on the ambiguity of the definition of death. Remember this scene from the popular movie, The Princess Bride? Suspecting that the protagonist is dead, his friends bring him to a miracle-worker and have the following conversation.
Miracle Max: “Whoo-hoo-hoo, look who knows so much. It just so happens that your friend here is only MOSTLY dead. There’s a big difference between mostly dead and all dead. Mostly dead is slightly alive. With all dead, well, with all dead there’s usually only one thing you can do.
Inigo Montoya: What’s that?
Miracle Max: Go through his clothes and look for loose change.
In real life, death used to be determined by cardiopulmonary criteria – when the heart and lungs stop working. In recent decades the idea that death can be determined using neurologic criteria – when the brain stops working – has gained acceptance. As neuroscience and technology has evolved, so too have our definitions. Now that we know more about how the brain works, we know that there may be some brain activity even after a person has met the criteria for death by neurologic criteria (DNC). This leads to philosophically rich and practically relevant questions of ethics – for example, when do we stop providing life-sustaining care? In the field of bioethics and beyond, there is high demand for discussion on this topic.
There has been controversy over defining death since the 1650’s — when a woman named Anne Greene woke up after being hanged. It wasn’t until the 1980’s that a consensus definition of death was first identified. Here is a brief history:
Widespread availability of ventilators led to the identification of a state described as death of the neurological system.
Advances in organ transplantation foster discussion on the ethics of defining death.
A committee at Harvard Medical School examined the definition of Brain Death. They created a definition of “Irreversible Coma,” which focused on loss of neurological function.
The 1980 Uniform Determination of Death Act (UDDA) provided a legal basis for clinically determining death as: an individual who has sustained either 1) irreversible cessation of circulatory and respiratory functions OR 2) irreversible cessation of functions of the entire brain.
1981: President’s Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research report. Findings are centered on questions of functioning of the organism as a whole and the brain’s role in coordinating it.
Clinicians arrive at general agreement that a patient in a state of coma or unresponsiveness, without brainstem reflexes and who fails an apnea test is dead by neurologic criteria. Largely it is accepted that “brain death is death” but there is not complete consensus.
2013: Case of Jahi McMath. A 13-year old girl was declared “brain dead” in California, and a death certificate was issued. However, the family fought to have her maintained on life support. They moved to New Jersey, the only state which recognized objections to brain death, and the “brain dead” declaration was reversed. Jahi lived there for 4 years before passing away. This famous case caused people to reconsider the concept of brain death.
Recent innovations in heart transplantation technology will likely challenge the acceptance of the Dead Donor Rule (DDR) which requires that an individual is clinically declared dead before vital organs are removed for transplantation.
2021: Assembly of the Determination of Death Committee, tasked with updating the Uniform Determination of Death Act (UDDA). Duke faculty (and founding director of Science & Society) Nita Farahany, is involved with this process.
What ethical issues and practical questions challenging Death by Neurologic Criteria (DNC) today? Dr. Malek shared the following case.
Following a tragic car accident, Ms. Jones, a 20-year-old college student, was brought to the hospital, having suffered significant anoxic brain injury. The medical team determined that she met criteria for DNC. However, her family refused to allow for further testing. Several days passed. Ms. Jones was maintained on life support, during which she did not show signs of improvement. After several difficult conversations, the family consented for assessment and Ms. Jones was declared dead — using the criteria associated with DNC.
What is the proper amount of time to continue life-sustaining treatment if a physician suspects the patient will never recover?
Although this may sound like an uncommon occurrence, nearly half of neurologists have been asked to continue neurologic support for patients that may meet criteria for DNC.
Obligating life support for patients suspected of meeting DNC, either through the family’s refusal for testing or by direct request, would likely result in ethical harms such as violation of the dignity of decedent, unjustly using scarce resources, or causing moral distress in caregivers.
However, it may be permissible to maintain life support in these situations. Dr. Malek says that we do not yet have a good ethical framework for this. Reasonable accommodations that are in line with professional guidelines probably have minimal impact, and might provide some psychosocial benefits to families.
Is consent required to test for DNC? Should it be?
These are extremely difficult questions, and there is continuing controversy over what the correct answers should be. Dr. Malek advises medical experts to work with healthcare administrators to develop clear institutional policies.
Post by Victoria Wilson, 2023 MA student in Bioethics & Science Policy
Black-capped chickadees have an incredible ability to remember where they’ve cached food in their environments. They are also small, fast, and able to fly.
So how exactly can a neuroscientist interested in their memories conduct studies on their brains? Dmitriy Aronov, Ph.D., a neuroscientist at the Zuckerman Mind Brain Behavior Institute at Columbia University, visited Duke recently to talk about chickadee memory and the practicalities of studying wild birds in a lab.
Black-capped chickadees, like many other bird species, often store food in hiding places like tree crevices. This behavior is called caching, and the ability to hide food in dozens of places and then relocate it later represents an impressive feat of memory. “The bird doesn’t get to experience this event happening over and over again,” Aronov says. It must instantly form a memory while caching the food, a process that relies on episodic memory. Episodic memory involves recalling specific experiences from the past, and black-capped chickadees are “champions of episodic memory.”
They have to remember not just the location of cached food but also other features of each hiding place, and they often have only moments to memorize all that information before moving on. According to Aronov, individual birds are known to cache up to 5,000 food items per day! But how do they do it?
Chickadees, like humans, rely on the brain’s hippocampus to form episodic memories, and the hippocampus is considerably bigger in food-caching birds than in birds of similar size that aren’t known to cache food. Aronov and his team wanted to investigate how neural activity represents the formation and retrieval of episodic memories in black-capped chickadees.
Step one: find a creative way to study food-caching in a laboratory setting. Marissa Applegate, a graduate student in Aronov’s lab, helped design a caching arena “optimized for chickadee ergonomics,” Aronov says. The arenas included crevices covered by opaque flaps that the chickadees could open with their toes or beaks and cache food in. The chickadees didn’t need any special training to cache food in the arena, Aronov says. They naturally explore crevices and cache surplus food inside.
Once a flap closed over a piece of cached food (sunflower seeds), the bird could no longer see inside—but the floor of each crevice was transparent, and a camera aimed at the arena from below allowed scientists to see exactly where birds were caching seeds. Meanwhile, a microdrive attached to the birds’ tiny heads and connected to a cable enabled live monitoring of their brain activity, down to the scale of individual neurons.
Through a series of experiments, Aronov and his team discovered that “the act of caching has a profound effect on hippocampal activity,” with some neurons becoming more active during caching and others being suppressed. About 35% percent of neurons that are active during caching are consistently either enhanced or suppressed during caching—regardless of which site a bird is visiting. But the remaining 65% of variance is site-specific: “every cache is represented by a unique pattern of this excess activity in the hippocampus,” a pattern that holds true even when two sites are just five centimeters apart—close enough for a bird to reach from one to another.
Chickadees could hide food in any of the sites for retrieval at a future time. The delay period between the caching phase (when chickadees could store surplus food in the cache sites) and the retrieval phase (when chickadees were placed back in the arena and allowed to retrieve food they had cached earlier) ranged from a few minutes to an hour. When a bird returned to a cache to retrieve food, the same barcode-like pattern of neural activity reappeared in its brain. That pattern “represents a particular experience in a bird’s life” that is then “reactivated” at a later time.
Aronov said that in addition to caching and retrieving food, birds often “check” caching sites, both before and after storing food in them. Of course, as soon as a bird opens one of the flaps, it can see whether or not there’s food inside. Therefore, measuring a bird’s brain activity after it has lifted a flap makes it impossible to tell whether any changes in brain activity when it checks a site are due to memory or just vision. So the researchers looked specifically at neural activity when the bird first touched a flap—before it had time to open it and see what was inside. That brain activity, as it turns out, starts changing hundreds of milliseconds before the bird can actually see the food, a finding that provides strong evidence for memory.
What about when the chickadees checked empty caches? Were they making a memory error, or were they intentionally checking an empty site—even knowing it was empty—for their own mysterious reasons? On a trial-by-trial basis, it’s impossible to know, but “statistically, we have to invoke memory in order to explain their behavior,” he said.
A single moment of caching, Aronov says, is enough to create a new, lasting, and site-specific pattern. The implications of that are amazing. Chickadees can store thousands of moments across thousands of locations and then retrieve those memories at will whenever they need extra food.
It’s still unclear how the retrieval process works. From Aronov’s study, we know that chickadees can reactivate site-specific brain activity patterns when they see one of their caches (even when they haven’t yet seen what’s inside). But let’s say a chickadee has stored a seed in the bark of a particular tree. Does it need to see that tree in order to remember its cache site there? Or can it be going about its business on the other side of the forest, suddenly decide that it’s hungry for a seed, and then visualize the location of its nearest cache without actually being there? Scientists aren’t sure.
The Wild Ones club recently visited the Duke Forest with biology professor Paul Manos, Ph.D., and herpetology professor Ron Grunwald, Ph.D., to look for salamander eggs and other early spring delights.
It was warm and sunny, and wildflowers sprouted up alongside the trail, but most of the trees were still bare. “It’s kind of nice to look in a forest without any leaves,” says Manos. “They get in the way a lot.” We examined winged elm and shagbark hickory at the trailhead, then windflower and bluets right beside the path. Many early spring wildflowers take advantage of the higher levels of sunlight that reach the forest floor before trees develop leaves.
Manos was delighted to find a patch of sphagnum moss beside the trail. He says sphagnum, also known as peat moss, is usually found in higher latitudes, like the United Kingdom and Canada, where it grows in huge fields known as moorlands or quaking bogs.
When we reached a small pond, Grunwald swept a long-handled net through the water and leaf litter and pulled out a gelatinous glob that promptly became a highlight of my week/month/year: spotted salamander eggs. I don’t know what the rest of you spent your childhoods doing, but I spent a good portion of mine looking for frog eggs (and sometimes finding them) and wanting to find salamander eggs (and never finding them). But here they were, in front of me, tinted green with algae and glinting in the sunlight and close enough to touch.
This strikes me as an appropriate retort to many unrelated things. Calculus test? Yeah, okay, but I saw salamander eggs. The grosbeaks that Wild Ones went looking for two weeks ago are still thwarting me? Yes, and I still haven’t gotten over it. However: salamander eggs.
The egg mass was less firm and less slimy than I expected. It felt remarkably similar to jelly. “This gel,” Manos says, “apparently doesn’t allow oxygen to move through it very well,” but the developing spotted salamander larvae need oxygen. The solution is ingenious: a partnership with green algae. A species of algae grows on the egg masses and penetrates individual eggs, and eggs with more algae grow and develop faster.
The algae are photosynthetic, creating carbon and oxygen products from carbon dioxide gas and sunlight. That process likely provides supplemental oxygen to the salamander embryos, and one study found that the salamanders also absorb carbon produced by the algae’s photosynthesis.
That carbon fixation is the first known example of carbon transfer from algae to a vertebrate host, though similar partnerships have been found in invertebrates, and the authors of the study speculate that similar processes may be occurring in other amphibians as well.
The particular species of algae that grows on spotted salamander eggs is in the Oophila, which according to Manos means “egg lover.” The partnership, however, is temporary. “It’s a very short-lived, ephemeral story,” Manos says.
In addition to the spotted salamander eggs, Grunwald also found a marbled salamander larva. Marbled salamanders and spotted salamanders are in the same genus, but they have different approaches to breeding. Marbled salamanders, Grunwald explains, lay their eggs in the fall “where they think a pond is going to be” instead of waiting for ephemeral pools to develop in spring. How do they decide where to lay eggs if the pond isn’t even there yet? Scientists aren’t sure, but salamanders “live in a chemical world,” Grunwald says, relying on taste and chemical signals.
Since marbled salamanders laid their eggs last fall, their larvae have had time to hatch and start developing, though they aren’t yet adults. Spotted salamanders, meanwhile, don’t breed until spring—when the ponds actually exist—so their eggs haven’t yet hatched. For the larvae of both species, developing in small, temporary ponds helps protect them from large predators like fish.
Both marbled and spotted salamanders are in a genus sometimes called mole salamanders because they live underground when they’re not breeding. “There’s an entire city underground here of burrows and holes and crevices,” Grunwald says, a “whole porous network of spaces.” The mole salamanders can shelter underground, but they can’t travel far without coming back to the surface. “It’s not a highway,” Grunwald says.
I would like to know what it is like to be a mole salamander, navigating by taste and smell and spending much of the year in small spaces underground.
Before we left the forest, we went searching for lycophytes, an ancient lineage of plants that first evolved hundreds of millions of years ago. “In the Carboniferous Period 350 million years ago, these guys ruled,” Manos says. The lycophytes we saw in the Duke Forest were tiny, bright green sprigs in a small stream, but their ancestors were trees. Those ancient lycophyte trees are “responsible for all of the coal that we use,” says Manos. “The transformation of their organic material via millions of years of heat and pressure to metamorphic carbonized rock is the definition of coal.”
The lycophytes in the stream are members of the Isoetes genus, also known as quillworts. They look and feel much like grasses, but they are only distant relatives of true grasses. Grasses are flowering plants, while quillworts are lycophytes. Flowering plants and lycophytes diverged hundreds of millions of years ago. Lycophytes use spores to reproduce and have a life cycle similar to ferns. Even their leaves are anatomically and evolutionarily different from the leaves of flowering plants; lycophytes use “their own approach to making leaves,” according to Manos.
I have a nemesis (a bird that defies my searching). Actually, Ihaveseveral, but I have been preoccupied with this particular nemesis for months.
I have seen an evening grosbeak exactly once, in a zoo, which emphatically does not count. For years, I have been fixated on-and-off (mostly on) with the possibility of seeing one in the wild.
They have thick, conical beaks. The males are sunset-colored. (But good luck finding one at sunset, even though the first recorded sighting supposedly happened at twilight, hence their name.) I daydream about flocks of them descending on my bird feeders at home or wandering onto Duke’s campus. That hasn’t happened yet (unless it has happened while I have not been watching, an excruciating possibility I will simply have to live with).
Evening grosbeaks usually live in Canada and the northern U.S., but they are known to irrupt into areas farther south. Irruptions often occur in response to lower supplies of seeds and cones in a bird’s typical range, making it possible to predict bird irruptions, at least if you’re the famous finch forecaster. (Fun fact: “irrupt” literally means “break into,” whereas “erupt” means “break out.”)
Breaking news: The grosbeaks are in Durham, and they have been since December. I will wait while you perform any necessary reactions, including screaming, jumping up and down in delight, charging outside because you simply have to go find them right now, or telling me I must be mistaken.
I am not mistaken. There is a flock of evening grosbeaks overwintering at Flat River Impoundment, 11.8 miles from Duke University. I know this because I get hourly rare bird alerts by email, and I have been receiving emails about evening grosbeaks nearly every day for almost three months. Put another way, evening grosbeaks have been actively and no doubt intentionally taunting me for weeks on end.
Wild Ones, a student organization I’m involved with, had been thinking of organizing a birding trip. For reasons I will not even attempt to deny, I suggested Flat River Waterfowl Impoundment. Last Sunday, seven undergraduates drove there, armed with field guides and binoculars and visions of evening grosbeaks bursting into sight (okay, maybe that was just me).
The morning was chilly but sunny. Flat River is a gorgeous, swampy place full of small ponds and stretches of long grass edged with trees. As soon as we got there, we were serenaded with birdsong: the high, musical trill of pine warblers, the haunting coo of mourning doves, lilting Carolina wren songs, and squeaky-dog-toy brown-headed nuthatch calls.
It wasn’t long before people got to experience the frustrating side of birding. We were admiring a sparrow in a ditch, trying to guess its identity. Someone pulled out a field guide and flipped through the sparrow section only to turn back to the bird and find it gone. Birds can fly. But fortunately, we’d collectively noticed enough field marks to feel reasonably confident identifying it as a swamp sparrow.
Not long after the eagle sighting, we saw another flying raptor: an osprey. In fact, it must have been a good day for raptors because by the end of our trip we had recorded one osprey, two Cooper’s hawks, three bald eagles, and two red-tailed hawks.
We also saw a lot of birders—perhaps two dozen others, maybe more, not counting our own group. Each time we passed a group going in the opposite direction, I asked them if they’d found the grosbeaks.
I think everyone I asked had seen them, and they were all eager to point us in the right direction. Birders like to use landmarks like “by the eagles’ nest” and “the fifth pine on the right” and “past the crossbills.” We found the eagles’ nest, with help from some of the local birders. We think we found the fifth pine on the right, but there were a lot of pines there, so we’re not sure.
We did not find the red crossbills, another irruptive bird species overwintering here this year. (Crossbills are aptly named. The tips of their mandibles really do cross, which helps them access seeds inside cones.)
We found the spot where the evening grosbeaks had most recently been seen — just twenty minutes before we got there, according to the people we were talking to. We waited. We scrutinized the pine trees. We watched red-tailed hawks and bald eagles circle high above us. We admired the eagles’ nest, a huge collection of sticks high in a pine tree.
Would you like to guess what we did not find? My nemesis. Because the evening grosbeaks have devious minds and clearly flew all the way to Durham with the sole intent of hiding from me, dodging me, flying away as soon as I approached, and flying back again as soon as I was gone. (No, really. Other people reported them at Flat River that same day, both before and after our trip there.)
Birding can be intensely frustrating. It can plant images in your mind that will haunt you and taunt you for the rest of your life. Like, for instance, the tiny blue bird I caught a brief glimpse of in the trees one early morning in Yellowstone. For years, I wondered if it could have been a cerulean warbler, but cerulean warblers don’t live in the western U.S. Or let’s talk about the green bird—yes, I swear it was green; no, I can’t prove it—that came to my bird feeders several years ago and never came back. Not while I was watching, anyway. The only thing I can think of for that one is a female painted bunting, but painted buntings aren’t usually in upstate South Carolina. (If my local volunteer eBird reviewer in South Carolina ever happens to read this, I promise I won’t report either of those mystery sightings to eBird.) Or, of course, the evening grosbeaks that flew away twenty minutes before we arrived.
Birding can also be thrilling, meditative, and by all accounts wonderful. Yes, that little blue bird in Yellowstone and the maybe-green one in my backyard are branded in my memory, as are countless more moments of maybe and almost and what if? I will never know what they were. I will probably never get over it.
But there are other moments that stick in my mind just as clearly. The bald eagle soaring above us on this Wild Ones trip. The black-capped chickadee that landed on my finger years ago while my brother and I rested our hands on a bird feeder and waited to see what would happen. My first glimpse of a black-throated blue warbler (I am so proud of whoever named that bird species), chasing an equally tiny Carolina chickadee in my backyard.
The Cape May warbler I saw with a close friend in a small field covered in purple wildflowers. The first time I heard the loud, ringing Teacher-teacher-teacher! song of the ovenbird. A blackpoll warbler, the first I’d ever seen, in a grove of trees in a swampy field that only birders seem to find reason to visit.
The moment two Carolina wrens took food from my hand for the first time. Prothonotary warblers (another nemesis bird) practically dripping from the trees on a rainy, buggy hike along a boardwalk. The downy woodpecker that landed on my gloved hand, apparently too impatient to wait for me to finish what I was doing with the suet feeder, and pecked at the suet with that sharp beak, her black tongue flicking in and out, her talons clinging to me with a trust that brought tears to my eyes.
Birding can change you. It can make your world come alive in a whole new way. It can make traveling somewhere new feel all the more magical — a new soundscape, new flashes of colors and patterns, a new set of beings that make a place what it is. In the same way, birding can make home feel all the more like home. Even when I can’t name all the birds that are making noise in my yard, there is a familiarity to their collective symphony, a comforting sense of “You are here.” I encourage you to watch and listen to birds, too, to join the quasi-cult that birding can be, to trek through somewhere wet and dark when the sky is just beginning to lighten—or to simply step outside, wherever you are, and listen and watch and wait right here and right now. You don’t even need to know their names (though once you start, good luck stopping). And you certainly don’t need a nemesis bird. In fact, your birding experience will be calmer without one. But that might not be up to you, in the end. Nemesis birds have minds of their own.
When it comes to balancing the needs of humans and the needs of nature, “Historically it was ‘develop or conserve’ or ‘develop or restore,’” says Carter Smith, Ph.D., a Lecturing Fellow in the Division of Marine Science & Conservation who researches coastal restoration.
However, according to Brian Silliman, Ph.D., Rachel Carson Distinguished Professor of Marine Conservation Biology, “We are having a new paradigm shift where it’s not just… ‘nature over here’ and ‘humans over here.’”
Instead, conservation initiatives are increasingly focusing on coexistence with nature and ecological resilience, according to this panel discussion of marine science experts during Duke Research and Innovation Week 2023.
Nature-based solutions — protecting and restoring natural shoreline habitats — have a proven role in protecting and restoring coastal ecosystems. According to the International Union for Conservation of Nature (IUCN), “Nature-based solutions… address societal challenges effectively and adaptively, simultaneously benefiting people and nature.”
According to Smith, nature-based solutions can “leverage nature and the power of healthy ecosystems to protect people” while also preserving biodiversity and mitigating climate change. She spoke about living shorelines as an effective and ecologically responsible way to protect coastal ecosystems.
“The traditional paradigm in coastal protection is that you build some kind of hard, fixed structure” like a seawall, Smith said, but conventional seawalls can have negative effects on biodiversity, habitats, nutrient cycling, and the environment at large. “In this case, coastal protection and biodiversity really are at odds.”
After multiple hurricanes, living shorelines had significantly less visible damage or erosion than sites with conventional hardscape protection, like seawalls.
Nicholas Lecturing Fellow Carter Smith
That’s where living shorelines come in. Living shorelines incorporate plants and natural materials like sand and rock to stabilize coastal areas and protect them from storms while also creating more natural habitats and minimizing environmental destruction. But “if these structures are actually going to replace conventional infrastructure,” Smith says, it’s important to show that they’re effective.
Smith and colleagues have studied how living shorelines fared during multiple hurricanes and have found that living shorelines had significantly less “visible damage or erosion” compared to sites with conventional storm protection infrastructure.
After Hurricane Matthew in 2016, for instance, both natural marshes and conventional infrastructure (like seawalls) lost elevation due to the storm. Living shorelines, on the other hand, experienced almost no change in elevation.
Smith is also investigating how living shorelines may support “community and psychosocial resilience” along with their benefits to biodiversity and climate. She envisions future community fishing days or birdwatching trips to bring people together, encourage environmental education, and foster a sense of place.
PhD student Stephanie Valdez then spoke about the importance of coastal ecosystems.
“Blue carbon ecosystems,” which include sea grasses, marshes, and mangroves, provide services like stabilizing sediments, reducing the destructive force of powerful waves, and storing carbon, she said. These ecosystems can bury carbon much faster than terrestrial ecosystems, which has important implications when it comes to climate change.
In the atmosphere, carbon dioxide and other greenhouse gasses contribute to global warming, but plants pull carbon dioxide out of the air during photosynthesis and convert it to carbohydrates, releasing oxygen as a byproduct. Therefore, ecosystems rich in fast-growing plants can serve as carbon sinks, reducing the amount of atmospheric carbon, Valdez explained.
Unfortunately, blue carbon ecosystems have suffered significant loss from human activities and development. We’ve replaced these wild areas with farms and buildings, polluted them with toxins and waste, and decimated habitats that so many other creatures rely on. But given the chance, these places can sometimes grow back. Valdez discussed a 2013 study which found that seagrass restoration led to a significantly higher carbon burial rate within just a few years.
Sea grasses, marshes, and mangroves provide services like stabilizing sediments, reducing the destructive force of powerful waves, and storing carbon.
PhD Student Stephanie Valde
Valdez also talked about the importance of recognizing and encouraging natural ecological partnerships within and between species. Humans have taken advantage of such partnerships before, she says. Consider the “Three Sisters:” beans, corn, and squash, which Native Americans planted close proximity so the three crops would benefit each other. Large squash leaves could provide shade to young seedlings, beans added nitrogen to the soil, and cornstalks served as a natural beanpole.
Recognizing that mutualistic relationships exist in natural ecosystems can help us preserve habitats like salt marshes. Valdez points to studies showing that the presence of oysters and clams can positively impact seagrasses and marshes. In restoration, it’s important “that we’re not focusing on one species alone but looking at the ecosystem as a whole”—from top predators to “foundation species.”
“There is hope for successful restoration of these vital ecosystems and their potential to aid in climate change mitigation,” Valdez said.
Finally, Prof. Brian Silliman discussed the role of predators in wider ecosystem restoration projects. Prioritizing the protection, restoration, and sometimes reintroduction of top predators isn’t always popular, but Silliman says predators play important roles in ecosystems around the world.
“One of the best examples we have of top predators facilitating ecosystems and climate change mitigation are tiger sharks in Australia,” he says. When the sharks are around, sea turtles eat fewer aquatic plants. “Not because [the sharks] eat a lot of sea turtles but because they scare them toward the shoreline,” reducing herbivory.
However, Silliman said it’s unclear sometimes whether the existence of a predator is actually responsible for a given benefit. Other times, though, experiments provide evidence that predators really are making a difference. Silliman referenced a study showing that sea otters can help protect plants, like seagrasses, in their habitats.
Restoring or reintroducing top predators in their natural habitats can help stabilize ecosystems impacted by climate change and other stressors.
And crucially, “Predators increase stress resistance.” When physical stressors reach a certain point in a given ecosystem, wildlife can rapidly decline. But wildlife that’s used to coexisting with a top predator may have a higher stress threshold. In our ever-changing world, the ability to adapt is as important as ever.
“I think there is great optimism and opportunity here,” Silliman says. The other speakers agree. “Right now,” Valdez says, “as far as restoration and protection goes, we are at the very beginnings. We’re just at the forefront of figuring out how to restore feasibly and at a level of success that makes it worth our time.”
Restoring or reintroducing top predators in their natural habitats can help stabilize ecosystems impacted by climate change and other stressors.
Smith emphasized the important role that nature-based solutions can play. Even in areas where we aren’t achieving the “full benefit of conserving or restoring a habitat,” we can still get “some benefit in areas where if we don’t use nature-based solutions,” conservation and restoration might not take place at all.
According to Valdez, “Previously we would see restoration or… conservation really at odds with academia itself as well as the community as a whole.” But we’re reaching a point where “People know what restoration is. People know what these habitats are. And I feel like twenty or thirty years ago that was not the case.” She sees “a lot of hope in what we are doing, a lot of hope in what is coming.”
“There’s so much that we can learn from nature… and these processes and functions that have evolved over millions and millions of years,” Smith adds. “The more we can learn to coexist and to integrate our society with thriving ecosystems, the better it will be for everyone.”
DURHAM, N.C. — Some of us live and die by our phone’s GPS. But if we can’t get a signal or lose battery power, we get lost on our way to the grocery store.
Yet animals can find their way across vast distances with amazing accuracy.
Take monarch butterflies, for example. Millions of them fly up to 2,500 miles across the eastern half of North America to the same overwintering grounds each year, using the Earth’s magnetic field to help them reach a small region in central Mexico that’s about the size of Disney World.
Or sockeye salmon: starting out in the open ocean they head home each year to spawn. Using geomagnetic cues they manage to identify their home stream from among thousands of possibilities, often returning to within feet of their birthplace.
Now, new research offers clues to how migrating animals get to where they need to go, even when they lose the signal or their inner compass leads them astray. The key, said Duke Ph.D. student Jesse Granger: “they can get there faster and more efficiently if they travel with a friend.”
Many animals can sense the Earth’s magnetic field and use it as a compass. What has puzzled scientists, Granger said, is the magnetic sense is not fail-safe. These signals coming from the planet’s molten core are subtle at the surface. Phenomena such as solar storms and man-made electromagnetic noise can disrupt them or drown them out.
It’s as if the ‘needle’ of their inner compass sometimes gets thrown off or points in random directions, making it hard to get a reliable reading. How do some animals manage to chart a course with such a noisy sensory system and still get it right?
“This is the question that keeps me up at night,” said Granger, who did the work with her adviser, Duke Biology Professor Sönke Johnsen.
Multiple hypotheses have been put forward to explain how they do it. Perhaps, some scientists say, migrating animals average multiple measurements taken over time to get more accurate information.
Or maybe they switch from consulting their magnetic compass to using other ways of navigating as they near the end of their journey — such as smell, or landmarks — to narrow in on their goal.
In a paper published Nov. 16 in the journal Proceedings of the Royal Society B, the Duke team wanted to pit these ideas against a third possibility: That some animals still manage to find their way, even when their compass readings are unreliable, simply by sticking together.
To test the idea, they created a computer model to simulate virtual groups of migrating animals, and analyzed how different navigation tactics affected their performance.
The animals in the model begin their journey spread out over a wide area, encountering others along the route. The direction an animal takes at each step along the way is a balance between two competing impulses: to band together and stay with the group, or to head towards a specific destination, but with some degree of error in finding their bearings.
The scientists found that, even when the simulated animals started to make more mistakes in reading their magnetic map, the ones that stuck with their neighbors still reached their destination, whereas those that didn’t care about staying together didn’t make it.
“We showed that animals are better at navigating in a group than they are at navigating alone,” Granger said.
Even when their magnetic compass veered them off course, more than 70% of animals in the model still made it home, simply by joining with others and following their lead. Other ways of compensating didn’t measure up, or would need to guide them perfectly for most of the journey to accomplish the same feat.
But the strategy breaks down when species decline in number, the researchers found. The team showed that animals who need friends to find their way are more likely to get lost when their population shrinks below a certain density.
“If the population density starts dropping, it takes them longer and longer along their migratory route before they find anyone else,” Granger said.
Previous studies have made similar predictions, but the Duke team’s model could help future researchers quantify the effect for different species. In some runs of the model, for example, they found that if a hypothetical population dropped by 50% — akin to what monarchs have experienced in the last decade, and some salmon in the last century — 37% fewer of the remaining individuals would make it to their destination.
“This may be an underappreciated aspect of concern when studying population loss,” Granger said.
This research was supported in part by the Air Force Office of Scientific Research (FA9550-20-1-0399) and by a National Defense Science & Engineering Graduate Fellowship to Jesse Granger.
CITATION: “Collective Movement as a Solution to Noisy Navigation and its Vulnerability to Population Loss,” Jesse Granger and Sönke Johnsen. Proceedings of the Royal Society B, Nov. 16, 2022. DOI: 10.1098/rspb.2022.1910
With mask mandates being overturned and numerous places going back to “normal,” COVID is becoming more of a subconscious thought. Now, this is not a true statement for the entire population, since there are people who are looking at the effects of the pandemic and the virus itself.
I attended a poster presentation for the “The Pandemic Divide” event hosted here at Duke by the Samuel Dubois Cook Center on Social Equity. To me, all the poster boards conveyed the theme of how COVID-19 had affected our lives in more ways than just our health. One connection that particularly caught my eye would be the one between American Education and COVID.
As a student who lived through COVID while attending high school, I can safely say that the pandemic has affected education. However, based on the posters I saw, it is important to know that education, too, has a strong and impactful impact on COVID-19.
The first evidence I saw was from Donald J. Alcendor, an associate professor of microbiology and immunology at Meharry Medical College in Nashville. His poster was about the hesitancy surrounding COVID-19 vaccines. One way he and his team figured out to lessen the hesitance from the public was to improve the public’s trust. To achieve this, Alcendor and his team sent trusted messengers into the community. One of the types of messengers they provided was scientists who studied COVID-19. These scientists were able to bring factual information about the disease, how it spreads, and the best course of action to act against it. Alcendor and his research team also brought in “vaccine ambassadors” to the community and a mobile unit to help give the community vaccines. He noted that this was accomplished with support from the Bloomberg Foundation’s Greenwood Initiative, which addresses Black health issues.
With this mobile unit, Alcendor and his team were able to reach people and help those who were otherwise unable to receive help for themselves because of their lack of transportation. They provided people from all backgrounds with help and valuable information.
Alcindor said he and his team planned pop-up events based on where the community they were trying to reach congregates. With the African American community, he planned pop-up events at churches and schools. Then for the Latino community, he planned pop-events where families tend to gather, and he held events in Latin0 neighborhoods. In addition, he made sure that the information was available in Spanish at all levels, from the flyers and the surveys, to the vaccinators themselves.
All of these amenities that he and his group provided were able to educate the community about COVID-19 and improve their trust in the scientists working on the disease. Alcendor and his team were able to impact COVID-19 through education, and by going to the event, it was evident to me that he was not the only one who accomplished this.
Colin Cannonier, an associate professor of economics at Belmont University in Nashville, asked and answered the question, “does education have an impact on COVID? Specifically, does it change health and wellbeing?” To answer this question, he researched how education about COVID can affect a person. He discovered that when a person is more educated about COVID, how it is spread, and its symptoms, they are more likely to keep the pandemic in check through their behavior. He came to this conclusion because he realized that when higher educated people know more about COVID, they exhibit behaviors to remain healthy, meaning that they would follow the health protocols given by the health officials.
While this may seem like common sense that the more educated a person is, the more they make smart choices pertaining to COVID, this shows how important education is and how deadly ignorance is. Cannonier’s research gave tangible evidence to show that education is a weapon against diseases. Unfortunately, it is evident that some officials did not believe in educating the public about the virus or the virus itself, and that proved to be extremely deadly.
To fully capture the relationship between COVID and education, one must also talk about how COVID-19 affected education.
Stacey Akines, a history graduate student at Carnegie Mellon University, studied how education was changed by the pandemic.
First, she realized that COVID schooling crossed over with homeschooling. Then she uncovered that more Black people started to research and teach their children about Black history. This desire to teach youth more about their history caused an increase in the number of Black homeschoolers. In fact, the number of Black homeschoolers doubled during the fall of 2020. While to some, this change to homeschooling may have a negative impact on one’s life, it actually gives the student more opportunities to learn things.
It is no secret that there are many books being banned here in the U.S., and there are many state curriculums that are changing to erase much of Black history. Homeschooling a child gives the parent an opportunity to ensure that the education they receive is true to and tells their history
Unlike me, where during high school, education felt lackluster and limited because of COVID, some parents saw an opportunity to better their child’s education.
I hope that it is clear that the relationship between COVID and education is a complex one. Both can greatly impact each other, whether it’s for the better or for the worse. COVID thrives when we are uneducated, and it very nearly destroyed education too, but for the efforts of some dedicated educators.
Some dogs have to eat in a high chair—or, more specifically, a Bailey Chair. The chair keeps them in a vertical position while they eat so that gravity can do the work their bodies can’t: moving food from the mouth to the stomach.
These dogs have megaesophagus, an esophagus disorder that can prevent dogs from properly digesting food and absorbing nutrients. When you swallow a bite of food, it travels down a muscular tube, the esophagus, to the stomach. In humans, the esophagus is vertical, so our esophageal muscles don’t have to fight against gravity. But because dogs are quadrupeds, a dog’s esophagus is more horizontal, so “there is a greater burden on peristaltic contractions to transport the food into the stomach.” In dogs with megaesophagus, the esophagus is dilated, and those contractions are less effective. Instead of moving properly into the stomach, food can remain in the esophagus, exacerbating the problem and preventing proper digestion and nutrient absorption.
Leigh Anne Clark, Ph.D., an associate professor at Clemson University, recently spoke at Duke about megaesophagus in dogs and its genetic underpinnings. She has authored dozens of publications on dog genetics, including five cover features. Her research primarily involves “[mapping] alleles and genes that underlie disease in dogs.” In complex diseases like megaesophagus, that’s easier said than done. “This disease has a spectrum,” Clark says, and “Spoiler: that makes it more complicated to map.”
Clinical signs of megaesophagus, or mega for short, include regurgitation, coughing, loss of appetite, and weight loss. (We might use the word “symptom” to talk about human conditions, but “a symptom is something someone describes—e.g., I feel nauseous. But dogs can’t talk, so we can only see ‘clinical signs.’”) Complications of mega can include aspiration pneumonia and, in severe cases, gastroesophageal intussusception, an emergency situation in which dogs “suck their stomach up into their esophagus.”
Sometimes megaesophagus resolves on its own with age, but when it doesn’t it requires lifelong management. Mega has no cure, but management can involve vertical feeding, smaller and more frequent meals, soft foods, and sometimes medication. Even liquid water can cause problems, so some dogs with mega receive “cubed water,” made by adding a “gelatinous material” to water, instead of a normal water bowl.
In dogs, mega can be either congenital, meaning present at birth, or acquired. In cases of acquired megaesophagus, the condition is “usually secondary to something else,” and the root cause is often never determined. (Humans can get mega, too, but as with acquired mega in dogs, mega in humans is usually caused by a preexisting condition. The best human comparison, according to Clark, might be achalasia, a rare disorder that causes difficulty swallowing.) Clark’s current research focuses on the congenital form of the disease in dogs.
Her laboratory recently published a paper investigating the genetic foundation of mega. Unlike some diseases, mega isn’t caused by just one genetic mutation, so determining what genes might be at play required some genetic detective work. “You see mega across breeds,” Clark says, which suggests an environmental component, but the disease is more prevalent in some breeds than others. For instance, 28 percent of all diagnoses are in German shepherds. That was a “red flag” indicating that genes were at least partly responsible.
Clark and her collaborators chose to limit their research study to German shepherds. Despite including a wide range of dogs in the study, they noticed that males were significantly overrepresented. Clark thinks that estrogen, a hormone more abundant in females, may have a protective effect against mega.
Clark and her team performed a genome-wide association study (GWAS) to look for alleles that are more common in dogs with mega. One allele that turned out to be a major risk factor was a variant of the MCHR2 gene, which plays a role in feeding behaviors. In breeds where mega is overrepresented, like German shepherds, “we have a situation where the predominant allele in the population is also the risk allele,” says Clark.
Using the results of the study, they developed a test that can identify which version of the gene a given dog has. The test, available at veterinary testing companies, is designed “to help breeders reduce the frequency of the risk allele and to plan matings that are less likely to produce affected puppies.”
It’s not enough to just publish a great scientific paper.
Somebody else has to think it’s great too and include the work in the references at the end of their paper, the citations. The more citations a paper gets, presumably the more important and influential it is. That’s how science works — you know, the whole standing-on-the-shoulders-of-giants thing.
So it always comes as a chest swelling affirmation for Dukies when we read all those Duke names on the annual list of Most Cited Scientists, compiled by the folks at Clarivate.
This year is another great haul for our thought-leaders. Duke has 30 scientists among the nearly 7,000 authors on the global list, meaning their work is among the top 1 percent of citations by scientific field and year, according to Clarivate’s Web of Science citation index.
As befits Duke’s culture of mixing and matching the sciences in bold new ways, most of the highly cited are from “cross-field” work.
Duke’s Most Cited Are:
Biology and Biochemistry
Charles A. Gersbach
Robert J. Lefkowitz
Christopher Bull Granger
Pamela S. Douglas
Adrian F. Hernandez
Manesh R. Patel
Eric D. Peterson
Tony Jun Huang
Edward A. Miao
David B. Mitzi
Christopher B. Newgard
John F. Rawls
Drew T. Shindell
Pratiksha I. Thakore
Mark R. Wiesner
Barton F. Haynes
Neuroscience and Behavior
Quinn T. Ostrom
Pharmacology and Toxicology
Evan D. Kharasch
Plant and Animal Science
Sheng Yang He
Psychiatry and Psychology
William E. Copeland
E. Jane Costello
Terrie E. Moffitt
Michael J. Pencina
John W. Williams
Congratulations, one and all! You’ve done us proud again.