If there was a contest for biggest female bullies of the animal world, lemurs would be near the top of the list. In these distant primate cousins, it’s the ladies who call the shots, relying on physical aggression to get their way and keep males in line.
Male and female blue-eyed black lemurs at the Duke Lemur Center. In these distant primate cousins, females get their way most of the time. Photo: David Haring.
Not all lemur societies are built about female rule, however. In one branch of the lemur family tree, some species have evolved, within the last million years, to have a more harmonious relationship between the sexes.
Now, new findings suggest that this amiable shift in lemurs was at least partly driven by changes in the action of the “love hormone” oxytocin inside their brains. The research could shed light on how hormones influence behavior in humans and other animals.
In a study published in the journal Biology Letters, Duke University researchers studied seven closely related lemur species in the genus Eulemur, noting which ones had domineering females and which were more egalitarian.
Take blue-eyed black lemurs, for example. Females get first dibs on food and prime resting spots; smacking, biting and chasing the males to get their way.
Their behavior isn’t the fierce protectiveness of a mother defending her babies, said senior author Christine Drea, a professor of evolutionary anthropology at Duke. Aggression in these females can be entirely unprovoked, simply to remind others who’s in charge.
“Males let females have priority access to whatever they want,” Drea said.
Others species, like the collared lemurs, are more peaceful and egalitarian, with males and females sharing equal status. “It’s more of an even playing field,” said first author Allie Schrock, who earned her Ph.D. in the Drea lab.
Collared lemurs huddle at the Duke Lemur Center. Photo: David Haring
The lemurs in the study died of natural causes some time ago, but their tissues live on, thanks to a bank of tissues from these endangered primates kept frozen at the Duke Lemur Center. Using an imaging technique called autoradiography, the researchers mapped brain binding sites for oxytocin, a hormone involved in social behaviors like trust and bonding.
The results revealed a striking pattern.
The researchers found that the more recently evolved egalitarian species had more oxytocin receptors than the others, essentially giving them more targets for oxytocin to act on.
The key difference was in the amygdala, a region of the brain typically associated with emotions such as fear, anxiety and anger.
The pattern held up for both sexes, suggesting that egalitarian species achieved gender parity by becoming less aggressive towards others overall, rather than males ramping up their aggression to match their female counterparts, Drea said.
In these cross-sectional images of two lemur brains, arrows show oxytocin binding in the amygdala in domineering and egalitarian species. Courtesy: Allie Schrock, Duke University
The potential implications go beyond lemurs, the researchers said. Problems with oxytocin signaling in the brain have been linked to aggression, personality disorders and autism in humans, rodents and other animals.
Next, the researchers plan to examine links between hormone receptors and additional aspects of social behavior in lemurs, such as whether they are solitary or social.
“There’s a lot more that we can learn from lemurs about how the brain regulates behavior,” Schrock said.
CITATION: “Neuropeptide Receptor Distributions in Male and Female Eulemur Vary Between Female-Dominant and Egalitarian Species,” Allie E. Schrock, Mia R. Grossman, Nicholas M. Grebe, Annika Sharma, Sara M. Freeman, Michelle C. Palumbo, Karen L. Bales, Heather B. Patisaul and Christine M. Drea. Biology Letters, March 19, 2025. DOI:10.1098/rsbl.2024.0647
Biomedical engineering. Climate science. Political science. Global Health.
While these departments are housed in buildings far from each other on campus, their current research was all spotlighted at the Duke Undergraduate Research Symposium on April 10. Over the course of two hours, 120 budding researchers presented their work in Penn Pavilion, eagerly chatting with peers, faculty, and community members alike.
Presenters, friends, and community members gathered in Penn Pavilion to hear opening remarks from the Undergraduate Research Support Office’s director.
The level of professionalism was obvious upon a glance at the poster titles. The symposium was strongly represented by the biomedical and health sciences; hence, membrane receptors and transport proteins bearing combinations of letters and numbers populated the majority of posters. However, many projects shared findings unrelated to enzymes or transgenic models: posters investigating “The Undocumented Republican Latino Vote” and “Palimpsest and Identity in Hong Kong” attracted as much attention.
I began my journey by talking to Eduardo Fadul Chavez, a junior who is researching chemistry. He gave me an invigorating talk on Nedd4 E3 ligase ligands (a field I admittedly have no background knowledge in). What was greatly appealing about his presentation was his focus on the relevance and impact of his team’s work, especially in innovating treatments for Parkinson’s and other cancers. “Yes, we hope to apply our findings from a pharmacological perspective,” Chavez said. “Nedd4 plays an important role in Parkinson’s disease, so figuring out how to inhibit its activity can greatly inform therapeutic development.”
Chavez’s poster on his work on Nedd4 ligase ligands, which play a role in Parkinson’s disease.
After this inspiring talk aiming to improve health and cure ailments from a biological perspective, I wandered around in search of a project looking into the sociocultural perspective. Walking across the room, I encountered Austin Brown and his colleagues presenting their work with the Help Desk.
“The Help Desk is a student-led initiative seeking to tackle social determinants of health,” Brown told me. The organization began as a Bass Connections project and has since attracted hundreds of student volunteers. Currently, about 50 volunteers work across three sites: the Duke Hospital Emergency Department, the Duke Endocrinology Clinic, and the Lincoln Community Health Center. “If patients screen positive on the background survey provided, our community resource navigators will provide support by connecting them with local organizations and follow up after the appointment to ensure they are doing well.”
The Help Desk has reached more than 3,200 patients since its inception, Brown said. Maintaining communication with patients after the initial meeting or appointment can be tricky, however. “Our biggest barrier is retention and keeping the channels of contact open,” Brown said.
By this point, I was already amazed by the depth and impact of my peers’ research. I was only more impressed when I came across the poster of Millie Evonlah, who presented on the impact of paternal cannabis consumption on adolescent offspring glutamatergic and cholinergic systems. Given the rise in recreational marijuana usage and legalization, there is a great need to study the impact of men’s usage, particularly intermittent usage, on their children’s brain regions regulating immune and cognitive function.
Evonlah in front of her poster on paternal cannabis exposure effects on adolescent offspring
“We hypothesized that there would be different expression results and responses between male and female offspring,” Evonlah said, “and our findings support this claim.” While there was decreased glutamatergic expression in the CA3 hippocampal region in both male and female offspring, males and females experienced increased acetylcholine expression in different brain regions. Additionally, only the “weekenders,” or animal subjects who partook in intermittent cannabis exposure, imparted significant biological alterations in their offspring’s brains.
All these presentations were inspiring to listen to, and selecting the few to cover in detail was a difficult task. However, I would be amiss not to mention a few other invigorating presentations I listened to. For instance, Michael Wang, who studied GRK-2 mediated regulation of brain-derived neurotrophic factor in the ischemic heart, and I had a lengthy conversation about daily research activities and cell culturing principles. I also had a spirited discussion with Madeline Morrison and her co-presenters, who talked about their experiences conducting fieldwork in Roatán, Honduras, and their perspectives on the importance of global health research.
After two hours of interacting with student researchers, it was clear to me that Duke’s research efforts indeed transform, improve, and save lives. The undergraduate student body’s collective desire to pursue scientific discovery, clinical innovation, and sociocultural advancement is a motivating force that cannot be understated.
Forests and farmland meet in the SAVA region of northern Madagascar. New research suggests that wildlife-human interactions in such areas could spread disease. Credit: James Herrera, Duke Lemur Center
COVID-19 continues to plague us, Mpox is an emerging global threat, and the avian flu is decimating industrial poultry as well as endangered wildlife. What do all these epidemics have in common? They originated in wild animals and spread to domestic animals and people.
This pattern of spread is a trademark of many diseases, termed zoonoses or zoonotic diseases. Our new research shows that in rural settings of Madagascar where forested landscapes were converted to agriculture and settlements, the potential transmission of a deadly virus, Hantavirus, is likely facilitated by invasive rodents, especially the black rat. Also responsible for cyclically occurring plague events in Madagascar, the black rats could be transmitting multiple diseases to people in rural communities, based on our studies.
The work was published April 7 in the journal Ecology and Evolution.
People can get Hantavirus from the droppings or urine of rodents like rats and mice. Credit: Wikimedia Commons
Hantavirus is mainly spread from rodents to people via exposure to their urine and feces in the environment, and being bitten. It can cause severe and deadly disease of the lungs and kidneys, resulting in fever, fatigue, aches and pains, followed later by coughing, shortness of breath, and fluid in the lungs, causing death in almost 40% of people who experience later-stage symptoms. In rural settings like in Madagascar, there are no tests available to diagnose Hantavirus, and the generalized symptoms are often confused for influenza or other diseases. With no specific treatment, either, Hantavirus is an important, though neglected, zoonotic pathogen.
This research, funded by the U.S. National Institute of Health and National Science Foundation, as well as Duke University, connects scientists from around the world with diverse specialties, including field biology, infectious disease epidemiology, social sciences, veterinary health, and more. Over the last eight years, our international and interdisciplinary team studied zoonotic pathogens in wildlife, domestic animals, and people. We compare how pathogens vary among different animals and in different landscapes.
Herrera and Malagasy student Tamby Ranaivoson check local mammals for pathogens.
There are more than 29 species of small mammals and another 12 species of bats in these wildlife communities, including native rodents and animals that look like hedgehogs and shrews but are a unique group from Madagascar, the tenrecs. There are also ubiquitous introduced mammals, including black rats, the house mouse, and the shrew, which have spread around the world wherever almost everywhere people go. We studied natural, pristine rainforests and compared to different features of the agroecosystem including regenerating forests, agroforests, and rice fields. We captured rodents and shrews in people’s households, as well, to compare how small mammals and zoonotic pathogens change over this gradient of human land use.
Our results show that black rats were the only species in our system that were infected with Hantavirus, with 10% of sampled individuals infected. Rat abundance and infection were higher in agricultural settings, including rice fields and agroforests, where rats were larger. While some rats in people’s homes were infected, no infected individuals were found in the more mature forests. Hantavirus infection was lower in the homes than in the agricultural fields, but exposure to infected rats is likely higher in homes because of the close contact in enclosed settings. The results highlight how infectious disease risk varies across the landscape because of complex impacts of human land use on natural ecosystems.
The Hantavirus results closely mirror those our team have shown for other disease-causing emerging pathogens, including Astroviruses and Leptospira. Rats and the house mouse were the most commonly infected species, and in the case of Astrovirus, only a single individual of a native species was infected. While Astrovirus infection was more common in the regenerating scrubby environments, Leptospira infection was most common in seasonally flooded rice fields. These varying landscapes of disease risk have important implications for the emergence of zoonotic diseases as well as applications to policy for public health.
Preserving natural forest and facilitating the regeneration of transformed forests may decrease disease risk because infected individuals were rarely captured in natural forests. This may be because there are natural predators to keep rodent populations in check, though further research is needed. Calls to eradicate black rat populations have seldom been successful, but through nature-based solutions like restoration to encourage natural predators, it may be possible to decrease abundance of nuisance rodents. Awareness-raising campaigns to teach about the signs and symptoms of common rodent-borne diseases for rural communities will also be rolled out, and encouraging local health care workers to check for these symptoms in the community members they serve.
We share our results with the Ministry of Public Health and Ministry of Environment and Sustainable Development, and will be organizing more think-tank meetings with relevant actors to co-design intervention strategies that can address these potentially emerging threats to human well-being.
By James Herrera, Ph.D., Duke Lemur Center SAVA Conservation Initiative
I had just spent the weekend at the Duke Marine Lab, listening to my classmates discuss solutions to the shrinking population of a critically endangered porpoise species. So when I attended the March 25 Oceans Week panel immediately after, marine megafauna were already at the forefront of my mind.
Image from Florida Fish and Wildlife Conservation Commission, CC BY-NC-ND 2.0
The open and interconnected nature of the ocean already presents unique conservation issues compared to terrestrial ecosystems, but it’s even more difficult to work on policies for marine megafauna that regularly traverse oceans. Countries establishing coastal estuaries or coral reefs as Marine Protected Areas (MPAs) can be effective for inhabitants like reef sharks that have limited ranges. However, protecting highly migratory animals like whale sharks and blue whales often requires international agreements and collaboration between countries.
To better protect these species, Dr. César Peñaherrera launched the nonprofit MigraMar, which researches them through extensive tagging in the Eastern Pacific and partners with a large network to share and aggregate data. They’ve tagged 642 hammerhead sharks so far, according to their website, and this is just one of the migratory species they work with. Peñaherrera, whose background is in quantitative marine science, spends much of his time when he isn’t in the field making sense of the vast sets of data points. One of MigraMar’s main goals is to provide evidence for greater connectivity between Marine Protected Areas. Think wildlife corridors, but underwater. By mapping out the most predictable migration routes for marine megafauna, they can inform the best routes for these “Swimways.”
Peñaherrera shared an image of a diver approaching hammerhead sharks with a pole spear, which helps them attach an acoustic tag to a shark.
Conserving sea turtles is a little different than other species–they face different threats throughout life as they go from land to sea and back to land to lay eggs. Carlos Diez, who researches turtles extensively at the Puerto Rico Department of Natural and Environmental Resources, outlined four “unresolved” main threats within terrestrial ecosystems: coastal development, light pollution, exotic species, and conflicts over habitat use.
Climate change also poses a potential threat, since sex determination in sea turtles is dependent on temperatures. As many parts of their range warm, the sex ratio of turtles in some locations has leaned increasingly female. That’s one area that Diez has conducted research in: determining when, where, and how much the balance of turtle sexes is changing.
While collecting accurate data on wildlife is necessary, the complexity of marine conservation hinges as much on the behavior of people as it does wildlife.
Perhaps that’s why shark researcher, science communicator and Puerto Rican native Melissa Cristina Márquez said one of her focuses is on the “human dimensions of shark conservation.”
Deep connection to the inhabitants of the oceans leads to more active conservation. Indigenous cultures, for example, have fished sustainably for ages. Márquez, who is currently based in Australia, said, “We’ve seen that a lot in Fiji, in Papua, New Guinea, with sharks and their cultural connection to sharks, and how that kind of spurred forward a bit more protection of those animals.”
“The cultural, historic and political contexts in conservation… these factors really shape the value placed on marine biodiversity, the policies that are developed and the resources that are allocated for conservation efforts,” she said.
As a fisheries officer for the Food and Agriculture Organization of the United Nations, Carlos Fuentevilla has a more specific focus when it comes to the human dimension: reconciling sustainable management with the need to feed people.
“We currently now eat around 20.7 kilograms per capita per day of food,” said Fuentevilla, pointing out that the world would have to ramp up production if this rate is to remain the same at 2050. “So it’s not a question of we have to eat less… It’s a question that we have to produce more–how can we do it sustainably?”
Much of it will have to come down to how we manage our fisheries. While most fish aren’t technically megafauna, Fuentevilla pointed out that marine megafauna regularly interact with, and are affected by, our fishing activities.
Fishery scientists will tell you they don’t manage fish, they manage people.
Scientists like Fuentevilla and those in government use ecosystem based management, which considers the species in an area as well as the stakeholders and competing interests that affect them, including fishermen and coastal developers. “You know, fishery scientists will tell you they don’t manage fish, they manage people, and that’s right,” Fuentevilla said.
The overarching theme is that the ocean is an open system, and nothing in marine conservation occurs in a vacuum. Fulfilling this work means having to go beyond national policy to international frameworks and understanding the other key players in sea and on land.
On the first Friday of each month, Duke Libraries will hold a “Flipping the Bird” event where members of the public can watch exhibit curators flip the pages of two of Audubon’s original “Birds of America” books.
At 12:15 PM on the first Friday of each month, you can watch Duke Libraries curators crank open a half-ton case made by the same company that designed the storage system for England’s Crown Jewels. Inside, protected by elaborate security features and carefully controlled temperature and light conditions, is a different collection of valuable, colorful items: Audubon’s “Birds of America” paintings.
“People love these birds for lots of different reasons,” said Duke Libraries Head of Exhibitions Meg Brown. The Audubon exhibit preserves and displays the birds while also raising awareness of Audubon’s complicated legacy as both a very talented artist and a deeply flawed man.
John James Audubon is one of ornithology’s most well known and mostcontroversialfigures. He painted 489 bird species with precision and accuracy, part of an ambitious and unfinished quest to paint every bird in America.
Even in his own lifetime, Audubon’s “Birds of America” paintings were very valuable. They were sold in “subscriptions” in which patrons would receive paintings periodically as loose sheets and then have them bound themselves. The frequency ranged from weeks to years depending on the speed of Audubon’s work. Today, more than a century and a half after Audubon’s death, his paintings remain subjects of fascination, value, and beauty. One reason the paintings are so valuable is that each set is unique. Audubon used between 20 and 40 colorists who applied color to each print by hand, meaning different copies of the same painting may have slightly different colors.
Approximately 120 complete “Birds of America” sets survive today. “Typically a ‘set’ is all four volumes,” said Aaron Welborn, Duke Libraries Director of Communications. Duke owns “one complete set of four volumes,” two of which are on display in the Mary Duke Biddle Room in Perkins. At the inaugural “Flipping the Bird” event earlier this month, Duke Libraries Head of Exhibitions Meg Brown spoke to visitors about what it takes to preserve and flip these fragile birds.
Head of Exhibitions Meg Brown and Exhibition Intern Grace Zayobi flip the pages of one of the two Audubon books on display in Duke Libraries.
The books are stored in glass and metal cases that weigh more than 1000 pounds according to Brown. The company that made these cases also made the glass under which England’s Crown Jewels are stored. The standard for the glass strength was that it had to be able to withstand 18 minutes of someone actively trying to break through.
The paintings are protected by another unusual security feature as well: “These won’t fit through any of our doors,” Brown said. The cases were brought in during library renovation, and their assembly was completed inside the library.
Duke acquired the collection from Margaret L. Barber, an art and antique collector who loaned items from her private collection for an exhibition in the Women’s College Library in 1931. Duke later purchased the “Birds of America” paintings from her. Originally all four were on display, but for preservation reasons only two are displayed at one time today.
Strips of Mylar—a soft, inert plastic—keep the open pages in place. Curators avoid putting the strips directly on the paintings, instead positioning them closer to the edges of the paper.
Preserving paintings from two centuries ago requires special care. Curators keep sheets of paper between the pages to prevent pigment from transferring to adjacent pages over time. And since watercolor is very sensitive to light exposure, the library uses strategically placed lamps to illuminate the pages without exposing them to bright light. (Specifically, they aim to keep ambient light under 6 foot candles.) UV light is particularly damaging. The exhibit is in an interior room that does not use UV lighting, but there is “one time of day, one time of year” when light streaming through the windows of Saladelia Cafe in Perkins Library can reach the Mary Duke Biddle Room, Brown explains, so the shades on the window facing the cafe are kept below the level that sunlight could reach.
Exhibit curators also monitor temperature and humidity using sensors in the glass cases. The two volumes not on display are kept in the library’s closed stacks, where the temperature is colder to help preserve the paintings. Every couple years the books on display are rotated out with those in the closed stacks.
From left: Yoon Kim, Senior Library Exhibition Technician; Meg Brown, Head of Exhibitions; and Grace Zayobi, Exhibition Intern.
Flipping such old and delicate pages is its own challenge. The display cases have a motorized system to lift the glass, allowing curators to flip the pages before sealing them inside again. The pages of the books on display are flipped once a month. The flipping used to happen when the exhibit was closed, but now any library visitor can witness the process themselves on the first Friday of each month, from 12:15-12:45 PM.
Yoon Kim and Grace Zayobi flipping the book from a page displaying raptors to a page showing the “Bachman’s Finch,” now known as the Bachman’s sparrow.
Though the Audubon exhibit is permanent, other exhibits in the space are temporary. A recent exhibit there has highlighted female scientific illustrators, including Maria Martin Bachman, who painted some of the floral backgrounds for Audubon’s birds. While that exhibit has been up, the library has been focused on “displaying pictures that [Martin] had a part in” rather than just flipping to the next page in order.
Bachman’s husband, Reverend John Bachman, was also a naturalist. He lived in South Carolina and collaborated with Audubon on a later collection of mammal paintings. Like Audubon, Bachman is also a controversial figure with multiple birds named after him. Thereisathemehere. Also like Audubon, the Bachmans owned enslaved people, some of whom were involved in the production of Audubon’s paintings. A man enslaved by the Bachman family, Thomas Skining, was very skilled at stuffing birds. “He became so good at it that he sort of became the main person who did it,” Brown said.
One of Audubon’s paintings depicts the Carolina parakeet, which he called the Carolina parrot. The species is now extinct. Image courtesy of the John James Audubon Center at Mill Grove, Montgomery County Audubon Collection, and Zebra Publishing.
Light, temperature, and humidity conditions are carefully controlled to help preserve the paintings.
“These are here forever,” Brown said. Audubon’s paintings remain widely loved and influential, and they will remain on display for people to admire, ponder, and learn from. At the same time, the Audubon exhibit seeks to raise awareness of Audubon’s complicated legacy and about the individuals involved in his work who he never fully credited in his lifetime. Context is important, Brown said, and “We never want to shy away from the truth and the history about the important stories that aren’t being told.”
You can view the “Birds of America” books in the Mary Duke Biddle Room, across from the main entrance to Perkins. The species on display this month are the Bachman’s sparrow on the right and mourning, blackburnian, and black-throated green warblers on the left. And at 12:15 on March 7 or the first Friday of any other month, you, too, can watch exhibit curators flip the birds.
Meet Ke Dong, a biology professor at Duke University. She’s a lover of nature, a great cook, and a Lupus survivor. About 20-25 years ago, she developed Lupus during her research years at Michigan State University. Her time with this autoimmune disease was not kind. “The Lupus brought depression,” she said.
Fortunately, she was surrounded by amazing peers and her passion: research. Dong’s research focuses on ion channels and their reaction to various toxins and stimuli. These ion channels are incredibly important to the physiology of insects because of their impact on neuronal activity.
Duke biology professor Ke Dong.
However, her passion didn’t develop from thin air. Dong grew up on a college campus in southeastern China. With both parents leading careers as professors — her father in history and her mother in biochemistry — she had the amazing opportunity to develop her passions early in childhood.
Growing up, she “had never been afraid of insects” as her mother’s work focused on the development of an increased production rate of silk in silkworms. However, it was the incidents in the area around her that sparked her passion. People in the area were often poisoned from the consumption of insecticides from the rice they were growing. This piqued her interest in toxicology as she was curious about how these insecticides were toxic to the townspeople.
Combining her fearlessness in the face of insects and her interest in toxicology, Dong has found the best of both worlds.
Dong also loves to dabble in the culinary worlds of a diverse range of cultures. As she travels from country to country, she brings with her the memorable flavors of each dish she tastes. Once arriving back home, she immediately purchases cookbooks from those countries to add to her rolodex of culinary skills. As she reads each recipe on her nightstand, she dreams of ways to introduce various flavors and techniques into her dishes. A creative cook, she has no time for following measurements. Her kitchen is her sandbox and allows her to dance with each flavor in her pot, adding less sugar but a little more salt.
Dong has been through ups and downs in her life, but there’s nothing that’s going to stop her from her passion: research.
Dr. Akankshi Munjal is a developmental biology researcher at Duke University, who studies the development and mutations of inner ear tissue in zebrafish, and how that may be caused by genome disorders.
Akankshi Munjal, assistant professor of cell biology
From a young age, Munjal has been fascinated by watching things being built and developed. Her grandfather was a civil engineer, and she was inspired by the many blueprints littering his home. Growing up, she wanted to be an architect.
Though she found inspiration elsewhere, and did not pursue architecture, in a way, her career mirrors this, “I guess I am not an architect, but I still watch embryos being built, so that kept with me – how you shape things.”
The inspiration of Munjal’s current career came to her in high school. Growing up, she lived in a large city in India, and did not have much exposure to science fields and research. “If you don’t see it around you, it’s not something you see as an option.”
However, she was able to find inspiration from a few of her instructors, “There were some teachers who were very inspiring in exposing that there is research out there, that you can be at the bench, ask questions, and address them using experiments.”
She was also involved with a project dealing with bacteria that could process heavy metals in the Yamuna river near Delhi, India, and this helped introduce the idea of research as a potential career path.
Though most of Munjal’s work has moved toward lab management, the research is what she really loves, “I could spend days in the microscope room, watching development happen.”
The interesting thing about zebrafish, is that their eggs are transparent, and develop outside of the parent organism. This provides an incredible way to observe the development of tissues under a microscope. Zebrafish also share 70% of the DNA of humans, which makes them a great model organism to observe human disorders and how they affect tissue. The ability to witness this development is Munjal’s favorite part of the job,“It’s why I love what I do, we are able to watch these things happen, in the lab.”
When asked what she wished she would’ve learned earlier on, she mentioned the classic comparison of teaching a man to fish, as opposed to giving him a fish. She applies this saying to the process of learning. In her earlier education, there was an emphasis on collecting and memorizing information and facts, rather than learning how to gather knowledge. An emphasis on academic intelligence, as opposed to emotional intelligence.
Looking back, this presentation and memorization of facts was less helpful, “Some of them are not facts, some of them are interpretations, so if there was more information on collecting knowledge, that would be more helpful.”
Munjal loves to watch things being developed. This not only applies to her research in developmental biology, and her former passion for architecture, but also to her love of collecting knowledge.
A few blocks from Duke’s East Campus, there is a small building whose past lives include a dentist office, a real estate office, and a daycare. Now it is a museum.
A mural on the back wall of the museum, showing animals like the elephant bird at full size. Photo courtesy of Matt Borths, Ph.D.
Glass cases in the front room are lined with ancient fossils and more recent specimens less than 10,000 years old. Take Lagonomico, a creature that lived some 12-15 million years ago and whose name means “pancake,” in reference to the smashed shape of its remains. Or the tiny skull of a modern-day cotton-top tamarin. Even the enormous egg of an elephant bird, a ten-foot-tall bird that lived in Madagascar until it went extinct sometime in the last 1000 years.
A back room holds fossil discoveries still encased in rock. Special tools and scanning technology will reveal the creatures inside, relics of a very different world that can still yield revelations millions of years after their deaths.
These fossils are still partly encased in rock. Special technology like CT scans can reveal which part of a rock contains a fossil. The marks on the paper indicate where a fossil is located.
Matt Borths, Ph.D., curator of the Duke Lemur Center’s fossils, explained that while many fossil collections focus on a particular location, this one has a different theme: the story of primate evolution.
Lemurs, Borths said, are our most distant primate relatives. About 60 million years ago, soon after the extinction of the dinosaurs, the “lemur line and monkey-ape-human line split.” Studying both modern lemurs and their ancestors can give us a “glimpse of a distant past.”
An ancient lemur ancestor from Wyoming. Primates went extinct in North America over 30 million years ago.
Primates are a group of mammals that include humans and other apes, monkeys, lemurs, lorises, bushbabies, and tarsiers. Many primates today live in Africa and South America, but they did not originate on either continent. Primates are believed to have evolved further north and migrated into Africa about 50 million years ago. As the global climate grew cooler and dryer, equatorial Africa remained warm and wet enough for primates. Over time, apes, monkeys, and lemurs diverged from their shared primate ancestors, but not all of them stayed in Africa.
Africa is currently home to bushbabies and lorises, which are both lemur relatives, but most of lemur evolution and diversification took place in Madagascar, the island nation where all of the world’s 100 species of lemurs live today. “New World monkeys,” meanwhile, are found in South America. How did lemurs and monkeys get from Africa—which was at the time completely surrounded by water—to where they live today? Both groups are believed to have crossed open ocean on rafts of plant material.
Scientists have direct evidence of modern animals rafting across bodies of water, and they believe that ancient lemur and monkey ancestors reached new land masses that way, too. Mangrove systems, adapted to ever-changing coastal conditions, are particularly prone to forming rafts that break away during storms. Animals that are on the plants when that happens can end up far from home. Not all of them survive, but those that do can shape the history of life on earth.
“Given enough time and enough unfortunate primates,” Borths said, “eventually you get one of these rafts that goes across the Mozambique Channel” and reaches Madagascar. Madagascar has been isolated since the time of the dinosaurs, and most of its species are endemic, meaning they are found nowhere else on earth. When lemur ancestors reached the island, they diversified into dozens of species filling different ecological niches. A similar process led to the evolution of New World monkeys in South America.
Some of the species in this case went extinct within the past few centuries.
The history of primate evolution is still a work in progress. The Duke Lemur Center Museum of Natural History seeks to fill in some of the gaps in our knowledge through research on both living lemurs and primate fossils. This museum, Borths said, “brings basically all of primate evolution together in one building.” Meanwhile, living lemurs at the Lemur Center can help researchers understand how primate diets relate to teeth morphology, for example.
Paleontology is the study of fossils, but what exactly is a fossil? The word “fossil,” Borths said, originally referred to anything found in the ground. Over time, it came to mean something organic that turns to stone. Some ancient organisms are not fully fossilized. They can still preserve bone tissue and even proteins, evidence that they have not yet transformed completely into stone. The current definition of a fossil, according to Borths, is “anything from a living organism that is older than 10,000 years old.” Specimens younger than that are called subfossils.
Fossil Preparator Karie Whitman in the Duke Lemur Center Museum of Natural History. The grooves in the stones are made by air scribe tools, which are used to separate fossils from surrounding rock.
The Lemur Center does important research on fossils, but that is not the only component of its mission. Education Programs Manager Megan McGrath said that the Lemur Center weaves together research, conservation, and education in an “incredibly unique cocktail” that “all forms a feedback loop.” McGrath and Borths also co-host a Duke Lemur Center podcast.
Conservation is a crucial component of the study of lemurs. Lemurs are the most endangered mammals on the planet, and some are already gone.
Human and wildlife survival are interlinked in complex ways, and conservation solutions must account for the wellbeing of both. Subsistence agriculture and other direct human activities can decimate ecosystems, but extinctions are also caused by broader issues like climate change, which threatens species on a global scale. Humanity’s impact on Madagascar’s wildlife over the last several thousand years is a “really complicated puzzle to tease apart,” McGrath said.
A display case in the museum, including an egg from the extinct elephant bird and a seed from a mousetrap tree. The mousetrap tree relies on large animals to disperse its seeds. That role was once filled by now-extinct species like the elephant bird. Now humans and cattle disperse the seeds instead.
Some of the museum’s specimens are truly ancient, but others are from modern animals or species that went extinct only recently. Giant elephant birds roamed Madagascar as recently as a thousand years ago. The sloth lemur may have survived until 400 years ago. Borths puts the timescale of recent extinctions into perspective. At a time when modern species like the white-tailed deer were already roaming North America, Madagascar was still home to creatures like sloth lemurs and ten-foot elephant birds.
A model of a sloth lemur skeleton (center, hanging from branch). Sloth lemurs lived in Madagascar until they went extinct about 400 years ago.
A model of a sloth lemur hangs in the museum, but no one alive has ever seen one breathing. No one will ever see or hear one again. But a ghost of it may exist in Malagasy stories about the tretretre, a monster that was said to have long fingers and a short tail. The word tretretre is thought to be an onomatopoeia of the call of a sloth lemur, an animal whose own voice is gone forever.
Learn about these and other stories of our evolutionary cousins at the museum’s next open house on Saturday, November 23, from 1-4 PM.
In some parts of the world, animals are going extinct before scientists can even name them.
Such may be the case for mouse lemurs, the saucer-eyed, teacup-sized primates native to the African island of Madagascar.
Various species of mouse lemurs found in Madagascar. Photos by Sam Hyde Roberts
There, deforestation has prompted the International Union for the Conservation of Nature (IUCN) to classify some of these tree-dwelling cousins as “endangered” even before they are formally described.
Duke professor Anne Yoder has been trying to take stock of how many mouse lemur species are alive today before they blink out of existence.
It’s not an easy task. Mouse lemurs are shy, they only come out at night, and they live in hard-to-reach places in remote forests. To add to the difficulty, many species of mouse lemurs are essentially lookalikes. It’s impossible to tell them apart just by peering at them through binoculars.
When Yoder first started studying mouse lemurs some 25 years ago, there were only three distinct species recognized by scientists. Over time and with advances in DNA sequencing, researchers began to wonder if what looked like three species might actually be upwards of two dozen.
In a new study, Yoder and dozens of colleagues from Europe, Madagascar and North America compiled and analyzed 50 years of hard-won data on the physical, behavioral and genetic differences among mouse lemurs to try to pin down the true number.
While many mouse lemur species look alike, they have different diets, and males use different calls to find and woo their mates, the researchers explain.
By pinning down their number and location, researchers hope to make more informed decisions about how best to help keep these species from the brink.
The study was published Sept. 27 in the journal Nature Ecology & Evolution.
Braxton Craven Distinguished Professor of Evolutionary Biology, Anne Yoder was director of the Duke Lemur Center from 2006 to 2018.
From tiny flies, Duke researchers are finding new clues to how the brain sets up its circuitry.
In her time at Duke, Khanh Vien figures she’s dissected close to 10,000 fly brains. For her PhD she spent up to eight hours each day peering at baby flies under the microscope, teasing out tiny brains a fraction the size of a poppy seed.
“I find it very meditative,” she said.
Vien acknowledges that, to most people, fruit flies are little more than a kitchen nuisance; something to swat away. But to researchers like her, they hold clues to how animal brains — including our own — are built.
While the human brain has some 86 billion neurons, a baby fruit fly’s brain has a mere 3016 — making it millions of times simpler. Those neurons talk to each other via long wire-like extensions, called axons, that relay electrical and chemical signals from one cell to the next.
Vien and other researchers in Professor Pelin Volkan’s lab at Duke are interested in how that wiring gets established during the fly’s development.
By analyzing a subset of neurons responsible for the fly’s sense of smell, the researchers have identified a protein that helps ensure that new neurons extend their axons to the correct spots in the olfactory area of the young fly’s brain and not elsewhere.
Because the same protein is found across the animal kingdom, including humans, the researchers say the work could ultimately shed light on what goes awry within the brains of people living with schizophrenia and other mental illnesses.
Their findings are published in the journal iScience.
Khanh Vien earned her PhD in developmental and stem cell biology in Professor Pelin Volkan’s lab at Duke.
