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

Category: Animals Page 1 of 14

Why Ruffed Lemurs (and Their Gut Microbes) Need to Eat Greens

Sticky post

We offered fruit-eating ruffed lemurs at the Duke Lemur Center fresh lettuce each afternoon for 10 days. They happily ate it and their gut microbiomes shifted, suggesting that leafy greens could be incorporated into the lemurs’ standard dietary regimen to boost foraging opportunity and fiber intake.

Red-ruffed lemurs and black-and-white ruffed lemurs are some of Madagascar’s most iconic wildlife. Sporting a long snout and a neck ruff to rival those of the Elizabethan court, these primates naturally live in the rainforests, where they mostly eat fruits and flowers, and make their living as seed dispersers and pollinators.

Ruffed lemurs really like romaine lettuce and their gut bugs do too! (Lydia Greene)

Ruffed lemurs also live in zoos worldwide, where they are given fruit-rich diets to match those foraged by their wild peers. But scientists are starting to realize that the fruit eaten by wild lemurs is quite different from the domesticated fruit provided at zoos. Wild fruits are seedy, pulpy, and thick-skinned, whereas orchard fruits are fleshy, plump, and sweet. From a nutritional standpoint, wild fruits contain more fiber, whereas orchard fruits contain more sugar. 

Our team wondered if a fiber boost might benefit Duke’s ruffed lemur colony. But would these fruit-loving lemurs eat their veggies?  

Cue the salad bar.

To test this idea, we offered ruffed lemurs at the Duke Lemur Center a lot of lettuce. Lettuce seemed like a pretty palatable way to stimulate foraging behavior, while boosting fiber intake.

With help from the research department, we offered 19 ruffed lemurs 150-200 grams of romaine lettuce each day, which is about double the weight of their standard diet. We repeated this regimen every day for 10 days, while recording the lemurs’ feeding behavior and collecting fecal samples for gut microbiome analysis. Because gut microbes are chiefly responsible for converting plant fiber into energy for the lemurs, measuring changes to the lemurs’ microbiomes offered a way to ‘see’ the impact of lettuce consumption.

It turns out that ruffed lemurs really like lettuce. They consistently ate lettuce every day and showed no decline in consumption across the study. Younger animals ate more lettuce than did geriatric lemurs, but all lemurs spent more time crunching on lettuce stalks than the leaves.

And their gut microbiomes responded. We noted two microbes that were more abundant on the lettuce diet: a known fiber digester from the Ruminococcaceae family, and a microbe known for its positive association with host health in other animals called Akkermansia.

Despite their classification as fruit eaters, ruffed lemurs readily eat lettuce. We think lettuce can be used to extend the lemurs’ foraging time while boosting dietary fiber. And it might just help replicate the lifestyles experienced by wild ruffed lemurs in their native Malagasy rainforests.     At the Duke Lemur Center, lettuce is now a routine item offered to ruffed lemurs (and other species too!). Next time you come out for a tour (once it’s safe to do so), you might get to see them crunching away on their new favorite snack!

( Read our paper here: https://onlinelibrary.wiley.com/doi/abs/10.1002/zoo.21555 )

Guest Post by Lydia Greene Ph.D., an NSF-sponsored postdoctoral fellow in biology working at the Duke Lemur Center.

Saving Africa’s Biggest Trees to Help Earth Breathe

Sticky post

Like wine, cheese, and savvy financial investments, many tropical trees become more valuable with age. This is particularly true when it comes to carbon storage, because old trees are often the biggest trees and the larger the tree, the more carbon it stores.

The value of big, old trees in combating climate change was underscored in a recent study of Gabon’s forests, led by the Nicholas School of the Environment’s John Poulsen. The team’s striking finding — that half of Gabon’s wealth of carbon is found in the largest 5% of trees — has implications that reach far beyond the sparsely populated Central African country’s borders.

Nicholas School Ph.D. student Graden Froese admires a forest giant in Ivindo National Park, Gabon.

Tropical forests play a key role in the global carbon cycle by keeping carbon out of the atmosphere. Trees take in CO2 — one of the infamous, heat-trapping greenhouse gases — during photosynthesis and use the carbon to grow, making new leaves, thicker and taller trunks, and more expansive root systems.

Scientists can estimate how much carbon a tree holds by measuring its trunk. So, like rainforest tailors, trained technicians traveled to all corners of the country to measure the girth and height of tens of thousands of trees.

This extraordinary two-year long effort was one of the first nationwide forest inventories in the tropics, making Gabon a leader in comprehensive forest monitoring.

John Poulsen is an associate professor of tropical ecology.

Poulsen and collaborators used the tree measurements to estimate the amount of carbon stored in Gabon’s forests and to determine why some forests hold more carbon than others.

“The field techs deserve all the credit”, Poulsen explained, “as they often walked for days through thick forest, traversing swamps and enduring humid, buggy conditions to measure trees. We turned their sweat and toil into information that could be used by Gabon’s government to prioritize areas for conservation.”

Who needs ladders, when you have colleagues? The field team collaborates to measure a forest giant.

The team analyzed a suite of environmental factors to see their effects on carbon storage. Of the natural factors, only soil fertility had a noticeable positive effect on tree biomass. Much more important was the impact of humans. As human activities such as agriculture and logging tend to target large trees, more heavily human-disturbed forests had a much different structure than pristine forests. The farther a study area was from human settlements, the more likely it was to host large trees and consequently, higher amounts of carbon.

The paper notes that Gabon stands out as a country with “one of the highest densities of aboveground forest carbon.” In fact, Gabon’s undisturbed forests store more carbon than those in the Amazon, which have been referred to as the lungs of the planet.

According to Poulsen, “Gabon is the second most forested country in the world with 87% forest cover, a deforestation rate near zero…” Because of its impressive forest cover and its location straddling the equator, Gabon’s forests host an incredibly diverse array of plants and animals, including many threatened and endangered species. Rural communities depend on these forests for their livelihoods.

Unfortunately, even Gabon’s ‘small’ trees make for spectacular felled logs.

However, Gabon’s impressive forests are valuable to more than just wildlife, climate researchers, and local communities. The logging industry also sees these forests as a chance for profit. More than half (about 67%) of Gabon’s forests are under contract with logging companies to harvest timber, putting them at risk of losing many of their carbon-storing giants.

Poulsen’s study highlights the importance of a more nuanced approach to forest conservation in Gabon. One that doesn’t simply focus on stopping deforestation or promoting restoration, as is prescribed in many international climate change plans, but an approach that recognizes the necessity of preserving high conservation value, old growth forests.

Anna Nordseth

Guest Post by Anna Nordseth, a graduate student in the Nicholas School of the Environment.

Following In The Footsteps of Elephants

Sticky post

Imagine for a moment that you’re 6,000 pounds, living in one of the wildest places on Earth, with no schedule, nowhere to be. How do you decide where to spend your time? Where to go next? Do you move where food is most plentiful? Is water your main priority?

Amelia Meier in the field.

These are some of the questions addressed by Duke Ph.D. candidate Amelia Meier and former postdoctoral researcher Dr. Chris Beirne in Dr. John Poulsen’s lab. Their recent study published in Trends in Ecology and Evolution focused on the African forest elephant–the slightly smaller yet still undeniably huge cousin of the savanna elephant.  

The team wanted to know what influences certain aspects of elephant behavior. Specifically, how much climate and resource availability drives elephant movement and influences their diet. To do this, the team looked at fruit abundance (a high-energy staple of elephants’ diets), water availability from rainfall, and elephant identity and how those factors affect how an individual moves and eats.

One might think that such a massive animal is easy to spot in the forest. However, the dense vegetation of Central African rainforests can be an impenetrable wall, allowing the massive animals to move unseen through the forest, leaving broken branches and steaming dung piles in their wake.

To better track them, the researchers fitted individual elephants with GPS collars that turn an iPhone into an elephant-tracking tool. This also allowed trackers to follow the elephants at a distance and avoid conflict with the sometimes temperamental animals.

Collared elephant, Marijo, (left) enjoying the rich minerals found at the Langoue Bai forest clearing.

Meier, Beirne, and colleagues also wanted to know more about the diets of the tracked elephants to see if what they ate changed with how much fruit is available. This less-than-glamorous job was done by dissecting fresh dung piles, estimating the proportions of leafy and woody material, and counting the number of seeds in each one.

Tropical rainforests are lush, yet have patchy resources, making it important for many frugivores to have flexible diets. Some trees only produce fruit in the wet season. Others fruit every other year. To gauge fruit availability, the research team conducted “fruit-walks” at the beginning and end of each day of following an elephant, in which trackers counted all of the ripe fruit on the ground.

A key finding of the study was that the most important factor driving movement was an elephant’s individuality; some respond to food or water availability differently and some simply move around more than others.

Field researcher Marius Edang getting the straight poop on elephant diets.

Interestingly, elephants appear to be affected by resources differently depending on the timescale the authors looked at. Water was important on both a day-to-day and month-to-month basis. Yet on a daily basis, fruit and water were more equally matched, with water still maintaining a slight lead.

Fruit availability was also critical in determining how much elephants moved and what they ate. When there was more fruit available, the elephants ate more fruit, as evidenced by the proportion of seeds in dissected dung piles.

Aside from being an awe-inspiring species, forest elephants are important to the health of their native ecosystems. They are unwitting gardeners, planting seeds of the fruits they consume in piles of dung and giving those seeds a better chance of survival. That’s part of why understanding what motivates forest elephant movement is more than the satisfaction of an elephant enthusiast’s curiosity; it is critical to managing and conserving a species that is vulnerable to multiple threats from humans.

Meier’s dissertation research focuses on elephant social behavior and the effects of human disturbance on elephant social groups, allowing her to pursue her long-term interest in animal behavior with a practical conservation application.

“I was living in Congo and I knew I wanted to keep working in the region. There, you have elephants–this amazing, highly intelligent, social species that is surrounded by conflict.”

Poachers seek elephants for their ivory tusks, which are valuable on the black market. The pachyderms are also prone to conflict with humans when they start foraging in village plantations, destroying crops and damaging livelihoods.

The team’s findings open the way for new questions about why different elephants exhibit different patterns of movement. What underlying factors affect behavior, and why? Does it have to do with age? Sex? Their social environment?

These questions remain unanswered for now, but the work of Meier and colleagues represents a critical step in understanding elephant behavior to improve forest elephant management and conservation strategies.

Guest Post by Anna Nordseth, a Ph.D. Candidate in the Nicholas School of the Environment

Squirmy Science

Unearthing A New Way Of Studying Biology

Yes, students, worms will be on the test. 

Eric Hastie, a post-doctoral researcher in the David Sherwood Lab, has designed a hands-on course for undergraduates at Duke University in which biology students get to genetically modify worms. Hastie calls the course a C.U.R.E. — a course-based undergraduate experience. The proposed course is designed as a hands-on, semester-long exploration of molecular biology and CRISPR genome editing.

An image taken of the adult gonad structure of a C. elegans worm in the Sherwood Lab,

In the course, the students will learn the science behind genome editing before getting to actually try it themselves. Ideally, at the course’s end, each student will have modified the genome of the C. elegans worm species in some way. Over the course of the semester, they will isolate a specific gene within one of these worms by tagging it with a colored marker. Then they will be able to trace the inserted marker in the offspring of the worm by observing it through a microscope, allowing for clear imaging and observation of the chosen characteristic.

When taught, the course will be the third in the nation of its kind, offering undergraduates an interactive and impactful research experience. Hastie designed the course with the intention of giving students transferrable skills, even if they choose careers or future coursework outside of research.

“For students who may not be considering a future in research, this proposed class provides an experience where they can explore, question, test, and learn without the pressures of joining a faculty research lab,” he told me.

Why worms? Perhaps not an age-old question, but one that piqued my interest all the same. According to Hastie, worms and undergraduate scientific research pair particularly well: worms are cost-effective, readily available, take up little space (the adults only grow to be 1mm long!), and boast effortless upkeep. Even among worms, the C. elegans species makes a particularly strong case for its use. They are clear, giving them a ‘leg up’ on some of their nematode colleagues—transparency allows for easy visibility of the inserted colored markers under a microscope. Additionally, because the markers inserted into the parent worm will only be visible in its offspring, C. elegans’ hermaphroditic reproductive cycle is also essential to the success of the class curricula.  

Undergraduate researcher David Chen studying one of his worm strains under a microscope.

“It’s hard to say what will eventually come of our current research into C. elegans, but that’s honestly what makes science exciting,” says undergraduate researcher David Chen, who works alongside Hastie.  “Maybe through our understanding of how certain proteins degrade over time in aging worms, we can better understand aging in humans and how we can live longer, healthier lives.”

The kind of research Hastie’s class proposes has the potential to impact research into the human genome. Human biology and that of the transparent, microscopic worms have more in common than you might think— the results derived from the use of worms such as C. elegans in pharmaceutical trials are often shown to be applicable to humans. Already, some students working with Hastie have received requests from other labs at other universities to test their flagged worms. So perhaps, with the help of Hastie’s class, these students can alter the course of science.

“I certainly contribute to science with my work in the lab,” said junior Ryan Sellers, a research contributor. “Whether it’s investigating a gene involved in a specific cancer pathway or helping shape Dr. Hastie’s future course, I am adding to the collective body of knowledge known as science.”

Post by Rebecca Williamson

For Lemurs, Water Holes Are a Matter of Taste

It’s 1 PM and you’re only halfway through a 6-hour hike, climbing in steep terrain under a 100° cloudless sky. Your water bottle is nearly empty, and you’ve heard the worst of this hike is yet to come.

And then, just as you are making peace with the fact that you may collapse from dehydration at any second, you approach a small river. The germaphobe side of your brain is shouting for you not to drink from that. The dehydrated animal in you, however, is seriously considering it.

What do you do?

That is the question that Dr. Caroline Amoroso and her collaborators from Duke’s department of evolutionary anthropology, set out to answer. With a slight difference: rather than unprepared hikers, they asked that question to red-fronted lemurs in Madagascar.

Although we often associate Madagascar with lush forests, some regions have a very marked dry season during which water becomes a limited resource. Water holes are few and far apart.

A red-fronted lemur in Kirindy Forest, Madagascar, tanks up at a watering hole. (Photo: Caroline Amoroso)

“On my first visit to Kirindy forest I was amazed at how these waterholes – which are essentially just puddles of standing water – serve as a source of life for so many animals,” says Amoroso.

However, with animals, comes poop. Throughout the season, these water holes quickly become contaminated with fecal matter from all the mammals, birds and reptiles that come have a drink. Amoroso says that fecal contamination was easily detectable even to human observers. “Approaching some waterholes I could tell that lemurs had been there recently because their droppings left such a smell!”

By experimentally manipulating water quality, following groups of radio-collared lemurs and observing lemur behavior at natural water holes, Amoroso and her team found that, all else being equal, lemurs prefer to drink clean water.

Indeed, when offered the choice between a bucket of clean water and a bucket of water containing lemur feces that had been disinfected by boiling, to kill all possible pathogens, lemurs virtually always drank from the clean water bucket. When the buckets were removed and lemurs had to go visit natural water holes, however, they prioritized water holes closer to their resting site, even if they were more contaminated than further ones. Proximity was more important than cleanliness, but if multiple water holes were at similar distances, then lemurs seem to choose the least-contaminated source.

“I was surprised to find evidence that the lemurs chose natural waterholes with lower levels of fecal contamination,” says Amoroso. “I thought that [in a natural setting] avoidance of fecal contamination would be relatively low on the lemurs’ list of priorities.”

After some watchful waiting for predators, and a discussion perhaps, a quartet of Kirindy lemurs visits a tiny watering hole. (Photo: Caroline Amoroso)

The authors highlight that many other factors can influence a lemur’s choice of water hole, such as exposure to potential predators or visits by competing groups. Indeed, Amoroso says that drinking water can be a very risky business for lemurs: “Lemurs would spend upwards of thirty minutes scanning the vegetation nervously and making sure there was no sign of predators before approaching the waterhole and drinking.”

Lemurs prefer clean water, unless it’s too much trouble. In that hike you were on? Lemurs would definitely drink from the river.

Guest Post by Marie Claire Chelini, a postdoctoral fellow in evolutionary anthropology.

Man’s Best Friend, Our Relationship to Dogs

The average dog costs its human owner $10,000-20,000 over the course of its lifetime, from vet care and grooming to treats and toys to the new fad of doggie DNA testing. But what’s in it for us? Researcher Kerri Rodriguez – a Duke alum of evolutionary anthropology and current grad student with Purdue University’s College of Veterinary Medicine – explores just that.

Rodriguez is a member of the OHAIRE Lab at Purdue, which stands for the Organization for Human-Animal Interaction Research and Education. Continuing her work from undergrad, Rodriguez researches the dynamic duo between humans and dogs – a relationship some 15,000 to 40,000 years in the evolutionary making. Rodriguez returned to Duke to speak on February 12th, honoring both Darwin Day and Duke’s second annual Dog Day.

It’s well-known that dogs are man’s best friend, but they do much more than just hang out with us. Dogs provide emotional support when we are stressed or anxious and are highly attentive to us and our emotional states.

In a study of 975 adult dog owners, dogs ranked closely to romantic partners and above best friends, children, parents, and siblings when their owners were asked who they turn to when feeling a variety of ways. Dogs provide non-judgmental support in a unique way. They have also been found to reduce levels of the stress hormone cortisol, lower perceived stress in individuals, improve mood, and improve energy up to 10 hours after interactions. Therapy dogs are prevalent on many college campuses now due to these impacts and are found in hospitals for the same reasons, having been found to reduce subjective pain, increase good hormones and dampen bad ones, causing some patients to require less pain medications.

(Creative Commons)

 Along with reduced stress, dogs make us healthier in other ways, from making us exercise to reducing risk of cardiovascular disease. A study of 424 heart attack survivors found that non-dog owners were four times more likely to be deceased one year after the attack than victims who owned dogs.

The increased social interaction that dogs offer their human companions is also quite amazing due to the social facilitation effect they provide by offering a neutral way to start conversations. One study with people who have intellectual disabilities found that they received 30% more smiles along with increased social interactions when out in public with a dog. Similar studies with people who use wheelchairs have produced similar results, offering that dogs decreased their loneliness in public spaces and led to more social engagements.

Rodriguez also shared results from a study dubbed Pet Wingman. Using dating platforms Tinder and Bumble, researchers found that after one month, simulated profiles containing pictures with dogs received 38% more matches, 58% more messages, and 46% more interactions than simulated profiles without. Even just having a dog in photos makes you appear more likable, happier, relaxed, and approachable – it’s science!

 A large bulk of Rodriguez’s own work is focused on dogs in working roles, particularly the roles of a service dog. She explained that unlike therapy or emotional support dogs, service dogs are trained for one person, to do work and perform tasks to help with a disability, and are the only dogs granted public access by the American Disability Association. Rodriguez is particularly interested in the work of dogs who help American veterans with post-traumatic stress disorder (PTSD).

(Creative Commons)

 Around one out of five post-9/11 military veterans have PTSD and the disorder is difficult to treat. Service dogs are becoming increasingly popular to help combat effects of PTSD, ranking at the third highest placed type of service dog in the United States. PTSD service dogs are able to use their body weight as a grounding method, provide tactile interruption, reduce hypervigilance, and prevent crowding of their veterans. However, because of the lack of research for the practice, the Veterans Association doesn’t support the use of the dogs as a therapy option. This is an issue Rodriguez is currently trying to address.           

 Working with a group called K9s for Warriors, Rodriguez’s research evaluated the mental health, social health, quality of life, and cortisol levels of veterans who have received service dogs and those who were on the wait list for dogs. Veterans with service dogs had lower PTSD symptoms, better mental health, and better social health. Rodriguez is now working on a modification to this study using both veterans and their spouses that will be able to measure these changes to their well-being and health over time, as well as assessing the dog’s health too. Unlike other organizations, K9s for Warriors uses 90% shelter dogs, most of which are mutts. Each dog is as unique as the human it is placed with, but no bond is any less special.

By Cydney Livingston

The Anthropology of “Porkopolis”

Alex Blanchette, cultural anthropologist and lecturer in anthropology and environmental studies at Tufts University, is a scholar of pork production.

As America’s pork industry is continually pushed to ever greater production, so are the human beings who labor to breed, care for, and slaughter these animals.

Blanchette, who gave a talk hosted by the Ethnography Workshop at Duke on November 4th, said there is an intimate relationship between pig and person. The quality of the factory farm worker’s life is tied to that of the porcine species.

Alex Blanchette of Tufts University

Blanchette’s current work will be published in the 2020 ethnographic book – Porkopolis: American Animality, Standardized Life, and the “Factory” Farm. The book is focused on the consequences of human labor and identity that are bound to the pig – an animal which has become more industrialized over time due to corporations’ goal of a mass produced, standardized pig predictable in nature, uniform in existence, and easy to slaughter.

A common practice in factory farming is the ‘runting’ of litters, genetically making piglets smaller to increase the number each sow produces. But this practice has propelled a fundamental shift in the need for human workers to act as neonatal nurses, what Blanchette calls “external prosthetics,” to care for the newborns. Blanchette described one extraordinary worker responsible for taking care of piglet litters, saving the weak and deformed after birth. She has taken measures so drastic as to give a piglet mouth-to-mouth, incubate them in her pockets, and quickly form body-casts out of duct-tape for the small creatures. This worker has had the chance to study over 400,000 piglets in her seven-year career, encountering conditions of the pig body that no scientist has seen in real life.

Blanchette explained the active engagement required in any portion of the factory production. For example, people working with pregnant sows have to be extremely conscious of the way that the pigs are perceiving them to keep the sensory state of the mother pigs balanced. This means avoiding touching them unless work requires it, not wearing perfumes on the job, and taking overall care and precision in every motion throughout the workday. The danger is the risk of causing mass miscarriages and spontaneous abortions within a barn of sows because of their genetically engineered weakness and inability to handle stresses.

Piglets nursing in a device known as a farrowing crate.

Blanchette said one worker could be seen standing in the exact same place over the course of 1,000 compiled picture frames. He developed this habit to prevent large hogs in open pens from knocking him down and biting his legs while he was working. This is something that Blanchette said he couldn’t manage for more than a few minutes even though he too has worked within the pork industry before.

Workers on slaughter and “disassembly” lines are responsible for making the same exact cut or slice 9,500 times a day.

And finally, the conformation of human labor to the precisions of the factory pig often does not stop at the end of the work shift. In rural factory farming areas, corporations try to re-engineer the human communities in which their workers live to further regulate the human body outside of work because of potential impacts on the pigs. For example, workers’ socialization has been monitored by companies in some cases due to the threat of communicable disease reaching the hogs through human kinship.

No worker knows the pig from birth to death, but for the individual portion of the pig’s life for which they are responsible, they are bound intimately and intricately to the hog, Blanchette said. These people are also disproportionately people of color and immigrant workers who are underpaid for how strenuous, demanding, and encapsulating this labor is. Workers in factory farms often have little protections, and Blanchette’s work gives new life to the consequences of industrial capitalism in America as the pig has become a product of vertical integration in rural communities.

We have long been moving at the speed limits of human physiology in the pork industry,  Blanchette said. In 2011, one company’s annual effort to improve their corporation was to build a new human clinic on the jobsite to treat cuts and injuries acquired on the slaughter lines. This clinic was also responsible for assessing new hires in order to match the strongest part of their body to a place on the line where they would be most productive.

The interior of a typical confined animal feeding operation (CAFO).

Factory farms are actively searching for new money to be found in the pig and to have a closed-loop system which uses every aspect of its life and death for profit. This has caused a deep integration of the “capital swine” into everyday human life for the laborers and communities sustained by these economic ventures.

The Trump administration recently removed standards for pork slaughter line speeds and ultimately reduced overall regulations. People like Blanchette are already considering something you too might be wondering, What happens next? Where does pork and the human labor behind it go from here?

Post by Cydney Livingston

Legendary Paleontologist Richard Leakey Visits Duke

Hoping to catch up with an old friend who is a professor at Duke, Richard Leakey accepted an invitation to speak at the university on Oct. 22, though he “gave up public speaking to a large extent many years ago.”

Richard E. Leakey visited Duke on Oct. 22, 2019.

Leakey, age 74, is a world-renowned pioneer in Paleoanthropology – the study of the human fossil record – and is also well-known for his involvement in Kenyan politics and lifelong efforts towards conservation and wildlife protection. Once, he famously burned twelve tons of elephant tusks that were confiscated from poachers, which gathered international attention and helped usher in a global ban on the ivory trade.

Leakey came to paleontology by heredity. He is one of an entire family of Paleo-pioneers. His mother, Mary, discovered a skull in Africa that was dated to 1.75 million years ago (MYA) in 1960. Leakey said that this “electrified interest in the origin story” – that is, the human origin story. When his father, Louis, showed that the “quite clever” ancient tools he had discovered were made around 1.75 MYA, the original idea that human origins began outside of Africa began to change.

Leakey said the British people were hoping that “if we had evolved … let it happen in England” and if not England, then Asia, but this was not to be the case. At first, Louis Leakey was ostracized because of his work and discoveries of human origins in Africa. This helped steer Richard away from academics because of the fights that he saw his father endure.

Leakey’s famous 1984 Kenyan discovery, “Turkana Boy,” a 1.5 million-year-old, nearly-complete specimen of Homo erectus. (Wikipedia)

Successfully achieving his self-described ambition to not finish high school, Richard Leakey was thrown out of school at age 16. Yet today he is accredited with many awards, has written at least eight books, and has advanced the Leakey family legacy of discovery. From 1968 to the present day, he and fellow workers have discovered enormous numbers of fossils of our ancestors along the East and West shores of Lake Turkana in Kenya, which have an age span from 4.5 MYA to our very recent ancestors, which Leakey calls “fossil us.”

Leakey described for the Duke audience in an overflowing auditorium at the Nasher Museum a scenario he facilitated with colleagues and students.

He had taken a group to a camp site to talk about evolution and asked them to perform some tasks. First, they were charged to make tools from stone. The following day, they were led to a freshly slaughtered goat. Leakey told his pupils to butcher the goat and remove the flesh from its carcass.

After several hours watching the individuals try to pull at the goat with their hands to no avail, Leakey suggested that they might use their new stone tools. So they did, but they still could not get through the animal’s tough hide, even with a blade.

He said that during human evolution, our imagination was turned on genetically and this gave early humans the “capability to think of things that weren’t.” There is lots of work to be done studying an ancient period over 3.5 million years that Leakey says lends itself to “early ancestry of speech, imagination, [and] cooperation.” He is hopeful for the knowledge and new understandings that will come from investigation of this period. 

“Why not ask someone to help you?” Leakey prompted again, and within an hour, nothing was left of the goat. The exercise demonstrated that though other monkeys and apes use stone, it is the human’s vocal communication and sense of working together that sets us apart, says Leakey.     

Leakey’s current project is a “mega-museum” to “cerebrate and celebrate the story of the African origin.” The origin story which his parents first provided crucial evidence for is hugely important to the African continent and to the people of Africa and because we have “desecrated our motherland,” he said. Leakey wants the museum to highlight stages of evolution, genetics, climate, ecology, other species, and extinctions.

An architectural rendering of Ngaren: The Museum of Humankind to be built near Nairobi. (Studio Libeskind )

Before moving into the panel and Q&A portion of his talk, which was moderated by Duke professors Steven Churchill and Anne Yoder, Leakey prompted the audience to think about climate change, asking why we do not think we need to save ourselves. If we die, then other species go with us.

“Don’t for a minute think that climate change isn’t a real crisis that we’re in together,” Leakey said, earning a round of applause.

Post by Cydney Livingston

Love at First Whiff

Many people turn to the Internet to find a Mr. or Ms. Right. But lemurs don’t have to cyberstalk potential love interests to find a good match — they just give them a sniff.

A study of lemur scents finds that an individual’s distinctive body odor reflects genetic differences in their immune system, and that other lemurs can detect these differences by smell.

Smell check: Fritz the ring-tailed lemur sniffs a tree for traces of other lemurs’ scents at the Duke Lemur Center.
Smell check: Fritz the ring-tailed lemur sniffs a tree for traces of other lemurs’ scents. Photo by David Haring, Duke Lemur Center.

From just one whiff, these primates are able to tell which prospective partners have immune genes different from their own. The ability to sniff out mates with different immune genes could make their offspring’s immune systems more diverse and able to fight more pathogens, said first author Kathleen Grogan, who did the research while working on her Ph.D. with professor Christine Drea at Duke University.

The results appeared online August 22 in the journal BMC Evolutionary Biology.

Lemurs advertise their presence by scent marking — rubbing stinky glands against trees to broadcast information about their sex, kin, and whether they are ready to mate.

Lemurs can tell whether a mate’s immune genes are a good genetic match by the scents they leave behind.
Lemurs can tell whether a mate’s immune genes are a good genetic match by the scents they leave behind. Photo by David Haring, Duke Lemur Center

For the study, Grogan, Drea and colleagues collected scent secretions from roughly 60 lemurs at the Duke Lemur Center, the Indianapolis Zoo, and the Cincinnati Zoo. The team used a technique called gas chromatography-mass spectrometry to tease out the hundreds of compounds that make up each animal’s signature scent.

They also analyzed the lemurs’ DNA, looking for differences within a cluster of genes called MHC that help trigger the body’s defenses against foreign invaders such as bacteria and viruses.

Their tests reveal that the chemical cocktail lemurs emit varies depending on which MHC types they carry.

To see if potential mates can smell the difference, the researchers presented lemurs with pairs of wooden rods smeared with the bodily secretions of two unfamiliar mates and observed their responses. Within seconds, the animals were drawn to the smells wafting from the rods, engaging in a frenzy of licking, sniffing, or rubbing their own scents on top.

In 300 trials, the team found that females paid more attention to the scents of males whose immune genes differed from their own.

MHC genes code for proteins that help the immune system recognize foreign invaders and distinguish “friend” from “foe.” Since different genetic versions respond to different sets of foreign substances, Grogan said, sniffing out genetically dissimilar mates produces offspring more capable of fighting a broad range of pathogens.

Just because females spent more time checking out the scents of dissimilar males doesn’t necessarily make them more likely to have kids together, Grogan said. Moving forward, she and her colleagues plan to use maternity and paternity DNA test results from wild lemurs living in Beza Mahafaly Reserve in Madagascar to see if lemur couples are more different in their MHC type than would be expected by chance.

Similar results have been found in humans, but this is the first time the ability to sniff out partners based on their immune genes has been shown in such distant primate kin, said Grogan, who is currently a postdoctoral fellow at Pennsylvania State University.

“Growing evidence suggests that primates rely on olfactory cues way more than we thought they did,” Grogan said. “It’s possible that all primates can do this.”

This research was supported by the National Science Foundation (BCS #0409367, IOS #0719003), the National Institutes of Health (F32 GM123634–01), and the Duke University Center for Science Education.

CITATION: “Genetic Variation at MHC class II Loci Influences Both Olfactory Signals and Scent Discrimination in Ring-Tailed Lemurs,” Kathleen E. Grogan, Rachel L. Harris, Marylène Boulet, and Christine M. Drea. BMC Evolutionary Biology, August 22, 2019. DOI: 10.1186/s12862-019-1486-0

Post by Robin A. Smith

Alex Dehgan and The Snow Leopard Project

Traveling through war-torn areas at risk of encountering landmines, militia, and difficult terrain, Alex Dehgan was protected only by a borrowed Toyota Corolla. Dehgan, the Chanler Innovator in Residence at Duke, has spent much of his life overseas addressing conflict in Afghanistan through promoting wildlife conservation.

As a result, Dehgan has served in multiple positions within the U.S. Department of State, including the office of the secretary, and the bureau of Near Eastern affairs. There, he aided in addressing foreign policy issues in Iran, Iraq, and Egypt and contributed to the improvement of science diplomacy. Recently, he founded the Office of Science and Technology as the Chief Scientist at the U.S. Agency for International Development.

Dehgan Speaking at Duke

Dehgan recently gave a talk at Duke on the snow leopard project, an effort he spearheaded focusing on snow leopard (Panthera uncia)  and other wildlife conservation in Afghanistan. Because of the conflict, most people are not aware of the incredible wildlife and natural beauty within the country’s borders.

Snow Leopard Project Gallery Photo

In his conservation efforts, Dehgan visited the Pamir, Karakoram, Hindu Kush, and Tien Shian mountain ranges hoping to learn more about the wildlife that lived there and the best way to promote their conservation. He used camera traps and collected scat to figure out species were in the area.

He began by talking about the Pamir mountains. Despite the fact that this is a very dangerous region to be, Dehgan ventured in ready to work with locals and discover the wildlife there. Once,  a member of his team asked if they could forgo checking the camera traps for the day because they were being bombed by the U.S. Army. However, it was worth it because Dehgan had the opportunity to work with locals and collect images as well as data on several unique species.

This included the Marco Polo sheep (Ovis ammon polii), enormous sheep that live in single-sex groups for most of the year. They only come together to mate and when they do, the males clash heads with one another for the ability to procreate. He was also able to find a markhor (Capra falconeri), which he prefers to call a “Twin-horn unicorn.” Markhor means snake eater, but the animal does not actually eat snakes. These animals are so valuable that a hunter once paid $110,000 to shoot one. Dehgan and his team were able to collect hair and genetic samples of musk deer (Moschus), which can be found in very steep areas of the Pamir mountains. These animals derive their name from the musk they produce which is often used in perfumes.

Snow Leopard Project Gallery Photo

The area is known as Nuristan, the land of the enlightened, and is unique in that each valley has its own tradition, crafts, and even dialect. Dehgan and his team worked with people from the region and trained them to look for the specific animals

One of the most remarkable places Dehgan visited was Band-e Amir, which he described as looking like the grand canyon. The most unique natural aspect is a system of six lakes formed by the same process that creates stalactites and stalagmites. Above the lakes is an incredible mountain range and on top of the mountains are marine fossils because it used to be at the bottom of the sea. Here, Dehgan was able to use camera traps to collect images of ibexes (Capra ibex), Persian leopards (Panthera pardus saxicolor), and poachers. Poaching would eventually become one of Dehgan’s key focuses. Dehgan and his team also discovered Asiatic wild asses and assumed the presence of Asiatic leopards after finding their skins in the nearby villages.

Dehgan discovered that there was a massive trade in wildlife driven by the U.S. military. Skins of snow leopards and Persian leopards could be found all over Afghanistan as a part of illegal wildlife trade and other wildlife like Saker Falcons could be sold for up to $1 million.

As a result, Dehgan started a program around wildlife trafficking. A major part of his effort took place on Chicken Street, a busy shopping area where illegal animal skins could frequently be found. Dehgan worked closely with U.S. Military police, training them on how to identify furs.

Dehgan also worked with Afghani airport employees on how to inspect baggage for illegal furs. This resulted in the shut down of nearly all illegal fur trade, which Dehgan said was one of his biggest successes. In fact, one day while in Afghanistan, Dehgan received word that a fur trader wished to speak with him. Assuming they were angry at him for reducing their business Dehgan said that he actually feared for his life. However, it turned out that the fur trader simply wanted to be trained to identify illegal furs because they too wanted to protect Afghanistan’s wildlife.

Dehgan explained that Afghanistan was one of the easiest places he ever did conservation. This is because 80 percent of the human population is dependent on natural resources and thus when the wildlife fails, they fail. Because of this, they are eager to help aid in promoting conservation efforts.

Additionally, Dehgan was able to create the Wildlife Conservation Society’s Afghanistan Program which resulted in Afghanistan’s first and second national parks. Villages held local elections to set up a committee and to set up rules to govern the national parks.

Ultimately, his conservation work not only helped wildlife, but supported democracy by empowering, working with and training local communities.

To learn more, check out Dehgan’s recently published book, “The Snow Leopard Project” as well as his twitter, @lemurwrangler.

By Anna Gotskind

Page 1 of 14

Powered by WordPress & Theme by Anders Norén