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

Students exploring the Innovation Co-Lab

Category: Field Research Page 3 of 15

Building a Just Foundation for Our Energy Transition

Swine Country Documentary Project

As conversations about the energy transition away from fossil fuels become increasingly important (and time-sensitive), some experts in environmental policy aren’t just worried about the conversations themselves. They’re worried about who has a seat at the table — and who doesn’t. 

Sherri White-Williams

On November 8, at “Building a Just Foundation for Our Energy Transition,” a few of these experts — Sherri White-Williamson, Environmental Justice Policy Director at the NC Conservation Network; Josh McClenney, the North Carolina Field Coordinator at Appalachian Voices; and J. Spenser Darden, the Assistant Dean for Diversity and Inclusion at Duke’s Sanford School of Public Policy — spoke about this and other issues. Thomas Klug, a Research Associate at the Duke Energy Access Project, moderated the panel, which was put together by the Sanford Energy & Environment Club.

Klug asked the panelists to define what a “just transition” really means in the context of the panelists’ work, and whether it differs from a diverse and inclusive transition.

J. Spenser Darden

McClenney answered that a just transition entails recognizing that Black, brown, and indigenous communities, as well as low socio-economic status individuals, have historically faced the worst effects of fossil fuel economies. Living in the “physical and economic traction zones,” they’re the ones that lose jobs — like coal miners, in the case of McClenney’s work with Appalachian Voices. 

However, where a diverse and inclusive transition involves “getting people to the table,” just policies will actually reflect the conversations had at the table. An unjust transition, McClenney said, is one where “people clap themselves on the back for doing such a great job having these diverse, inclusive discussions — then make policies that work against their participants.” Ensuring inclusion for communities that have historically been excluded is important, but it’s equally important to make sure the resulting policies are actually inclusive.

Josh McClenney

White-Williams agreed with McClenney — inclusion should never end at “checking the box.” The goal should be to incorporate the input of marginalized voices into resulting policy. White-Williams also added that fairness, while not necessarily guaranteed by diversity and inclusivity, is a key part of a just energy transition. 

Spenser stressed the need to move away from “extractive, colonial” ways of thinking about energy and who makes up society, and to instead incorporate indigenous ways of thinking. He stated that diversity and inclusion is reactive: people realize flaws in the way they’ve built something and try to address it later by incorporating new elements. A just system, on the other hand, is built to be “for and by” communities that have been excluded from the very start.

Klug asked the panelists to recount some of the ways they’ve seen organizations, utilities, and decision makers putting the processes required for a just transition into practice.

McClenney spoke of revelations from the onset of COVID-19 in March 2020. Preventing utility shutoffs became critically important: people were losing jobs or forced to stay at home. They couldn’t come up with the money to pay their utility bills. While fighting utility shutoffs with Appalachian Voices, he saw a group of Knoxville organizations, including Knoxville Water and Energy for All, bringing attention to the fact that the shutoffs were not just a COVID problem. For some Black and brown communities, McClenney said, “keeping the lights on had always been an issue.” These grassroot groups’ advocacy expanded beyond the pandemic: they wanted energy and water recognized as human rights.

Klug asked the panelists how they feel about President Joe Biden’s performance with regard to just transitions in the energy sector — specifically, his January executive orders and recent bipartisan $1.2 trillion infrastructure bill

White-Williams cited a major concern with Biden’s policies: they don’t give enough attention to rural issues. In Sampson county here in North Carolina, massive hog farms overwhelmingly surround communities of color. North Carolina’s new Farm Act will allow Smithfield Foods to build a system to trap methane from hog waste to be processed and eventually used as renewable electricity. But residents living near hog farms already experience toxic water, unbearable stench, and heightened risk of other diseases, and this system would likely make the problem even worse. It’s a textbook example of an unjust energy transition. That’s why environmental and civil rights organizations have asked the EPA to intervene — to no avail, at least thus far. (White-Williams is featured in this article about the current state of affairs.) “Rural America is suffering,” White-Williams said. She wants to see federal agencies using their power to ensure a just energy transition.

McClenney echoed White-Williams’ concern about hog farms, adding that deaths have resulted from providing workers with limited information about the conditions they would be working in — especially those who don’t speak English and whose undocumented status puts them in a vulnerable position. 

On a different note, he thinks Biden’s expansions to Broadband and clean water are a step in the right direction. He stated that with North Carolina’s House Bill 951, which requires the Utilities Commission to cut emissions by 70% by 2030 (even more ambitious than Biden’s executive order, which seeks to cut US emissions in half by 2030), “there are opportunities right now to effect positive change — we just have to do a good job.” It’s about how we get to that carbon reduction goal.

Klug asked how people at universities — faculty, students, and staff alike — can contribute to this work in policy and in advocacy.

White-Williams told the audience to recognize that “having a degree does not make you an expert when you walk into these communities.” Community members have lived experience: they can tell policymakers and activists what they need, not the other way around. Change should be a partnership, and so should research: “Academics have a research question before they’ve even spoken to anyone.” Instead, “listen and learn from the people who have been there all their lives.”

Spenser invited the audience to think about “who the real experts are” in unique and different ways. Institutions like Duke are often separate from the communities they inhabit, serving as a sort of beacon on the hill. “We need to invert this paradigm,” he said.

McClenney added to Spenser’s criticism of schools like Duke, who “throw food out every day and hold dorm rooms empty during the summer while people go hungry and unhoused.” What’s needed is a fundamental reimagination of the university’s relationship to the community it inhabits. He also added to White-Williams’ point about research: it can be merely “another type of extraction” if not carried out in a just manner.

Klug asked the panelists whether we need to assess the impacts of energy policy differently through the lens of research.

McClenney flagged the words “affordability” and “reliability” in energy research, asking the audience to consider who that applies to. Affordability is not just about how rates compare to New York City or California, but whether someone has to forego insulin or go hungry in order to make a payment. By thinking through these words and what they really mean, we can “begin to understand impacts on a deeper level.”

Spenser implored researchers to use an intersectional lens: instead of considering economic impact and efficiency in isolation, to consider the way in which policies “contribute or ameliorate historic disparities.” In order to truly measure impact, efficacy, and outcome, researchers must be “historically aware and community invested.”

White-Williams agreed with McClenney and Spenser, asking researchers to consider whether policies are a “band-aid or a true fix.” She cited North Carolina’s Weatherization Assistance Program, which allocates tens of millions of dollars toward fixing “patched-up” homes that may have serious underlying problems. She wonders whether it may be better to simply spend the money on programs to place people in housing that is “actually livable.”

Klug opened the panel to questions. One audience member asked the panelists what concrete steps they recommend in order to “harness the power of diversity.”

White-Williams reiterated the importance of working with impacted communities, stressing the need for local leaders who can serve as experts on the needs of the community. Elected officials might “sacrifice the needs of these communities for some other interest,” but local advocates can apply pressure where needed.

Spenser pushed back on the question, stating that instead of urgency and speed, “we need to commit to a longer process” — honoring historical legacies and “spending time helping people understand what the conversation is.” 

“Environmental policy isn’t sexy,” Spenser concluded. (“Except,” he added, “for pipelines.”)

Maybe not. But it’s important that it gets made — and that it gets made justly.

Post by Zella Hanson

250,000-Year-Old Child Adds to the Mystery of Our Human Origins

Based on the small size of Leti’s skull and on the combination of baby teeth and unerupted adult teeth, researchers estimate that the Homo naledi child would have been 4-6 years old.

Look at the palm of your hand and spread your fingers wide. Now imagine squeezing your body through a gap narrower than the distance between the tip of your thumb and the tip your pinkie finger. Let’s make this a bit worse: the gap is in complete darkness, its walls are rough stone, and all you have is a tiny headlamp. Ok, now that you are there, all you have to do is carefully find and recover dime-sized fragments of an invaluable treasure.

That’s how researchers recovered the first Homo naledi child’s skull ever to be found.

The finding was revealed this week in two papers published in the journal PaleoAnthropology by an international team of 21 researchers.

Homo naledi are possibly our most mysterious long-lost cousins. They are an ancient human relative that lived in what is now South Africa, approximately 350 to 250 thousand years ago. They were first discovered in the Rising Star Cave system in 2013, in a research expedition led by Lee Berger, Professor and chair of Palaeo-Anthropology and Director of the Centre for Exploration of the Deep Human Journey at the University of Witwatersand.

The research team, which includes Steven Churchill, professor of evolutionary anthropology at Duke, named the child Leti (pronounced Let-e), after the Setswana word “letimela” meaning “the lost one”.

Leti was found in one of the previously unexplored narrow fissures that radiate from Rising Star’s known chambers. His resting site was a 15 cm wide and 80 cm long gap where only the smallest (and bravest) of explorers could fit.

Explorer Becca Peixoto wedges herself between cave rock walls to get to Leti’s skull.

Marina Elliot, lead author of the first paper and one of the explorers to first discover Homo naledi, said in a press conference that excavating Leti’s remains required explorers to wedge themselves practically upside down between two rock walls.

Finding yet another fossil in a prolific site may not seem groundbreaking, but finding a child’s skull is a major achievement. First of all, children’s bones are thin and fragile, and rarely withstand the test of time.

Second, finding a child’s skull gives researchers a precious glimpse into the development of Homo naledi.

“A child’s skull allows us to study how Homo naledi grew and developed, and how their growth rate and schedule compares to other hominid species, and to our own,” Churchill said.

In addition to skull fragments, researchers also recovered two worn baby teeth and four unworn adult teeth that were yet to erupt. These findings show that Leti would have been between four and six years old at the time of her or his death.

Based on similarities between the soil of the fissure where Leti was found and the better-known areas of the cave, Tebogo Makhubela, senior lecturer of Geology at the University of Johannesburg and author of the papers, estimated that Leti has been hidden in Rising Star for over 250,000years.

The discovery of Leti’s skull also deepens the mystery of how Homo naledi’s remains ended up in such a deep, dark, and treacherous cave.

Berger’s team had previously hypothesized that the first 15 Homo naledi individuals found in Rising Star had been disposed there by their own species, as a burial. This hypothesis created an uproar: could a small-brained hominin from over 300,000years ago bury their dead, just like we do?

Leti’s skull was found on a small shelf at the back of the cave’s fissure. No other bones were found, suggesting that Leti’s head may have been deliberately placed there. Leti, as well as all other Homo naledi fossils ever found, showed no evidence of being dragged by predators, carried by water, or tumbled around in any other way.

“Those were social individuals. Seeing one of their own being picked apart by animals could have been very distressing,” Churchill said. “Purposeful disposal of their bodies still seems like the most likely explanation.”

Berger is undeterred by nay-sayers. “This is science,” Berger said at a press conference. “We will continue testing and challenging our hypotheses with every piece of data that we get.”

The researchers hope that other teams around the world will study Leti and other Homo naledi fossils. To that end, Leti’s skull was CT-scanned, and its scans can be downloaded from Morphosource, an open access repository of museum specimens’ 3D scans hosted at Duke University.

Leti will probably not be the last treasure to come out of Rising Star’s spider web of narrow passages.

“I can’t wait to go back to South Africa and see what else is waiting for us in that cave,” said Juliet Brophy, Professor of Geography and Anthropology at Louisiana State University and lead author of the paper describing Leti’s skull.

“This finding makes us remember that exploration is always worth doing,” said Elliot, who is a researcher at Simon Fraser University and Witwatersand University. “There is a lot still out there to be found”.

The Rising Star cave system is known for being extremely dangerous to explore.

Elliot et al. was funded by the National Geographic Society, the Lyda Hill Foundation, the South African National Research Foundation, and the Gauteng Provincial Government, for funding the discovery, recovery and ongoing analyses of the material. Additional support was provided by ARC (DP140104282).

Brophy et al. was funded by the National Geographic Society, the Lyda Hill Foundation, the South African National Research Foundation, the South African Centre for Excellence in Palaeosciences, The University of the Witwatersrand, the Vilas Trust, the Fulbright Scholar Program, Louisiana State University, North Carolina State University, the Texas A&M University College of Liberal Arts Seed Grant program and the Texas A&M College of Liberal Arts Cornerstone Faculty Fellowship.

Citations:

“Expanded Explorations of the Dinaledi Subsystem, Rising Star Cave System, South Africa.” Marina C. Elliot,Tebogo V. Makhubela, Juliet K. Brophy, Steven E. Churchill, Becca Peixoto, Elen M. Feuerriegel, Hannah Morris, Rick Hunter, Steven Tucker, Dirk Van Rooyen, Maropeng Ramalepa, Mathabela Tsikoane,Ashley Kruger, Carl Spander, Jan Kramers, Eric Roberts, Paul H.G.M. Dirks,John Hawks,Lee R. Berger. PaleoAnthropology, November 2021. DOI: https://doi.org/10.48738/2021.iss1.68.

“Immature Hominin Craniodental Remains From a New Localityin the Rising Star Cave System, South Africa.” Juliet K. Brophy, Marina C. Elliot, Darryl J. De Ruiter, Debra R. Bolter, Steven E. Churchill, Christopher S. Walker, John Hawks, Lee Berger. PaleoAnthropology, November 2021, DOI: https://doi.org/10.48738/2021.iss1.64.

By Marie-Claire Chelini
By Marie-Claire Chelini

In the World Capital of Vanilla Production, Nearly Three out of Four Farmers Say They Don’t Have Enough to Eat

A new study investigates why and what they can do about it

Madagascar, famous for its lemurs, is home to almost 26 million people. Despite the cultural and natural riches, Madagascar is one of the poorest countries in the world. Over 70% of Malagasy people are farmers, and food security is a constant challenge. Rice is the most important food crop, but lately an internationally-prized crop has taken center stage: vanilla. Most of the world’s best quality vanilla comes from Madagascar. While most Malagasy farmers live on less than $2 per day, selling vanilla can make some farmers rich beyond their dreams, though these profits come with a price, and a new study illustrates it is not enough to overcome food insecurity.

In a paper published June 25, 2021 in the journal Food Security, a team of scientists collaborating between Duke University and in Madagascar set out to investigate the links between natural resource use, farming practices, socioeconomics, and food security. Their recently published article in the journal Food Security details intricate interactions between household demographics, farming productivity, and the likelihood of experiencing food shortages.

Vanilla beans, Wikimedia Commons

The team interviewed almost 400 people in three remote rural villages in an area known as the SAVA region, an acronym for the four main towns in the region: Sambava, Andapa, Vohemar, and Antalaha. The Duke University Lemur Center has been operating conservation and research activities in the SAVA region for 10 years. By partnering with local scientists, the team was able to fine-tune the way they captured data on farming practices and food security. Both of the Malagasy partners are preparing graduate degrees and expanding their research to lead the next generation of local scientists.

Farmers harvesting the rice fields in Madagascar. Credit: Wikimedia Commons.

The international research team found that a significant proportion of respondents (up to 76%) reported that they experienced times during which did not have adequate access to food during the previous three years. The most common cause that they reported was small land size; most respondents estimated they owned less than 4 hectares of land (<10 acres), and traditional farming practices including the use of fire to clear the land are reducing yields and leading to widespread erosion. The positive side is that the more productive the farm, especially in terms of rice and vanilla harvests, the lower the probability of food insecurity. There was an interaction between rice and vanilla harvests, such that those farmers that produced the most rice had the lowest probability of food insecurity, even when compared to farmers who grew more vanilla but less rice. Though vanilla can bring in a higher price than rice, there are several factors that make vanilla an unpredictable crop.

The vanilla market is subject to extreme volatility, with prices varying by an order of magnitude from year to year. Vanilla is also a labor- and time-intensive crop; it requires specific growing conditions of soil, humidity, and shade, it takes at least 3 years from planting to the first crop. Without the natural pollinators in its home range of Mexico, Malagasy vanilla requires hand pollination by the farmers, and whole crops can be devastated by natural disasters like disease outbreaks and cyclones. Further, the high price of vanilla brings with it ‘hot spending,’ resulting in cycles of boom and bust for impoverished farmers. Because of the high price, vanilla is often stolen, which leads farmers to spend weeks in their fields guarding the vanilla from thieves before harvesting. It also leads to early harvests, before the vanilla beans have completely ripened, which degrades the quality of the final products and can exacerbate price volatility.

In addition to the effects of farming productivity on the probability of food insecurity, the research revealed that household demographics, specifically the number of people living in the household, had an interactive effect with land size. Those farmers that had larger household sizes (up to 10 in this sample) had a higher probability of experiencing food insecurity than smaller households, but only if they had small landholdings. Those larger families that had larger landholdings had the lowest food insecurity. These trends have been documented in many similar settings, in which larger landholdings require more labor, and family labor is crucial to achieving food sovereignty.

The results have important implications for sustainable development in this system.  The team found that greater rice and vanilla productivity can significantly reduce food insecurity. Therefore, a greater emphasis on training in sustainable, and regenerative, practices is necessary. There is momentum in this direction, with new national-level initiatives to improve rice production and increase farmers’ resilience to climate change. Further, many international aid organizations and NGOs operating in Madagascar are already training farmers in new, regenerative agriculture techniques. The Duke Lemur Center is partnering with the local university in the SAVA region to develop extension services in regenerative agriculture techniques that can increase food production while also preserving and even increasing biodiversity. With a grant from the General Mills, the Duke Lemur Center is developing training modules and conducting workshops with over 200 farmers to increase the adoption of regenerative agriculture techniques.

Further, at government levels, improved land tenure and infrastructure for securing land rights is needed because farmers perceive that the greatest cause of food insecurity is their small landholdings. Due to the current land tenure infrastructure, securing deeds and titles to land is largely inaccessible to rural farmers. This can lead to conflicts over land rights, feelings of insecurity, and little motivation to invest in more long-term sustainable farming strategies (e.g., agroforestry). By improving the ability of farmers to secure titles to their land, as well as access agricultural extension services, farmers may be able to increase food security and productivity, as well as increased legal recognition and protection.

To move forward as a global society, we must seek to achieve the United Nation (UN) Sustainable Development Goals (SDGs). One of the SDGs is Goal #2, Zero Hunger. There are almost one billion people in the world who do not have adequate access to enough safe and nutritious food. This must change if we expect to develop sustainably in the future. Focusing on some of the hardest cases, Madagascar stands out as a country with high rates of childhood malnutrition, prevalence of anemia, and poverty. This year, more than one million people are negatively impacted by a three-year drought that has resulted in mass famine and a serious need for external aid. Sadly, these tragedies occur in one of the most biodiverse places on earth, where 80-90% of the species are found no where else on earth. This paradox results in a clash between natural resource conservation and human wellbeing.

Achieving the UN’s SDGs will not be easy; in fact, we are falling far short of our targets after the first decade. The next ten years will determine if we meet these goals or not, and our collective actions as a global society will dictate whether we transform our society for a sustainable future or continue with the self-destructive path we have been following. Further research and interventions are still needed to conserve biodiversity and improve human livelihoods.

A Virtual Stroll through the 2021 Bass Connections Showcase

Posters, presentations, and formalwear: despite the challenge of a virtual environment, this year’s annual Fortin Foundation Bass Connections Showcase still represented the same exciting scholarship and collegiality as it has in years past.

While individuals could no longer walk around to see each of this year’s 70+ teams present in person, they were instead able to navigate a virtual hall with “floors” designated for certain teams. With labels on each virtual table, it almost mimicked the freedom of leisurely strolls down a hall lined with posters, stopping at what catches your eye. Three sessions were held over Thursday, April 15 and Friday, April 16.

The beginning of each session featured five-minute “lightning” presentations by a diverse set of teams, representing the range of research that students and faculty participated in.  One such presentation was lead by Juhi Dattani ’22 (NCSU) and Annie Roberts ’21, who covered research generated by their team, “Regenerative Grazing to Mitigate Climate Change.” The team was an inter-institutional project bringing together UNC, NCCU, NCSU, and Duke. And as they aptly summarized, “It’s not the cow, but how.” Cows can help fight instead of contribute to the climate crisis, through utilizing regenerative grazing – which is an indigenous practice that has been around for hundreds of years – to improve soil health and boost plant growth.

The team during the 2019-2020 year, pre-COVID, on the Triangle Land Conservancy’s Williamson Preserve.

Research is not just relegated to the physical sciences. Brittany Forniotis, a PhD candidate ’26, and Emma Rand ’22 represented the team “Mapping History: Seeing Premodern Cartography through GIS and Gaming.” Their team was as interdisciplinary as it gets, drawing from the skills of individuals in everything from art history to geography to computer science. They posited that mapmakers use features of map to argue how people should see the world, not necessarily how they saw the world. To defend this hypothesis, they annotated maps to record and categorize data and even converted maps to 3D to make them virtual, explorable worlds. The work of this team enabled the launch of Sandcastle, which aims to “enable researchers to visualize non-cartesian, premodern images of places in a comparative environment that resembles the gestural, malleable one used by medieval and early modern cartographers and artists.”

The work of the team added to a project launch of Sandcastle.

Sophie Hurewitz (T ’22) and Elizabeth Jones (MPP ’22) presented on behalf of the “North Carolina Early Childhood Action Plan: Evidence-based Policy Solutions”, Their recommendations for alleviating childhood food insecurity in North Carolina as outlined by the North Carolina Early Childhood Action Plan will provide a roadmap for NC Integrated Care for Kids (NC InCK) to consider certain policy changes.

One of the most remarkable parts of Bass Connections is how it opens doors for students to pursue avenues and opportunities that they may have never been exposed to otherwise. Hurewitz said that “Being a part of this team led me and a team member to apply for the 2021 Bass Connections Student Research Award, which we were ultimately awarded to study the barriers and facilitators to early childhood diagnosis of Autism Spectrum Disorder (ASD) among Black and Latinx children in North Carolina.” In addition to the award, Hurewitz and fellow team member Ainsley Buck were able to present their team’s research at the APA Region IV Annual Meeting.

The 2019-2020 team, pre-COVID.

From gene therapy for Alzheimer’s disease to power grids on the African continent, this year’s teams represented a wide range of research and collaboration. Erica Langan ’22, a member of the team “REGAIN: Roadmap for Evaluating Goals in Advanced Illness Navigation”, said that “For me, Bass Connections has been an extraordinary way to dive into interdisciplinary research. It’s an environment where I can bring my existing skills and knowledge to the table and also learn and grow in new ways.” This interdisciplinary thinking is a hallmark of not just Bass Connections, but Duke as a research institution, and it’s clear that this spirit is alive and well, even virtually.

Post by Meghna Datta

Duke Researcher Busts Metabolism Myths in New Book

Herman Pontzer explains where our calories really go, and what studying humanity’s past can teach us about staying healthy today.

Photo by Elena Georgiou, My City /EEA

Duke professor Herman Pontzer has spent his career counting calories. Not because he’s watching his waistline, exactly. But because, as he sees it, “in the economics of life, calories are the currency.” Every minute, everything the body does — growing, moving, fighting infection, even just existing — “all of it takes energy,” Pontzer says.

In his new book, “Burn,” the evolutionary anthropologist recounts the 10-plus years he and his colleagues have spent measuring the metabolisms of people ranging from ultra-athletes to office workers, as well as those of our closest animal relatives, and some of the surprising insights the research has revealed along the way.

Much of his work takes him to Tanzania, where members of the Hadza tribe still get their food the way our ancestors did — by hunting and gathering. By setting out on foot each day to hunt zebra and antelope or forage for berries and tubers, without guns or electricity or domesticated animals to lighten the load, the Hadza get more physical activity each day than most Westerners get in a week.

So they must burn more calories, right? Wrong.

Herman Pontzer
Herman Pontzer, associate professor of evolutionary anthropology at Duke

Pontzer and his colleagues have found that, despite their high activity levels, the Hadza don’t burn more energy per day than sedentary people in the U.S. and Europe.

These and other recent findings are changing the way we understand the links between energy expenditure, exercise and diet. For example, we’ve all been told that if we want to burn more calories and fight fat, we need to work out to boost our metabolism. But Pontzer says it’s not so simple.

“Our metabolic engines were not crafted by millions of years of evolution to guarantee a beach-ready bikini body,” Pontzer says. But rather, our metabolism has been primed “to pack on more fat than any other ape.” What’s more, our metabolism responds to changes in exercise and diet in ways that thwart our efforts to shed pounds.

What this means, Pontzer says, is you can walk 16,000 steps each day like the Hadza and you won’t lose weight. Sure, if you run a marathon tomorrow you’ll burn more energy than you did today. But over time, metabolism responds to changes in activity to keep the total energy you spend in check.

Pontzer’s book is more than a romp through the Krebs cycle. For anyone suffering pandemic-induced pangs of frustrated wanderlust, it’s also filled with adventure. He takes readers on an hours-long trek to watch a Hadza man track a wounded giraffe across the savannah, to the rainforests of Uganda to study climbing chimpanzees, and to the foothills of the Caucasus Mountains to unearth the 1.8 million-year-old remains of some of the first people who trekked out of Africa.

His humor shines through along the way. Even when awoken by a chorus of 300-pound lions just a few hundred yards from his tent, he stops to ponder whether his own stench gives him away, and what he might do if they come for his “soft American carcass, the  warm triple crème brie of human flesh.”

Pontzer spoke via email with Duke Today about his book:

Q: What’s the lesson the Hadza and other hunter-gatherers teach us about managing weight and staying healthy?

A: The Hadza stay incredibly fit and healthy throughout their lives, even into their older ages (60’s, 70’s, even 80’s). They don’t develop heart disease, diabetes, obesity, or the other diseases that we in the industrialized world are most likely to suffer from. They also have an incredibly active lifestyle, getting more physical activity in a typical day than most Americans get in a week.

My work with the Hadza showed that, surprisingly, even though they are so physically active, Hadza men and women burn the same number of calories each day as men and women in the U.S. and other industrialized countries. Instead of increasing the calories burned per day, the Hadza physical activity was changing the way they spend their calories — more on activity, less on other, unseen tasks in the body.

The takeaway for us here in the industrialized world is that we need to stay active to stay healthy, but we can’t count on exercise to increase our daily calorie burn. Our bodies adjust, keeping energy expenditure in a narrow range regardless of lifestyle. And that means that we need to focus on diet and the calories we consume in order to manage our weight. At the end of the day, our weight is a matter of calories eaten versus calories burned — and it’s really hard to change the calories we burn!

Q: You’re saying that exercise doesn’t matter? What’s the point, if we can’t eat that donut?

A: All those adjustments our bodies make responding to exercise are really important for our health! When we burn more calories on exercise, our bodies spend less energy on inflammation, stress reactivity (like cortisol), and other things that make us sick.

Q: What’s the biggest misunderstanding about human metabolism?

A: We’re told — through fitness magazines, diet fads, online calorie counters — that the energy we burn each day is under our control: if we exercise more, we’ll burn more calories and burn off fat. It’s not that simple! Your body is a clever, dynamic product of evolution, shifting and adapting to changes in our lifestyle.

Q: In your book you say we’re driven to magical thinking when it comes to calories. What do you mean by that?

A: Because our body is so clever and dynamic, and because humans are just bad at keeping track of what we eat, it’s awfully hard to keep track of the calories we consume and burn each day. That, along with the proliferation of fad diets and get-thin-quick schemes, has led to this idea that “calories don’t matter.” That’s magical thinking. Every ounce of your body — including every calorie of fat you carry — is food you consumed and didn’t burn off. If we want to lose weight, we must eat fewer calories than we burn. It really comes down to that.

Q: Some people say that if the cavemen didn’t eat it, we shouldn’t either. What does research show about what foods are “natural” for humans to eat?

A: There’s no singular, natural human diet. Hunter-gatherers like the Hadza eat a diverse mix of plant and animal foods that varies day to day, month to month, and year to year. There’s even more dietary diversity when we look across populations. Humans are built to thrive on a wide variety of diets — just about everything is on the menu.

That said, the ultra-processed foods we’re inundated with in our modern industrialized world really are unnatural. There are no Twinkies to forage in the wild. Those foods are literally engineered to be overconsumed, with a mix of flavors that overwhelm our brain’s ability to regulate our appetites. Now, it is still possible to lose weight on a Twinkie diet (I’m not recommending it!), if you’re very strict about the calories eaten per day. But we need to be really careful about how we incorporate ultra-processed foods into our daily diets, because they are calorie bombs that drive us to overconsume.

Q: If we could time travel, what would our hunter-gatherer ancestors make of our industrialized diet today?

A: We don’t even need to imagine — We are those hunter-gatherers! Biologically, genetically, we are the same species that we were a hundred thousand years ago, when hunting and gathering were the only game in town. When we’re confronted with modern ultra-processed foods, we struggle. They are engineered to be delicious, and we tend to overconsume.

Q: Has the COVID-19 pandemic brought any of these lessons home for you? What can we do to keep active and watch what we eat, even while working from home?

The pandemic has been a tragedy on so many levels — the loss of life, those suffering with long-term effects, the social and economic impacts. The impact on diet and exercise have been bad as well, for many of us. Stress eating is a real phenomenon, and the stress and emotional toll of the pandemic — along with having easy access to the snacks in our kitchen — have led many to gain weight. Physical activity seems to have declined for many. There aren’t easy answers, but we should try to make a point to get active every day. And we can help ourselves make better decisions about food by keeping ultra-processed foods out of our houses. You can’t plow through a bag of chips if you don’t have chips in your cupboard.

Q: You’ve measured the energy costs of activities ranging from taking a breath to doing an Ironman. What is one of the more extreme or surprising calorie-burning activities that you’ve measured, or would like to measure, in humans or some other animal?

A: With colleagues from Japan, I measured the energy cost of a heartbeat – a tricky bit of metabolic measurement! Turns out each beat of your heart burns about 1/300th of a kilocalorie! Amazing how efficient our bodies can be.

Q: What is something people have questions about that we just don’t know the answer to yet? What would it take to find out?

A: Right now we’re excited about measuring the adjustments our bodies make when we increase our exercise: how exactly does burning more energy on physical activity impact our immune system, our stress response, our reproductive system? It will take a long-term study of exercise to see how these systems change over time.

Robin Smith - University Communications
Robin Smith – University Communications

Bass Connections Teams Tackling COVID-19 Problems, from Food Security to Voting-by-Mail

Most people at Duke are familiar with Bass Connections, the powerhouse interdisciplinary research program that brings together students and faculty from a wide variety of backgrounds to tackle complex problems.

Like most people, when the country went on COVID-19 pandemic lockdown, team leaders and members within Bass Connections needed to adapt their approach.

Instead of merely adapting, though, some Bass Connections teams saw a problem-solving opportunity. They pivoted to address some of the most pressing problems that the pandemic has created or exacerbated. On Tuesday, March 2nd, eight teams gathered to present their research at the first Bass Connections Works in Progress Symposium.

Equity and Efficiency of Using Wearables Data for COVID-19 Monitoring was one team that presented at the Symposium.

These teams tackled issues ranging from the ethics of contact tracing to the availability and access to contraception.

One team focused on the issue of food security amongst Latinx populations in Durham. Their presentation was lead by Elaijah Lapay, Faraan Rahim, and Karina Moreno Bueno. The team aimed to tackle three major goals: “How is the pandemic affecting the food security of Latinx residents, and how do environmental public health factors contribute to this population’s risk for COVID-19 infection? How does the incorporation of fresh, local foods mitigate these effects? How is the pandemic affecting the food assistance services locally, nationally, and internationally for the Latinx community?”

Of the Hispanic/Latinx respondents to the 2019 Durham Community Health Survey, 20.9% said they sometimes skipped or limited their meals. Combining that with the fact that 36% of the total number of COVID-19 cases in Durham have been within the Hispanic population, it’s fairly clear that there is a link between food security and health outcomes.

To this end, the Bass Connections team partnered with Root Causes to help advance their project goals through Root Cause’s Fresh Produce Program. Root Causes is an organization started by Duke Medical School students prior to the pandemic that previously provided fresh produce to food-insecure patients at the Duke Outpatient Clinic. But in order to adapt to contactless delivery and new needs due to COVID-19, Root Causes and the Bass team partnered to expand its reach to nearly 150 households in Durham.

Pipeline for Fresh Produce Program, taken from the symposium presentation of Improving Food Security to Increase Resiliency to COVID-19 for Latinx Populations

This expansion was aided immensely by the Duke Campus Farm, which despite the pandemic mobilized to change the produce it grew to be more culturally relevant to the households they were supporting.

In the future, the team hopes to continue to expand their survey data in the Triangle and continue to assess the impact of the Fresh Produce Program.  

Another Bass Connections team broadly addressed the challenges COVID-19 posed to the election process, through three sub-projects focusing on absentee balloting, organizing, and overall voter participation. The symposium presentation for the absentee balloting research was lead by Chase Johnson, Emma Shokeir, and Kathryn Thomas.

To hear more about the work of this Bass Connections team, watch the presentation above.

The 2020 election saw more people than ever relying on absentee voting, either by the one-stop process or by voting through mail. However, this team aimed to address the many voters that are disenfranchised because their votes are rejected due to errors in their ballot. While NC courts ruled that voters are required to be notified if their ballot needs curing, the difficulty of curing one’s ballot often dissuades people from even starting the process, leading to those votes not being counted.

The team utilized the app BallotTrax, a company that the North Carolina State Board of Elections hired to track these ballots. The team then focused on phone banking to increase BallotTrax usage, and then analyzed voter outcomes.

In the future, they hope to analyze the effect that BallotTrax outreach had on voting success, the efficacy of BallotTrax for voters in North Carolina, and the efficiency of North Carolina’s vote-by-mail system compared to other states.

A goal of this symposium for many teams was to ask audience members for suggestions on ways to direct their research further. The beauty of seeing research midway through the process is that it opens the door for collaborative thinking, out-of-the-box ideas, and being open about obstacles and mistakes.

This virtual Symposium is a testament not just to Duke’s collaborative research spirit, which is alive and well despite the pandemic, but to the adaptability of Duke student researchers and faculty. There’s no doubt that these eight Bass Connections Teams, among the many other teams part of the program this year, have been generating relevant and impactful knowledge and will continue to do so.

Post by Meghna Datta

Student Team Quantifies Housing Discrimination in Durham

Home values and race have an intimate connection in Durham, NC. From 1940 to 2020, if mean home values in Black-majority Census tracts had appreciated at rates equal to those in white Census tracts, the mean home value for homes in Black tracts would be $94,642 higher than it is.

That’s the disappointing, but perhaps not shocking, finding of a Duke Data+ team.

Because housing accounts for the biggest portion of wealth for families that fall outside of the top 10% of wealth in the U.S., this figure on home values represents a pervasive racial divide in wealth.

What started as a Data+ project in the summer of 2020 has expanded into an ongoing exploration of the connection between persistent wealth disparities across racial lines through housing. Omer Ali (Ph.D.), a postdoctoral associate with The Samuel Dubois Cook Center on Social Equity, is leading undergraduates Nicholas Datto and Pei Yi Zhuo in the continuation of their initial work. The trio presented an in-depth analysis of their work and methods Friday, February 5th during a Data Dialogue.

The team used a multitude of data to conduct their analyses, including the 1940 Census, Durham County records, CoreLogic data for home sales and NC voter registrations. Aside from the nearly $100,000 difference between mean home values between Black census tracts (defined as >50% Black homeowners from 1940-2020) and white census tracts (defined as >50% white homeowners from 1940-2020), Ali, Datto, and Zhou also found that over the last 10 years, home values have risen in Black neighborhoods as they have been losing Black residents. Within Census tracts, the team said that Black home-buyers in Durham occupy the least valuable homes.

Home Owners Loan Corporation data

Datto introduced the concept of redlining — systemic housing discrimination — and explained how this historic issue persists. From 1930-1940, the Home Owners’ Loan Corporation (HOLC) and Federal Housing Administration (FHA) designated certain neighborhoods unsuitable for mortgage lending. Neighborhoods were given a desirability grade from A to D, with D being the lowest.

In 1940, no neighborhoods with Black residents were designated as either A or B districts. That meant areas with non-white residents were considered more risky and thus less likely to receive FHA-guaranteed mortgages.

Datto explained that these historic classifications persist because the team found significant differences in the amount of accumulated home value over time by neighborhood rating. We are “seeing long-lasting effects of these redlined maps on homeowners in Durham, “ said Datto, with even “significant differences between white [and non-white] homeowners, even in C and D neighborhoods.”

Zhou explained the significance of tracking the changes of each Census tract – Black, white, or integrated – over the last 50 years. The “white-black disparity [in home value] has grown by 287%” in this time period, he said. Homes of comparable structural design and apparent worth are much less valuable for simply existing in Black neighborhoods and being owned by Black people. And the problem has only expanded.

Along with differences in home value, both Black and white neighborhoods have seen a decline in Black homeowners in the 21st Century, pointing to a larger issue at hand. Though the work done so far merely documents these trends, rather than looking for correlation that may get at the underlying causes of the home-value disparity, the trends pair closely with other regions across the country being impacted by gentrification.

“Home values are going up in Black neighborhoods, but the number of Black people in those neighborhoods is going down,” said Datto.

Ali pointed out that there are evaluation practices that include evaluation of the neighborhood “as opposed to the structural properties of the home.” When a house is being evaluated, he said a home of similar structure owned by white homeowners would never be chosen as a comparator for a Latinx- or Black-owned home. This perpetuates historical disparities, as “minority neighborhoods have been historically undervalued” it is a compounding, systemic cycle.

The team hopes to export their methodology to a much larger scale. Thus far, this has presented some back-end issues with data and computer science, however “there is nothing in the analysis itself that couldn’t be [applied to other geographical locations,” they said.

Large socioeconomic racial disparities prevail in the U.S., from gaps in unemployment to infant mortality to incarceration rates to life expectancy itself. Though it should come as no surprise that home-values represent another area of inequity, work like Ali, Datto, and Zhou are conducting needs more traction, support, and expansion.

Post by Cydney Livingston

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

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

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

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

Page 3 of 15

Powered by WordPress & Theme by Anders Norén