Mystery of monarch migration takes new turn

Sun beams light the wings of monarchs resting in a tree in Mexico. Photo by Jaap de Roode.

By Carol Clark

During the fall, hundreds of millions of monarch butterflies living in eastern North America fly up to 1,500 miles to the volcanic forests of Mexico to spend the winter, while monarchs west of the Rocky Mountains fly to the California coast. The phenomenon is both spectacular and mysterious: How do the insects learn these particular routes and why do they stick to them?

A prevailing theory contends that eastern and western monarchs are genetically distinct, and that genetic mechanisms trigger their divergent migratory paths.

An analysis led by Emory University biologists, however, finds that the two groups of monarchs are genetically mixed. Their research, published in the journal Molecular Ecology, suggests that environmental factors may be the key to the butterflies’ choice of winter homes, and to where they wind up in the spring.

Fluttering monarchs fill the sky over Mexico. Photo by Jaap de Roode.

“Our data gives the strongest signal yet that the eastern and western monarchs belong to a single genetic population,” says Emory biologist Jaap de Roode, who led the research. “This distinction is important to help us better understand the behavior of the organism, and to conserve the monarch flyways.”

In addition to researchers in the de Roode lab, the study involved a scientist from the Institute of Integrative Biology in Zurich, Switzerland.

Biologists have long been fascinated by the innate and learned behaviors underlying animal migrations. When monarchs are breeding, for instance, they can live up to four weeks, but when they are migrating, they can live as long as six months.

“As the day length gets shorter, their sexual organs do not fully mature and they don’t put energy into reproduction. That enables them to fly long distances to warmer zones, and survive the winter,” de Roode says. “It’s one of the basic lessons in biology: Reproduction is very costly, and if you don’t use it, you can live much longer.”

Watch a YouTube video of monarchs gathering in Mexico, narrated in Spanish by Mexican actor Alan Estrada:


Mass movements of animals have huge ecological impacts. They are also visually arresting, from the spectacle of giant herds of wildebeest trekking across the Serengeti to hundreds of thousands of sandhill cranes flocking along the banks of Nebraska’s Platte River.

In the case of long-lived mammals and birds, the younger animals may learn some of the behaviors associated with migration. That’s not the case with the monarchs, notes Amanda Pierce, a graduate student in Emory’s Population Biology, Ecology and Evolution program, and a co-author of the study.

“We know there is no learning component for the butterflies, because each migration is separated by two to three generations,” Pierce says. “To me, that makes the problem even more interesting. How can these small, delicate animals travel thousands of kilometers and arrive at the same destination as their great-great grandparents?”

A tree in Mexico wears a fluttering cloak of monarchs. Photo by Jaap de Roode.

The question of whether eastern and western monarchs are genetically the same has been hotly debated, and may be an essential piece to the puzzle of their divergent migration patterns.

The researchers used 11 genetic markers to compare the genetic structures of eastern and western monarchs, as well as non-migratory monarch populations in Hawaii and New Zealand. The results showed extensive gene flow between the eastern and western monarchs, and a genetic divergence between these North American butterflies and those from Hawaii and New Zealand.

“In a sense, the genetic markers provide a DNA ‘fingerprint’ for the butterflies,” de Roode says. “Just by looking at this fingerprint, you can easily separate the butterflies of North America from those in Hawaii and New Zealand, but you can’t tell the difference between the eastern and western monarchs.”

The Emory researchers have now joined a project headed by Harvard, which also involves the University of Georgia and the University of Massachusetts, to sequence the full genomes of monarch butterflies from places around the world. That data should rule out genetic differences between the eastern and western monarchs, or reveal whether any smaller genetic differences, beyond the 11 markers used in the study, may be at play between the two groups.

Pismo Beach is a California overwintering site for monarchs. Photo by Jaap de Roode.

The idea that eastern and western monarchs are distinct populations has been bolstered by tagging-and-tracking efforts based in the United States. That data, gathered through citizen science, indicates that the butterflies stay on separate sides of the Rocky Mountains – a formidable high-altitude barrier.

De Roode, however, theorizes that when spring signals the eastern monarchs to leave the overwintering grounds in Mexico, they may simply keep radiating out, reproducing and expanding as long as they find milkweed plants, the food for their caterpillars.

“Few people have tagged the monarchs within Mexico to see where they go,” he says, “because Mexico doesn’t have as much citizen science as the U.S.”

If the theory is correct, some of the monarchs leaving Mexico each spring may wind up in western North America, while others may filter into the eastern United States. This influx to the western U.S. could be crucial to survival of monarchs on that side of the continental divide.

“There are far fewer monarchs west of the Rockies,” de Roode says. He notes that all of the overwintering monarchs on a typical overwintering site along the California coast consist of about the same number clustered onto a single big tree in Mexico’s Monarch Butterfly Biosphere Reserve, where hundreds of millions of monarchs blanket the landscape in the winter.

The monarch butterfly migration has been called an endangered phenomenon, due to the loss of habitat along the routes. The Mexican overwintering sites, located in the Trans-Mexican Volcanic Belt region northwest of Mexico City, particularly suffer from deforestation. Drug trafficking in the region has decimated eco-tourism and hampered efforts to protect the trees.

“We hope our research can aid in the conservation of the monarch flyways,” de Roode says.

Raising monarchs for release at weddings, memorials and other events is a growing industry, but U.S. Department of Agriculture regulations restrict shipping the butterflies across state lines.

De Roode stresses that this regulation should remain in force, even if further research confirms that eastern and western monarchs are genetically identical, because parasites that the butterflies carry can differ by region. “It’s not a good idea to be shipping parasites around,” he says.

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Cooking with acorns, painting with moss

Heather Buzzard says she likes to "hack away at the barriers between the indoors and outdoors."

By Mary Loftus, Emory Magazine

At Indie Fixx's TreeHouseHold, Emory graduate Heather Buzzard has written how-to pieces on making seed paper, cooking with acorns, and making moss spray paint—all of which might come in handy during her upcoming stint as artist in residence at the Hostel in the Forest, a spiritual sustainability and environmental education retreat center in Brunswick, Georgia.

Buzzard studied sociology, creative writing, religion, and environmental science at Emory. She cites a course called CORE, on religion and ecology, as particularly influential. “I’ve always been drawn intimately to the natural world,” Buzzard says, “but prior to the class, I hadn’t focused much on sharing that with others, being mindful of sacred space, and incorporating a sense of place and roots into how I live daily.”

At the Hostel in the Forest, she will be applying her understanding of sawdust composting toilets, solar panel water heaters, vegetable oil–powered lighting, organic gardening, and living off the grid.

“I like to take specific elements of the outdoors and integrate them into our everyday lives through sustainable art, design, and food, while focusing on the beauty and magic of the natural world,” she says.

And if you’re wondering if you really can cook with acorns, try her recipe.

Acorn Molasses Cakes

1/2 cup acorn flour

1/2 cup cashews, chopped


1/2 cup pecans or walnuts, chopped

1/2 cup raisins or dates

1 cup cooked brown rice

molasses (or honey) to taste

agave to taste

1/2 tsp cinnamon

1/4 tsp nutmeg
1/2 tsp ginger
a
pinch brown sugar or sucanat

Mix all ingredients together in large mixing bowl. Add enough molasses/honey so that concoction clumps together nicely without falling apart. Prepare a cookie sheet with parchment paper or a thin spread of butter, and ball the mixture together into smallish round cakes. Sprinkle the tops with brown sugar or sucanat. Bake at 325 for 10–15 minutes.

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Image credits: Top, courtesy of Heather Buzzard; bottom, iStockphoto.com. 

The art of enriching lives hit by Alzheimer's

In the above video, Beth Galvin of Fox Atlanta news reports on a new program called “Museum Moments,” started by Emory medical student Emily Lu. The program uses art as a bridge to help people like Cecile Bazaz, who has early onset Alzheimer’s disease, reconnect with the world around her.

“I’m bored out of my mind,” says Bazaz, 53. Museum Moments gives Bazaz something special to look forward to, since her condition has forced her to give up a high-powered job and lose much of her independence.

Guides at Emory’s Michael C. Carlos Museum are specially trained to engage people who are suffering from memory loss by asking them questions, rather than just lecturing.

“It’s called Museum Moments because we hope we give you a moment to be yourself again, just be an individual looking at art, where there are no wrong answers,” Lu explains.

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Injury made normal river bacteria hazardous

How could something in Georgia's Little Tallapoosa River have made Aimee Copeland so sick? Atlanta's 11 Alive News took a water sample of the river to Emory's Center for Global Safe Water to test for Aeromonas Hydrophilia, the bacteria that gave the 24-year-old from Snellville necrotizing fasciitis, a vicious, flesh-eating infection. (See video, above.)

The Emory analysis showed that a tablespoon of the river water contains about 140 cells of aeromonas, which is not an unusual amount to find in any untreated lake or river water. Necrotizing fasciitis is a rare disease, and aeromonas bacteria normally do not pose a risk, unless you have a deep cut or traumatic wound.

"The water and the bacteria get forced into the really deep tissue and then it's difficult to get them back out when you clean," says Amy Kirby, a research assistant professor in Emory's Rollins School of Public Health.

Copeland remains in critical condition and faces multiple amputations, following an initial amputation of her left leg after a zip line broke and she fell into the river. Read more at 11alive.com.

The rare book that changed medicine

In 1543, Flemish physician Andreas Vesalius published “On the Workings of the Human Body,” or “de Humani corporis fabrica,” containing the first accurate representations of human anatomy.

Only 60 original copies remain of the seminal work, including one housed in Emory's Manuscript, Archives and Rare Book Library.

The book's publication was not just a monumental feat of science and art, it was an act of bravery, says Robert Gaynes, a professor in the Emory School of Medicine. Vesalius’ book debunked the preceding 1,200 years of anatomical knowledge, which were based on the work of Galen of Pergamon, a prominent Roman surgeon. “At that time, criticizing Galen was essentially heresy,” Gaynes says.

Vesalius was a surgeon and professor of anatomy who was the first to perform human dissections as a teaching tool, inviting his students to gather around the operating table and observe first-hand as he worked. “He began to have this disquieting feeling that many of the things that Galen said in his anatomical text were wrong,” Gaynes says. “He realized that Galen had never dissected a human and was inferring human anatomy from animal anatomy.”

Vesalius worked with a leading artist to produce the stunningly detailed and accurate drawings, some of which include Renaissance-style landscapes as background. The drawings were used to produce fine woodcuts, which were then printed on linen pages. The result is a work of science and art that survives more than 450 years later, and remains relevant.

The title page of the book shows Vesalius standing over a cadaver in an elaborate lecture hall, jam-packed with observers. You have to look closely to notice a dog in one corner of the drawing has a human foot for its left hind paw – a dig at Galen.

“Observation, and believing what you could see, was the watchword that Vesalius worked by, and it changed everything in medicine,” Gaynes says. “Medicine finally began to move forward because of this book.”

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How a natural leader bloomed

"Ultimately, the goal is to help prepare students to be leaders in a different world," says anthropology professor Peggy Barlett.

By Carol Clark

Peggy Barlett has this advice for graduates: "Don't listen to the people who say ‘conform to the rules and stay practical.' Listen to your inner wisdom about where this country needs to be and what you can do to help it get there."

Barlett, the Goodrich C. White Professor of Anthropology and faculty liaison for the Office of Sustainability Initiatives, embodies that advice. She is the recipient of this year's Thomas Jefferson Award, the University's premier honor for significant service to the institution through personal activities, influence and leadership.

Barlett joined the Emory faculty in 1976. The campus, the city and the world had a much different mindset. Many people appreciated natural beauty and worked to maintain it. But broad-based approaches to sustainability were largely confined to specialists like Barlett, who studied the intersection of economic, ecological and demographic change among farmers.

Entering the 21st century, amid growing awareness of the greenhouse effect, attitudes began shifting. A pivotal moment at Emory occurred in 1999, when the decision to build a shuttle route in Lullwater forest sparked controversy. "I began to see more energy on campus around environmental concerns," Barlett recalls. "I decided to take a year off from research and spend that time seeing if we could galvanize some of that momentum."

It was a risky move, since sustainability work on campus didn't fit into the conventional role of faculty. "I thought I was going to run into a brick wall," Barlett recalls. "One person urged me, ‘Just keep calling the meetings, Peggy. Things will change.' To my surprise, people started showing up and expressing interest, at all levels. A lot of people who love Emory wanted to help create a better future."

Barlett began serving as the sustainability point person for faculty, staff, administrators, students and alumni, planting the seeds for Emory to become a nationally recognized green campus. The Piedmont Project, for example, infuses sustainability into the curriculum across disciplines, and has become a model for the country, inspiring hundreds of others.

Meanwhile, she published prolifically. "Sustainability on Campus: Stories and Strategies for Change," co-edited by Barlett, offers firsthand accounts, both inspiring and practical.

Barlett also helped develop the Sustainability Vision for Emory, adopted by the President's Cabinet in 2005 as a core principle of the University's strategic plan. The vision called for an Office of Sustainability Initiatives, and laid out clear and ambitious goals to achieve by 2015. Among them: Reduce average campus energy use by 25 percent, reduce the total waste stream by 65 percent, and procure 75 percent of the food for campus dining facilities from local or sustainably grown sources.

"Ultimately, the goal is to help prepare students to be leaders in a different world," says Barlett, who doesn't take a pessimistic view of the sustainability challenges they face. "This is an exciting time to be part of change, so much is happening. Businesses, governments and nonprofits are moving dynamically. Whole new professions are emerging around sustainability."

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Primatologist says humans may be nice by nature

Hugs, and our capacity for empathy, go way back in our evolutionary history, says primatologist Frans de Waal.

In the decades following the devastation of World War II, the idea that humans are naturally “killer apes,” with a stronger tendency toward aggression than pacifism, gained credence and became a dominant theme in behavioral research.

“Although it is far from my intention to depict us as angels of peace, this literature is now recognized as one-sided,” writes Emory primatologist Frans de Waal in the journal Science. His article, “The Antiquity of Empathy,” is part of a special issue on human conflict.

Humans are biologically geared to find pleasure in eating, sex, nursing and socializing. “If warfare were truly in our DNA, we should happily engage in it,” de Waal writes. “Yet soldiers report a deep revulsion to killing, and only shoot at the enemy under pressure. Many end up with haunting memories and disturbed social lives. Far from being a recent phenomenon, combat trauma was already known to the ancient Greeks, such as Sophocles, who described Ajax’s “divine madness,” now known as post-traumatic stress disorder (PTSD).”

Read the whole article here.

Image: istockphoto.com

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A glimpse of world's most elusive gorillas

Using camera traps, the Wildlife Conservation Society recently captured the above video of rare Cross River gorillas, in their habitat of Cameroon’s Kagwene Gorilla Sanctuary. They are the world’s rarest and least observed gorilla species: Fewer than 250 of them are left.

While poaching and habitat loss are taking the biggest toll on the gorillas, they are also threatened by viruses and bacteria carried by people. They share 95 to 99 percent of our DNA, raising the potential for pathogen exchange, says Tom Gillespie, associate professor of global health and biodiversity conversation at Emory University.

Gillespie, a leading primate disease ecologist, researches ways to understand, and minimize, the exchange of pathogens between humans and apes. HIV, for example, originated from apes.

Gillespie’s lab, together with partners at the Robert Koch Institute in Berlin, is analyzing fecal samples from the Cross River gorillas, to monitor for evidence of disease or parasites. Ebola, polio, gastrointestinal parasites and respiratory diseases are examples of human diseases that have also impacted gorillas.

Midway through the video a male silverback thumps his chest and charges toward the camera. “It’s a very humbling experience” to get charged by a gorilla, says Gillespie, who often encounters them face-to-face in the wild. Although gorillas are generally peaceful animals, and do not resort to violence unless provoked, Gillespie says they put on an impressive display. Click here to read more.

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What is your dog thinking? Brain scans unleash canine secrets

By Carol Clark

When your dog gazes up at you adoringly, what does it see? A best friend? A pack leader? A can opener?

Many dog lovers make all kinds of inferences about how their pets feel about them, but no one has captured images of actual canine thought processes – until now.

Emory University researchers have developed a new methodology to scan the brains of alert dogs and explore the minds of the oldest domesticated species. The technique uses harmless functional Magnetic Resonance Imaging (fMRI), the same tool that is unlocking secrets of the human brain.

The Public Library of Science (PLoS ONE) published the results of their first experiment, showing how the brains of dogs reacted to hand signals given by their owners.

“It was amazing to see the first brain images of a fully awake, unrestrained dog,” says Gregory Berns, director of the Emory Center for Neuropolicy and lead researcher of the dog project. “As far as we know, no one has been able to do this previously. We hope this opens up a whole new door for understanding canine cognition and inter-species communication. We want to understand the dog-human relationship, from the dog’s perspective.”

Callie wears ear protection as she prepares to enter the scanner. The research team includes, from left, Andrew Brooks, Gregory Berns and Mark Spivak. Photo by Bryan Meltz.

Key members of the research team include Andrew Brooks, a graduate student at the Center for Neuropolicy, and Mark Spivak, a professional dog trainer and owner of Comprehensive Pet Therapy in Atlanta.

Two dogs are involved in the first phase of the project. Callie is a two-year-old Feist, or southern squirrel-hunting dog. Berns adopted her at nine months from a shelter. McKenzie is a three-year-old Border Collie, who was already well-trained in agility competition by her owner, Melissa Cate. Both dogs were trained over several months to walk into an fMRI scanner and hold completely still while researchers measured their neural activity.

The researchers aim to decode the mental processes of dogs by recording which areas of their brains are activated by various stimuli. Ultimately, they hope to get at questions like: Do dogs have empathy? Do they know when their owners are happy or sad? How much language do they really understand?

Callie, a two-year old Feist, is one of two dogs involved in the initial phase of the project. Photo by Carol Clark.

In the first experiment, the dogs were trained to respond to hand signals. One signal meant the dog would receive a hot dog treat, and another signal meant it would not receive one. The caudate region of the brain, associated with rewards in humans, showed activation in both dogs when they saw the signal for the treat, but not for the no-treat signal.

“These results indicate that dogs pay very close attention to human signals,” Berns says. “And these signals may have a direct line to the dog’s reward system.”

Berns is a neuroeconomist, who normally uses fMRI technology to study how the human mind works. His human brain-imaging studies have looked at everything from why teens engage in risky behavior to how adults decide to follow, or break, established rules of society.

Callie training in a scanner mock-up. 

Dog lovers may not need convincing on the merits of researching the minds of our canine companions. “To the skeptics out there, and the cat people, I would say that dogs are the first domesticated species, going back at least 10,000 years, and by some estimates 30,000 years,” Berns says. “The dog’s brain represents something special about how humans and animals came together. It’s possible that dogs have even affected human evolution. People who took dogs into their homes and villages may have had certain advantages. As much as we made dogs, I think dogs probably made some part of us, too.”

The idea for the dog project came to Berns about a year ago, when he learned that a U.S. Navy dog had been a member of the SEAL team that killed Osama bin Laden. “I was amazed when I saw the pictures of what military dogs can do,” Berns says. “I realized that if dogs can be trained to jump out of helicopters and airplanes, we could certainly train them to go into an fMRI to see what they’re thinking.”

All procedures for the dog project were approved by the Institutional Animal Care and Use Committee of Emory. “From the outset, we wanted to ensure the safety and comfort of the dogs,” Berns says. “We wanted them to be unrestrained and go into the scanner willingly.”

The dogs were trained to wear earmuffs, to protect them from the noise of the scanner. They were also taught to hold their heads perfectly still on a chin rest during the scanning process, to prevent blurring of the images.

“We know the dogs are happy by their body language,” says Mark Spivak, the professional trainer involved in the project. Callie, in particular, seems to revel in the attention of breaking new ground in science.

“She enters the scanner on her own, without a command, sometimes when it’s not her turn,” Spivak says. “She’s eager to participate.”

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