"I want to help Native American tribes to reclaim knowledge of their very ancient evolutionary histories — histories that have been largely wiped away because of colonialism," says Emory geneticist John Lindo. Photo by Kay Hinton, Emory Photo/Video.
By Carol Clark
The ancient genomes of the Tsimshian indigenous people left tell-tale markers on the trail of their past, revealing that at least 6,000 years ago their population size was on a slow but steady decline.
The American Journal of Human Genetics published the findings, which draw from the first population-level nuclear DNA analysis of a Native American group from ancient to modern times.
“The finding contradicts a popular notion,” says John Lindo, a geneticist in Emory University’s Department of Anthropology and first author on the paper. “There is this idea that after Native Americans came in through the Bering Strait that they were all expanding in population size until Europeans showed up. At least for this one population, we’ve shown that was not the case.”
A boon in next-generation DNA sequencing technology has opened the possibility to explore the evolutionary history of different populations. “Ancient nuclear DNA analysis is a relatively new field,” Lindo says. “Not until recently have we had methods to sequence an entire genome quickly and inexpensively.”
Nuclear DNA provides information on an individual’s lineages going back hundreds of thousands of years. Lindo is one of the few geneticists looking at ancient whole genomes of Native Americans. He is especially interested in understanding how the genomes of their different populations evolved over time.
“Their evolutionary histories are radically different,” Lindo says. “Over thousands of years, various Native American populations have adapted to living in every ecology throughout North and South America, from the Arctic to the Amazon. That’s about as an extreme as you can get for differences in environments.”
The Tsimshian people historically lived in longhouses in coastal British Columbia and southern Alaska where they harvested the abundant sea life. Lindo and his colleagues sequenced the genomes of 25 living Tsimshian people and 25 ancient individuals who lived in the same region between 6,000 and 500 years ago, and confirmed that they were a continuous population through time.
Members of the Tsimshian Native American tribe hold a tea party near Fort Simpson, British Columbia, in 1889. Image from the Library and Archives Canada.
In a previous paper, drawing from the same data set, they found a dramatic shift between the two time periods in a class of genes associated with the immune system, suggesting a strong evolutionary pressure on the population to adapt to pathogens. A demographic model indicated a crash in the Tsimshian population size of about 57 percent during the early-to-mid 19th century. That finding fitted with historical accounts for how smallpox, introduced by European colonization, devastated the Tsimshian population during two epidemics within that time-frame.
The current paper looked at broader genetic variations between the ancient and modern DNA. An analysis showed both how the variation declined slowly in the ancient population before the collapse, but has since recovered.
“After a population collapse, only a subset of the genetic diversity remains,” Lindo says. “We find a more nuanced story, that despite the population collapse, the genetic diversity of modern Tsimshian people varies significantly.”
Intermarriage with other Native American groups and non-native populations increased the genetic diversity of some of the modern-day Tsimshian people so that it is near the levels prior to their population collapse, the analysis showed.
“A population with relatively high genetic diversity has a greater potential to fight off pathogens and avoid recessive traits,” Lindo says. “It exemplifies the benefits of gene flow between populations, especially following catastrophic events such as the small pox epidemics that the Tsimshian endured.”
Senior authors on the paper are Michael DeGiorgio from Pennsylvania State University and Ripan Malhi from the University of Illinois. The paper’s coauthors include Tsimshian representatives Joycelynn Mitchell and Barbara Petzelt from the Metlakatla Treaty Office in Prince Rupert, Canada.
Malhi, a leader in forging trusting relationships between genetic researchers and indigenous people, was a mentor to Lindo, who earned his PhD at the University of Illinois at Champaign-Urbana.
Lindo is continuing that tradition of building trust and working closely with indigenous populations. His ancient DNA research at Emory integrates the approaches of ancient whole genomes, statistical modeling and functional methods.
One of his projects is focused on genetic fluctuations to help understand ancient adaptions in various Native American populations. He is currently working with 10 different tribes from throughout North America.
“Community engagement is essential when working with indigenous communities,” says Lindo, explaining that he first meets personally with a tribal community to talk about how a genetic study might add to their knowledge of their own history.
“I listen to their stories and how they are working to keep their cultures alive,” he says. “One elder from a southwestern tribe told me that his grandfather was taken away in the early 1900s because he was a shaman and Christianity was swelling through the area. Each tribe’s stories are different but they are all powerful, and sometimes difficult, stories to hear.”
Most ancient DNA analyses have come out of Europe, where more ancient DNA labs are based and cold temperatures have helped preserve specimens.
Lindo wants to bring some of the same insights that those of European ancestry are gaining about their past to Native Americans.
“I’d like to disentangle this idea that Native Americans are part of a singular race,” he says. “I want to help Native American tribes to reclaim knowledge of their very ancient evolutionary histories — histories that have been largely wiped away because of colonialism.”
Art by Emory senior Pamela Romero, Science.Art.Wonder. founder and president, portrays how aphids can develop wings in response to environmental changes. The DNA painted along the edges of the canvases is the same, except that different genes are switched on. Photo by Ann Watson, Emory Photo/Video
By Carol Clark
A small crowd gathers in Emory’s White Hall before the menacing sight: Large rubber worms arrayed on triangular red spikes. The jagged spikes, from a few inches to more than a foot tall, lean crazily in all directions. Some of the worms — suspended on near-invisible fishing line — appear to rise off the spikes, escaping to a circular mirror hanging from above.
“This is how evolution works!” says Ethan Mock, a sophomore majoring in ancient history, who created the sculpture, titled "The Crucible." He looks dapper in a leather vest and tweed cap and speaks with theatrical flair to the crowd. “The spikes represent the trials and tribulations of the worms’ struggles. Most are trapped in the spikes but a few climb out, not realizing that they are simply climbing into a new trial, a new test.”
The onlookers include a mix of college students, children and their parents, brought together by campus events during the recent Atlanta Science Festival. Joining the regular attractions of Physics Live! and Chemistry Carnival is the debut of an art exhibit by a new, student-run program called Science.Art.Wonder., or S.A.W. Just over 100 artists — most of them untrained college students — teamed with scientists from Emory and Georgia Tech to translate their research into art.
Ethan Mock and his art, "The Crucible"
Mock worked with the lab of Levi Morran, an assistant professor in Emory’s Department of Biology who studies co-evolutionary dynamics by experimenting with a host (a microscopic worm called C. elegans) and a parasite (a bright red species of bacteria called Serratia marcescens that is lethal to C. elegans upon consumption).
“This is so cool!” says Pareena Sharma, a first-year biochemistry major at Emory, as she snaps a photo of the sculpture. “It’s so relatable to me. I’ve been doing this same experiment since the first of the semester in Biology 142.”
Two young boys draw near the spikes. “Look up into the mirror,” Mock encourages them. “Now tell me what you see.”
“The same thing,” one of the boys replies.
“That’s right!” Mock says. “The process of evolution keeps repeating, going in a loop.”
Morran, arriving with his eight-year-old daughter, Maggie, is impressed. “You could see the light come on in those boys’ eyes,” he says. “They understood what Ethan is trying to convey. And it’s not an easy concept to grasp — the continual evolutionary struggle.”
Both artists and researchers engage with visitors as they peruse more than 140 works of art, set up on the Quad, in White Hall, the Math and Science Center and the Atwood Chemistry Center during the festival.
“This artwork gives you a snapshot of how much research is being done in Atlanta. I’m taken aback by how cutting edge and varied it is,” says Pamela Romero, president of S.A.W. The program is the brainchild of Romero, a senior majoring in neuroscience and behavioral biology and minoring in computer science.
Young visitors to the Emory campus peruse science-inspired art on the Quad. Photo by Ann Watson, Emory Photo/Video
The Emory S.A.W. contributions span labs across the University and beyond. The artists picked their mediums, from acrylic to watercolor and everything in between.
Emily Isaac, a first-year Emory student majoring in environmental sciences and theater, stands on the Quad next to a large watercolor she painted. “Art can help scientists make a point without using any scientific jargon,” she says.
She teamed with Robert Wallace from Georgia Tech’s Agricultural Technology Research Program. One of Wallace’s projects gave plots of farmland to women in India who had been victims of an acid attack. Isaac did a portrait of a woman with a scarred face. The woman’s head is partially wrapped in strips of bandages that Isaac painted to look like rows of newly sprouting plants.
“I wanted to show hope, and how connecting with the environment can help people,” Isaac says.
This year’s 36 Emory S.A.W. artists are mainly undergraduates — many of them science majors — but they also include a few graduate students, faculty and staff members. Georgia Tech makes up the bulk of other contributing artists and researchers in this year’s S.A.W., although 10 independent artists also got involved, along with Georgia State University undergraduates and the Atlanta campus of SCAD.
“S.A.W. is collaborative, not only across disciplines and institutions, but also across students, faculty, staff and members of the Atlanta community,” Romero says. “We even have one international artist, from Puerto Rico.”
A painting by Georgia Tech student Bianca Guerrero portrays a virtual reality game used to measure players' perception of time as well as eye movement. The art is based on research by Georgia Tech psychologist Malia Crane. Photo by Ann Watson, Emory Photo/Video.
As long as she can remember, everyone thought Romero would become an artist, or maybe an architect. She began taking art classes at the age of three in her home town of Tegucigalpa, Honduras. She continued making and studying art, developing a surrealist style.
In ninth grade, however, a psychology course sparked a fascination for neurobiology. Romero took online classes and started reading up on subjects like optogenetics and deep-brain stimulation.
By the time she was accepted to Emory, she had decided to forge a career as a scientist. “A lot of people told me that if I chose neuroscience I would have to forsake art, because I would be a bad scientist if I tried to do both,” she recalls. “I was determined to prove them wrong.”
Romero sought out kindred spirits like Nicole Gerardo, associate professor of biology, who also grew up with twin passions for science and art. Gerardo once had students create artwork using microbes in her lab under the direction of Nancy Lowe — a former lab technician at Emory who went on to create a retreat center in North Carolina called AS.IF: Art and Science in the Field.
Gerardo later paired students with labs to create ceramic representations of research under the direction of Diane Kempler, who formerly taught visual arts at Emory.
“Art provides a way to reach people who may be intimidated by science,” Gerardo says. “And working with an artist lets scientists see their own work in a different way. That could lead to new scientific approaches.”
When Romero first joined forces with Gerardo it was simply to produce art for her lab, which focuses on evolutionary ecology. “We were test subjects for S.A.W.,” Romero says.
Emory senior Maureen Ascona, a neuroscience and behavioral biology major, discusses her art with visitors to the Quad. Ascona teamed with Helen Mayberg, from the Emory School of Medicine, who uses deep-brain stimulation to help patients with treatment-resistant depression. Photo by Ann Watson, Emory Photo/Video.
One of the pieces Romero created consists of triangular canvases that can be shifted into different positions. The acrylic painting depicts how aphids develop wings in the presence of predators, like ladybugs, or if food becomes scarce. “When Dr. Gerardo explains her work to people, she can move the canvases to show how the aphids change in response to their environment,” Romero says.
Romero wanted to give other students the chance to enter research labs and experiment with art.
“Pamela is an amazing woman, a force of nature,” says Gerardo, who is the faculty mentor for S.A.W. “What she has done with the support of her fellow students is incredible. I had envisioned maybe 20 pairings of scientists and artists. I’m still surprised by how big it became.”
Connections from across the University helped S.A.W. grow. Wei Wei Chen and John Wang, student leaders of Emory Arts Underground, provided the platform for Romero to launch S.A.W. and encouraged her to form a charter, bylaws and an executive team. That team includes Emory undergraduates Alex Nazzari (vice-president), Aila Jiang, Veronica Paltaraskaya, Anne Pizzini, Deborah Seong and John Wang, along with Georgia Tech students Olivia Cox, Siyan Li and Iris Liu.
The students’ efforts paid off with S.A.W.’s smash debut at the Atlanta Science Festival.
“One of my favorite parts was guiding artists through the process of disentangling the science, reassuring them that they could do it,” Romero says. “Many of them felt overwhelmed after first talking to a scientist. Some of them were first-year students who hadn’t even had introductory biology or chemistry.”
A piece by Alice Yang, a first-year Emory student majoring in neuroscience and behavioral biology who teamed with researchers of human genetics in the Emory 3q29 Project. Photo courtesy of S.A.W.
Exploring a lab through an art project allows students to develop a relationship with a researcher and often find a mentor, Romero says.
Alice Yang, a first-year Emory student majoring in neuroscience and behavioral biology, teamed with Jennifer Mulle, assistant professor at Rollins School of Public Health. Mulle is co-principal investigator of the Emory 3q29 Project, which seeks to understand a genetic deletion associated with an increased risk for schizophrenia.
“I’m so grateful for the experience,” Yang says of spending time with the 3q29 Project team. “I learned what it’s like to actually do science. And I caught their passion. People are just now realizing how genetics can be involved in mental illness. It’s a very new field.”
To create her art pieces, Yang ordered special scratch-off paper from her native China. “This paper’s easy to work with and it’s great for showing patterns and textures,” she says. She explains how she carefully cut slices from the black top layer of the paper to reveal the glowing, rainbow colors beneath. Her pictures portray the nanomapping of fluorescent-labeled alleles from the 3q29 lab while also paying tribute to Salvador Dali’s surrealism.
Even those who are not aspiring scientists can catch the science-art bug. Independent artist Aaron Artrip teamed with scientists Matthew Jackson and Dan Cook at Georgia Tech to demonstrate interaction with sound.
A group of children buzzes around Artrip’s exhibit in White Hall. A piece of paper sprinkled with powdered black ink is taped to a wooden speaker, which is plugged into an electronic synthesizer. As Artrip taps a keyboard, the powder moves across the page, creating patterns.
“I’m making drawings with vibrations. Forcing sound through the ink causes it to move,” he explains.
“Would you like to try?” he asks a young girl watching him.
She doesn’t have to be asked twice.
A painting by Georgia Tech student Kate Bernart, "Connecting the Cycle," portrays Austin Ladshaw's research at Georgia Tech's School of Environmental Engineering on the nuclear fuel cycle and ways to prevent excessive accumulations of radioactive waste. Photo by Ann Watson, Emory Photo/Video
Ultimately, S.A.W. hopes to find ways to integrate its art-science model into grades K-12.
“We would like to have artists and researchers go into K-12 classrooms to talk about the art and the research together,” Romero says.
She presented S.A.W. at the recent Georgia Tech STEAM Leadership Conference, which brought together educators and policymakers to explore new ways to teach science, technology, engineering, art and math, or STEAM.
S.A.W. is now working to put together an anthology of its art into a booklet, to include descriptions of the science. The booklet will be aimed at high school students “to give them a glimpse of some of the possible fields available to them in college,” Romero says.
S.A.W. is also creating a web site where the art will be accessible in digital form, including videos of some of the interactive art pieces, along with other resources for K-12 teachers.
After graduating this spring, Romero plans to take a gap year, then go on to graduate school with the aim of becoming a professor with a research lab. “S.A.W. has an incredible executive team and I’m making sure that the program continues after I leave Emory,” she says. “I would also like to stay involved with it in some way.”
As she prepares for graduation, Romero is working on an art narrative piece funded by the Emory Center for Creativity and Arts. The work will combine acrylic painting and sculpture to represent the element Vanadium, discovered by Mexican mineralogist Andrews Manuel del Rio in 1801. A series of circular canvases will each represent an atom in Vanadium. Each canvas will also represent a country or group of countries in Latin America, on which Romero will depict the research of a scientist from that area.
“My main goal with this piece is to celebrate and encourage more Latin American science,” Romero says. She is calling the piece “Elementally Latino,” to describe how Latinos are an elemental, or basic, part of science and how they also embody an elemental force. “Latinos are such a passionate people that I can only adequately describe them as a force of nature,” she says.
Emory disease ecologist Thomas Gillespie served on an international committee that developed best practice guidelines for health monitoring and disease control in great ape populations, part of a growing public education effort.
By Tony Rehagen
Emory Magazine
Thomas Gillespie’s parents and teachers always wanted him to go into medicine.
“Growing up in Rockford, Illinois, if you were smart and interested in biology, you were supposed to be a doctor,” he says.
Gillespie, meanwhile, was always more interested in primates. In seventh grade, he phoned animal psychologist Penny Patterson, famous for teaching the gorilla Koko how to use sign language, and interviewed the scientist about Koko’s diet while punching out notes on a typewriter. He was premed at the University of Illinois, but spent his internship at the Brookfield Zoo in Chicago, working in the “Tropic World” primate exhibit. His favorite undergrad course was biological anthropology, the study of biological and behavioral aspects of humans and nonhuman primates, looking at our closest relatives to better understand ourselves.
Gillespie eventually took a year off before graduate school to work with primate communities in the Peruvian Amazon. The apes finally won out — Gillespie would choose a doctorate in zoology over medical school.
But it wasn’t long before the two fields of study collided. While monitoring the group behavior of colobine monkeys in Africa, Gillespie observed that some of the animals were eating bark from the African cherry tree — not a typical food source for them. When he dug deeper, Gillespie learned that human doctors in the region used that same bark to treat parasites in their patients. The monkeys, he realized, were self-medicating.
“That discovery in these monkeys brought me back toward the health science side of biology,” says Gillespie.
Gillespie’s return to a medical approach to zoology came not a moment too soon—for the sake of the primates and maybe even all of humankind. As an associate professor in Emory’s Department of Environmental Sciences specializing in the disease ecology of primates, Gillespie and his team of researchers have helped uncover a crisis among our nearest taxonomic neighbors. According to an article coauthored by Gillespie and thirty other experts and published in the journal Science Advances, 75 percent of the world’s five-hundred-plus primate species are declining in population, and a whopping 60 percent face extinction, largely due to human encroachment.
Hair-raising, spine-tingling fun: A young visitor to the Emory campus during last year's Atlanta Science Festival experiences the thrill of static electricity.
By Carol Clark
From the lumbering, 200-year-old Frankenstein to sleek, modern-day robots, this year’s Atlanta Science Festival — set for March 9 to 24 — highlights creations that spark wonder and fun, giving glimpses of the past and the future.
The five-year-old festival expanded to more than two weeks, encompassing 120 events sponsored by 90 different partners at 70 venues across metro Atlanta, including many on the Emory campus. The festival culminates with a day-long “Exploration Expo” on Saturday, March 24, set in Piedmont Park.
“Rise Up, Robots!” kicks off the festival on the evening of Friday, March 9 at the Ferst Center, when three robots and their inventors will take the stage.
“We thought about how we could possibly top last year’s featured speaker, astronaut Mark Kelly — someone so inspirational to children and adults all over the planet,” says Meisa Salaita, co-director of the Atlanta Science Festival. “We finally realized that no human could match him, and we would have to resort to artificial intelligence.”
Heather Knight, professor of robotics at Oregon State University, will demonstrate the interactive quips of “Data,” the world’s first robotic comedian. Georgia Tech’s Gil Weinberg will jam with “Shimon,” a marimba playing robotic musician. And Stewart Coulter, from DEKA Research and Development, will show how a bionic arm named LUKE (Life Under Kinetic Evolution) changed an amputee’s life.
Tickets are required for the event, which starts at 7 pm. Door open early with an Interactive Robotic Petting Zoo, starting at 6 pm.
Frankenstein rises up on the Emory campus on Thursday, March 22. Three Atlanta playwrights will reanimate Mary Shelley’s creation, which turns 200 this year, in the context of scientific research ongoing at Emory. Following the short plays join ethicists, scientists and the playwrights to discuss the work over refreshments. The event, titled “Frankenstein Goes Back to the Lab,” begins at 5:30 pm in Emory’s Science Commons.
On Friday, March 23, from 3:30 to 7 pm, Emory will host “Chemistry Carnival,” where visitors can join scientists in carnival games like Peptide Jenga and Bacterial Telepathy, in the Atwood Chemistry Center. On the same day and time, the ever-popular “Physics Live!” will again feature giant soap bubbles and liquid nitrogen ice cream, among other treats in the Math and Science Center.
A new Emory event this year, “Science.Art.Wonder,” will run concurrently with the chemistry and physics events, on the Emory Quadrangle and in nearby buildings, including White Hall and the Atwood Chemistry Center. For the past year, the program has paired local artists and scientists to explore ideas of research through the visual arts. You can stroll through an exhibit of the resulting artwork and meet some of the artists and scientists involved in the project.
Adult fare is featured on Monday, March 19, including “The Science of ‘Motherese,’” an overview of early vocal development in infants at the Marcus Autism Center, and “CDC in the Scene,” which features CDC scientists sorting fact from fiction surrounding movies like “Outbreak,” in the Mathematics and Science Center.
During “Unveiling the Internet,” on Wednesday, March 21, Emory computer scientists will give interactive lessons on everything from the workings of YouTube to Snapchat.
“STEM Gems: Giving Girls Role Models in STEM Careers,” on Saturday, March 10, is an interactive discussion where panelists offer advice and guidance specific to girls and young women intrigued by science, technology, engineering and math. “Women and Minorities in STEM: Surprises, Setbacks and Successes,” set for the evening of Thursday, March 22 at the Oxford campus, is a panel discussion with voices from a diverse set of scientific fields who will share their stories and take questions.
Click here for more details of Emory campus events, and events throughout the city featuring members of the Emory community.
Among the dozen Emory booths at “Exploration Expo” will be chemistry students running their non-Newtonian fluid dance pit. The Center for the Study of Human Health will explore the human gut microbiome in a booth called “Your Hundred Trillion Best Friends.” And the “Science.Art.Wonder” team will display art from the program and invite you to help create a mural.
The Atlanta Science Festival was founded by Emory, Georgia Tech and the Metro Atlanta Chamber and is a collaboration among diverse community partners and sponsors.
“In ancient Egypt, cats and dogs were gods, and they have not forgotten this!” says Melinda Hartwig, curator of Ancient Egyptian, Nubian and Near Eastern Art at the Michael C. Carlos Museum.
That exalted stature is illuminated in the exhibition “Divine Felines: Cats of Ancient Egypt,” which opened Feb. 10 at the museum and will be on view through Nov. 11.
The exhibit showcases cats and lions, plus dogs and jackals, as domesticated pets, creatures of the wild or mythic symbols of divinities, in ancient Egyptian mythology, kingship and everyday life. Animal burial practices and luxury items decorated with feline and canine features are also on display.
“Cats and dogs reveal so much about ancient Egyptian culture,” says Hartwig. “These animals were just as important to the ancient Egyptians as they are to us today.”
The kings of Egypt were associated with the lion, thus, the human head on the lion’s body or the sphinx.
“Cats were first domesticated in Egypt around 4000 BC. They were lovable pets, hunters of vermin and divine embodiments of fertility and protection. Lions and jungle cats were admired for their power, and were linked with royalty and divinity,” Hartwig continues. “Dogs were also kept as pets. Their loyalty and hunting abilities were keenly valued. Often found roaming the ancient necropolises, dogs and jackals became embodiments of the gods who protected the dead.”
Famed primatologist Jane Goodall with Emory disease ecologist Thomas Gillespie, who is working with the Jane Goodall Institute to study the health of chimpanzees in Tanzania's Gombe National Park.
The American Journal of Primatology just published a special edition bringing together experts who have contributed to the understanding of chimpanzee health at Gombe National Park in Tanzania and beyond. Gombe is the site where Jane Goodall pioneered her behavioral research of chimpanzees. Goodall’s work at Gombe began in 1960, and continues today through the Jane Goodall Institute, making it the longest field study of any animal.
Thomas Gillespie, associate professor in Emory’s Department of Environmental Sciences, was a guest editor of the special journal edition, along with fellow scientists Dominic Travis and Elizabeth Lonsdorf. Gillespie works at the interface of biodiversity conservation and global health. Much of his research examines how and why anthropogenic influences within tropical forests alter disease dynamics and place wild primates, people and other animals in such ecosystems at increased risk of pathogen exchange.
Following is an interview with Gillespie about the special journal issue and why research on chimpanzee health is important.
What is the current status of chimpanzees?
Both the common chimpanzee and the bonobo, the two chimpanzee subspecies, are endangered. Chimpanzees are the most closely related species to humans and we see them declining precipitously due to habitat loss and poaching. Typical estimates for the chimpanzee population are in the hundreds of thousands. That’s far less than the number of people in Atlanta for the entire chimpanzee species spread across all of Africa. There is a real risk of chimpanzees going locally extinct in core parts of their habitat. Chimpanzee communities in West Africa, for instance, have very little habitat left. They’re often found living in scraps of habitat between villages.
How important is health to conservation?
Wildlife health is a critical conservation issue, but that’s something that’s only recently been recognized. Wildlife populations already dealing with poaching and habitat loss are more vulnerable to being knocked out by disease. It becomes even more difficult when they are exposed to new pathogens, from humans or domesticated animals.
On top of that, primates are dealing with shifts in the dynamics of pathogens like Ebola. Ebola’s been around for a long time in natural systems but now we’re seeing big mortality events in wild chimpanzees and other apes. The Lowland Gorillas are actually listed as critically endangered due to Ebola.
How did you become involved with Gombe and the Jane Goodall Institute?
Fifteen years ago, as evidence mounted that disease was playing an important role in the population declines observed in Gombe chimpanzees in Tanzania, Dominic Travis and Elizabeth Lonsdorf developed a prospective health monitoring system. They began to collect specific behavioral data on signs of respiratory and gastrointestinal illnesses, combined with body condition scoring on a monthly basis for the chimpanzee communities at Gombe, that paralleled efforts by the Mountain Gorilla Veterinary Project in Rwanda and Uganda.
When I met Dom and Elizabeth at a workshop in Germany in 2004, I was six years into efforts to understand how logging and forest fragmentation in and around Kibale National Park, Uganda, affected disease dynamics in resident primates. My findings in Uganda highlighted that some forms of anthropogenic disturbance can alter the dynamics of natural pathogens in wildlife, such as a legacy of selective logging. It also revealed that other forms of disturbance, such as active forest fragmentation, can lead to opportunities for pathogens to jump between species, including the introduction of pathogens from people and domesticated animals to wild primates.
Dom and Elizabeth asked me to join their effort and expand the scope of their project to a One Health approach. I initiated diagnostic surveillance linked to geographical indicators of species overlap for Gombe’s chimpanzees and baboons, as well as the people and domesticated animals within the Greater Gombe Ecosystems. It serves as a map of all the places these species are interacting, for a greater sense of how transmission may be occurring. Integration of these new data streams, along with the ongoing observational health data and in-depth post-mortem necropsies, have allowed us to establish baselines of health indicators to inform outbreak contingency plans.
Dom, Elizabeth and I now co-direct this effort, which is known as the Gombe Ecosystem Health Project.
How does Gombe fit into the bigger picture of wildlife conservation?
As a result of Jane Goodall’s initial observations of disease outbreaks impacting Gombe’s chimpanzees, it became apparent that infectious diseases have the capacity to threaten the conservation of endangered species.
Some people call Gombe “a living laboratory.” It’s unique in the sense that it’s a place where there has been long-term data collection on the behavior patterns of chimpanzees, and for the past 15 years we’ve been collecting all this data on their health.
Methods have been developed at Gombe that allow us to monitor chimpanzee health non-invasively, through fecal sampling, so that we don’t have to dart the animals and tranquilize them to take blood samples. Many of the tools and approaches developed at Gombe have the capacity to manage disease-related threats to other wildlife populations globally.
Ashley Sullivan from the Jane Goodall Institute contributed to this report.
Every day, the average American throws away about 4.4 pounds of waste, about the weight of one chihuahua. Multiple that by every day of the year and over 300 million Americans and you get 167,000,000 tons of trash a year — or the equivalent of 76 billion chihuahuas.
Meggie Stewart, a senior majoring in Environmental Sciences, did the math for her two-minute video about landfills (above) — the first place winner for the Emory Office of Sustainability Initiatives 2017 Waste Video Competition. Emory is striving to achieve zero landfill waste on campus, since landfills have negative social, economic and environmental impacts.
The tortoise beetle, which eats thistle leaves, has evolved a symbiotic relationship with bacteria that allows it to have such a specialized diet. Photo by Hassan Salem.
By Carol Clark
A leaf-eating beetle has evolved a symbiotic relationship with bacteria that allows the insect to break down pectin — part of a plant’s cell wall that is indigestible to most animals.
The journal Cell published the findings on the novel function of the bacterium, which has a surprisingly tiny genome — much smaller than previous reports on the minimum size required for an organism not subsisting within a host cell.
“This insect is a leaf eater largely because of these bacteria,” says Hassan Salem, lead author of the study and a post-doctoral fellow in Emory University’s Department of Biology. “And the bacteria have actually become developmentally integrated into the insect’s body.”
Two organs alongside the foregut of the beetle Cassida rubiginosa house the bacteria and appear to have no other function than to maintain these microbes. “The organs are equivalent to the liver in humans, in the sense that they contain the tools to break down and process food,” Salem says.
The newly characterized bacterium has only 270,000 DNA base pairs in its genome, compared to the millions that are more typical for bacterial strains. That makes its genome closer to that of intracellular bacteria and organelles than to free-living microbes. Mitochondria, for example, the organelles that regulate metabolism within cells, have 100,000 base pairs.
The two symbiotic organs of the tortoise beetle, dyed a fluorescent green, are shown on either side of the insect's foregut. Microscopy image by Hassan Salem.
Salem is a researcher in the lab of Emory biologist Nicole Gerardo, an associate professor who specializes in the evolutionary ecology of insect-microbe interactions. The lab combines genomic and experimental approaches to learn how both beneficial and harmful microbes establish and maintain relationships with their hosts.
A human gut holds about 10,000 species of bacteria. These microbial communities, which can be genetically characterized as microbiomes, are transferred generationally but are also dynamic and respond to environmental changes. The microbiome of an urbanite, for example, has different characteristics from that of a hunter-gatherer.
Unlike humans, insects tend to have specialized feeding ecologies. They offer simple models to study symbiotic relationships between microbes and their hosts.
Salem with Buchner's book
Salem became fascinated by Cassida rubiginosa, more commonly known as the tortoise beetle, while he was a graduate student at the Max Planck Institute for Chemical Ecology in Jena, Germany. He was leafing through a 1953 edition of a book by the late Paul Buchner, a German scientist and one of the pioneers of systematic symbiosis research in insects. Buchner referenced a paper published in 1936 by one of his students, Hans-Jurgen Stammer, on Cassida rubiginosa.
“Stammer wrote that, unlike most leaf-eating beetles that he had studied, this one had sac-like organs that he had never seen before and the organs were filled with micro-organisms,” says Salem, who looked up Stammer’s original paper in a now-obscure journal. “He didn’t have the high-powered microscopes that we have now, or genome sequencing technology, so he wasn’t able to comment on the functionality of the mysterious microbes. At that point, the idea that microbes could do anything beneficial for an animal was mushy science.”
Intrigued by the article, Salem went to a nearby woodland to collect some of the leaf beetles. “To find these beetles, you don’t go looking for them,” he explains. “You go looking for the plants they eat.”
The tortoise beetle feeds on the tough, spiny leaves of the Californian thistle (Asteraceae). This prolific weed grows throughout much of the world and is difficult to control. “It pops up in a lot of areas where sheep are maintained,” Salem says. “In fact, it’s a huge pest to New Zealand sheep farmers. The more thistles covering a farmland, the less food the sheep have to eat and the lower the yield. But the thistle is hard to get rid of because its roots run so deep.”
Salem followed the trail of his curiosity to New Zealand, spending time with an agricultural researcher, Michael Cripps, who breeds the tortoise beetle as a bio-control model for thistles. “You drop 100 beetles on a thistle plant and the insects will just drain the plant metabolically until it dies,” Salem explains.
As an herbivore that specializes in eating leaves, the tortoise beetle must consume large amounts of plant cell walls, made of hard-to-digest materials like pectin. One of nature’s most complex polysaccharides, pectin is a gelatinous substance that gives plant cell walls their shape and rigidity. While it was unclear how the beetle obtained needed nutrients of amino acids and vitamins from such a diet, Salem suspected that symbiotic bacteria played a role.
In this cross-section of the symbiotic organ the bacteria it contains are lit up in fluorescent green dye. Microscopy image by Hassan Salem.
When he joined the Gerado lab at Emory, Salem continued to study the tortoise beetle and its micro-organisms with the help of fellow post-doc Aileen Berasategui, a co-author of the Cell paper.
They used genome sequencing technology to characterize the microorganisms as a new species of bacterium. Despite its tiny genome, the bacterium has the power to degrade pectin.
“Just as an apex predator has claws and strong mandibles to obtain the nutritional value that it needs from its prey, the bacterium has pectin-digesting genes that enable the beetle host to deconstruct a plant cell,” Salem says.
After the bacterium breaks down the pectin, the beetle’s digestive system can then access all of the amino acids and vitamins within the plant’s cells for its nutrients.
Salem christened the new bacterium Candidatus Stammera capleta, after Hans-Jurgen Stammer, the ecologist who first glimpsed it and wondered about it more than 80 years ago.
“The most amazing thing to me is that we made this discovery because I read a really old book,” Salem says. “It speaks to the importance of natural history collections and libraries for old journals. We truly stand on the shoulders of giants, extending the work of those who came before us.”
Additional co-authors of the paper are from the Max Planck Institute for Chemical Ecology, the University of Luxembourg, the Lincoln Research Centre in New Zealand, Johannes Gutenberg University in Germany and the National Institute for Advanced Industrial Science and Technology in Japan.
“Due to the current void in national leadership on the issue of climate change, efforts at the state and local level are more important than ever,” says Eri Saikawa, an assistant professor of Environmental Sciences. Saikawa is part of an Emory delegation to the U.N. Climate Change Conference talks in Bonn, Germany, which includes two faculty and 12 students.
By Carol Clark
U.S. state policies aimed at mitigating power plant emissions vary widely in effectiveness, finds a new study by researchers at Emory University.
Nature Climate Change published the analysis, which shows that policies with mandatory compliance are associated with the largest reductions in power plant emissions.
“Based on the results of our study, we recommend that states adopt a policy of mandatory greenhouse gas emissions registry and reporting for power plants,” says Eri Saikawa, an assistant professor in Emory’s Department of Environmental Sciences. “We also found a significant impact in states that adopt public benefit funds aimed at energy efficiency and renewable energy programs. These two policies not only are effective in reducing power-plant emission levels but also emissions intensity.”
Saikawa, an expert in public policy and the science of emissions linked to global warming, co-authored the study with Emory graduate Geoff Martin, whose thesis project focused on the topic. Martin received his master’s degree in environmental sciences in May and now works as an energy coordinator for the town of Hartford, Vermont.
Their findings were released today as the U.N. Climate Change Conference (COP23) opens in Bonn, Germany. Delegates from around the world are gathering to hammer out details for meeting the goals of the 2015 Paris Agreement.
The United States was among the 195 countries that committed to this framework to reduce greenhouse gas emissions — although the Trump administration has said it plans to withdraw from this historic accord.
“Due to the current void in national leadership on the issue of climate change, efforts at the state and local level are more important than ever,” Saikawa says. “U.S. cities and states need to step up and do what they can.”
Emory is one of 50 universities from around the country to hold official U.N. observer status for COP23. Saikawa and Sheila Tefft, senior lecturer from the Department of English, will be on the ground in Bonn — leading a delegation of 11 Emory undergraduates and one graduate student as part of their co-taught class, “Climate Change and Society.”
The students will report news live from the event on Twitter under the hashtag #EmoryCOP23. They will also post longer reports, podcasts and videos on a web site they created for the event, Climate Talks Emory University.
Global atmospheric CO2 levels increased at record speed last year, to reach a level not seen for more than three million years, the U.N. warned in a report released last week. The U.S. government’s National Climate Assessment, also released last week, affirmed that climate change is driven almost entirely by human action and detailed how the country is already experiencing more extreme heat and rainfall events, more large wildfires and more flooding due to the warming climate.
About 30 percent of U.S. greenhouse gas emissions come from the electric power sector. For the Nature Climate Change paper, the researchers started out to review the potential impact of President Obama’s Clean Power Plan — which established the first national carbon pollution standards for power plants. When President Trump took office, and announced plans to repeal the Clean Power Plan, the researchers shifted focus.
They analyzed 17 policies adopted by various states relating to climate and energy. States that adopted a mandatory policy for power plants to register and report greenhouse gas emissions, along with three to four other policies, showed the largest reductions, at an average of 2.6 million metric tons of carbon dioxide (CO2) emissions per year.
The second most significant policy involved public benefit funds allotted for energy efficiency and renewable energy programs. That policy was associated with a reduction of about 1.5 million tons of CO2 emissions from power plants, when adopted with three to four other policies.
It’s unclear whether one of these single policies was the actual driver of the reduction in emissions, or an indicator that a state takes climate change mitigation seriously and is attacking the issue on many fronts, Saikawa says.
For instance, three states — New York, Connecticut and Oregon — have each adopted both of the top two most effective policies, along with at least eight other policies.
In 2007, China surpassed the United States as the largest emitter of greenhouse gases globally. “But the per capita emissions in the United States are more than double that of China,” Saikawa notes.
The Obama administration played a key role in securing the Paris Agreement, to keep global warming to no more than 2 degrees Celsius since the start of the Industrial Revolution.
“It will be interesting to hear the take of officials from the Trump administration this year,” Saikawa says.
“U.S. coalitions from the state and city level are forming and they will likely have a strong presence at side events for COP23,” she adds. “Many groups are working at the local level around the world to try to meet the goal of the Paris Agreement.”
Emory is co-hosting an event on Thursday, November 16 at COP23, focused on ways to mitigate climate change impacts in the developing world. Saikawa will appear on a panel, along with John Seydel, director of sustainability for the city of Atlanta.
“We’ll be discussing how efforts at the city and state level in the United States might be replicated in other parts of the world,” Saikawa says.
This marks the third year in a row that Emory has sent a delegation to the U.N. climate talks.
Climate change. Partisan politicians debate its reality, and many citizens see it as a faraway threat, something that endangers the future of polar bears but not them personally.
The health effects of global warming, however, are already being felt. Extreme weather events such as wildfires, droughts, and flooding are becoming more frequent, resulting in more injuries, deaths, and relocations. Heat and air pollution are sending people with asthma and other respiratory ailments to the emergency room. Diseases carried by mosquitoes, fleas, and ticks are expanding their territory—dengue has become endemic in Florida, Lyme disease has worked its way up to Canada and over to California, and some fear that malaria may re-emerge in the U.S.
Tie these health burdens—which are only likely to worsen—with the current administration’s decision to pull out of the Paris climate agreement and dismantle environmental regulations, and the call to action becomes more urgent. “The federal government’s actions might be a headwind from a funding perspective, but they are also very much a tailwind from an inspiration and motivation perspective,” says Daniel Rochberg, an instructor in environmental health who worked for the U.S. State Department as special assistant to the lead U.S. climate negotiators under presidents Bush and Obama. “As others have said, ‘We are the first generation to feel the sting of climate change, and we are the last generation that can do something about it.’ We have to get busy doing something about it.”
Rollins School of Public Health has gotten busy. Faculty researchers are building the science of climate impacts, strategies for reducing greenhouse gas emissions, and approaches for increasing resilience to climate change. Climate@Emory, a university-wide organization of concerned students, faculty, and staff, is partnering with other academic institutions, industries, and governments to support education and climate remediation efforts. Through Climate@Emory’s initiative, Emory University is an accredited, official observer to the UN climate talks and has sent students and faculty to the climate conferences in Paris in 2015 and in Marrakech in 2016. And, of course, Rollins is educating the next generation of scientists who will be dealing with the fallout of today’s climate decisions.
“For environmental scientists, it’s a challenging climate,” says Paige Tolbert, O. Wayne Rollins Chair of Environmental Health. “That means we have to be creative, because we can’t step aside and wait four years. It’s more critical than ever that we keep moving forward and make whatever contributions we possibly can.”
Emory anthropologist Jessica Thompson next to Malawi rock art paintings, likely made by hunter-gatherers. Thompson's work in Malawi is part of a major new paper in the journal Cell, filling in thousands of years of human prehistory of hunter-gatherers in Africa. (Photo by Suzanne Kunitz)
By Carol Clark
Emory anthropologist Jessica Thompson was at a human origins conference years ago when she heard a presenter lament: “Of course, there is no ancient DNA from Africa because of the poor preservation there.”
That’s when it clicked in Thompson’s mind: She had visited a place in Africa — the highlands of northern Malawi — that had neither extremes of heat or wetness — two main environmental factors that degrade DNA. She also knew that scant archaeological research had been done in the region, although a team had unearthed several ancient skeletons there decades ago.
“It’s a strange and fascinating landscape,” says Thompson, who made that 2005 visit as a tourist and was struck by the surreal beauty of the high mountain grassland.
It’s also remote and off the radar of most of the world. “We saw maybe three other tourists while we were there,” she recalls.
That fateful trip laid the groundwork for discoveries of the oldest-known DNA from Africa. The journal Cell just published an analysis of the new discoveries, filling in thousands of years of human prehistory of hunter-gatherers in Africa, led by Harvard geneticist David Reich.
Thompson is second author of the paper. She contributed and described the cultural context for nearly half of the 15 new DNA finds, including the oldest samples. Her fieldwork in Malawi uncovered human remains that yielded DNA ranging in age from about 2,500 to 6,100 years old. And her work is ongoing at a site where a skeleton recovered in 1950 was just dated to 8,100 years old and also yielded DNA.
The other DNA in the Cell paper ranges in age from 3,000-to-500 years ago and comes from South Africa, Tanzania and Kenya.
“Malawi is positioned in between where living hunter-gatherers survive,” Thompson says. “For the first time, we can see the distribution of ancient hunter-gatherer DNA across Africa, showing how these populations were connected in the past.”
Ancient hunter-gatherers do not have a lot of living representatives in Africa today, and they occur as remnants of people scattered across the continent. The remains of Malawi hunter-gatherers that Thompson is studying may represent a population that was once thriving but subsequently pushed into marginal areas during the expansion of agriculturalists and pastoralists during the past 3,000 years.
Some of this population may have survived until much more recently.
“There are legends in Malawi of the original people who came there, passed down through oral histories,” Thompson says. “They are described as hunters and little people, short in stature. There is also a story of a last, epic battle — that occurred about 200 years ago — when these people got eradicated.”
Mount Hora, where the oldest DNA included in the Cell paper was obtained, from a woman who lived more than 8,000 years ago. (Photo by Jessica Thompson)
Malawi captivated Thompson during that first visit as a tourist, in 2005. She was a graduate student when she spent a summer working on a dig in the Serengeti. She and two companions decided to make a road trip before returning to the United States, including a stop in Malawi.
The landlocked country is located in southeast Africa, bordered by Zambia, Tanzania and Mozambique. It is one of the least-developed and smallest countries in Africa, about the size of the state of Tennessee, and runs north to south along the Rift Valley. An enormous body of water, Lake Malawi, makes up about one-third of the country.
“My traveling companies wanted to relax by the lake in the lowlands,” Thompson recalls. “I had read about the Malawi highlands and really wanted to see this unique ecosystem, so I convinced them to go there instead.”
Her companions complained of the cold — it’s windy and regularly freezes in the highlands of Malawi and summer temperatures peak at around 65 or 70 degrees Fahrenheit. Despite the cold, Thompson admired the rugged, isolated beauty of rocky outcrops and grasslands studded with orchids and fairy ferns where zebra and shaggy antelope grazed.
Thompson, who joined Emory as an assistant professor of anthropology in 2015, dug through the archaeological literature surrounding Malawi and started making exploratory trips there in 2009. She learned of two digs in the Malawi highlands — in 1950 and 1966 — that revealed human skeletons alongside rich cultural evidence of an extinct hunting-and-gathering lifeway.
Dancers at a festival in Malawi. The people living in the country today are the descendants of the Iron Age agriculturalists and pastoralists who swept across the African continent about 3,000 years ago. (Photo by Jessica Thompson)
The 1950 dig turned out to be led by the renowned archaeologist J. Desmond Clark, who Thompson calls her “academic grandfather.” Although Clark died before Thompson could meet him, he served as the mentor to her mentor, Curtis Marean.
On the slopes of Mount Hora — a striking 1,500-meter peak and a major landmark in the highlands — Clark uncovered two skeletons: A woman who had died at around age 22 and a nearby male, who had died in his 40s. The skeletons had been taken out of the country, to the Livingstone Museum in Zambia, and were never dated.
“It was impossible to accurately do radiocarbon dating on bone in 1950,” Thompson explains. “The skeletons became, quite frankly, forgotten over time.”
Guided by the clues from the previous excavations, Thompson began heading digs in the Malawi highlands. A site at a landmark outcrop, known as Fingira Rock, is particularly isolated, requiring the team to hike up a mountainside to more than 2,000 meters on the Nyika Plateau. “Working there you feel the wind, you feel the chill,” Thompson says.
Poachers are a hazard in the area, along with the occasional black mamba — one of the world’s deadliest snakes.
The Fingira site had not been excavated since 1966. “We were appalled to discover that it had been heavily disturbed since then,” Thompson says. Her team uncovered two human leg bones, from two different adult males, which yielded DNA that was about 6,100 years old.
The leg bone of a hunter-gatherer that lived 6,100 years ago, found at the Fingira Rock site. (Photo by Jessica Thompson)
In the back of a cave, they found fragments of a child’s skull in a termite mound. A tiny leg bone next to it indicated that the remains were from a baby younger than age one. DNA analysis revealed that she had been a girl and radiocarbon dating showed that she had died about 2,500 years ago. The analysis also showed that the bones from the infant and the two men were from the same hunter-gatherer population — even though they were separated by thousands of years of time.
The archaeological sediments suggest that Fingira was a place where the dead were buried, although the skeletal material has become scattered over time. Human bones are mixed with the bones of animals that they hunted and ate, as well as with stone tools and shell beads that they used for ornaments.
“When you visit the site,” Thompson says, “you wonder, why were these people living up here when it’s not the most comfortable conditions you can imagine? What was bringing them here? Why were they burying their dead, over and over again, for many thousands of years, in the same place?”
Meanwhile, Thompson tracked down the skeletons that Clark had discovered at Mount Hora in 1950. She learned they had been moved from Zambia to the University of Cape Town in South Africa.
Here’s where Emory graduate student Kendra Ann Sirak enters the story. Sirak had the distinction of being the last graduate student of Emory anthropologist George Armelagos, one of the founders of the field of paleopathology. He spent decades working with graduate students to study the bones of ancient Sudanese Nubians to learn about patterns of health, illness and death in the past. Armelagos sent Sirak to one of the best ancient DNA labs in the world, at University College Dublin (UCD), in Ireland, with samples of the Nubian bones.
After Armelagos died in 2014, at age 77, Thompson stepped in as one of Sirak’s mentors.
Thompson,
left, examines fragments of artifacts from the Malawi excavations in her
lab with Emory graduate student Kendra Ann Sirak. Sirak helped with the
radiocarbon dating and DNA extraction of the "forgotten" 8,100-year-old
skeleton from Mount Hora. (Photo by Ann Borden, Emory Photo/Video)
Thompson contacted the curator of the two skeletons from Mount Hora, to ask about the possibility of getting DNA from them. Alan Morris, now Professor Emeritus at the University of Cape Town, had had the same idea. A sample from the female skeleton was already slated to be sent to the UCD lab where Sirak was working. So Thompson, Morris and Sirak teamed up on the quest.
The petrous bone, which contains components of the inner ear, is the most promising site to drill for ancient DNA. The skeleton's petrous bone had already broken away from the skull, so only this tiny, triangular-shaped piece of the skeleton was sent to Dublin.
"It was extremely fragile," says Sirak, whose job was to drill into the petrous bone and get about 200 millimeters of bone powder without shattering the specimen.
She drank a cope of coffee, donned a hair cover, overalls, a face mask, two pairs of gloves and shoe covers, then entered a small, sterile room where the petrous bone awaited. "I said to myself, 'Here we go, I've got this!'" Sirak recalls.
Sirak was successful. Her colleagues in Dublin processed the sample and then sent it to the genetics team at Harvard Medical School for DNA analysis, which was also successful.
Meanwhile, radiocarbon dating revealed that the skeleton was 8,100 years old.
"It was like Christmas," Sirak says, "knowing that we had DNA data on such an ancient specimen."
The skeleton's genetics connected her to the same population of hunter-gatherers who died thousands of years later and were found 70 kilometers away at Fingira.
Another surprise revealed by the genetic analysis of the Malawi hunter-gatherers: They did not contribute any detectable ancestry to the people living in Malawi today, the descendants of the Iron Age agriculturalists and pastoralists who began sweeping across the African continent about 3,000 years ago.
“In most parts of Africa, you see quite a bit of admixture,” Thompson says. “When you take genetic samples from modern people who are living today, you find that they are a combination of the folks who were expanding into a region and also the folks who were living there before. In Malawi we see that’s not the case. It appears that there was a complete replacement of the original hunter-gatherer people. They are not just gone as a lifeway, they are actually gone as a people as well.”
One of the mysteries Thompson hopes to solve is how that replacement happened. Was it violent? Was it a sudden or a slow process? Did the entrance of strange new technologies, like pottery and iron working, play a role?
“We can’t use genetics to answer these questions,” Thompson says. “We have to use the archaeology.”
Emory anthropology undergraduates assisting with the Malawi excavations this past summer included, from left: Alexa Rome, Alexandra Davis, Suzanne Kunitz and Aditi Majoe. Graduate student Grace Veatch is on the far right.
She continues to excavate in Malawi, aided by local technicians and other collaborators. This summer, five Emory anthropology students accompanied her in the field: Graduate student Grace Veatch, senior Alexandra Davis, juniors Aditi Majoe and Suzanne Kunitz, and sophomore Alexa Rome. They uncovered more human remains at Mount Hora — a charred bone from a human arm and parts of two legs. These bones, recently dated to between 9,500 and 9,300 years old, show that the Hora site still has many secrets to reveal.
While radiocarbon dating of charcoal samples from just above and below the bones establishes their age, it is not clear whether they will yield DNA. “We don’t have high hopes,” Thompson says, “as they were burned and that tends to create even more preservation problems.”
The students assisted in the tedious work of carefully sifting through grey dust and ash, marking coordinates through GPS and other surveying tools, and recording the data into a computer.
Back in her lab at Emory, Thompson uses the data to generate three-dimensional images of the digs and pinpoint where each bone fragment, shell bead or stone tool was found. Her digital model for the this summer’s Mount Hora dig uses different-colored dots to give a glimpse of how hunter-gatherers were depositing both human remains and ordinary objects from their day-to-day lives over time.
“And then at this point,” Thompson says as she moves her cursor on her computer screen, “you see the introduction of pottery and iron technology. And right after that you see this fundamental change in the way that the site was used. People are no longer going there frequently. They’re no longer making these big bonfires. And they’re no longer interring their dead there.”
Thompson and her students are also sorting through hundreds of gallon-sized Ziploc plastic bags containing fragments from the Malawi sites. “As you excavate,” she explains, “you clean away the dirt and you’re left with all these tiny pieces of stone and bone artifacts. The bones are mostly animals. But every once in a while you find something that looks like it might be human. Any one one of them could be a new individual, a new piece to the story.”
She pulls out a small plastic bag labeled “Human distal phalanx.” It contains a piece of bone about the size of a Tic-Tac. “In this case, we think we have a finger bone, most likely from a child,” Thompson says.
Ultimately, Thompson seeks to understand how and when the earliest members of our species — Stone Age Homo sapiens — interacted with one another and with their environments in Africa.
“One thing that’s really easy to forget, when we look at the way people live today, is that for most of our evolution we lived as hunter-gatherers,” she says. “So if we want to understand our own origins as a species, we have to know what those lifeways looked like in the past.”
"I can't imagine not living with dogs. That would be really sad for me," says Emory neuroscientist Gregory Berns, with Callie (left) and Cato. His latest book is called "What It's Like to Be a Dog."
Five years ago, Emory neuroscientist Gregory Berns became the first to capture images of actual canine thought processes. To explore the minds of the oldest domesticated species, the Berns lab trained dogs to remain still and alert while undergoing functional Magnetic Resonance Imaging (fMRI) — the same tool that is unlocking secrets of the human brain. The project opened a new door into canine cognition and social cognition of other species.
Berns went on to conduct a series of experiments on dogs, gathering both behavioral and fMRI data on questions such as: How capable are dogs of self-restraint? Do dogs prefer praise from their owners or food? How do dogs process faces in their brains? What’s going on in a dog’s brain when it smells the scent of its owner?
In 2013, Berns wrote a New York Times bestseller called “How Dogs Love Us.” He described how the death of his beloved pug Newton planted the seeds for his eventual switch from the studying the human brain to focus on non-invasive studies of the cognition of dogs and other animals.
In the following Q&A, Berns talks about his new book, “What It’s Like to Be a Dog: And Other Adventures in Animal Neuroscience,” just published by Basic Books. The book focuses on his hopes that understanding how animals think will revolution how we treat them.
Question: Can you talk about all the dogs you’ve had as pets during your life?
Gregory Berns: When I was a child growing up in Southern California we had two golden retrievers, Pretzel and Popcorn. It’s embarrassing, but my parents always named their dogs after food. I’m not sure why. Most of the children in the area had dogs and horses and we would go traipsing around the hills. Kids and dogs go together.
Berns and Callie
After I was done with medical school and stopped moving around, my wife and I had three pugs, Simon, Newton and Dexter, and then a golden retriever, Lyra.
We now live with our two daughters and have three dogs: Callie, a Feist, which is a Southern squirrel hunting dog; Cato, a Plott hound, which is the state dog of North Carolina; and Argo, a yellow dog of some kind of mix. We also have two bearded dragons and a chameleon.
I can’t imagine not living with dogs. That would be really sad for me.
Q: “What It’s Like to Be a Dog” describes all the experimental work you have done so far with canine cognition. What’s the biggest surprise to come out of your research?
GB: If you take language out of the picture, what we’re finding is that we see a lot of similarities between dogs and humans. In one study, for instance, we used fMRI to measure the relative value of food versus praise to the dogs and found that almost all the dogs’ brains responded to praise as much, and sometimes more, than to food. We ourselves know how it feels when someone praises us, there’s a positive feeling associated with it. That’s perhaps similar to what dogs are feeling.
We also did a study on dogs and delayed gratification. We found that part of the prefrontal cortex is more active in dogs during self-control. And, just like experiments with humans have found, we showed that the dogs who are better at this task use more of their prefrontal lobes.
Now that we are gaining a basic understanding of canine cognition, we are starting to focus more on the individuality of dogs — what it’s like to be this dog, as opposed to that dog.
Q: You’re also using diffusion tensor imaging (DTI) to study the brains of other mammals, mapping the neural pathways in brains from animals that are long deceased and stored in museum collections. How did this project come about?
GB: It started in 2015 when we gained access to the brains of two dolphins that had died, and we showed that we could use DTI to map their sensory and motor systems. Dolphins are incredibly intelligent, social animals but they’ve remained relatively mysterious. We provided the first picture of the entire dolphin brain and all the white matter connections inside of it.
Through a project I call the Brain Ark we’re collecting a digital archive of high-resolution, three-dimensional brain structures of megafauna. It’s publicly available to other researchers to contribute to and draw data from.
Q: What is the ultimate goal of your animal neuroscience research?
GB: The Brain Ark is an attempt to catalog and study brains of large mammal species before they are gone. Or, as in the case of the Tasmanian tiger, after they’re gone. Many megafauna are in danger of extinction because their habitats are being chopped up in ways that don’t allow them to sustain themselves or to migrate.
In the grand scheme of things, I’d also like to explore the commonalities that we have with other animals. That has important ethical implications for how we treat them and for their right to exist in the first place.
Animal welfare laws cover things like abuse — pain and suffering. I think we should go beyond that and acknowledge that animals also have a right to lead a good life — whatever that means for that animal.
