A flip, a flap, a slow twirl and a splash of colors. Few things are as iconic as butterfly wings. For most of us, they are one of nature’s jewels: colorful, iridescent, a sign of warmer days. For Anyi Mazo-Vargas, they are a portal into nature’s secrets.
The newly hired assistant professor of Biology uses butterflies, in particular their wings, to understand how nature’s huge diversity in forms, colors and body shapes develops over one organism’s lifetime and evolves over millions of years.
Butterflies are particularly well-suited to these questions. Anyone who has taken a summer stroll in Duke Gardens knows that these winged insects come in myriad colors, shapes and forms. Add that to the diversity of their nocturnal cousins, the moths, and you get an almost infinite array of color and shape combinations.
That’s not all, though. Many of these shapes and colors play a very specific ecological role: The orange of monarchs (and all the other species that mimic them) announces their toxicity. The eyelets at the back of a buckeye butterfly’s wings make it look like a much larger animal. The coattails of a swallowtail wing draw predators to the less-vital side of the butterfly’s body. And we don’t even need to mention the thousands of species that camouflage themselves by blending perfectly against tree bark or leaves.
With such a wide range of options, how does Mazo-Vargas select which species to focus on?
“I am interested in local species,” she said. “Around Duke there's a nice diversity of local species, like luna moths. I can bring them to the lab and start to dig in. What genes are expressed? When does their long tail become evident during development?”
To answer these questions, Mazo-Vargas uses a combination of tools that go from the most minute of micros (proteins and genes) all the way to the macro (an evolutionary tree).
Starting with the microscopic, genomic tools allow Mazo-Vargas to look under the hood and understand how butterflies are built. Focusing on species that do well in captivity and can be bred for many generations, she looks at which genes activate at which points in the caterpillar’s developmental process.
Once she has an idea of which genes are involved, Mazo-Vargas engages in testing using CRISPR — the revolutionary Nobel-winning technique that allows researchers easily to modify an organism’s genetic code — to manipulate the butterflies’ genome.
“I built my career with CRISPR basically,” she laughs. “Many of the species I bring to the lab I can modify with CRISPR, and in just one generation I can get a sense of what role a gene has in this species or determine if we see the same effect in other species.”
Once she knows which gene does what and when, Mazo-Vargas can turn her eyes to the outside: How do these butterflies behave? How are they using this specific morphological characteristic? She relies heavily on what is known about the ecology and field observations of different species, which leads us to the evolutionary component of her work: The best way to understand how a piece fits into an evolutionary puzzle is to look at the pieces that surround it. What else bears this trait? How widespread is it? Is it only present in species from a certain genus, or a certain geographic location?
Although the bulk of her work happens in the lab, Mazo-Vargas is eager to go to the field and to get students involved in field work.
“I like to have students in my lab think about it,” she said. “This is not a butterfly that we're keeping in a cage in a growth chamber in the lab. Just go outside and look at them. And then you can see their interactions with the plants, with the flowers and their environment.
“They need to go out. It's important for any biologist, or actually any person, right?”
Mazo-Vargas’ interest in diversity started with her undergraduate studies in biology, with a focus on entomology, at the Universidad del Valle, in Cali, in her native Colombia. “Colombia and the tropics, they are such rich areas,” she said. “Crazy shapes, crazy colors, the huge range of morphologies, that caught my eye from early on.”
Wanting to venture into the molecular side of diversity, Mazo-Vargas got a master’s degree at the Universidad de Puerto Rico Mayagüez, where she dove into the genetic diversity of weevils from the Caribbean. “It was amazing to see how this small molecule, just a short sequence of the whole genome, can start to separate populations and species.”
With her master’s diploma in her pocket, in 2011 family circumstances brought her to Duke, of all places, where she worked as a technician in professor Nicolas Buchler’s laboratory in the Biology department.
Buchler’s lab was as far from the field as one could get. “It was my first time in this type of quantitative and computational environment, where you have physicists and computer science researchers, and they're talking about equations, and I was like, ‘This is not biology’,” she laughed. “But then I learned about gene networks, and about how genes connect to each other and modify the things they express in a very specific manner.”
Still, she was reticent: “I thought, ‘Okay, this is cool, but I can’t work in this, I need to go back to my insects.’” And she did. Tugging along her newly acquired tools, she pursued a Ph.D. at Cornell, connecting butterfly genomes to their wing colors and patterns. “I was hooked,” she said.
Now back in Durham, she is shocked by how much the city has changed. “I feel like I’m venturing into a new territory,” she said.
One of the aspects of change that resonates with her is the growth of the Latino/a/e population. Mazo-Vargas is eager to bring her research into the community. “As a Latina, I want to bring my research and the connection with butterflies to people who look like me,” she said. “Sometimes there are limitations in language that I have felt a lot myself — I'm not a native speaker. Communicating some of my science in Spanish will be amazing for me, but is also something that I can give back to the community around us.”
Department of Biology