“Is a Plant, a Plant, a Plant?”

Sarah Wood talks with participants at the USA Science & Engineering Festival.

UT undergraduate teaches science on the National Mall

For as long as she can remember, Sarah Jeanne Wood has always loved science.

As a little girl, she watched in amazement as her dad showed her how the same substance, water, could have different properties depending on its temperature. From then on, Wood’s scientific curiosity could not be satisfied by textbook knowledge alone—she had to get her hands on it. Now in her sophomore year at the University of Tennessee, Knoxville, her longing to experiment has enabled her to contribute to the largest science festival the U.S. has ever seen.

This past October, 2 weeks of events in the Washington, D.C., area led up to a 2-day science expo on the National Mall, where more than 500,000 people of all ages came together to celebrate science and engineering as part the inaugural USA Science and Engineering Festival. Another 250,000 people attended the 82 satellite events held in 27 states across the country. The festival was a national effort to revitalize young people’s interest in the science, technology, engineering, and mathematics (STEM) disciplines.

Exhibits line the National Mall at the USA Science & Engineering Festival.

Wood, who is an ecology and evolutionary biology major, was the only representative from the university displaying her research alongside 550 other leading science organizations, institutions, and universities. The exhibits spanned aerospace, green energy, medicine, biotechnology, climatology, robotics, nanotechnology, botany, neuroscience, and other scientific fields.

“When I applied to participate in the festival, I didn’t realize just how big it was going to be,” says Wood, who was a freshman when she applied. “I received an e-mail about it through the American Society for Biochemistry and Molecular Biology, and I thought it sounded interesting. I love D.C. anyway, and I was curious to see the science interests of other people my age.”

When Wood was accepted last February to participate, she first planned to do an exhibit on how the earth formed. But she changed her mind after working this past summer with Aimée Classen, an assistant professor of ecology and evolutionary biology, and Lara Souza, a post-doctoral research associate, in an ecosystem ecology lab.

Classen’s lab focuses on how biotic processes, those of plants and animals, interact with abiotic processes like temperature and precipitation. Currently lab members are testing these processes by studying the differences in plants of a single species from different regions, through the Solidago project, which is funded by the Joint Directed Research and Development program of the Science Alliance. In collecting and evaluating data for this project, Wood learned the importance of inter- and intraspecific variations, which became the basis of her exhibit.

“Dr. Classen and Dr. Souza became enthusiastic mentors when I told them I was accepted to participate in the USA Science and Engineering Festival,” Wood says. “I couldn’t have done it without them. Together we designed an experiment to demonstrate the wide variation that exits across different species (interspecific variation) and within the same species (intraspecific variation).”

Inter vs. Intra: What’s the difference?

Sarah Wood at her exhibit, “Is a Plant, a Plant, a Plant?”

“Traditionally, most ecologists and conservation biologists have focused on interspecific variations for the purpose of preserving diversity among species, which is really important for maintaining properties like disease resistance,” Classen says. “But up until this point, people have sort of ignored the importance of intraspecific variation. And that is what the Solidago project is all about; we’re interested in understanding how important variation within a species actually is, especially in the constructs of global climate change.”

Classen explained that a plant could have certain characteristics that might, for example, allow it to adapt to really hot conditions, whereas the same species growing in a different region or climate zone may not have that characteristic. This characteristic is the variation within the species, or intraspecific variation.

For the experiment, Wood collected and evaluated data on a number of plants and selected the family that had the greatest numbers of differences in characteristics, which turned out to be Asteraceae, the aster family. Three members of this family of plants—Solidago altissima (goldenrod), Helianthus virticillatus (whorled sunflower), and Verbesina virginica (white crownbeard)—represented plants with interspecific variations.

Then she chose three genotypes of the Solidago altissima species to represent intraspecific variations; two were from Connecticut and one was from Tennessee. Then in order to get an exact copy their genotypes, Wood took rhizomes of each plant and propagated them in the greenhouse so that she could take them with her to the National Mall.

“Everyone knows that different species of plants are different, but I never thought about how extremely different plants of the same species can be and why that is significant,” Wood said. “Just as humans have different characteristics that allow us to be successful at different things, variation in plants is necessary for species to be able to weather and adapt to adverse conditions.”

In the weeks leading up to the festival, Wood spent many hours preparing a poster of her research and creating a hands-on activity for her exhibit, which was a requirement of the festival. She sought feedback from Classen, Souza, and the lab group several times to fine-tune her presentation. Then on October 22, she packed up her plants and headed to Washington, D.C., with her older brother to show the nation just how significant inter- and intraspecific variations are.

Are plants of the same name actually the same?

Students conduct research on variation in plants at Sarah Wood’s exhibit.

Wood’s exhibit, which was supported by UT Knoxville’s Department of Ecology and Evolutionary Biology, was one among 1,500 interactive booths set up along the National Mall on October 23 and 24. In introducing “Is a Plant, a Plant, a Plant?,” she wanted people to explore and question whether plants of the same species really are the same. Participants ranging from preschoolers to grandparents came up to measure leaf lengths and leaf widths, put their findings on data sheets, and construct a graph to show the inter- and intraspecific variations.

Wood said the kids loved the experiment, and adults asked a lot of questions about the significance of inter- and intraspecific variation. “When I told people that the Connecticut and Tennessee Solidago plant were the same species, they were amazed because the morphology of their leaves looks completely different,” Wood says. “A middle-school teacher came up to me and said, ‘I have never even thought about telling students the importance of intraspecific variations before now.’ And that’s exactly what I wanted to accomplish through this exhibit.”

As enjoyable as it was sharing her research with others, Wood’s favorite part of the festival was walking around and seeing all the types of applications of science played out in the exhibits. “As a student, I tend to become narrowly focused on all the classes I have to take, but there I got to see that what I am studying is real life. There is actual stuff you can do with it,” Wood says.

Exhibits ranging from soccer-playing robots to a 1,500-pound chunk of glacier from Alaska to virtual-reality space shuttles and fighter jets lined the National Mall for 2 days. Besides the exhibits, there were 75 stage shows featuring such science stars as Erno Rubik, MythBusters’ Kari Byron, and Nobel laureates, as well as comedians, magicians, and musicians. Lockheed Martin hosted the festival in the hope of inspiring the next generation to consider a career in the STEM disciplines.

Sarah Wood shows students how to measure plant traits.

In a recent report by Norm Augustine, former CEO of Lockheed Martin, the U.S. ranks 48th in STEM education. Dr. Ray O. Johnson, senior vice-president of Lockheed Martin, said the festival was an acknowledgement that vigorous math and science education is in our country’s strategic interests. “Never have the global security challenges been greater, and never have we needed a STEM-educated workforce in the U.S. more than we do today,” Johnson says. “Students need to know that engineers and scientists create the future.”

Classen, who was a K–12 teacher earlier in her career, agrees that initiatives like this one have a great impact on the way people think about the world and about science. “Science has huge application when students can take what they learn in the classroom outside the classroom and put it into context,” Classen says. “For these thousands of students to go and see that science is active and exciting and not just an accumulation of known facts in a textbook—that’s big!”

Classen is currently mentoring three graduate students, two postdoctoral fellows, and 10 undergraduates in her research lab. She says she enjoys working with students because they always bring good ideas and good opportunities along. “What is cool about Sarah taking the initiative on this project is that it added to our research program and department a huge element of sharing science with the community that we might otherwise have missed out on. She put a lot of effort into it, and I think it actually paid off.”

Although it has not yet been announced whether the national science and engineering festival will be hosted next year, Wood hopes to be able to participate again and get more students involved. “It took more than six months of preparation for only one weekend, but I would do it again any day,” she said.

For more information on the USA Science & Engineering Festival, visit www.usasciencefestival.org.

—Sara Collins Haywood