Teen researchers find exceptions to scientific rules
A group of teens in a summer program at Stanford’s School of Earth Sciences found exceptions to a few long-held rules about evolution.
High school students put the finishing touches on posters that summarize their summer research findings for presentation in December at a major scientific conference, the American Geophysical Union Fall Meeting in San Francisco.
"Cope's rule is that they get bigger over time," said Mayra Pelagio, who charted the size of crinoids, a marine invertebrate that looks like a flower. "But they're getting smaller and smaller," she said, pointing to a graph with a downward slope on her computer screen.
Pelagio, who graduated from Yerba Buena High School in San Jose and is now a freshman at UC Davis, spent the summer measuring crinoids from images in textbooks and entering their size and evolutionary time period into a database.
Saigopini Panneerselvam noticed that Bergmann's rule wasn't holding water, either. The senior at Lynbrook High School in San Jose measured the class echinoidea, which includes sand dollars, sea urchins and sea stars. Bergman's rule states that animals should grow larger as sea temperatures decrease, "but it is not working," Panneerselvam said. "The body size is staying relatively constant," she said, though sea temperatures have risen and fallen through the ages.
A genuine research experience
The students contributed valuable data toward Geological and Environmental Sciences associate professor Jonathan Payne's study of how classes, genera and species have changed in size over millions of years. "The students collected real data that we actually need," said Payne, who created the summer program for the students, and named it the History of Life Project. "They conducted genuine research: they didn't know what the answer's going to be ahead of time, and neither did we."
The students were in the Stanford Earth Sciences High School Internship Program, an annual summer initiative that brings local high school students interested in the Earth sciences to campus. In 2013, 34 students were in the program: 19 contributed to the History of Life Project and 15 worked in various School of Earth Sciences labs or at field sites under the supervision of graduate students and postdoctoral researchers.
In its 10th year, the internship program receives funding through the dean's office and a National Science Foundation CAREER grant and is supported by graduate students and postdocs who volunteer their time to work with the interns.
"The purpose of the program is to give high school students an opportunity to do real science," said Jenny Saltzman, director of outreach education at the School of Earth Sciences, "but it’s also about providing graduate students and postdocs experience in supervising."
The high school students, who traveled by bus, train and car to Stanford, were selected from a pool of 175 applicants, mostly because of their enthusiasm for Earth sciences. About a quarter received an honorarium of $1,000 or $2,000, allowing some who needed to earn money during the summer to accept the internship.
The students were treated to field trips to observe slippage caused by the San Andreas fault, study research collections at the University of California Museum of Paleontology at UC Berkeley and discover fossils in the cliffs at Capitola Beach. And they attended weekly seminars about fellow students' projects, received advice about applying to colleges and wrote three blog posts about their work.
"The work can be tedious," said Noel Heim, a researcher working with Payne who oversaw the History of Life students. "But that's good for them to know — it's part of being a scientist." Heim broke up the measuring and data entry work with activities such as card games that mimic the natural selection process.
The internships were eight weeks long, often five days a week, seven hours a day — something of a first job for many of them. "The students learn about being at work on time, communicating effectively with supervisors —job skills that they'll need," Saltzman said. They may also discover whether the Earth sciences, or science in general, is a good fit.
In addition to exposing high school students to science and training researchers to supervise, the summer program helps the professors and postdocs move their research forward. "In terms of data collection, this is an enormous help," said Heim of the students' fossil measurements.
Learning to write up scientific results and submitting abstracts to a major conference takes the real-life research experience a step further. The vast majority of the students will be among 20,000 attendees at the annual meeting of the American Geophysical Union held each December in San Francisco. Many of the high school students will present their research in a poster session called "Bright STaRS: Bright Students Training as Research Scientists." This allows the students to gain experience that aspiring scientists may first encounter as college juniors or seniors or even as graduate students.
"It's a lot of repetition, but it’s fun"
Jared Fernandez, a junior at Homestead High School in Cupertino, thinks he might pursue a career in the Earth sciences. He spent the summer dating rocks taken from ancient stream beds in Palm Springs with the goal of discovering how quickly the Mission Creek Fault is moving.
Because the beryllium in the rocks is produced when it is exposed to energy from outside the solar system, scientists can measure how long the rocks have been exposed above the surface. They then compare dates of rocks taken from parallel stream beds that have been offset due to movement along the fault.
Fernandez, wearing a bunny suit in a basement lab filled with ovens, sinks and containers full of sand, explained the process. "You take the rocks, grind them up, sieve the sand, wash it in hydrochloric acid then with hydrofluoric acid, heat it, roll it on rollers, and remove magnetic particles, then send them to a lab to be analyzed for beryllium 10," he said. "It's a lot of repetition but it's fun."
While Fernandez helped build knowledge about plate movement, Shikha Avancha, now a junior at Crystal Springs Uplands School, worked on a project with public health applications: She experimented with soil samples to see if there are ways to reduce arsenic in rice.
The soil is from Cambodia, where groundwater contains high levels of arsenic, a poison absorbed by cultivated rice that Cambodians consume. Avancha added sulfur and iron to the soil, then poured on water to mimic the flooding of rice paddies, to determine whether the sulfur and iron would bind with the arsenic and prevent the rice from taking it up.
"It's a lot of hands-on work," she said. "I was super-excited to find something real-life to work on. In class, you learn everything theoretically. Here I do everything myself."
For at least one student, the internship was the realization of a longtime dream of studying paleontology. "I guess a lot of kids have that dinosaur fascination when they're younger," said Mohammad Ahsan, a senior at Gunn High School in Palo Alto who charted the changing size of ostracods, a tiny creature with two shells. "For me, it just never wore off."
Back to school, putting knowledge to work
Recently, a student reported that in her high school fall term advanced placement classes, she's applying much of what she learned in the History of Life Project.
"The experiences I gained over the summer have helped me in this school year," said Cathy Tang, a senior at Independence High School in San Jose. Her AP statistics teacher was surprised that she knew what a box plot describes and the meaning of p-value. In her AP human geography class, she was able to explain in detail different types of maps, and was the fastest student to interpret a map's data. In that same class, her teacher talked about GIS – geographic information systems – and Cathy said she was so excited she exclaimed that she'd used the program before. Needless to say, Cathy reported, her teacher was impressed.
Mandy Erickson is a writer based in the San Francisco Bay Area