Evolution first fascinated George Gilchrist during an undergraduate invertebrate zoology class at Arizona State University, when Professor Ronald Rutowski presented a lecture on the evolution of sex. "I walked out of the classroom and said, 'This is the most interesting thing I have ever heard of,'" remembers Gilchrist, now program director for evolutionary processes in the Division of Environmental Biology at the National Science Foundation (NSF) in Arlington, Va.
"It had never occurred to me that sex was an evolved trait," he recalls, noting that scientists have tried to understand why there are males and females, why there are only two sexes (as opposed to three or four), and why mating evolved. (So far, scientists have some answers, but not all.)
Gilchrist, who grew up in Phoenix, decided to pursue evolutionary biology and began working in Rutowski's lab on sexual selection and mating behavior of butterflies. Over time, as he arrived in the field at 8:00 a.m. day after day to observe butterfly mating behavior, his interests shifted to daily cycles and climatic changes.
"The realization that came to me was that evolution really operated very quickly—on the same timescale that ecology operates," says Gilchrist, who was recently elected as an AAAS fellow. "That, to me, seemed exciting because it suddenly opened up a lot of questions about knowing how rapidly things can change, and why they don't change more frequently than they do."
In his current position at NSF, Gilchrist manages the review process for principal investigators applying for grants and organizes review panels. His program funds about 25 awards each year, and he faces the major challenge of selecting those two dozen projects from the 400 or so that cross his desk.
"Being able to look at those projects and make some sort of informed decision about how well they would serve our community constantly pushes you to learn and think about new things," says Gilchrist, who is also an emeritus faculty member at the College of William and Mary.
The field of evolution isn't restricted to biological realms, Gilchrist explains. In an almost sci-fi twist, scientists are also studying evolution in digital worlds.
In his role as technical coordinator of the BEACON Center for the Study of Evolution in Action, a NSF Science and Technology Center headquartered at Michigan State University, Gilchrist oversees some 200 evolutionary biologists, computer scientists, and engineers who apply biology-based evolution principles to high-tech computer programs.
One system, Avida, is populated with digital organisms called avidians (or pieces of software with a 20-letter-string of DNA-like computer code) that compete for CPU cycles as they reproduce and even parasitize. And like DNA, the code slightly mutates each time it reproduces. "It's an independent system of evolution with a group of organisms that are composed of computer code that compete for CPU cycles," explains Gilchrist. Studying how digital systems evolve can help scientists understand biological organisms; using these tools can help solve tough problems that have too many variables, such as designing impact zones on automobiles.
He's studied contemporary evolution in collaboration with Raymond Huey through a particular species of fruit fly (Drosophila subobscura) that originated in Europe and was accidentally introduced into the Americas in the late 20th century. These fruit flies have been useful for genetic research because an ordinary light microscope can reveal the banding patterns in their chromosomes, he explains.
Notable among his published research is a series of papers he and colleagues wrote on how the fruit flies' wing size and chromosomes show contemporary evolution along latitudinal climate gradients. By examining these fruit flies in Europe, South America, and North America, they've found that natural selection works quickly and produces the same results time and again in different locations. Such a swift response suggests that some organisms have the genetic capacity to adapt to current climate change.
At NSF, Gilchrist gets to step back and examine the big picture of evolution science, and how our understanding of evolution is itself evolving. Scientists are discovering that in addition to satisfying basic curiosity about how things got to be the way they are, evolution can help answer questions about medicine and health: Why do humans get cancer? Why do we have back problems? Why don't we live to 150 years old? In addition, we're encountering modern-day evolution conundrums, from antibiotic resistance to the mutations of engineered grasses produced for renewable energy sources.
"Really, up until about 25 years ago, people thought evolution was a slow and stately process that took place over millions of years and wasn't relevant to questions of ecology and things people were doing [today]," he says, "but studies have shown that, in fact, evolution takes place on a very short timescale."