Linking Climate Change to Genetics

Luke Evans operates in a complex world. As a PhD student in biology at Northern Arizona University, he focused on how the basic genetic sequences of a cottonwood tree affect the diverse array of organisms that depend on it. This holistic look at how regions of a particular genome influence whole living communities is a cutting-edge way to study ecosystems. According to Evans, this revolutionary approach—known as community and ecosystem genetics—begins with a very simple idea.

"In the realms of conservation and biology, you have to know what matters in order to understand what to conserve, or what to restore," he says. "A lot of state agencies are now required to restore habitat, for example, and it is important to know what makes (restoration) a success or a failure. You have to understand what forces are important in the system: for example, genetic variation in cottonwood trees is important to the microbes in the soil, to the bugs that eat the trees, to the birds that eat the bugs, and to lots of different things."

Learning from a pioneer

According to Evans, he became interested in ecology and genetics as an undergraduate student at Dartmouth (NH) College. He was drawn to Flagstaff after Northern Arizona University professor Tom Whitham visited Dartmouth.

"Tom gave a couple of seminars, and I got to meet him and interact with him a little bit," says Evans. "Tom has been a pioneer in the field of community genetics, and I was interested in community ecology and a bit of genetics, and that's what kind of hooked me. So when it came time to think about graduate schools, and where I wanted to be, he seemed like he would be a really good person to work with."

After earning his MS in Biology in 2007, Evans continued on as a PhD student in biology. After spending nearly two years researching how genetic variation in cottonwood trees affected the evolution of bud-galling mites, his work took a new twist: Evans began researching how climate change affects the evolution of trees. According to Evans, this important—and little-researched—field has the potential to reveal a number of important ecological implications related to conservation and restoration.

"If you want to restore a particular spot, the paradigm has always been to plant local genotypes," he says. "And I think that's been a pretty good status quo. But the fact is we've already seen changes due to climate change, and I'm not sure that status quo will always hold. So 50 years from now, if the last trees in a particular area are just barely hanging on, do you want to plant those trees, or do you want to plant trees from an area that has historically experienced conditions similar to that of the current site? I don't have the answer to that, but I think we have to know the basics to make an informed, ethical judgment."

Support for his work

In seeking to answer these questions, Luke found support from a number of communities. He was awarded a Science Foundation Arizona Fellowship, an Integrative Graduate Education and Research Traineeship, as well as a $15,000 National Science Foundation (NSF) Doctoral Dissertation Improvement Grant to fund his climate change research. The support of the NSF, he says, was very rewarding.

"I got the call from the NSF that said they were recommending me for full funding and I was kind of speechless," he said. "It was exciting—you put in a lot of work applying for this grant, and it was nice to have it work out."

Now a postdoctoral scholar at West Virginia University, Evans continues his work with cottonwood trees as part of a project to develop cellulosic ethanol, a biofuel.

Evans remains glad that he headed west following his undergraduate studies. The research was great, he says, but there are other facets of university life that were just as enjoyable.

"I've just really enjoyed the people I got to work with—it's a great group," he says. "I've been fortunate in that I spent my time working both in the lab and in the field. It was a lot of fun."