I interviewed ecologists at the 2011 Ecological Society of America meeting in exchange for reader donations, which paid for my conference attendance. This is one in a series of posts about those interviews.

If I hadn’t been certain that Ithaca would have dramatically increased the amount of time I spent incapacitated by migraines, I might have tried to work with my next interviewee, Steve Ellner, for graduate school. He’s got his fingers in a lot of very interesting pies united by the interplay of ecology and evolution and he’s really nice. I wished I’d invited him for dinner instead of a quick pre-lunch chat!

He wants to know how important rapid evolution is – to understand the feedback between ecology and evolution. If rapid evolution does turn to be a big deal in ecological interactions, it changes our ideas about the way ecosystems function and will require most of ecological theory to be redone from the bottom up! It will certainly invalidate much of what people are trying to do to plan for climate change, and the ecological consequences of climate change would be even harder to predict.

His research tools include modeling, math, simulations, and experiments.  Many of his experiments are done in a very simple system – just a small glass container with one input and one output and a couple microbes. Like Nick Gotelli,he’s condensing what can be very complex systems into as few pieces as possible. Ellner works with such simple systems as a way to test the theory he develops.

Simple systems let you see principles. There are no excuses with a simple experiment: if your theory can’t explain what’s happening in Lake Ontario, there are a raft of potential other explanations, but if you can’t explain what’s going on in a 1/3 liter chemostat in your lab, there’s something wrong with your theory!

Patterns may also be easier to see in a simple system, providing a ‘search image’ for natural systems. For example, in Ellner’s work, out of sync predator and prey population patterns in his micro-‘lake’ were a tip off to the importance of prey evolution. Now when we see similar patterns in Lake Oneida, they mean something different than what we may have thought before.

Even though Ellner works with very simple systems, he’s still continually surprised, especially now that he’s adding a few more species to the mix. Many times he’s gone in with very clear predictions but saw things evolutionarily that were totally surprising. Such surprises make experiments worth doing, even if they are quite simple: a lot of Ellner’s work was driven by experiments where they ‘knew’ what was going to happen – and then it didn’t!

When I asked Dr. Ellner what his favorite paper is (that he wrote), he accused me of forcing him to choose a favorite child. But after just a few moments of dithering, he chose an ‘obscure’ paper with Eli Holmes, which is a comment on one of her papers. It started out as an argument between them – Holmes essentially saying that “Ellner’s out to lunch and here’s the proof.” But during the process of arguing, they ended up agreeing and figured out what united their arguments. Usually when journals publish a comment on a paper, they allow one entry for the comment and another for a rebuttal by the original author. But in this case Ellner and Holmes combined the comment and rebuttal into one article. It was really fun for Ellner to write – 3 weeks of rapid fire responses, wrestling with Holmes’ brain over email – and resolves a 20 year debate about what kind of predictions you can make about extinction risk. The story of Ellner’s favorite paper reminded me of the advice in this post on writing about ideas you disagree with.

Ellner is kind of a rockstar in the world of theoretical ecology, and though he’s not a pure theorist he believes it’s important for people to be able to make a career as a purely theoretical ecologist. But I haven’t run into many young theoretical ecologists. Ellner believes that there’s theoretical work that needs to be done and important questions that need thinking about, but the funding structure here in the US makes it difficult for someone to pursue that kind of career. Despite the sometimes acrimonious divide between theory and empiricism in ecology, Ellner believes it’s important for ecology to have people working along the entire theory to empiricism continuum. Fortunately for the field, Europe seems to be fostering more pure theorists.

Being a theoretical ecologist takes some sturdy math skills, and Ellner developed those early in his career. Pulled in by how useful math seemed for problems like managing natural resources, he majored in math at Berkeley. While Berkeley’s math program was relentlessly pure math, he found other avenues to pursue ‘useful’ math. One of the most important was a seminar in mathematical biology by Hans Bremmerman – one of the grand-founders of mathematical biology. Bremmerman’s influence and advice had a lot to do with where Ellner ended up later in his career.

I asked Dr. Ellner what he thinks the most important question in ecology is, and I’ve been wrestling with his response ever since:

How can we contribute to improving the state of the planet, now and in the future? We have an answer – it has to do with studying or predicting the ecological effects of climate change (or some other aspect of the human footprint) – and it’s wrong. An increasing fraction of ecological research is motivated or justified with reference to climate change, but a very high fraction of that work will have no effect on outcomes or responses because there’s no actual link to policy or management. Is that the best we can do, or can we do more useful things?

I think his question would make a lot of ecologists squirm, because – as Gotelli put it – we’re intellectual hedonists first, pursuing questions because we think they’re cool. But do we have a responsibility or even an obligation to answer the questions that will make the most difference to human well-being and survival?