A few reflections on last week’s ESA meeting, more notes to myself than anything.
- Great work from Brett Melbourne and members of his group, and Jennifer Williams, Jon Levine, and members of their groups, on eco-evolutionary dynamics of range expansions. Impressively-tight linking of mathematical theory with experiments in tractable model systems, to ask important basic questions that just couldn’t be asked in any other way. Intriguing that experiments with Arabidopsis and flour beetles yield such similar results in many respects, but such different results in a few respects. Some of this work has already been published–Williams et al. 2016 was a deserving Mercer Award winner this year–but I still enjoyed hearing about it. (Aside: and as far as I know it’s the first microcosm experiment to win the Mercer, though mesocosm experiments have won in the past. 🙂 )
- Modern coexistence theory continues to take off, theoretically and empirically. A couple of years ago I said that it was starting to take off. That was a pretty obvious prediction to make at the time, but it was still nice to see it borne out at this year’s meeting. I tried to see as many talks as I could on modern coexistence theory. Many were great:
- Steve Ellner gave a typically-excellent talk about his very important work with Peter Adler and Robin Snyder on simulation-based approaches to estimating the strength of different classes of coexistence mechanisms. This work is unusual because in the course of developing a simulation-based approach to more easily link modern coexistence theory to real data, Steve, Peter, and Robin discovered new classes of coexistence mechanism not identified by previous analytical theory. And they can show that those new classes of coexistence mechanism are important in real data (Ellner et al. 2016). A nice example of “applied” work leading to new fundamental insight. But as Steve said, this doesn’t mean that analytical theory is now irrelevant–the simulations complement rather than replace analytical theory. The next big step is to figure out how to partition multiple classes of coexistence mechanism at once. I also liked Steve’s talk because there was a throwaway remark at the end that was more interesting than most entire talks.
- Simon Hart gave a fabulous talk on his ongoing theoretical (and now empirical) work on effects of standing intraspecific phenotypic variation on species coexistence. He reviewed, and then extended, his results from Hart et al. 2015. This is important stuff that deserves to be much better known. Back in 2010 Jim Clark published a very influential paper arguing that intraspecific variation generally promotes species coexistence by “blurring” differences among species. Others have made similar arguments. That argument is very intuitively appealing–but as Simon’s results show, it’s wrong (even in the limited circumstances in which it gives the right answer, it does so for the wrong reasons). In general, intraspecific variation seems at least as likely to inhibit species coexistence as to promote it. I love work like this–work that replaces your previous intuitions with new, better intuitions.
- Martin Turcotte talked about his collaborative work with Simon Hart developing duckweeds into a powerful model system to look at eco-evolutionary dynamics of competing coexisting species in the field. I’m always impressed and humbled by somebody who figures out how to do in the field something I’d have thought could only be done in the lab.
- I enjoyed Nathan Kraft’s talk relating phenotypic traits of annual plants to their niche and fitness differences; some of that work is in the very fine Kraft et al. 2015. Although I’m not convinced that many empirical generalities are going to emerge from this approach. Nathan’s results reveal a lot of idiosyncrasy in trait-coexistence relationships even just within a relatively limited range of species combinations and environments. And other talks and recent papers I’ve seen report similarly idiosyncratic results. Which is itself a useful result, I think, because it throws cold water on the somewhat-naive idea that interspecific phenotypic variation should map onto species coexistence in some simple way. For instance, that species should coexist more easily, the more “different” they are. We went through this already with phylogenetic differentiation (as new experimental results presented by Shao-Ping Li also showed), now we’re going through it with trait differentiation.
- Lauren Shoemaker spoke very well about quantifying spatial and non-spatial coexistence mechanisms in a protist microcosm experiment. Ok, I’m predisposed to like this work because I’m involved in it in a modest way (mostly I’ve given technical advice on growing protists). But I do think it’s a nice proof of concept that has a lot of potential to be built upon. More species, more patches, additional trophic levels, etc. This links back to the need for methods to partition different classes of coexistence mechanisms that operate simultaneously.
- Mark Genung gave a fabulous talk on his work applying the Price equation to attribute among-site variation in ecosystem function or service to among-site variation in species richness, species composition, and species abundances. The big headline result is that, across many ecosystems functions/services measured in many different systems, the relative importance of species richness vs. species composition vs. species abundances varies in a very predictable way with evenness of species’ functional contributions (which in turn probably reflects evenness of their abundances in most cases). Basically, if function/service is mostly performed by a few high-functioning species, then variation in species richness among sites doesn’t matter much. Intuitive (though not trivial; it doesn’t necessarily have to work that way), but nice to see it fall out of the data so clearly. Again, I’m predisposed to like this work because I pioneered the application of the Price equation to BEF studies, and because I’ve given Mark a bit of feedback. But I’d have liked it anyway. I also really appreciated how deftly Mark explained the Price equation. In all honesty, that was the best explanation of the Price equation and its application to BEF that I’ve ever seen, including in any talk of mine.
- Colin Kremer also gave a very good talk on applying my Price equation approach to BEF data in cool ways that would never have occurred to me. One of the best feelings you can have as a scientist is when you have an idea and then other people pick up that idea and run with it. The results led to reinterpretation of some classic datasets.
- For the first time in several years my entire lab was at the meeting. All two of them. 🙂 Both their presentations went well. We had a celebratory lab dinner on Thursday evening.
- My talk on the relationship between species richness and strength of coexistence mechanisms. Oh, it wasn’t terrible or anything. Several people were kind enough to come up to me later and say they enjoyed it. And I knew going in (and told the audience up front) that it was going to be one of those talks that raises a hopefully-interesting question without actually doing much to answer it. But based on the feedback I got from friends, the question (which I’ve blogged about in the past) isn’t actually interesting, because the first-order answer is kind of obvious. Strengthening coexistence mechanisms allows more species to coexist, all else being equal, and chucking more species into the system weakens coexistence mechanisms, all else being equal. At one level I’m totally fine with that feedback, because that’s precisely why I gave the talk: to put the idea out there and get feedback on whether it was a good idea worth pursuing. But at another level I’m slightly embarrassed to get that feedback, because I feel like I should’ve been able to figure out for myself that the idea wasn’t all that interesting, and so talked about something more interesting instead. I think it’s fine to give a talk that tosses out ideas that are less-than-fully developed–but the ideas need to have some interesting core. They can be half-baked, but not unbaked. I recall back when I was a grad student that I didn’t like going to talks by charismatic speakers who didn’t have anything really new or substantial to say. As an audience member, I felt like I was being entertained, but not made to think. I don’t like feeling like I just gave a style-over-substance talk myself. I’m proud that over the years I’ve earned a reputation for giving a pretty good ESA talk. Next year I’m going to do my best to live up to that reputation.
- I heard the demand for the nursing/pumping room was pretty overwhelming. Seems like ESA ought to really ramp up the availability of nursing/pumping room space next year.
- The survey of meeting attendees indicates that ESA continues to mull over rotating the meeting between a few popular locations. Personally I’d be fine with that, though I’d prefer if ESA continued to occasionally visit new cities not in the regular rota. I was glad to see that the list of cities under consideration includes Denver, which I’ve been wanting the ESA to visit for years, and Long Beach, which I’ve visited and think would be a good location. Where else would you like to see the ESA meeting go, or go back to? Everybody likes Portland, obviously, and I’m looking forward to New Orleans. I’m looking forward to Louisville too, never been to that part of the country. Minneapolis, Pittsburgh, Austin and (dating myself here) Madison are favorites of mine to which I’d like to see ESA return. What about going to a Canadian city and meeting jointly with CSEE once every few years? The exchange rate typically would make a Canadian meeting cheaper than an American one for both American and Canadian attendees. Toronto, Vancouver, Ottawa, Montreal, and Quebec City all seem like promising candidates to me, though Montreal is the only one I know for sure to have a convention center of the appropriate size for ESA. Calgary sadly doesn’t have a convention center quite big enough to accommodate a typical ESA meeting. Plus our downtown lacks a high density of good restaurants at all price points easily accessible from the convention center.