Simon Hart gave a very good modeling talk on how intraspecific genetic variation can actually inhibit rather than promote interspecific competitive coexistence. Nice use of very simple models to make a very general and important point. As came out in questions, his results do depend at least in part, and perhaps mostly, on the assumption that there’s real variation in demographic rates (e.g., some individuals have higher expected fecundity than others) that is not purged by natural selection favoring the fittest individuals. I can imagine situations in which that’s true–and plenty of situations in which it’s not. But even if the case considered was unrealistic, it was still an important limiting case. If you want to understand how intraspecific variation affects the outcome of interspecific interactions, you have to start by considering a situation in which intraspecific variation is maintained. That’s the baseline case that lets you understand the effects of variation-destroying forces like directional selection.
Josh Landau gave a really nice talk on the compilation and analysis of datasets on marine bacterial diversity from around the world’s oceans. There are clear latitudinal gradients in diversity and composition, and the diversity maximum exhibits predictable seasonal shifts between the northern and southern subtropics. A microbial talk to warm the heart of “macrobial” ecologists.
I looked in on a couple of the talks in the trait-based ecology symposium. I guess this is just my personal bias, but I was struck by how none of the talks that I saw made even passing reference to modern coexistence theory. David Ackerly gave a great talk at the ESA meeting two or three years ago in which he argued passionately that it was time for people doing “trait-based” ecology to step back and rethink their approach in light of modern (i.e. Chessonian) coexistence theory. Maybe it’s just that I had a very small sample size (?), but I haven’t seen much evidence at this meeting that that’s happening.
On another note, the rooms are too bright. It’s hard to read the slides even if you’re sitting close. I plan to get my session moderator to turn down the lights in my session.
I’m really tired and it’s only Tuesday (bingo!), so I’m keeping this short and going to bed.