Social Evolution Forum: Evolution in response to ecological conditions changes ecological conditions

Daphnia magna adult and juvenile. (Flickr: NTNU Faculty of Natural Sciences and Technology)

Daphnia magna adult and juvenile. (Flickr: NTNU Faculty of Natural Sciences and Technology)

I am very happy to be among the members of the Evolution Institute’s new community blog, the Social Evolution Forum. The team includes a bunch of terrific geneticists and anthropologists and people with more social-science-y backgrounds … and me, with a publication record that’s easily 90% research on plants, which do not have societies in any meaningful sense, and interactions between plants and other things that are not really very social, either — moths, or bacteria. Still, nothing in biology makes sense except in the light of evolution, and evolution is very much what I study, and I have written about the biology of the most quintessentially social species, Homo sapiens quite a bit in the past.

All the same, for my inaugural post to SEF, I’m leaning into my role as the generalized evolutionary ecologist with a kind of post I haven’t written in some time, it feels like: a brief discussion of a cool new experiment in rapid evolutionary change and its ecological consequences.

Evolution in response to natural selection over a few weeks or months may not seem like it could matter much, but a recent experiment with one tiny evolutionary champion shows that it can, in fact, have measurable effects on a whole community of interacting species. The communities in question are the kinds found in ponds all over the world, in which swarms of small crustaceans compete to graze and prey on algae and other microorganisms, and evade death in the gaping maws of minnows and sticklebacks. One of these crustaceans is Daphnia magna, the common water flea, which has a life cycle that turns out to be quite convenient for scientists who want to watch evolutionary change in real time.

As you’ll find if you read the whole thing, Jelena H. Pantel and her coauthors raised clonally-reproducing Daphnia in artificial environments with communities of competing crustaceans for about three months — ten water-flea generations or so. They then used individuals sampled from those evolved populations to colonize new communities, and compared what happened to those communities to ones started with Daphnia that hadn’t had time to evolve. It’s a nice experiment in ecological consequences of evolutionary change — and how that change can actually feed back to alter the conditions that caused it in the first place.

And, when you’re done with that, check out great opening articles by Arun Sethuraman, Lee Alan Dugatkin, Jennifer Raff, and Anthony Biglan — that should give a pretty good sense of the variety of voices and expertise you can expect at SEF.