Tag Archives: population ecology

Teaching population dynamics with simulations in R

Graphic: Results of a discrete-time simulation with two competitors having a shared predator. Exercise for the reader: which trace is the predator?

Warning: wonkish. Of interest primarily to those who teach upper-level ecology courses.

I don’t have an important message today, or a big unresolved question to talk about. I just thought I’d share some teaching resources. If you teach ecology (past the introductory level), you may find this useful.

One of the major themes in my 3rd-year population ecology course is the diversity of population dynamics that can emerge even in fairly simple systems: extinction, stable equilibrium, damped oscillations, stable limit cycles, neutral cycles, chaos, and so on. We spend a lot of time on the kinds of ecology that tend to favour oscillations (things like time lags and enemy-victim interactions) as opposed to those that tend to favour stable equilibria (things like immediate density-dependence and, under some circumstances, interspecific competition). Continue reading


The “one thing I teach that nobody ever forgets” may be wrong!

Image credit:  “Semele consumed by Jupiter’s [=Zeus’s] thunder”, 1733, Bernard Picart. In Tafereel, of Beschryving van den prachtigen Tempel der Zang-Godinnen, H. Chatelain, Amsterdam.

Recently I blogged about the one thing I teach that nobody ever forgets: the meaning, and etymology, of the life-history term semelparity. If you haven’t read that post, and want this one to make sense, go ahead and read it now (I’ll wait). But it turns out that etymology I explained there might be wrong*.

A sharp-eyed reader (Jon Benstead) alerted me to an alternative etymology, laid out by James Rader in a brief letter to Natural History. According to Rader, “the notion that the semel in semelparity…has some connection with the Semele of Greek mythology looks like a bit of biologists’ folklore”. Continue reading

The one thing I teach that nobody ever forgets

Image credits: Sockeye salmon: (c) William Rosmus, CC BY-SA 4.0 via wikipedia.org. “Semele consumed by Jupiter’s [=Zeus’s] thunder”, 1733, Bernard Picart. In Tafereel, of Beschryving van den prachtigen Tempel der Zang-Godinnen, H. Chatelain, Amsterdam.

NOTE: the etymology in the story I tell below may not be right!  Or it may… it’s not entirely clear, and I think the story is interesting.  Blog post on it here (but read the story below first).

I’ve been teaching undergraduate courses in ecology and population biology for 23 years*. I’ve seen a lot of students from behind my (metaphorical) lectern: brilliant ones and less brilliant ones; motivated ones and passive ones; a few with their whole future careers mapped out and a few hopelessly drifting and lost.

Like every teacher, I’d love to think that my students retain most of what I teach them – ideally, for their entire lives; but at least until the final exam. But of course they don’t, and every year I find grading the exams a bit depressing because (and here’s a shocker) some students get some questions wrong. But there’s one thing I teach that nobody ever forgets – and it came up in my Population Biology course just last Friday. Continue reading

What’s your most undercited paper?

Back in February, I asked “What’s your most overcited paper?. That left an obvious question hanging: what, instead, is your most undercited paper? I’m going to tell you about mine, and I hope you’ll tell me about yours in the Comments. You may be worried that this will be an exercise in which I whine that nobody appreciates my work, but in fact that’s not what I have in mind. Well, not exactly*. Continue reading