Recently I polled readers on which classic ecological topics they personally still care about, and which ones they think ecologists collectively should still care about. For comparison, I also asked about a few contemporary and applied topics. Respondents were asked to indicate the level of care on a 4-level scale from “don’t care/shouldn’t care” to “care a lot/should care a lot”. I coded those levels numerically as 1-4, which is fine for my crude analytical purposes.
The results were pretty interesting! (UPDATE: scroll down to the bottom for the full results table. And here’s a link to the full dataset.)
We got 205 respondents, with typical demographics for our polls: 27% grad students, 24% postdocs, 16% faculty for <6 years, 25% faculty for >6 years, 6% non-academic professional ecologists, 2% other. Thanks to everyone who took the poll! 🙂 It’s not a random sample of all ecologists, but it’s a large and diverse enough sample to be worth talking about.
A few of the topics are less well-known than others, and so some respondents skipped them (cough *CSR theory* cough). But we got many responses for every topic.
Here’s a figure that illustrates several of the key results. Each point gives data for one topic. Some of the topics are labeled.
From this figure, you can see that:
- The listed topics vary widely in how much ecologists care about them, or think ecologists collectively should care about them. They range from topics about which most respondents care only a little or not at all (CSR theory, aka “Grime’s triangle”), to topics about which most respondents care some or a lot (predicting species range shifts in response to climate change).
- Ecologists care least about old topics that have been widely criticized. Verbal hypotheses from the 1970s that haven’t stood up to scrutiny seem to be on their way out (and here’s further evidence that the intermediate disturbance hypothesis is going from a zombie idea to a ghost idea). Although it’s possible that readers of this blog care much less about those topics than other ecologists do.
- How much ecologists think others should care about a topic is tightly correlated with how much they personally care about it. r=0.97 for the data in the figure above. And for any given idea, the correlation between how much individual respondents personally care about it, and how much they think ecologists collectively should care about it, ranges from 0.49 to 0.86 depending on the idea. But it’s not that ecologists all think they personally care about each topic the “right” amount and that ecologists collectively should care exactly as much as they do. Because…
- Ecologists mostly think that ecologists collectively should care about any given idea more than they themselves do. All the points in the figure above fall above the 1:1 line. And for any given topic, somewhere between 14% and 42% of respondents said that ecologists collectively should care about it more than they personally do, vs. only 5-17% who said that ecologists collectively should care about the topic more than they themselves do. That is, it’s much more common for ecologists to say (in so many words) “I personally don’t much care about this topic but others should” than it is for them to say “I personally care about this topic but others shouldn’t.”
- The more the average ecologist personally cares about a topic, the more likely ecologists are to say that “ecologists collectively should care about this topic more than I personally do”. That is, points that are further to the right in the figure above tend to be further above the 1:1 than are points to the left. It’s not a huge effect, but I’m pretty sure it’s real, not a blip. That’s interesting because you might think it would work the other way. After all, ecologists who personally care a lot about a topic (the maximum possible level of care in this poll) couldn’t indicate that ecologists collectively should care even more about it. But apparently, if many ecologists personally care a lot about a topic, many other ecologists who don’t personally care a lot about that topic will say that ecologists collectively should care a lot about it. Conversely, if few ecologists personally care a lot about a topic, ecologists who don’t personally care a lot about it are unlikely to say that ecologists collectively should care a lot about it.
A few other results:
There were no obvious differences in opinion on any topic among ecologists at different career stages. So it’s not the case that senior faculty still care a lot about old topics that grad students and postdocs don’t give a crap about. Conversely, it’s not the case that grad students care about old topics they were taught as undergrads, having not yet learned that faculty don’t care much about those topics any more.
Finally, ecologists vary widely in how much they care about any given topic, and in how much they think ecologists collectively should care. For instance, here are histograms of all responses for one of the topics:
Almost every topic has at least a few respondents who don’t care about it and don’t think ecologists collectively should care either. And also has at least a few respondents who care a lot and think ecologists collectively should too. Yet more proof, if proof were needed, that ecologists disagree with one another a fair bit.
A few final thoughts:
- I’m curious how responses would’ve differed if I’d asked more refined questions about which topics should still be the subject of active research, vs. which ones should still be taught. And if they should still be taught, to whom should they be taught and why? Brian, Meghan, and I have been emailing about this, and I can feel a follow-up post coming on. This seems to be one of those rare-and-thus-interesting cases where Brian and I disagree…
- Decent numbers of respondents still care about top-down vs. bottom-up effects and chaos, and think ecologists collectively should too? Really?! 1995 called, people. It wants its favorite ecology topics back, but says you can keep its Hootie and the Blowfish CD. 😉
- Diversity-stability is an interesting case of a classic topic that people still care about because the key terms have been redefined. If I’d asked respondents how much they care about “complexity-stability sensu May (1973)”, I bet respondents would’ve cared much less about it.
- I’m surprised the metabolic theory of ecology and explaining latitudinal diversity gradients didn’t get more support as topics ecologists collectively should care about. Not saying I disagree (or agree) with the respondents on this. Just surprised.
- Dammit, I forgot to include the paradox of enrichment in the poll. My bad.
Full results (topic, mean for “I personally care”, mean for “ecologists collectively should care”):
Clements vs. Gleason, 2.0, 2.1
Island biogeography, 2.9, 3.0
Diversity-stability, 2.9, 3.1
Keystone predation/keystone species, 2.7, 3.0
Explaining the latitudinal diversity gradient, 2.4, 2.7
Whether succession proceeds to a stable endpoint, or maximizes the value of various ecosystem-level variables: 2.4, 2.7
IDH, 1.9, 2.0
Whether the diversity-productivity relationship is humped, 2.0, 2.2
Causes of population cycles, 2.7, 3.1
Optimal foraging, 2.3, 2.7
r/K selection, 2.0, 2.1
CSR theory, 1.8, 1.9
Janzen-Connell hypothesis, 2.3, 2.5
Pseudoreplication, 3.1, 3.3
Metapopulations, 2.9, 3.2
Food web structure (e.g., connectance, food chain length, proportion omnivores, intervality, etc.), 2.6, 3.1
Chaotic population dynamics, 2.4, 2.5
Alternate stable states, 2.8, 3.1
SLOSS debate, 2.3, 2.6
Top-down vs. bottom-up effects, 2.7, 2.8
Biodiversity-ecosystem function, 2.9, 3.2
Ecosystem engineers, 2.5, 2.8
Metabolic theory of ecology, 2.3, 2.7
Neutral theory, 2.1, 2.2
Rapid evolution/eco-evolutionary dynamics, 2.8, 3.3
Modern coexistence theory, 2.7, 3.0
Species range shifts under climate change, 3.2, 3.5