Brian likes to emphasize–and I agree–that ecology as a whole lacks what Brian calls a problem solving mentality. We’re too often satisfied with evidence that merely suggestive or consistent with our hypotheses, and we’re too reluctant to permanently discard ideas that are past their sell-by date.
So here’s a question. Actually, two of them:
- What’s the biggest idea ecologists have ever permanently rejected? Define “biggest” in any plausible way you like–most important, most influential, most widely-believed, most widely-studied, most fundamental, most cited, etc.
- How many big ideas have ecologists ever permanently rejected? Can we come up with a complete list? If we can, that would be consistent with Brian’s and my concern–because that would mean the list is short!
Here’s an opening bid: Clements’ notion of communities as superorganisms. Even community ecologists (like me!) who believe species aren’t independent of one another because interspecific interactions matter don’t believe in anything like Clementsian superorganisms as far as I know. And subsequent attempts to revive the idea by talking about speculative possibilities like community-level selection haven’t gotten very far. I suppose there’s an echo of the superorganism idea in the notion that stability constraints “select” for stable communities, but it’s a pretty faint echo.*
Here’s a second bid: “broken stick” models of species abundance distributions. Not all that big an idea in the grand scheme of things. But beggars can’t be choosers–we’ll end up with a really short list if only really big ideas qualify for inclusion.
Hopefully, the list (or lack thereof, if no one can think of any other entries!) will start a conversation about what it takes for an idea to end up on the list. What does it take for ecologists to give up on an idea? What combination of circumstances–features of the idea, the ecologists working on it, the available theory and data, and nature itself–conspire so as to cause an idea to be widely influential in ecology, and then later get permanently rejected?
I predict that at least one comment will be from someone arguing that superorganisms or broken stick models aren’t dead. Thereby confirming the first paragraph of the post. 🙂
*Aside: Here’s a brand-spankin’ new TREE paper by a bunch of sharp people on stability constraints possibly selecting for stable ecological systems. I think it’s an interesting topic that’s worth studying. I think you’ll need to look to microcosms or other appropriate model systems to get decent direct evidence (as opposed to highly indirect evidence that is sorta suggestive if you squint at it, wave your arms, and make lots of really strong assumptions). And I predict that the the effects of selection for stability (using whatever sense of stability you think is most relevant) will turn out to be quite weak to nonexistent in practice, because they’ll be swamped by other factors. But it’d be very cool if I turned out to be wrong about that. See this old post for further discussion.