Economics blogger Tyler Cowen recently listed prominent economic theories that are widely misunderstood even by economists. I thought it would be interesting to ask the same question for theories in ecology and evolution.
Only well-known theories are candidates for this list. A theory can’t be misunderstood if nobody’s heard of it. And I’m not talking about loosely-defined verbal theories about which there is legitimate disagreement as to exactly what the theory says or means. I’m talking about cases where many people are confused or wrong about what the theory says or means.
Some opening bids:
Modern coexistence theory as developed by Peter Chesson and colleagues is definitely an example. Take my word for it, there are a lot of really sharp ecologists, including people who do mathematical modeling themselves, who just don’t get it. A while back I had a go at trying to explain some (not all!) of modern coexistence theory in an accessible yet precise way; starts here. I think understanding of modern coexistence theory is slowly increasing, thanks to an increasing number of empirical studies grounded in this theoretical framework, and thanks to accessible explanatory papers from folks like Peter Adler, Jon Levine, Janneke Hille Ris Lambers, and others (e.g., Adler et al. 2007). But it’s going to be a long haul.
“Optimism” and “pessimism” in animal behavior. Houston et al. (2012) argue cogently that lots of current work on this topic rests on misunderstandings. But then again, they suggest that many of these misunderstandings arise from the use of imprecisely-defined verbal models, so maybe that’s not a great example here.
The Price equation. Misunderstood from the get-go; Richard Lewontin famously dismissed it as trivial when George Price first wrote to him about it, only to later change his mind and write to Price apologizing for failing to get it. And I once had a conversation with a very good theoretician who said to me “The Price equation…yeah, I’ve never been able to get that.” The Price equation is much better and more widely understood than it used to be, thanks to the tireless efforts of Steven Frank and others. But even in his latest paper Frank is still at pains to refute unfounded criticisms of the Price equation. And reviewers ask to have explanatory appendices or text boxes added to pretty much every paper I write on the Price equation. Then again, maybe this isn’t the greatest example, because the Price equation still isn’t widely known?
Zombie ideas about the IDH. The three zombie ideas I listed in my original post on the intermediate disturbance hypothesis all are misunderstandings about how disturbance and environmental fluctuations can affect species coexistence. Note that I’m referring here to those three specific theoretical claims, not to broader disagreement or confusion about what ideas define the IDH.
The “portfolio effect” and its relationship to other mechanisms affecting the diversity-stability relationship. I was talking with a colleague recently who dug into the literature on diversity-stability relationships, and who asked me, “So, what’s the portfolio effect, exactly? And how does it relate to “mean-variance scaling”, “statistical averaging”, and “density compensation”? Because I’ve been reading all these papers and I can’t pin it down.” And I demurred because I’m not exactly sure either! I may do a post on this at some point, as an excuse to try to clear up my own embarrassing confusion. Feel free to explain it to me in the comments–and hope that nobody else replies that you’ve misunderstood!🙂
Limiting similarity. I think confusion about what models of limiting similarity assume and predict is the longest-standing and most important theoretical misunderstanding in ecology.
R* theory, resource ratio theory, and dynamic energy budget theory. Actually, I don’t think any of those are widely misunderstood. But Marquet et al. made me wonder a little…
Just looking at the above list, I don’t see any obvious reason why these theories are widely misunderstood. It’s not as if they use especially advanced mathematics, for instance. Indeed, if anything the Price equation is hard to get because it’s so simple mathematically that it seems trivial. And it’s not inevitable that any popular theory will be widely misunderstood. For instance, I don’t think the theory of island biogeography is widely misunderstood. Perhaps some patterns will emerge with more examples, but I’m guessing not. The causes of misunderstanding are just too diverse for that.
You will note that I did not try to summarize any of the theories that in my view are widely misunderstood. I figured that exposing my own misunderstanding of any of those theories would undermine my point! But now it occurs to me that it might’ve strengthened my point.🙂