“The interesting thing is that the story has certainly borne out, and now we can start to look at things in much more detail as to exactly how this convergence happens. What we’re doing now is looking at the convergence from a genomic perspective. [...] And so with the genomic data, what we would like to do is be able to get a feel for exactly how evolution has happened – what switches have gone on and off to get the repeated evolution of the same ecomorphs, and how they diverge, one from the other. Now, we can hopefully get at that with this genomic data.”

“The lab version of reality is highly abstracted and it cannot capture the range of interacting factors that you see in nature. People will say you do it in the lab because you can control it and be clear about what’s going on. That’s true, but if you want to know why animals or plants are the way they are in the real world, then you need to work in the real world, because the full scope of factors that interact in shaping evolution can’t be anticipated or replicated in the lab. I made a similar argument one time, way back when people asked me why I wasn’t doing these experiments in the lab. I said it’s because I want to know why things are the way they are in the real world, and I don’t have faith in the lab being able to reproduce that. The way this project has developed has shown that there’s no way that any lab work could have led me to an understanding of ongoing interactions between ecology and evolution. You just can’t capture that in the lab. I couldn’t have anticipated that when designing the lab study. Therefore, I think it’s important to work in nature whenever you can.”

“The main conclusion of scale-dependence in productivity-diversity (and many other relationships) certainly holds true. However, the answer isn’t as simple as we suggested - naturally. First, there are good reasons we found what we found, but there are also good reasons different patterns could emerge. For example, local patterns aren’t always (or even usually) hump-shaped. And there are so many different ways to measure beta-diversity and productivity, that people have found lots of different results. But in all, I think the idea that scale is critical for understanding diversity relationships is pretty well ensconced.”

“The paper is obviously rather primitive by current standards when it comes to plant phylogeny, but remains of high standard when it comes to insect data. Interestingly, we used these insect data to make some rather daring extrapolations in order to estimate global insect numbers. Despite the fact that these numbers are of interest to many biologists and non-biologists, we have not progressed much with making these estimates more precise over the past 14 years.”

“The result has proved repeatable. In the new experiments we have four replicates, and we show that it’s happening, but we also have a much better idea about why it’s happening, than we did then. The aspect of that paper that didn’t hold up was that it was written around the idea that it was differences in age-specific mortality that caused the life-history patterns that we saw. [...] we now know that that’s not the explanation. Indirect effects of predators and density regulation are playing a very important role.”

“The situation is quite different now. Two years ago, Bill Rice and I edited a collected volume on sexual conflict, The Genetics and Biology of Sexual Conflict, and I wrote a review chapter for that volume on the theoretical literature on sexual conflict. The conclusion that I was getting there, from a theoretical perspective, was that there are at least six different types of dynamics that can happen in models of sexual conflict. The Nature paper identified only two of them – continuously coevolutionary change and random drift along the line of equilibrium. Subsequent work produced a number of other things. And then, in terms of Bill’s idea about sexual conflict being “an engine of speciation”, I think I end my review paper from two years ago by saying that, yes, indeed, it’s an engine of speciation, but it works only under the right conditions. If conditions are not right, the engine will just stall. So, the story, of course, is much richer today.”

“There is much to update really. The most obvious update would be the much more comprehensive understanding that we have today on the role of predation in species coexistence. The paper had just a small section on this. In effect, it has been updated though in my essay on “Species Competition and Predation” in Robert Meyers’ Encyclopedia of Sustainability Science and Technology. Another big update would be more on the effects of spatial and temporal scale, especially spatial scale. Early in the paper, I make the statement, “Many models of species coexistence are thought of as models of coexistence in some defined local area. However, to make any sense, the area addressed must be large enough that population dynamics within the area are not too greatly affected by migration across its boundary (103). At some spatial scale, this condition will be achieved, but it may be much larger than is considered in most models and field studies.” This is actually a warning against the focus on the “local community” in empirical studies. At the time, I did not have much to say about how to get around that problem. But that has changed with the further development of Scale transition theory, which provides an adequate framework now for how to deal with multiple spatial and temporal scales including non-stationarity of the environment in space and time, which we need for addressing long-term climate change. Finally, an update would provide a better guide on how to use the various concepts empirically.”

“This was not a question-driven or hypothesis-driven study. It was a retrospective study and very much based on, what I call, serendipitous events. Things that happened that we were perhaps lucky to see. [...] Another important message is that what one discovers about nature may not be at all what one was expecting to see and learn. And I don’t know how strongly that comes through, but you know it took us several years to open our minds to the possibility that these things were going on, even though the evidence was there earlier that there were major changes happening. My belief system about the way that system was put together, and the fact that I thought the sea otter population was at carrying capacity, really prevented me from seeing the truth till later. I don’t know if that comes through from the paper.”

“This was the first in a series of papers. If you’re interested in, let’s say, the speciation component, there are other papers to read. If you’re interested in co-evolutionary components, there are other papers that I would recommend to read. I wouldn’t hold this up as a model paper, but I think it does tell a story that has largely stood the test of time. I think it could have been said more succinctly, and I think there are other ways to have said it or just show it, but then some of those datasets were not available. I think there are probably stronger papers that have been published since for the different components, just because we had more time to reflect and gather more data to more convincingly test some of these ideas.”

“Unless they were interested in the history of science, I would tell them to ignore the empirical sections and just read the concepts and discussion. So much has been done empirically that they would do better to read something more recent! However, the concepts should still provide a useful introduction to reviews of modern sperm competition theory. The first caveat I would add is to remind them that it was written almost 50 years ago. The second (given to me long ago by Philip Sheppard) is to get working fast, because they will have had all their best ideas by the time they are 35; after that they will spend their time refining them.”

“Viewed today, there are many caveats. For instance, there is no paternity determination, as DNA methods were not then available. And the adaptive reasons for female choice of males with long tail could not be studied in this brief experiment. But the successful experimental demonstration of female choice in the wild may have helped encourage subsequent better studies.”

“We had a really simple question, actually: are introduced populations less parasitized than their native counterpart populations, if you look at species pairs. One thing that we were not able to do is look at how that translates into the performance of introduced species. I think now data are accumulating to do that. And the question is much more complex. But there are much more data assessing some of those components, that it would be worth exploring that further, to see the extent to which that question could be addressed now.”

“We have improved our measures of network patterns and the use of null models. We have also a more complete data set. More importantly, there is now abundant theory trying to make sense of these network patterns. But overall, I think it is fair to say the paper remains as valid today as it was back in 2003 in the sense of advocating the existence of simple patterns in the architecture of species-rich mutualisms.”

“We have many more good empirical measures of costs now, but not one of the big conceptual questions I posed in this paper has been answered yet! Go for it!! Mutualism is a very young field, and there’s a lot of low-hanging fruit for an enterprising biologist.”

“We have now studied the dispersal of many more species. Not only have our conclusions from 2003 been supported, we have found increased dispersal in even more types of species with different modes of dispersal, such as wind-dispersed plants. My take-home lesson from this has been that the effects of corridors on dispersal are very broad and general.”

“We provided an additive partitioning with two components, because we wanted it to be as simple as possible and as transparent as possible. Jeremy Fox and others have developed our approach to build equations with three or more components. Although mathematically correct, I don’t feel these more complex equations have led to major new discoveries so far, because the new components don’t always have a clear interpretation. To be honest, I was not especially interested in developing the method. It’s not a kind of magical recipe that will solve all problems. I have never believed in that kind of thing. I prefer to concentrate on new questions and not just to refine one particular approach. But that’s my bias. I know some people like to continue building what they have done. I’m different. Once I solve a problem I tend to move to another problem. That’s my way of doing science.”

“We would do a number of things differently. So first of all, we would search much more broadly. We would not restrict the studies to a certain number of journals, we would just, you know, use scientific databases to search whatever had been published in different journals. So we would have a much wider range of studies, but then it would be too many studies to handle, so we would have to have to narrow it down in some way I guess. We used fixed effects models in that paper, which were the only statistical models that were available at that time. Now we would you use mixed effects, we would do much more complex modelling, and we would use meta-regression and not just heterogeneity tests. So we would use different statistical approaches as well as different search and inclusion approaches. We would also record and report the data differently, given the recent emphasis on reporting standards and open science.”

“We wrote the paper to get people to pay attention to this subject, and I think people are paying attention to the subject now. And so, in that regard, it’s maybe less important as a paper now, and maybe somebody would be better off reading a more updated version. But I still think that it lays out a lot of the core topics pretty well.”

“Well, I guess, maybe, it’s a testimony to my own lack of mental flexibility, but I guess I’d have to say that that’s pretty much the way I still think.”

“Well, I probably never spent as much time writing a paper as I did with this. It took a lot of time and effort and a lot of rewriting. When I read it now it seems pretty dense. Every sentence has information in it. Nowadays, for a paper like this there would be a 100-page supplement that would have all the data and all kinds of other analyses. So that’s one difference. I think the writing style also seems somewhat different although it is hard for me to pinpoint exactly where the difference lies. It’s very natural history-focussed at the beginning, but there are three clear predictions after that, followed by the evidence in support of them. Even if I wrote it now, that would still be the way I would want to do it. You know, come up with such and such predictions and then come up with the evidence to support them. But what strikes me when I read this paper now is just how little data there really is! And how much effort went in to getting those data. It was Herculean.”