“Often it seems like my favourite papers never get published. The papers that I like the most, reviewers don’t like at all! I have a computer full of such manuscripts. There is a Finnish journal which I think is Journal of Negative Results. I have been wondering whether, perhaps, we should establish a Journal of Unpublished Results!”

“Oh, it’s certainly one of the papers I’m most proud of. [...] I think it had a real impact on the field of conservation science, and a strong indirect impact on the way a lot of forests in the United States are managed. And I’m proud of both those things.”

“Once in a while, I go back and dig something out to remind myself what I did. Surely, it would never even be reviewed now because of its length. This is probably a good thing because it would be more readable, yet I have always enjoyed my “story telling” approach to ecology, that involves an understanding of the big picture in time and space. Even as a student I realized how important scaling time and space were, and that would be lost if the paper were to be chopped up as demanded by today’s standards.”

“Papers are always an updates on the current thinking, the way things are at that moment in time, which is then expanded by future work. The really exciting thing about science is that it’s always moving; it’s always changing.”

“Perhaps I would emphasise the context in which it was written. People tend to forget history very easily. It’s important to understand history, to see the context in which science develops. In ecology there is this tendency: people start working in an area, there is a debate without resolution, and the area collapses. Twenty years later someone starts exactly the same thing and the cycle repeats. There’s little memory. For me, memory is important. I view this paper as one among others that are still useful today. So I would submit it among other papers to read in that field, but it doesn’t have a special status. For me, personally, it was an important paper, one of my favourites, but to my students it’s just one among other papers to read if they work in that area.”

“Read it and then the highly cited papers that cite it. Also let it help you understand about the importance of sharing data. I always published my raw data, from my D.Phil. and subsequently. Over the years, improved analyses will follow and science will progress.”

“Reading a paper from the past and not reading the follow-up literature won’t give you a complete picture of the phenomenon. Subsequent studies have provided quite a bit more shape and nuance to our understanding of this behaviour and how it varies across species. That being said, the flip side is also true, that it’s important to read the foundational papers from a field to understand where the field came from and how it developed. I also think it’s important to recognize that this was a very simple experiment, and sometimes a simple study is what is needed.”

“Since the 2000s, there has been a kind of a renaissance in the literature on how to estimate and measure species diversity, and there are still lots of new and interesting papers coming out on that topic. I guess I would say to people who are reading our Ecology Letters review for the first time – recognize and pay attention to this whole new literature that came after this paper!”

“Since the time of publication, we have only seen even stronger evidence that species diversity reduces invasion success in manipulative experiments, while at the same time, does not causally drive the positive associations between native diversity and invasion often seen in observational studies.”

“So much has happened with the development of Multilevel Selection Theory that my 1975 paper is NOT the way to start! A student should begin with my most recent book, Does Altruism Exist?, and proceed from there, reading my 1975 paper for a sense of history.”

“So much has happened with the development of Multilevel Selection Theory that my 1975 paper is NOT the way to start! A student should begin with my most recent book, Does Altruism Exist?, and proceed from there, reading my 1975 paper for a sense of history.”

“Sure, more or less, although it’s also really clear that parasites alone are not going - and we actually recognized this then too - that parasites alone are not ever going to explain all the variation you see in secondary sexual characteristics among species. The other major thing that’s happened since we did that work is a growing recognition that it’s not parasites per se, it’s the immune response and resistance to those pathogens, which are going to play a role in the evolution of secondary sexual characteristics. And I think that there’s been a lot of really interesting work on what’s now called eco-immunology.”

“That was the end of the endeavor. By that time, electrophoretic data was outmoded, and people were beginning to sequence DNA. I knew that if we were going to go on with this, we were going to have to use DNA-based methods of calculating relatedness and genetic distance. I was doing other things at the time, so I just wasn’t interested. And I knew that other people would take up the work, because it’s an interesting problem. Sure enough, people have. I’ll be leaving it to them to continue working.”

“The Nature paper got a lot of attention because it was the first paper to demonstrate inequity in a non-human species, but it actually proposed more questions than it answered: Why are they doing this? What is the underlying mechanism? Does this response occur across species? What happens if they get more than their partner instead of less than their partner? What is the relative impact of social inequity versus contrast effects? I’ve spent the better part of the last 15 years following up on these questions.”

“The applicability of the nearly neutral theory has expanded. For a long time, there have been arguments for the importance of gene regulation for morphological evolution than genes themselves. But only recently are the molecular mechanisms on gene regulation being clarified. It is now found that numerous complex molecular systems are involved. It is amazing that these systems are well organized and work to provide homeostasis as a whole. The proteins or RNAs of the systems are evolving under weak selection, and the nearly neutral theory is applicable. I have written about these subsequent developments in 2002 and again in 2011.”

“The conclusions are still totally right, but I don’t think you can universalize it easily to any other system.”

“The core conclusion, yes, in terms of, host-plant adaptation promotes the evolution of reproductive isolation, at least to some extent. And this gets to the answer to the previous question – having a little bit of reproductive isolation isn’t really going to make you a distinct species; you need a lot of reproductive isolation. And so there could be many other factors. And in fact, this was why the title to the paper was carefully chosen. Even back in my PhD years, Bernie and I were careful to not put the word ‘speciation’ in the title. Because it was not clear if this kind of beginning or onset of speciation would really lead to distinct species. And so, we left ‘speciation’ out of the title and used ‘reproductive isolation; instead. So I think, at that level, it still holds, that adaptation promotes reproductive isolation. But really how important that is for speciation is a bit unclear, and in fact, we even have a paper that’s been in review for a while now that argues that there may be really a lot of other factors that are involved to really get you distinct species. There may be genetic or geographic factors that are really important. So, the core conclusions hold, but there’s likely a lot more to speciation than just adapting gradually to different host plants.”

“The field of microbial sociality has developed significantly in the past few years. I like to think of that developing field as the natural extension of the fun side projects that I began long ago on social evolution among simple replicators.”

“The general conclusion has turned out to be supported strongly, by massively more data and more cases. Plus, we have an enormous number of additional insights into the process of genome degradation in endosymbionts. Probably the biggest extension is the finding that these genomes are highly reduced in size and number of genes, due to mutations inactivating non-essential genes, which then are deleted over time. This was revealed for Buchnera in 2000, when the first endosymbiont genome sequence was published by Shuji Shigenobu and others in the Ishikawa lab in Japan. We now have many many more cases of this kind of genome reduction in endosymbionts from different bacterial phyla and from other microbial groups.”

“The idea that fragmentation can exacerbate threats to species is valid. The way in which the matrix may affect what happens inside a particular patch of habitat, or I should say, the impact of the surrounding matrix on what happens inside a forest or other ecosystem, is clearly critically important. But, you know, the really interesting thing is, three decades later, we’re still–and by ‘we’, I mean the scientific community in general – we’re still not sure of the degree to which all these different factors are contributing to the observed changes in songbird populations. So, the hundreds of studies that have been done since that paper of mine, most of which were vastly more sophisticated than mine, have made it clear that the question of, to what degree are songbirds declining and why are they declining, is a really difficult question to answer. I think the factors that I identified in my paper are valid in many cases. But I don’t think they’re valid in all cases. And even where it is valid, I couldn’t tell you, with certainty, how it compares to other possible threats. It’s a complicated story.”