In 1977, Tim Clutton-Brock and Paul Harvey published a paper in the Journal of Zoology reporting the results of their comparative analysis of the ecology and social organization of 100 primate species. This study was probably the first to statistically account for the non-independence of data as a result of species’ phylogenetic relationships, a theme that remained a major focus of Paul Harvey’s research subsequently. Forty years after the paper was published, I asked Paul Harvey about the motivation behind this study, the challenges of putting together this dataset, and the impact this paper had on his subsequent research.
Citation: Clutton‐Brock, T. H., & Harvey, P. H. (1977). Primate ecology and social organization. Journal of Zoology, 183(1), 1-39.
Date of interview: Questions sent by email on 27th September 2016; responses received by email on 30th September 2016.
Hari Sridhar: What was your specific motivation to do the work presented in this paper? What brought you and Professor Clutton-Brock together to do this work, and what did each of you bring to this study?
Paul Harvey: As faculty colleagues at the University of Sussex, we had written a previous piece, a book chapter, where Tim’s (aka Clutton-Brock’s) expertise in primates and their ecology came together with my interest in evolutionary biology. That chapter was a hard grind and forged a deeply personal relationship. We had discussed but not tested the evolutionary rules likely to shape primate societies. This paper tested the available data against the likely evolutionary forces, using comparative methods that had been employed by Brian McNab on mammals (e.g.) and Tom Schoener on birds, though we modified the methods to help deal with statistical non-independence. Tim mined the data, while I performed the analyses. Tim had previously persuaded an undergraduate to perform preliminary analyses on an early data set and the results looked promising.
HS: Stepping back a bit, what got you interested in comparative analyses in evolution?
PH: I did my D.Phil. on the visual polymorphism of a land snail, following a conference I attended during my first year as an undergraduate. One paper had attracted my attention: Mme Guerrucci-Henrion saw and interpreted a difference in morph frequencies between the north and south of Brittany. I argued that, if she was correct, the same patterns would be evident between the north and south coasts of Cornwall and the north and south coasts of Pembrokeshire. I collected the data with two colleagues. The patterns were replicated, and I published that in 1972.
HS: At the time when you did this study, it surely wouldn’t have been easy to put together all the sources that you used to extract data. Could you give us a sense of how you identified and obtained this data on 100 primate species?
PH: Yes, Tim got the data from the literature and from colleagues. I believe that the key enabler in getting the data collected in the first place was probably Robert Hinde, Tim’s D.Phil. Supervisor, who supervised studies on different primate species, gathering equivalent data on each of them.
HS: One of the challenges you allude to in the paper is the availability of quality data. Subsequent to this study, did better data become available and was a similar analysis repeated with an updated dataset?
PH: Oh yes, many analyses, and using much better data sets. But remember, the quality data required was not just on each species but on the phylogenetic relationships among the species. Comparative analyses improved in tandem between improved species field/morphological data and improved phylogenetic information.
HS: Would you remember how long, approximately, it took you to write this paper, and where and when you did most of the writing? Could you also give us a sense of how you and Professor Clutton-Brock worked together for this study, i.e. how often did you meet, where did you meet, how did you share drafts etc.?
PH: Yes, it took less than a year. Tim and I worked closely, usually in the same room, and almost every day, including weekends and holiday, often from early morning to late evening. I performed the analyses and Tim did the writing, reading out loud as he progressed with me correcting. We were thought by one of his students to be arguing very loudly and that our relationship would not survive, but it was creative composition. I have never witnessed a closer collaboration.
HS: You thank a long list of people at the end of the paper. Could you tell us a little more about the different ways in which these people helped, and whether there were certain individuals who were key to this study?
PH: They provided the data for the most part; much like Darwin w,e acknowledged data sources. We also freely acknowledged anyone we had received help from.
HS: Did this paper have a relatively easy ride through peer-review? Was Journal of Zoology the first place you submitted this to?
PH: Yes, it was an easy ride and it was the first place we sent it to. It was for many years (and may still be) the most highly cited paper published by that journal.
HS: At the time it was published, did this paper attract a lot of attention?
PH: Yes, it did. We got invited to give talks about it and it was featured in Nature through a News and Views.
HS: Over the years it has been cited over 900 times. Would you know what this paper mostly gets cited for?
PH: The first major quantitative-comparative analysis of primate ecology and social organisation, and the first to properly acknowledge the statistical non-independence of species data (species within a genus were generally the same or very similar, so we used the genus as the unit of analysis unless there was intra-generic variation).
HS: Did this paper have any kind of direct impact on your career? How did it influence the future trajectory of your research?
PH: Yes, I went on to do perform many other comparative analyses and to develop and write about how to perform comparative analyses. The book I co-authored on the topic about a decade later was probably the main reason I got elected to the Royal Society.
HS: Today, 39 years after it was published, would you say that the main findings of this study still hold true more-or-less?
HS: If you were to redo this study today, would you change anything?
PH: Yes, we’d use better data and independent contrast analysis.
HS: Have you ever read this paper after it was published? When you compare this paper to papers you write today, do you notice any striking differences?
PH: Yes I have, and no it is the sort of paper I carried on writing, though the statistical analyses became more sophisticated.
HS: Would you count this paper as a favorite, among all the papers you have written?
PH: Yes I would. I loved the constructive collaboration with a new found, and even more ambitious, colleague, who cared as much about getting the science right as I did.
HS: What would you say to a student who is about to read this paper today? What should he or she take away from this paper written 43 years ago? Would you add any caveats?
PH: 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 by raw data, from my D.Phil. and subsequently – over the years improved analyses will follow and science will progress.