Rod Peakall

Rod Peakall is a Professor of Evolutionary Biology in the Research School of Biology at The Australian National University in Canberra, Australia. Before joining the ANU, he completed his BSc (Hons) and PhD at the University of Western Australia (UWA), followed by postdoctoral research at Macquarie University in Sydney, Australia. Orchids have featured strongly in his research as ideal subjects for exploring a range of interesting ecological, chemical, molecular and evolutionary questions. His research on sexually deceptive orchids, in particular, has captured the imagination of the public, educators and scientists around the world. He is also well known as the first author of the widely used population genetic software package GenAlEx (Peakall and Smouse (2012). Bioinformatics 28, 2537–2539). What turned you on to biology in the first place? I owe a great debt to my parents for my love of nature. They chose to bring up their five children on the outskirts of Perth, Western Australia, with nearby forest as our playground. Luxury holidays were off the agenda — instead, we spent our holidays camping at remote and wonderful locations, with hiking, canoeing, birdwatching and orchid hunting all part of the adventure. By high school I had purchased my first SLR camera and spent all of my pocket money on colour film for my budding hobby of nature photography. At that point I had decided I wanted to be an ornithologist. However, a chance conversation with a zoologist about the scarcity of jobs in zoology, combined with my growing fascination with native orchids and their pollination, led me to study botany at UWA. Another chance conversation would later seal the deal. I had bumped into my genetics lecturer, Sid James, who was passionate about plant chromosomes and evolution, and took the opportunity to ask if he had any Honours research projects on orchids. He said, ‘No, however, if you come back with a suitable plan, we can talk further’. So began my first research project, which combined my interest in orchids and their pollination with their cytology and population genetics. My PhD supervisor’s example of flexibility in taking on passionate students, even when their interests fell somewhat outside of his own, has been a guiding influence. Consequently, it has been my great pleasure to have supervised many passionate students who have worked on the ecology and genetics of a diverse range of organisms including fungi, plants, insects, birds, small mammals and even humpback whales. It sounds like some good luck set up your early research directions. Has serendipity been important across your career? Most definitely! Across my career, lucky breaks and unexpected discoveries have underpinned the many exciting twists and turns I have taken. One key example was the discovery of ‘chiloglottones’ representing a new class of natural products that we found to be emitted by sexually deceptive Chiloglottis orchids to sexually attract their male wasp pollinators. This breakthrough in 2003, led by a postdoc, Florian Schiestl, and the late Wittko Francke and his team of chemists, was a pivotal turning point in my career. It not only confirmed the fundamental role that floral volatile chemistry plays in the operation of sexual deception, but it opened up an exciting world of cross-disciplinary research. To this day, chemical ecology, which must invariably involve strong collaborations with chemists, continues to feature strongly in my research on the ecology, pollination and evolution of orchids. You have just mentioned ‘sexual deception’, tell us a little more about this seemingly bizarre pollination strategy. Yes, pollination by sexual deception is perhaps one of the most bizarre and remarkable of all pollination strategies. These plants sexually lure their specific male pollinators to the flowers by chemical and morphological mimicry of the female of their pollinator. The mimicry can be so compelling that attempted copulation (pseudocopulation) with the flower is frequent, and it is normally during this process that pollination occurs. This pollination strategy is in fact a worldwide phenomenon, with multiple independent origins on four continents (Australia, Europe, Africa and South America). Furthermore, while mostly ‘an orchid thing’, one case each is known in the daisy and iris families. My own research has focussed on Australian terrestrial orchids, which represent one centre of diversity for this pollination strategy. Our current best estimates are that at least 580 species — that is approximately 40% of all Australian terrestrial orchids — are involved. What is more, there have been multiple independent evolutionary origins, with the duped males being drawn from five Hymenopteran and three Dipteran families. In part, it is the sheer scale and diversity of this intriguing pollination strategy within Australia that has maintained my research interest in this group across my career. I can see how your research on orchid pollination might feature in natural history documentaries, but are you anticipating any applied outcomes from your orchid research? I often get asked versions of this question by the media and the public, and perhaps even more surprisingly by some nature enthusiasts. The short answer is that the goal of our research on orchids is first and foremost about understanding how nature works and evolves, and where appropriate apply this knowledge to the conservation of these species. Highly specialised plant–animal interactions, such as sexual deception, where each orchid species has only one pollinator species, can help to sharpen our understanding of ecological and evolutionary processes that may be more difficult to unravel in generalised systems, where selection pressures are more diffuse. For this reason, research on sexually deceptive species has revealed some of the most compelling evidence for pollinator-mediated selection on chemical and morphological traits in flowers. In essence, it is these specialised exceptions that prove the rule. A research focus on specialised systems can also have unexpected outcomes. For example, with an international and multidisciplinary team, we were able to elucidate the biosynthesis of the monoterpene citronellol for the first time, despite much prior research (Xu et al. (2017). Curr. Biol. 27, 1867–1877). Our breakthrough was made in a wild sexually deceptive orchid that uses a blend of citronellol and another unrelated compound to attract its pollinator. The tissue-specific production and virtual absence of other floral volatiles, in combination with differential gene expression analysis, were in part a key to revealing a more complex multigene pathway than predicted. Applied scientists are now attempting to apply this knowledge in a quest to genetically engineer citronellol production for the perfume industry. Do you believe there is a need for more crosstalk between scientific disciplines? Absolutely! I have particularly strong feelings about the importance of multidisciplinary research. In my own case, long-term collaboration with chemists has been crucial for advancing our understanding of sexual deception because ‘it takes chemistry to work’. Our reward for this cross-disciplinary research has been the discovery of many new-to-science compounds, and a much deeper understanding of how the systems operate and evolve. This collaborative interaction is, of course, mutualistic (unlike the deceptive exploitation of the pollinators by the orchids that we study), with both biologists and chemists benefitting from joint publications in high profile biological and chemical journals. What is the best academic advice you have been given? Four pieces of advice stand out for me. Firstly, always negotiate upfront the roles, responsibilities and order of authorship and collaboration. Talking about collaboration, a second piece of good advice has been: by all means test different collaborations, but only stick with the ones that work well. Third, be sure to always do your own field work. On this point, I have been particularly fortunate to work in a department where staff at all levels from the Head of Department down have been encouraged and supported in their pursuit of research topics that require an extensive fieldwork commitment. In my own case, 2 to 3 months of interstate field work per year is the norm. Further, as if by magic, all sorts of issues seem to resolve themselves (or are resolved by others in your absence) while you are largely off grid. Be sure to try it sometime! And finally, never forget that it is a privilege to be an academic. What advice would you offer to graduate students and early career researchers aspiring to a career in the biological sciences? Never say ‘never’. Across my career, we have made scientific discoveries that were never expected. These discoveries often revealed far more complexity than our initial hypotheses, and sometimes even reversed our prior thinking. Take full advantage of lucky breaks. This could be taking advantage of a rare combination of seasonal conditions to study a new ecological interaction or forging new collaborative partnerships that happen when you accidently cross paths. Be patient! Scientific breakthroughs often take time and can demand patience and persistence over multiple years. Finally, above all, have fun! When the science is no longer fun, it is time to get another job.