ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology during our centenary year, but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Brian Whyte is an author on ‘ The role of body size and cuticular hydrocarbons in the desiccation resistance of invasive Argentine ants (Linepithema humile)’, published in JEB. Brian conducted the research described in this article while a PhD student in Neil Tsutsui's lab at the University of California, Berkeley, USA. He is now a postdoc in the lab of Abel Bernadou at the Research Center on Animal Cognition, Center for Integrative Biology, CNRS - Université Paul Sabatier, France, investigating how animals recognize friend from foe and other social categories.
Describe your scientific journey and your current research focus
I think it began when I was working as a lifeguard at a pool that was often empty. I had many hours to read science books, such as The Selfish Gene and Six Easy Pieces. I could pace around the water and take my time to slowly understand them, and this made me confident enough to pursue science during college. I was most interested in evolution, because seeing the creationism versus evolution debate online when I was young made me realize how biology had profound implications on how we (humans) view ourselves. Understanding humanity from an evolutionary lens required understanding how sociality evolves, and once you consider questions of social evolution, its only a matter of time before one realizes how special the social insects are. Skipping ahead to the present, my research focus is on a social behavior that many social insects exhibit: colony recognition. How animals can distinguish an abstract boundary such as a social group is fascinating to me. It makes evolutionary sense why closely related individuals would prefer to treat each other as friends and reject strangers as foes, but judging relatedness is hopelessly imperfect, and where does one draw the fine line between friend and foe? More specifically, the proximate mechanisms of how animals do this (i.e. what information do they sense, and how do they use it to make these decisions) are still poorly understood in most social systems.
How would you explain the main finding of your paper to a member of the public?
In California, there is an infamous species of ant from Argentina which has been a common pest for over a century now. The success of this invader is facilitated by two features: their ability to resist the dry habitats of California, and their ability to form massive ‘supercolonies’, where multiple nests accept each other as one colony, even those that are far away from each other. Interestingly, both features are made possible from one trait these ants have: the wax on their body surface. This wax allows them to prevent losing water from their body on dry days, but it also allows the ants to all smell similar, so each ant essentially ‘identifies’ as part of the same colony. However, we would expect these two features to conflict with each other, because the same chemicals that are good at preventing water loss should be poor at communicating social information. Consider the analogy of choosing a nice wax for your car: you need it to function in protecting the surface of your vehicle, but it can't look dull and ugly, because you want your car to look nice to other members of your society. Surprisingly, in our research, we did not find an obvious conflict between these two features, possibly because of another factor we had previously overlooked: their body size. A larger body, regardless of the chemical properties of the wax surrounding it, loses water more slowly. So, it seems as though these ants have avoided an expected ‘chemical’ dilemma by simply growing larger than we expected.
What are the potential implications of this finding for your field of research, and is there anything that you learned during this study that you wish you had known sooner?
I believe this was an important result worth publishing because we found results that did not agree with the trends we see in the literature. The functional trade-off between desiccation resistance and colony identity signaling makes theoretical sense and has multiple experimental studies supporting it. However, when we don't find the same result happening in our experiments, I believe it is still important to share these results as evidence of exceptions and/or alternative considerations (as long as the experiments were conducted properly). While we cannot conclude any alternative theories from the unexpected results of our rigorous study, we hope this work serves as a useful citation as we learn more about how the same chemical compound classes of a cuticular wax can simultaneously be involved in seemingly contradictory functions.
Which part of this research project was the most rewarding/challenging?
I must say the most rewarding part of this project was the solidarity my whole lab felt while doing it. I started working on this project when I was a PhD student in Berkeley, and this project required such a massive effort of ant rearing and data collection that everyone in our lab (undergrads, grad students, postdocs and even our P.I.) was in the same place together, working with our hands for many hours. It really helped us get to know each other. The most challenging part, however, was learning new statistics in order to explain our results. Early on, we had a result that agreed with our hypothesis, but turned out to not be statistically valid (as shown to us by a JEB reviewer of our first submission). Throwing every method you have at this problem until you get the result you want is also invalid, so actually learning which methods would work, implementing them properly, and allowing them to reveal a conclusion we didn't expect was indeed difficult. So actually getting a valuable manuscript, with the help of my co-authors and anonymous reviewers, felt very victorious in the end.
Are there any modern-day JEB papers that you think will be the classic papers of 2123? If so, which paper, and how will it pave the way for future research?
I am unsure how famous this paper will be 100 years from now, but there is one recent JEB paper that immediately became a favorite of mine. It was massively influential to this research I just submitted to JEB: Menzel et al.’s 2019 paper ‘Communication versus waterproofing: the physics of insect cuticular hydrocarbons’ (doi:10.1242/jeb.210807). This paper not only did a fantastic job reviewing and summarizing this theoretical trade-off between communication and waterproofing in social insects, but it also provides lots of comparative chemical ecology across ant species, and even includes many chemical/physical tests to describe the properties of cuticular hydrocarbon profiles. It really is impressive and useful for a single paper to synthesize biology, chemistry and physics to answer a very specific evolutionary question.
If you had unlimited funding, what question in your research field would you most like to address?
I want to know how the soldier castes of certain parasitic trematodes can recognize competing colonies occupying their same host. This was a new topic I began studying during my dissertation, and while we know ants can use the wax of their exoskeleton to communicate their social identity, how parasitic trematode larvae also do this is totally unknown. Why this is so interesting to me is because I think social behaviors and social organization in endoparasitic species is rarely described but is likely more prevalent than we realize. And the layers to the interactions in such a system – where a host struggles to identify its parasites, while the parasites struggle to identify conspecific competitors – it sounds like it would be very fun to try to explain.
What's next for you?
I will happily be remaining in the ant world, as I will soon be starting a postdoctoral position at the University of Toulouse in France, studying social recognition, division of labor and dominance hierarchies in a bizarre clonal ant, Platythyrea punctata. Because of their clonal nature, we can create laboratory colonies and control their group sizes without relying on a handful of queens to make sure colonies grow and survive, so we can investigate how their social organization changes with group size.
Brian Whyte’s contact details: Research Center on Animal Cognition (UMR 5169), Center for Integrative Biology, 169 avenue Marianne Grunberg-Manago, CNRS - Université Paul Sabatier - Bât 4R4, 118 route de Narbonne, 31062 Toulouse cedex 09, France.