Alexandre Courtiol

My project focuses on the biology of pair formation in general, and on the evolutionary origins and consequences of this process in particular. Albeit being the focus of many publications coming from a myriad of fields, some of the most fundamental questions around pair formation remain unanswered and surprisingly unexplored.

First, little is known about how mating preferences (which dictate how individuals are attracted by potential mates or different traits) translate into real pair formation. In addition to preferences, partners’ availability, sampling strategies, intra-sex competition, coercion, environmental influence on mate assessment, or preferences exerted by the other sex, can also have a major influence on how mates pair together according to their characteristics (i.e. the mating pattern). Thus, the relationship between mating preferences and mating pattern appears not as straightforward as is usually assumed. This gap in our understanding is problematic because most evolutionary models implicitly assume a direct correspondence between mating preferences and pairings to investigate the origins of mating preferences that drive pair formation. During my stay at the Wiko, I am therefore working on the development of a new general theoretical framework that allows studying the evolution of mating preferences while explicitly considering a realistic pair formation process. Unsurprisingly, most of the predictions raised by this novel approach cast important doubts on major findings from previous analyses.

Second, pair formation is known to influence evolution of a myriad of traits in many organisms. It has a great explanatory power to understand many differences between sexes, from body size to mating preferences. The large body of evidence coming from the animal literature has led many to speculate about a similar influence of pair formation on human evolution. Using large datasets from two populations (Finland and Gambia), I am firmly assessing the effective scope that pair formation can have on the evolution of our species. In particular, I am looking at how the effect of pair formation has changed from pre-industrial period to very recent times.

Overall, by presenting an enormous variation between societies, humans capture many similarities shared by a wide range of organisms while also possessing their own specificities, such as the occurrence of demographic transitions. It is therefore not surprising that my project emphasises the benefits from travelling back and forth between the knowledge about the biology of animals and the knowledge on humans coming from a variety of fields. My collaborations involve other biologists, but also anthropologists, demographers, psychologists, and medical scientists. This Junior EURIAS fellowship at the Wiko provides me with a unique opportunity to consolidate these interactions with scientists from other fields.