Julien HARAN, CIRAD-CBGP
Tuesday 16 June 2026, 14:00, Grand meeting room + live on Youtube
The naturalist approach and the biological sciences: recognising, describing and classifying to gain a better understanding of living organisms
What is this species? What is its diet? What is its distribution? These are all questions that may seem basic in the biological sciences, as they form the foundation for all knowledge-building. Yet, despite the availability of a wide range of methodological approaches and the growing demand from both society and the scientific community for a better understanding of biodiversity, the key players and disciplines needed to provide this type of data have never been under such threat. What has happened, and how can we remedy the situation?
In this thesis, I offer a reflection on the role of the naturalist approach – or, more generally, the so-called descriptive sciences – in biology, an issue that forms the central theme of my research. Firstly, I shall discuss the technical developments and research paradigms in biology that have led to the marginalisation of naturalist skills, and their consequences for our collective ability to understand the diversity of life. I shall then present several concrete examples drawn from my own work to illustrate how the observation and description of biodiversity remain a fundamental tool for understanding biological phenomena. Through this process of patiently accumulating observations, the naturalist approach enriches the scope of interpretation by linking each phenomenon to a network of ecological, functional or evolutionary dimensions, thereby revealing both the continuities and the discontinuities in biological processes – which themselves form the basis of the biologist’s intuition.
Throughout my career as a taxonomist and systematist specialising in the Curculionidae family of beetles, the simple observation and description of these systems have provided crucial starting points for rethinking the management of certain pests, for exploring phenomena such as shifts in ecological niche, transitions from antagonism to mutualism in the context of pollination, and even resistance to extreme temperatures in insects. I shall conclude this thesis with a proposal for a practical roadmap to reintegrate the naturalist approach into the biological sciences, notably through the training of students, the appropriate use of molecular tools, and a reassessment of the scientific and social value of these skills.