Denis Duboule

Chaire Évolution du développement et des génomes

Collège de France

Année 2025-2026

Nos ancêtres les poissons

Conférence - Neil Shubin : How Do New Biological Inventions Arise in Evolution? Lessons from Fossils, Embryos, and Genes

Neil Shubin

Université de Chicago, Président élu de l'Académie nationale des sciences (NAS), États-Unis

Résumé

When we look at the history of life at a grand scale, from the earliest single celled organism to complex animals alive today, we see a past filled with great revolutions. Major transformations pervade this history, involving new features, new developmental processes, new ways of living, and new ecological interactions. In our own lineage, over the past 500 million years some fish evolved to live on land, reptiles evolved to fly, and primates evolved the ability to talk, walk, and think. For each of these major transitions we recognize features that allowed them to happen. The standard view is that these innovations were enablers for a major revolution: for example, feathers arose for flight, lungs, for life on land, etc. But this view couldn't be farther from the truth. Lungs evolved in fish well before they ever took steps on land, feathers arose in dinosaurs before they could fly, and so on. The features that play a role in great evolutionary changes arise by repurposing existing features for new functions. This view of evolutionary tinkering, first pioneered by François Jacob in the 1970's, carries profound implications for modern molecular and paleontological evolutionary biology.