Évolution du développement et des génomes - Denis Duboule

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

  Denis DubouleChaire Évolution du développement et des génomesCollège de FranceAnnée 2025-2026Nos ancêtres les poissonsConférence - Neil Shubin : How Do New Biological Inventions Arise in Evolution? Lessons from Fossils, Embryos, and GenesNeil ShubinUniversité de Chicago, Président élu de l'Académie nationale des sciences (NAS), États-UnisRésuméWhen 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.

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• Conférence - Neil Shubin : The Evolutionary Origins of Bones and Teeth

  Denis DubouleChaire Évolution du développement et des génomesCollège de FranceAnnée 2025-2026Nos ancêtres les poissonsConférence - Neil Shubin : The Evolutionary Origins of Bones and TeethNeil ShubinUniversité de Chicago, Président élu de l'Académie nationale des sciences (NAS), États-UnisRésuméTeeth and bones are fundamental features of vertebrate organisms. The earliest vertebrates date from fossils that are over 500 million years old and existed at the time of the Cambrian Explosion, a great burst of innovation in the evolutionary history. The first creatures with tissues similar to our teeth and bones aren't seen until tens of millions of years later. Some of these reports have been controversial because challenges imaging the fossils and comparing the tissues between fossil and living forms. New imaging technologies have transformed our ability to study this issue. Studies from multiple laboratories have revealed that tissues equivalent to our teeth and bones originally evolved outside the body—in the bony exoskeletons of our jawless fish ancestors. Inside this exoskeletal armor are small structures that are distinctly toothlike. Detailed comparisons of these features among living and fossil vertebrates and invertebrates reveal that the earliest teeth likely had a sensory function in the external tissues of these fish. Assessing diverse fossil fish reveals that many distinct features of our bones and teeth, such as the capacity to remodel, originally came about in jawless fish.

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• Conférence - Neil Shubin : Discovering How Fish Evolved to Walk

  Denis DubouleChaire Évolution du développement et des génomesCollège de FranceAnnée 2025-2026Nos ancêtres les poissonsConférence - Neil Shubin : Discovering How Fish Evolved to WalkNeil ShubinUniversité de Chicago, Président élu de l'Académie nationale des sciences (NAS), États-UnisRésuméThe ability to walk is fundamental to human lives. Like all our biological features walking has a complex and deep history. It is most commonly thought that walking arose as fish made the evolutionary transition to land, shifting from an aquatic environment to a terrestrial one. In this view, the transition out of water meant that animals now had to evolve new mechanisms to deal with gravitational loads. As a consequence, they developed more mobile joints, arm and leg bones with robust connections for expanded locomotory muscles, and other structures to allow them to move about. Surprising, this very intuitive view is not supported either by comparative anatomy or the fossil record. The closest fish relatives to terrestrial vertebrates were capable of walking with four appendages, a fact seen in the structure of the bones and joints in their fins. Moreover, walking either on four appendages or two is commonly seen in aquatic fish ranging from sharks, lobe fin fishes, and diverse ray finned fishes. Indeed, many of these fish use alternating gaits and appendage motions in aquatic settings that are similar to terrestrial tetrapods. This observation leaves open the question of why fish walk in water instead of swimming. To answer these questions scientists have developed underwater treadmills, experiments training fish to walk, and robots that simulate walking behaviors. One major factor in the origin of fish walking, hence our own, is energetics: at slow speeds, and in certain environmental conditions is it energetically more efficient to walk than swim.

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• Conférence - Neil Shubin : Nos ancêtres les poissons : Finding The History We Share With Fish

  Denis DubouleChaire Évolution du développement et des génomesCollège de FranceAnnée 2025-2026Conférence - Neil Shubin : Nos ancêtres les poissons : Finding The History We Share With FishNeil Shubin est invité par l'assemblée du Collège de France sur proposition du Pr Denis Duboule.PrésentationIl y a 380 millions d'années, nos ancêtres les poissons développaient des structures permettant la colonisation du milieu terrestre. Comment pouvons-nous, aujourd'hui, tenter de reconstituer cette transition évolutive extraordinaire afin d'essayer de comprendre comment cela a pu se passer ?This lecture will explore the deep history of our bodies, one that extends billions of years. As we uncover new fossils, understand the patterns and mechanisms that form diverse animal bodies, and compare the anatomy of organ systems of creatures alive today, we find that every structure in our bodies contains artifacts of our branch of the tree of life. Our limbs are based on the pattern of bones first seen in ancient fish as is the patterns of nerves, muscles, and organs in our circulatory, excretory, and nervous systems. The profound connections we share with the rest of life of our planet also inform biomedical studies. Analyses of fish play important roles in understanding and treating diverse human diseases.Neil ShubinUniversité de Chicago, Président élu de l'Académie nationale des sciences (NAS), États-Unis.Le Pr Neil Shubin est une figure dans le domaine de la paléontologie moderne, en particulier en ce qui concerne l'acquisition des caractères des animaux vertébrés au moment de leur transition d'un milieu aquatique vers un milieu terrestre. Une de ses découvertes majeures est celle de Tiktaalik, un fossile de la période du dévonien (un poisson sarcoptérygien) trouvé lors de fouilles qu'il effectue au Groenland et publié en 2006. Ce fossile, en effet, est une sorte de chaînon manquant entre les tétrapodes et nos ancêtres les poissons, un fossile qui eut un retentissement planétaire lors de sa publication.En plus de ses qualités de chercheur de terrain, Neil Shubin est un communicateur de science hors pair et reconnu. Ses livres (entre autres, The Inner Fish traduit en français chez Laffont : Au commencement était le poisson) lui ont valu une reconnaissance publique et médiatique rare dans ce domaine, pour laquelle il a reçu de nombreuses distinctions, couronnée par son élection récente à la présidence de la prestigieuse Académie nationale des sciences des États-Unis. Son nouveau livre Ends of the Earth vient de paraître (février 2025).

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• Colloque - Enhancers Sequences and Gene Regulation : Decoding Transcriptional Regulation

  Denis DubouleCollège de FranceÉvolution du développement et des génomesAnnée 2024-2025Colloque : Enhancers Sequences and Gene RegulationAlex Stark : Decoding Transcriptional RegulationIntervenant(s)Alex Stark, IMP, Vienna BioCenter, Vienna, Austria

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