Y a-t-il de la vie partout à la surface de la Terre ? Le cas de Dallol - Les limites de l'habitabilité

Discover in this webinar from David Moreira, Research Director at the Laboratory of Ecology, Systematics and Evolution (CNRS - Paris-Saclay University), how microbial life adapts to extreme conditions and why the Dallol site in Ethiopia's Danakil Depression represents a unique case study. Learn about polyextremophiles - organisms adapted to multiple extreme conditions like high temperatures, acidic or basic pH, and high salinity - and explore why the hyperacidic and hypersaline pools of Dallol are exceptionally devoid of microbial life, making them rare sterile aquatic ecosystems on Earth's surface. Examine the rich microbial diversity, primarily archaea, found in less extreme systems around Dallol, and understand how this site demonstrates that the presence of water doesn't automatically indicate life. Investigate the chemical and geological processes occurring without biological influence, including the formation of diverse abiotic biomorphs, while considering the implications for exobiology, habitability conditions, and the challenges of identifying true biosignatures versus contamination in sample analysis.