The International Geobiology Course is an intense, multidisciplinary summer course that explores the co-evolution of the Earth and it’s biosphere, with an emphasis on how microbial processes affect the environment and leave imprints in the rock record. Participants get a hands-on learning experience in cutting-edge geobiological techniques including molecular biology, microbiology, geochemistry, and sedimentology and work in research groups to solve real research questions. Themes for this years’ course include: (1) Molecular biology and biogeochemistry of Mono Lake and its sediments;(2) Viruses and microbial biosignatures in hot springs;(3) Sedimentology and ecology of fossil seep environments. The course is directed by Alex Sessions, Woody Fischer, and Victoria Orphan, and will remain in a format similar to previous years. It begins with a field trip up the eastern Sierra Nevada to visit hot springs, Pleistocene sediments, and Mono Lake, across to the central valley to work on ancient seep outcrops. Two weeks of lab rotations at Caltech will introduce students to cutting-edge analytical techniques, such as metagenomics, FISH-SIMS, biomarkers, X-ray spectroscopy, and stable isotopes. We finish with 10 days at the Wrigley Marine Science Center on Catalina Island where students pursue research projects based on data collected by the course. The 2020 course is open to graduate students and postdocs at any level. For postdocs, preference will be given to those who earned PhD’s in other fields, and are seeking to enter the field of geobiology. The cost of the course is US$4000 which includes food and lodging; financial aid is available for those with demonstrated need. Applications due February 3, 2020.