Tanja Bosak

Professor of Geobiology

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Experimental geobiologist exploring modern processes in microbial systems to interpret the record of life on early Earth and other planets.

Research Interests

I’m an experimental geobiologist studying the evolution of microbial life, and how those microbes influence—and are influenced by—their environment. As microbial populations grow, they interact with the planet’s surface, leaving behind chemical, mineral, and morphological evidence in their wake. By examining modern processes and conditions that are similar to what was typical on the early Earth, we can learn to identify these clues embedded in the rock record and begin to understand how the biosphere evolved—and even learn how to look for signs of past life and prebiotic processes on planets beyond. In my lab, we combine molecular biology, biogeochemistry, and sedimentology to explore the role of microbes in co-evolving systems.

Topics I investigate:

  • Microbial stable isotope fractionation
  • Microbial mats and stromatolite formation
  • Anoxygenic and oxygenic photosynthesis
  • Great Oxygenation Event and conditions of early Earth
  • Preparation and analysis of samples taken from the Jezero Crater as part of the Returned Sample Science team of the NASA Mars 2020 Perseverance rover mission.

Biographic Sketch

Tanja Bosak joined the EAPS faculty in 2007. After earning a BSc in geophysics from the University of Zagreb, Bosak completed a summer of research at the NASA Jet Propulsion Laboratory and went on to complete her PhD studies in Geobiology at the California Institute of Technology in 2005. Prior to coming to MIT, Bosak was a Microbial Sciences Initiative Fellow at Harvard University. Bosak has served as a past EAPS chair in the Program in Geology, Geobiology and Geochemistry, and has been recognized by MIT for her scientific contributions and leadership with the Harold E. Edgerton Faculty Achievement Award (2011) and with a School of Science Fundamental Science Investigator Award (2022). In 2011, Bosak was elected a fellow of the American Geophysical Union and awarded the organization’s James B. Macelwane Medal. She has also been named a Simons Collaboration on the Origins of Life Investigator (2014) and earned recognition from the Geological Society of America with the Subaru Outstanding Woman in Science Award (2007) and a GSA Geobiology and Geomicrobiology Division Award for Outstanding Research (2016). Bosak is currently the Returned Sample Science Co-Lead for the NASA Mars 2020 Perseverance rover mission.

Key Awards & Honors

  • 2021 • Fellow, American Academy of Microbiology
  • 2011 • James B. Macelwane Medal, American Geophysical Union
  • 2011 • Fellow, American Geophysical Union
  • 2011 • MIT Harold E. Edgerton Faculty Achievement Award
  • 2007 • Subaru Outstanding Woman in Science Award, Geological Society of America

Key Publications

  • Bosak, T., Moore, K.R., Gong, J. et al. Searching for biosignatures in sedimentary rocks from early Earth and Mars. Nat Rev Earth Environ 2, 490–506 (2021). DOI: 10.1038/s43017-021-00169-5

  • Daye, M., Klepac-Ceraj, V., Pajusalu, M. et al. Light-driven anaerobic microbial oxidation of manganese. Nature 576, 311–314 (2019). DOI: 10.1038/s41586-019-1804-0

  • Moore, Kelsey & Gong, Jian & Pajusalu, Mihkel & Skoog, Emilie & Xu, Megan & Soto, Tania & Sojo, Victor & Matreux, Thomas & Baldes, Matthew & Braun, Dieter & Williford, Kenneth & Bosak, Tanja. (2021). A new model for silicification of cyanobacteria in Proterozoic tidal flats. Geobiology. 19. 10.1111/gbi.12447. DOI: 10.1111/gbi.12447