Professor Jennifer (Jenn) Macalady is an Associate Professor and Geomicrobiologist in the Department of Geosciences at the Pennsylvania State University, where she studies microbial life in Precambrian-analog environments. She earned her undergraduate degree in Geology from Carleton College in 1991, and her Ph.D. in Soil Microbiology with Kate Scow at University of California Davis in 2000. She pursued postdoctoral research at the University of California Berkeley under the mentorship of Jillian Banfield, and briefly returned to Carleton College as a Visiting Assistant Professor in 2002. She accepted a permanent position at Penn State in 2004, where she serves as Director of the Center for Environmental Geochemistry and Genomics, Faculty-in-charge of the Graduate Program in Biogeochemistry, and Member of the Penn State Astrobiology Research Center. Her research is focused on the microbial ecology of sulfur-rich, oxygen-poor ecosystems. She can often be found underground in the deep and sulfidic Frasassi cave system, Italy, or with cave divers exploring inland blue holes and stratified aquifers in the Caribbean. Her group aims to discover ecological rules and genomic constraints governing how microbial populations distribute themselves into environmental niches, with an eye toward how geochemistry influences biosignatures preserved in Earth’s geologic record and potentially on other planets.