Geobiology Research Option
Mojave Desert, near Joshua Tree N.P. This is one of the field sites where we have studied the potential for hydrogen isotopes in plant leaf waxes to record aridity.
How exactly do single-celled organisms interact with their environment, and what evidence of these activities do they leave in the geologic record? Geobiologists approach such questions both from the standpoint of experimental biochemistry, and from observational geochemistry. What specific molecules allow bacteria to breathe arsenate, or respire methane? What biomarker or isotopic signals do they leave behind that might identify them? What exactly do these molecular fossils tell us about how ancient organisms lived?