Explores the �biomarker concept� as a tool to elucidate microbial, biogeochemical, and climatic processes in natural systems through three fundamental goals: a) characterization and classification of organic molecules in complex, natural mixtures; b) biosynthesis, transport, transformation, preservation and destruction of organic matter in nature; c) application of lipid biomarkers and their stable isotope composition to study biological, biogeochemical, and climatic processes in modern and ancient systems. Recommended prerequisites: CHEM 1113 or equivalent from undergraduate degree and GEOL 5270 or GEOL 5280 or GEOL 5305 or GEOL 5675. Same as GEOL 4611.