A recent study supported in part by the NASA Exobiology Program provides further details about lipid biomarkers in stromatolites. The research focuses on microbial mat communities in ponds at Guerrero Negro, Baja California Sur, Mexico.

Microbial mats play an important role in forming geological features known as stromatolites. These are rocky mounds built up over time as mats trap and interact with sediment. Stromatolites can be found in environments like Guerrero Negro today, but these structures also appear in the geologic record of the Earth. In fact, ancient stromatolite structures could be the oldest physical evidence of life on Earth yet known, and provide important clues about the early environment of our planet and the evolution of life as we know it.

Identifying ancient stromatolites is difficult however, because the composition of ancient microbial mats and the affects they had on sediment is unknown. In addition, these structures are incredibly old and have been altered over time by numerous geological and chemical processes. Studying the role of modern-day microbial mats in the formation of stromatolite structures can help researchers interpret potential evidence of similar structures in the geologic record of Earth.