Jochen Brocks

Jochen Brocks is an Australian organic geochemist and geologist at the Australian National University, known for his pioneering research on Precambrian molecular fossils, or biomarkers, to study the early diversification of eukaryotes. His work has pushed back the evidence for complex life forms in the geological record. He uses techniques to extract and identify ancient lipid molecules from sedimentary rocks.

Biomarkers are preserved molecular remnants of ancient organisms, such as steranes derived from eukaryotic membrane sterols, that can survive in rocks for billions of years. Jochen Brocks analyzes these compounds in Precambrian rocks to infer when different groups of life arose. The technique complements traditional fossil evidence.

Jochen Brocks is a professor at the Australian National University in Canberra, where he is affiliated with the Research School of Earth Sciences. His fieldwork has included expeditions to ancient rock formations in Australia, including the Pilbara and other Archean terrains. He collaborates internationally on early Earth research.

Some of Brocks's early reports of 2.7-billion-year-old sterane biomarkers were challenged by other researchers who argued the molecules could be later contamination. Brocks and collaborators subsequently developed more rigorous techniques to verify that the biomarkers are indigenous to the host rocks. This debate continues to refine the methodology of molecular paleontology.