Eastern Himalaya Lecture Series

On April 4, the 114th session of the Eastern Himalaya Lecture Series was successfully held in Room 507, Teaching Building 3, Ancient City Campus, Dali University. The lecture featured Associate Professor Simon Hohl from the State Key Laboratory of Marine Geology, Tongji University, who delivered a talk entitled “From fossilized microbial ecosystems to modern analogues: 3.5 billion years of biogeochemical nutrient cycling on Earth.”

Life on Earth began in shallow oceans about 3.5 billion years ago, and some of its earliest fossil evidence is preserved in layered microbial rocks known as stromatolites. These remarkable “living rocks,” which have existed throughout much of Earth’s history, are not only visually striking but also provide crucial evidence for understanding the long-term evolution of the biosphere, atmosphere, and hydrosphere. In his lecture, Prof. Hohl introduced the audience to these ancient microbial ecosystems and explained how they can help reveal the processes that shaped Earth’s earliest environments.

Drawing on years of research, Prof. Hohl discussed how ancient microorganisms relied on essential nutrient metals such as iron, nickel, molybdenum, zinc, and cadmium to sustain core metabolic functions. He showed how this ancient microbial “metallome” is directly connected to modern studies of how microorganisms cycle critical metals through time and across environments. His presentation highlighted the importance of integrating fossil evidence with modern ecological and geochemical research in order to better understand the deep history of life on Earth.

Prof. Hohl’s research focuses on some of Earth’s most iconic fossil ecosystems, especially the 3.5-billion-year-old stromatolites of Western Australia, where microbial mats first began influencing the biogeochemical cycling of critical metals. To better understand how such processes operated in deep time, he also studies modern alkaline lake systems in Inner Mongolia, which serve as living analogues of environments where early life may have thrived. More recently, his team has begun exploring how fungal–microbe interactions may have influenced the cycling of critical metals throughout Earth’s history. By combining fossil records with modern fungal–microbial systems, they aim to build a new framework for understanding the co-evolution of the geosphere and the fungal–prokaryotic biosphere.

During the discussion session, students and faculty engaged enthusiastically with Prof. Hohl. Students raised questions related to their own research interests, including the effects of fire on soil microorganisms, environmental factors, and ash dynamics. Faculty members also exchanged ideas with the speaker on broader themes in Earth system science, microbial ecology, and environmental change. The discussion was lively, constructive, and academically stimulating.

This lecture broadened the academic horizons of teachers and students at Dali University and further promoted interdisciplinary exchange across Earth science, ecology, environmental science, and biogeochemistry. It also provided valuable inspiration for future research on the links between ancient life, modern analogues, and the long-term evolution of Earth’s surface systems.