Scientists reveal potential role of iron sulfides in life origin

A group of scientists led by Chinese researchers have uncovered the significance of iron sulfides in supporting the life origin hypothesis in early Earth's terrestrial hot springs, according to an article published in the academic journal Nature Communications on Thursday.

According to the life origin hypothesis of the early Earth, hydrothermal systems, including deep-sea hydrothermal water and terrestrial hot springs, are generally considered two possible environments for life.

Iron sulfides, abundant in the early Earth's hydrothermal systems, may have functioned similarly to cofactors in modern metabolic systems, which can help transform carbon dioxide into organic compounds, potentially facilitating essential prebiotic chemical reactions, according to Nan Jingbo, associate professor from Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences.

Previous studies on iron sulfides and the origin of life have focused primarily on deep-sea alkaline hydrothermal vents. However, some scientists have proposed terrestrial hot springs as another plausible setting for life's origins, as they contain rich mineral content, diverse chemicals, and abundant sunlight.

To explore iron sulfides' role in terrestrial prebiotic carbon fixation, the research team conducted simulated experiments and created an environment similar to the early terrestrial hot spring, including temperatures of 80 to 120 degrees Celsius, enhanced ultraviolet light irradiation, and rich carbon dioxide, hydrogen and iron sulfides.

The results showed that iron sulfides act as a catalyst to promote the transformation of carbon dioxide into methanol. Methanol may further catalyze the formation of the methyl group, which is necessary for the oldest metabolic pathway, thus, laying the foundation for the origin of life.

"This research highlights the potential of iron sulfides in catalyzing prebiotic carbon fixation in early Earth's terrestrial hot springs, opening new directions for exploring life's origins and supporting future efforts in the search for extraterrestrial life," Nan said.

(Cover: Illustration of early Earth. /CFP)