Today, we can easily say that life began with microorganisms. But what existed before these first microorganisms?
Iron sulfide, abundant in ancient hydrothermal vents, may have played a crucial role in the emergence of life on Earth. New research from the Chinese Academy of Sciences suggests that these minerals facilitated the formation of essential molecules for life.
According to the researchers, iron sulfide in prehistoric hot springs could have catalyzed the formation of organic compounds. These sulfides, such as mackinawite, have long intrigued scientists due to their ability to mimic modern metabolic enzymes.
Iron sulfide may have helped form the basic molecules necessary for life.
The catalytic role is vital in the carbon formation process, which refers to the conversion of carbon dioxide into organic molecules.
Unlike previous studies focusing on deep-sea hydrothermal vents, this new research explores terrestrial hot springs as potential cradles of life due to their mineral diversity, access to sunlight, and water vapor.
In their experiments, the research team synthesized nano-sized iron sulfide, including pure forms mixed with elements like manganese, nickel, titanium, and cobalt.
They exposed these samples to hydrogen and carbon dioxide under conditions simulating hot springs at temperatures between 80 to 120 degrees Celsius.
The results of the experiments were remarkable. Manganese-doped iron sulfide emerged as the most effective catalyst in the group, producing methanol without the use of enzymes. Interestingly, sunlight also appeared to play a crucial role, especially in the creation of life millions of years ago.
The researchers noted that visible ultraviolet light enhanced the chemical reactions. This suggests that sunlit hot springs on early Earth may have amplified this process.
Water vapor further promoted catalytic activity. These factors indicate that a water-rich environment is ideal for prebiotic synthesis—compounds that support the growth of beneficial microorganisms.
The research discovered that the aforementioned reactions could occur via the reverse water-gas shift (RWGS) pathway. In this process, carbon dioxide is reduced to carbon monoxide and then converted into methanol. This likely supported the emergence of life on Earth.
Even more interestingly, modern computational techniques show that mixing iron sulfide with manganese improves efficiency and enhances the mimicry of enzyme behavior.
Terrestrial hot springs, with their rich chemical composition and favorable environmental conditions, could be optimal settings for the origin of life.
