Unlocking the Origins of Life: Scientists Recreate Ancient Chemical Reactions That Could Have Launched Existence

Life on Earth likely started in warm, underwater “chemical gardens” filled with hydrogen and iron. Recent research from Germany has shown that ancient life forms currently found in the deep sea can thrive in conditions similar to those early environments.

Understanding how life began on our planet is challenging. Today, ecosystems are interconnected, and most organisms do not rely solely on raw materials from Earth. In the very beginning, however, life had to make do with what was available in a planet devoid of oxygen and photosynthesis. Many deep-sea organisms live at hydrothermal vents, thriving in these dark, nutrient-rich environments.

These deep-sea microbes, such as those following the acetyl CoA pathway, extract energy from hydrogen found in volcanic gas. This method of carbon fixation can happen without enzymes, making it unique. A team of geochemists led by Vanessa Helmbrecht at Ludwig Maximilian University of Munich sought to explore how dissolved iron in ancient oceans affected early life.

According to the study, ancient hydrothermal deposits date back over 3 billion years and may hold signs of the earliest life forms. However, connections between these chemical environments and early life are not well understood.

To investigate, the researchers used a single-celled microbe called Methanocaldococcus jannaschii, which was first discovered in a hydrothermal vent near Mexico. This microbe taps into carbon dioxide and hydrogen for energy, resembling the likely processes of ancient life.

The experiments recreated deep-sea conditions in a glass vial, demonstrating how black precipitates formed quickly when injecting sulfidic fluid into oxygen-free water. This reaction mimicked the extreme environments where early life might have first evolved.

The findings were surprising: M. jannaschii not only survived but thrived without any added nutrients. The organisms grew rapidly, suggesting that the conditions were suitable for life, much like some of the earliest fossil traces found on Earth.

These results support the idea that mackinawite and greigite, two iron-sulfide minerals, could have acted as “hatcheries” for the first life forms. They may have been places where early metabolizing cells could evolve continuously in these harsh environments. This research reveals deeper insights into how life emerged on our planet, highlighting the importance of studying ancient chemical gardens.

The study is published in Nature Ecology & Evolution.

Source link

MSFT Content