Scientists have successfully simulated the formation of fatty acids, a crucial element in the creation of the Earth’s earliest cells. This breakthrough not only provides valuable insights into the initial stages of life on our planet but also sheds light on the potential origins of life on other moons and planets.
Over 3.5 billion years ago, life emerged from non-living geological materials, with the exact location of this emergence still under debate. Many scientists posit that the earliest life forms might have appeared around deep-sea hydrothermal vents, resembling rocky chimneys on the ocean floor that release superheated fluid from beneath the Earth’s crust.
Jon Telling, a biogeochemistry expert at Newcastle University, highlights the unique attributes of alkaline hydrothermal vents, emphasizing their role in synthesizing organic molecules through energy-rich chemical gradients. These vents contain metals like iron and nickel, found in ancient proteins present in microorganisms today. Additionally, they align with reconstructions of the ‘Last Universal Common Ancestor,’ suggesting a thermophilic organism using hydrogen gas for energy and harnessing proton gradients for biochemical reactions.
For life to originate at these vents, various key ingredients needed to converge. Scientists focused on molecules involved in storing and transferring biological information, catalyzing cellular reactions, and forming cell membranes, with fatty acids taking center stage in the latter category.
Fatty acids, as long organic molecules with water-attracting and water-repelling regions, spontaneously organize into cell-like compartments when placed in a watery environment. These molecules would have formed the first cell membranes, protecting the inner workings of the cell from the external environment.
Research led by Graham Purvis from Durham University, as detailed in a paper published in Communications Earth and Environment, reveals that fatty acids, among other organic molecules, can be formed on iron-mineral surfaces in hydrothermal vent conditions. The study demonstrates that changes in fluid mixing can cause these molecules to become negatively charged, leading to an ‘electrostatic explosion’ where they lift off the mineral surface and spontaneously form membrane-bound spheres.
This discovery opens the door to further experiments aimed at proving that these fatty acids can lift off and form membrane-bound spheres, a crucial step towards protocell formation. Moreover, similar conditions on other planets and moons, such as Europa and Enceladus, suggest that this research may inform the search for similar chemistry and the origins of life beyond Earth in our solar system.
