The Mistery of The Beginning of Life
To investigate the beginnings of life on Earth, researchers at Newcastle University are looking to ancient hot springs.
The study team looked into how life began on Earth more than 3.5 billion years ago when inert geological components gave rise to the earliest living entities. Researchers at Newcastle University have discovered that combining hydrogen, bicarbonate, and iron-rich magnetite in an environment that resembles a moderate hydrothermal vent produces a variety of organic compounds, the most notable of which are fatty acids with lengths of up to 18 carbon atoms.
Their research, which was published in the journal Communications Earth & Environment, may help us understand how some important molecules required to generate life are derived from inorganic compounds. This is a crucial phase in the process of how life first appeared on Earth billions of years ago.
Their findings could offer a believable explanation for the origin of the organic molecules that make up old cell membranes, which were possibly picked at random by early biochemical processes on the primordial Earth.
Fatty Acid Role on Early Phases of Life
In the early phases of life, fatty acids
It is possible that the earliest cell membranes were formed of fatty acids, which are long, organic molecules with sections that both attract and repel water. As a result, these molecules spontaneously form cell-like compartments in water. However, in the early stages of life, the origin of these fatty acids remained unknown, despite their significance.
One possibility is that they originated in the hydrothermal vents, which are places where hot water and hydrogen-rich fluids from underwater vents combine with CO2-containing saltwater.
In their lab, the team simulated key elements of the chemical milieu present in the oceans of the early Earth as well as the mixing of hot, alkaline water surrounding specific kinds of hydrothermal vents. They discovered that the kinds of molecules required to build primitive cell membranes were produced when hot, hydrogen-rich fluids were combined with carbon dioxide-rich water in the presence of iron-based minerals that were present on the early Earth.
Dr. Graham Purvis, the study’s lead author, is a postdoctoral research associate at Durham University and carried out the research at Newcastle University.
“Cellular compartments are essential for isolating internal chemistry from the external environment and are central to the genesis of life,” he stated. By concentrating molecules and aiding in the generation of energy, these compartments played a crucial role in promoting life-sustaining reactions and may have even been the foundation of life’s initial stages.”
“The results suggest that the convergence of hydrogen-rich fluids from alkaline hydrothermal vents with bicarbonate-rich waters on iron-based minerals could have precipitated the rudimentary membranes of early cells at the very beginning of life.”
A variety of membrane types may have been produced by this process, some of which may have functioned as the cradle of life at the beginning of time. Furthermore, certain acids that are present in the elemental composition of meteorites may have originated as a result of this transformation process.”
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The Future of This Research
Dr. Jon Telling, the primary investigator and a biogeochemistry reader at the School of Natural Environmental Sciences, continued, “We believe this research could offer a first step toward understanding the origins of life on Earth. The second crucial step is still being researched in our lab: how these organic molecules, which are first “stuck” to the mineral surfaces, can lift off to form spherical membrane-bounded cell-like compartments; the first possible “protocells” that eventually went on to form the first cellular life.”
Interestingly, the researchers also propose that comparable reactions that produce membranes might still be occurring in the oceans beneath the ice moons in our solar system now. This suggests that these far-off worlds may have different life origins.
Source : Graham Purvis et al, Generation of long-chain fatty acids by hydrogen-driven bicarbonate reduction in ancient alkaline hydrothermal vents, Communications Earth & Environment (2024). DOI: 10.1038/s43247-023-01196-4