Primitive droplets stabilized by rain? This could be the key to the emergence of life. New studies explore this surprising hypothesis.
The formation of modern cells, veritable microscopic factories, relies on sophisticated membranes. But the primordial structures, called protocells, were much simpler and more vulnerable.
Scientists believe that the early Earth saw the emergence of rudimentary life forms: vesicles and coacervates. The vesicles, small lipid bubbles, provided protection for vital molecules, but lacked proteins to regulate exchanges.
Coacervates are droplets without a membrane, facilitating chemical reactions but exposed to a chaotic environment. Their open nature posed a risk of dispersion of essential molecules.
The scientific problem consisted of understanding how these primitive structures were able to maintain their integrity long enough to initiate evolutionary processes. A new hypothesis highlights a actor unexpected: the water rain.
Placed in deionized water, the coacervates expel ions, forming a thin “skin” on their surface. This mesh stabilizes the droplet, preventing its fusion with others and allowing molecules such as RNA to be preserved.
The researchers suggest that this stabilization would have allowed the first cells to concentrate their genetic material. In pure water experiments, the coacervates maintained their RNA for several days, while in ionized water it dispersed within seconds.
This hypothesis could guide research into life elsewhere: similar environments could promote the stability of primitive cells, even outside Earth.
What is a coacervate and its role in the origin of life?
A coacervate is a droplet formed by the assembly of organic molecules, such as nucleic acids and peptides, without a protective membrane. This structure allows easy exchange of materialspromoting chemical reactions necessary for primitive life.
Coacervates are considered potential candidates for early life forms because they can concentrate essential molecules while creating an environment conducive to the emergence of metabolic processes and the replication of molecules, such as RNA.
