Life's Gooey Beginnings: A New Theory of Origin

A new theory proposes that life may have first emerged within semi-solid gel matrices clinging to rocks, rather than solely in water. This concept suggests that life originated in a sticky goo-like substance, similar to modern bacterial biofilms, both on Earth and potentially on other planets.

Most existing origin-of-life theories place early organic chemistry in water. However, these theories face challenges in explaining how simple molecules could have transformed into complex structures like RNA or DNA without additional support.

The gel-like environment offers solutions to several of these issues.

The Protective Power of Prebiotic Gels

According to Hiroshima University astrobiologist Tony Jia and his team, a gel medium could have trapped and organized molecules into stable formations, overcoming key barriers in pre-life chemistry. Early Earth's conditions, including intense ultraviolet radiation and extreme temperatures, would have made a protective environment beneficial for fragile chemical processes. Prebiotic gels could have offered this protection before membrane-bound cells developed.

Protocells: An Outcome, Not a Beginning

This framework, first proposed in 2005, posits that protocells were an outcome of chemical organization within primordial goo, not the initial step in life's origin. The researchers state that:

Such gels allowed primitive chemical systems to achieve molecular concentration, selective retention, reaction efficiency, and environmental buffering.

Chemistry within the Goo: Metabolism and Polymerization

Within these early gels, a primitive metabolism could have begun through electron exchange, with UV, visible, and infrared light providing energy for reactions. Gels are capable of concentrating monomers, such as activated nucleotides and amino acids, and selectively interact with certain chemicals.

Crucially, the moist, not-quite-wet environment within a gel matrix favors reactions that link monomers to form polymers, rather than hydrolysis reactions which break chemicals down.

Broadening the Search for Extraterrestrial Life

This theory broadens the search parameters for life beyond Earth.

It suggests that structures like gels, rather than specific chemicals, could be targets in future missions.

The research was published in ChemSystemsChem.