Long before the first cell divided, before DNA carried genetic instructions, and before membranes enclosed the chemistry of life, Earth may have been coated in something far humbler: slime.
Not the kind that oozes from a cartoon beaker, but thin, sticky gel-like films clinging to rocks, mineral surfaces, and tidal flats—soft, hydrated matrices capable of trapping molecules and coaxing them into ever more complex interactions.
According to a new theoretical framework proposed by an international team of researchers, life may not have begun in isolated “primordial soup” droplets at all, but inside surface-bound gels that functioned more like modern microbial biofilms than free-floating chemistry.
In a recent study published in ChemSystemsChem, scientists describe what they call a “prebiotic gel-first” model for the origin of life. Drawing on insights from soft-matter chemistry and modern microbial systems, researchers argue that gel-like matrices could have provided the missing environmental scaffolding that early chemical systems needed to transition from chaotic reactions to organized, evolving networks.
If correct, the framework doesn’t just reshape how we imagine life beginning on Earth—it could also change how we search for life elsewhere in the cosmos.
“We outline the ‘prebiotic gel-first’ framework, which considers how the origin of life (OoL) could have potentially emerged within surface-attached gel matrices,” researchers write.
For decades, origin-of-life research has often focused on the idea of a “primordial soup”—a watery mixture of organic molecules energized by lightning, ultraviolet radiation, or hydrothermal activity. While laboratory experiments have shown that amino acids and other building blocks can form under plausible early-Earth conditions, a central challenge has persisted: dilution.
In unconfined bulk water, potentially useful molecules drift apart, reactions compete with diffusion, and energy gradients dissipate quickly. Many researchers argue that for chemistry to cross the threshold into biology, it likely requires some form of spatial organization—mechanisms to concentrate molecules, retain them long enough to react, and buffer environmental fluctuations.
The new framework proposes that prebiotic gels could have filled that role.
Rather than imagining life’s precursors floating freely, the researchers point to surface-attached gels—hydrated, polymer-rich matrices that resemble the extracellular material produced by modern microbes in biofilms.
These structures are neither solid nor liquid, but something in between: soft matter that can retain water while also trapping and organizing molecules within a semi-stable network.
“Drawing on concepts from soft-matter chemistry and using modern microbial biofilms as a framing device,” researchers explain.
Nature’s Original Reaction Chamber
One of the most significant obstacles in prebiotic chemistry is achieving sufficiently high concentrations. Many reactions required for life—such as polymerization or autocatalysis—become inefficient in dilute environments. The gel-first model suggests that sticky matrices attached to mineral surfaces could have acted as natural concentrators.
“Prebiotic gels could have provided the means for localized environments conducive to chemical complexification and evolutionary potential well before cellularization,” researchers write.
“Chemical complexification”—captures the crux of the problem. Life is not defined merely by molecules, but by networks of interacting reactions that sustain and reproduce themselves. To get there, chemistry must become layered, self-reinforcing, and capable of variation.
According to the framework, gel matrices may have enabled systems to overcome “key barriers in prebiotic chemistry by enabling molecular concentration, selective retention, reaction efficiency, and environmental buffering.”
In practical terms, this means a gel could trap certain molecules while excluding others, slow diffusion enough to let reactions proceed, and dampen fluctuations in pH, temperature, or salinity. Rather than being passive environments, these matrices may have actively shaped chemical evolution.
Proto-Metabolism Before Cells
Perhaps most intriguing is the suggestion that gel-like systems could have supported rudimentary metabolic processes before true cells existed.
Researchers explore how such matrices might have facilitated proto-metabolic activity through redox chemistry—reactions involving electron transfer that are central to modern metabolism. They also consider the possibility of light-driven processes within gel environments, as well as chemo-mechanical coupling, in which chemical reactions influence the matrix’s physical properties.
More provocatively, the authors discuss how gels could have supported early forms of replication. Within a structured matrix, autocatalytic networks—sets of reactions that reinforce their own production—might have been stabilized long enough to persist, accumulate variation, and potentially undergo selection-like processes.
Template-directed synthesis, in which molecules help guide the formation of similar molecules, could have emerged in these semi-confined spaces.
In this view, life did not suddenly appear inside a neatly packaged membrane. Instead, organized chemical systems may have first arisen in sticky, surface-bound films. Only later would cellularization—the encapsulation of chemistry within membranes—refine and accelerate those processes.
This gradualist perspective aligns with a broader shift in origin-of-life research—from models centered primarily on individual key molecules toward systems chemistry approaches, where environment, structure, and dynamic interactions are treated as integral to chemical evolution.
From Ancient Gels to Alien “Xeno-Films”
The implications of the gel-first model extend far beyond early Earth.
In the paper, researchers consider how similar gel-like structures might form elsewhere in the universe. They introduce the concept of “Xeno-films,” alien biofilm-like systems composed of non-terrestrial—or partially terrestrial—building blocks.
Such structures might not resemble familiar cells, nor would they necessarily rely on DNA or proteins as we know them. Yet, if life can emerge within structured, hydrated matrices, then the search for extraterrestrial biology may need to look beyond cell-like forms.
The authors emphasize the importance of “agnostic life-detection strategies in the search for life as we know it, and do not know it.”
That shift in mindset is increasingly relevant as missions probe Mars, icy moons like Europa and Enceladus, and even the atmospheres of distant exoplanets. If life elsewhere begins in gels rather than cells, we may need instruments capable of detecting structured chemical networks or surface-bound organic matrices—subtle signatures that could otherwise be overlooked.
Ultimately, the gel-first hypothesis does not claim to provide a definitive answer to the origin of life. Rather, it offers a conceptual framework—one that integrates soft-matter physics, systems chemistry, and microbiology into a unified picture.
By framing early Earth as a planet where hydrated gels clung to mineral surfaces, concentrating molecules and buffering their reactions, the model bridges a longstanding gap between chemistry and biology. It suggests that before membranes enclosed living systems, sticky films may have provided the architecture necessary for evolution to begin.
If that is true, then Earth’s earliest living ancestors were not cells, but thin, glistening gels spread across ancient rock, patiently weaving the first threads of life from a chaotic world.
“This is just one theory among many in the vast landscape of origin-of-life research,” co-author and research scientist at the Space Science Center, National University of Malaysia (UKM), Dr. Kuhan Chandru, said in a press release. “However, since the role of gels has been largely overlooked, we wanted to synthesize scattered studies into a cohesive narrative that puts primitive gels at the forefront of the discussion.”
Tim McMillan is a retired law enforcement executive, investigative reporter and co-founder of The Debrief. His writing typically focuses on defense, national security, the Intelligence Community and topics related to psychology. You can follow Tim on Twitter: @LtTimMcMillan. Tim can be reached by email: tim@thedebrief.org or through encrypted email: LtTimMcMillan@protonmail.com