A team of researchers from Japan, Malaysia, the United Kingdom, and Germany has suggested that life on Earth may have begun in sticky, gel-like materials attached to rocks, rather than inside cells. This 'prebiotic gel-first' hypothesis posits that these primitive gels, similar to modern microbial biofilms, provided a protected environment for early chemical reactions to evolve into complex systems. The idea, published in ChemSystemsChem, also has implications for searching for life on other planets.
The origin of life has long puzzled scientists, with various theories drawing on chemistry, physics, and geology to reconstruct early Earth's conditions. In a new paper, researchers introduce the prebiotic gel-first framework, arguing that life's initial stages occurred within surface-attached gel matrices. These semi-solid, sticky structures, akin to biofilms formed by bacteria on rocks and surfaces today, could have concentrated molecules and shielded nascent chemical networks from harsh environmental fluctuations.
Tony Z. Jia, a professor at Hiroshima University and co-lead author, explained: "While many theories focus on the function of biomolecules and biopolymers, our theory instead incorporates the role of gels at the origins of life." The gels, the team suggests, would have facilitated proto-metabolic activity and basic self-replication, setting the stage for biological evolution before true cells emerged.
Kuhan Chandru, a research scientist at the National University of Malaysia and another co-lead author, emphasized the novelty: "This is just one theory among many in the vast landscape of origin-of-life research. 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."
The hypothesis extends beyond Earth, proposing 'Xeno-films'—gel-like systems from alien chemistries—that could indicate extraterrestrial life. Future lab experiments will test how simple chemicals under early Earth-like conditions form such gels and support emerging chemical systems. The work, supported by funding from the University of Leeds, the Alexander von Humboldt Foundation, the Japan Society for the Promotion of Science, and the Mizuho Foundation, appears in ChemSystemsChem (2025; 8(2), DOI: 10.1002/syst.202500038). Co-authors include Ramona Khanum, Nirmell Satthiyasilan, Navaniswaran Tharumen, Terence P. Kee, Christian Mayer, and P. Susthitha Menon.