CeleryKills

I was trying to answer someone else’s question when this essay started taking shape. The question seemed simple enough: if abiogenesis is a natural process, why don’t we see it happening now? That sent me down one of those familiar rabbit holes where one paper becomes three, three become ten, and before long the browser tabs start resembling a small geological formation. Along the way I kept encountering researchers working at the edges of origin-of-life studies, not looking for fully formed organisms, but for self-organizing chemical networks, autocatalytic systems, and other strange intermediates that might occupy the territory between chemistry and biology (Hordijk & Steel, Autocatalytic Networks at the Basis of Life’s Origin and Organization, 2018; Peng et al., The Hierarchical Organization of Autocatalytic Reaction Networks, 2022).

What struck me was not any single hypothesis. It was the accumulating implication. These researchers are not necessarily asking whether life’s emergence happened only once. Some are exploring whether life-like chemistry could emerge wherever energy, resources, and suitable conditions persist, even if that emergence never survives long enough for us to notice it (Xavier et al., Autocatalytic Chemical Networks at the Origin of Metabolism, 2020). Somewhere between finishing the reading and closing the last tab, a different possibility began to crowd out the original question. Maybe the mystery is not why we fail to observe emergent chemistry. Maybe the mystery is why we expect to observe it easily on a planet already dominated by the most successful chemical replicators in Earth’s history.

One reason we do not watch abiogenesis happen in a pond the way we watch ducks happen in a pond is that the modern Earth is already occupied. Thoroughly occupied. Aggressively occupied.

Life is the ultimate invasive species.

Imagine the early Earth as a chemical frontier. Molecules formed, interacted, accumulated, and occasionally stumbled into networks that persisted longer than their neighbors. Some chemistries became self-reinforcing. Some began exploiting local energy gradients. Some may have occupied that awkward territory between chemistry and biology that scientists still struggle to define (Peng et al., 2022; Hordijk & Steel, 2018).

Now imagine introducing those same fragile systems into a modern ocean.

Lunch.

That is the problem.

Anything even vaguely food-like encounters bacteria, archaea, fungi, protists, viruses, biofilms, scavengers, decomposers, and entire ecosystems whose collective specialty is locating useful chemistry and turning it into more life. The modern biosphere is less a backdrop than an enormous biochemical vacuum cleaner. A molecule that drifts today through seawater is moving through an environment packed with organisms that have had billions of years to evolve methods of capturing, metabolizing, digesting, or disrupting it.

Personally, I find this explanation far more intuitive than the assumption that prebiotic chemistry somehow happened once and then politely retired forever.

Researchers have increasingly explored environments where biology’s interference might be reduced. Deep hydrothermal systems remain a major target because geological energy gradients can drive complex chemistry while isolating reactions from much of the surface biosphere (Martin et al., 2008; Tutolo, Rethinking the Origin of Life at Seafloor Hydrothermal Vents, 2026). Similar interest extends to subsurface rock systems, isolated brines, volcanic regions, and other chemically active environments where complex organic networks might emerge faster than established organisms can consume them.

The more interesting possibility is that emergent life may already exist in forms we do not recognize. Our definitions are built around cells, genetics, metabolism, and reproduction because that is what won. But what if Earth once hosted intermediate states? Networks that were not fully alive yet not merely chemistry either. Some origin-of-life models explicitly explore autocatalytic systems and partially self-sustaining reaction networks that occupy exactly that gray territory (Xavier et al., 2020; Peng et al., 2022).

That raises an awkward question.

If a self-maintaining chemical ecosystem lacked DNA, lacked cells, reproduced imperfectly, and persisted in a geothermal crack beneath the seafloor, would we call it life?

Or would we walk right past it because the label on our clipboard says life must look like us first?

The longer I read this literature, the less convinced I become that the transition from chemistry to biology was a sharp boundary. The evidence increasingly resembles a shoreline. We keep asking where the ocean ends and the beach begins. Nature’s answer may be that there was never a line in the first place.

References

• Hordijk, W., & Steel, M. Autocatalytic Networks at the Basis of Life’s Origin and Organization (2018).
• Martin, W., Baross, J., Kelley, D., & Russell, M. Hydrothermal Vents and the Origin of Life (2008).
• Patel, B. H., Percivalle, C., Ritson, D. J., Duffy, C. D., & Sutherland, J. D. Common Origins of RNA, Protein and Lipid Precursors in a Cyanosulfidic Protometabolism (2015).
• Peng, Z., Linderoth, J., & Baum, D. A. The Hierarchical Organization of Autocatalytic Reaction Networks and Its Relevance to the Origin of Life (2022).
• Tutolo, B. M. Rethinking the Origin of Life at Seafloor Hydrothermal Vents (2026).
• Xavier, J. C., Hordijk, W., Kauffman, S., Steel, M., & Martin, W. F. Autocatalytic Chemical Networks at the Origin of Metabolism (2020).