Do-Nothing Prebiotic Chemistry: Chemical Kinetics as a Window into Prebiotic Plausibility
The study of the origin of life is an expanding and dynamic field, with new breakthroughs occurring each year. Recent discoveries include novel syntheses of life’s fundamental building blocks, mechanisms of activation and molecular interaction, and newly identified environments that create promising conditions for these processes.
Despite these significant findings, which are grounded in rigorous laboratory experiments, researchers often face uncertainty when it comes to applying them. One critical question in the field is: How can a bridge be built between laboratory experiments and the natural geochemical environment? In particular, a key issue in applying new results to the origins of life is determining how chemistry can occur without direct intervention from a chemist.
We believe that the first step in addressing this question lies in determining rate constants and constructing chemical networks that can describe prebiotic chemistry within geochemical environments. So far, our group has measured several rate constants relevant to different prebiotic reaction networks, beginning with the synthetic pathways of the cyanosulfidic network.
The reactions we explore often involve ultraviolet light-driven photochemistry, facilitated by our StarLab setup, which accurately simulates the spectrum of the young Sun and other stars. Our latest work investigates environments with active photochemistry but without cyanide. Specifically, we are measuring the effective rate constant for the production of formate from the reduction of carbon species using sulfite, within the context of early Martian waters.
The overarching goal of our group’s work is to predict the likelihood that specific geological conditions will result in certain chemical products. These predictions are combined with our insights into the necessary astrophysical conditions that might have contributed to the origin of life on extrasolar planets.
In the near future, we expect that a sufficient number of rate constants will be measured—both by our group and others—allowing prebiotic chemistry to be predicted using chemical kinetics models. Once these models have been validated against experimental data, the next step will be applying them to natural environments that closely mimic the conditions believed to have existed at the onset of life.
Following this, we can test these models by comparing their predictions to additional experiments. With refinement, these models will guide the optimal conditions for conducting laboratory experiments and help minimize or characterize any interference from chemists.
This approach has the potential to provide valuable insights into what is possible within geochemical environments, where all chemistry must occur without direct intervention, or what we refer to as “do-nothing chemistry.” TASIN-30