Abstract EANA2025-164

Previously, we presented a hypothesis on the Darwinian evolution of liposomes that relies solely on natural and ever-present phenomena: the day-night cycle of solar UV radiation, gravity, and the release of amphiphiles in aqueous media. We demonstrated the protective ability of certain ferric salts typical for Archean waters, notably iron trichloride and ferric ammonium citrate, against liposome destruction by UV. In the present study, we investigate the dynamics of interaction with UV for the liposomes with negative buoyancy in two natural scenarios: 1) liposomes already deeply submerged in the FeCl3 solution, a scenario mimicking the nighttime submergence; and 2) the dynamics of interaction with UV for liposomes slowly submerging under UV exposure, a relevant daytime scenario. We use custom-designed micron-sized, negative-buoyant (heavy), UV-sensitive liposomes. The results showed that for the nighttime scenario, all liposomes were free from UV damage when given sufficient time to submerge in a protective ferric salts solution. Submersion time favors larger and heavier liposomes containing a higher number of heavy molecules. Simple sugars, such as ribose—which is a vital component of RNA—can serve as the proposed heavy molecules in Origin of Life scenarios. Conversely, preliminary data exploring the daytime scenario indicates that liposomes slowly submerging under UV exposure sustain significant damage; experiments with larger and heavier liposomes under the daytime scenario are in progress. The results of these experiments, which aim to simulate natural events, showed that negative buoyancy and UV radiation are sufficient as natural drivers in a novel scenario of Darwinian evolution of liposomes.