Last Chance Lake in British Columbia, Canada is a modern analog for soda lakes that might have supported the introduction of cells on the early Earth. Credit: Zachary R. CohenA study suggests that soda lakes, characterized by high levels of liquified salt and carbonate, might have provided the right conditions for the very first cells. These early cells might have been composed of RNA inside lipid membranes.But RNA function needs divalent cations such as Mg2+, which disrupt primitive membranes made from fats. The concern emerges whether the fairly low concentrations of Mg2+ found in soda lakes might have enabled both RNA and membranes to work together.Exploring the Viability of Early Life in Soda LakesTo explore this possibility, Zachary Cohen and associates collected water from Last Chance Lake and Goodenough Lake in Canada after seasonal evaporation. These soda lakes each contained ~ 1 M Na+ and ~ 1 mM Mg2+ at pH 10. The authors discovered that spontaneous extension of short RNA primers happened in lake water at a rate equivalent to the rates in basic lab conditions. The authors added fatty acids, which might have been offered on the early Earth, to the lake water to see if the molecules would assemble into membranes.Findings and ImplicationsThe membranes formed in dilute water that imitates a rains occasion, and the membranes continued even when surrounded by concentrated lake water from the dry season.According to the authors, soda lakes on the early Earth might have supported crucial features of protocell advancement, with RNA copying and ribozyme activity occurring in the dry season and vesicle formation occurring throughout the wet season.Reference: “Natural soda lakes offer compatible conditions for RNA and membrane function that could have made it possible for the origin of life” by Zachary R Cohen, Dian Ding, Lijun Zhou, Saurja DasGupta, Sebastian Haas, Kimberly P Sinclair, Zoe R Todd, Roy A Black, Jack W Szostak and David C Catling, 19 March 2024, PNAS Nexus.DOI: 10.1093/ pnasnexus/pgae084.
