Optimal Migration of a Combination of Saturated and Monounsaturated Fatty Acids in Droplets as an Evolutionary Approach

The creation of life from chemical systems remains poorly understood. Previous studies have discussed the possibility that fatty acids played a crucial role in the emergence of early primitive cells. This work discusses the idea that a droplet containing the specific combination (C16-/C18═) of a saturated fatty acid with 16 carbons (C16-) and a monounsaturated fatty acid with 18 carbons (C18═) exhibits the best migration characteristics, including Lévy flights, sustained velocity, and a large active region, among many single types or mixtures of fatty acids. Common phospholipids in many modern cells also have this specific C16-/C18═ combination as their hydrophobic tails. Hence, a match is achieved between best migration and modern cells despite vast possibilities on both sides. Lévy flights are an optimal searching strategy for scarce resources; optimal searching is critical for survival among competitors. Droplets with other fatty acids have either random or ballistic motions that are less optimal for searching. This match thus points to the possibility that the best migration of the C16-/C18═ combination may potentially be the fundamental mechanism for the evolution of a chemical into a living system.