Researchers at the University of Hiroshima, in Japan, have created a microscopic drop-shaped particle with the ability to self-replicate and evolve into a molecule: it would be the link between the original chemical conditions and their development towards the simplest biological forms, the mechanism that it would ultimately have led to complex life as we know it today.
According to a Press release, a “droplet-based protocell” could have served as a link between chemistry and biology during the origins of life. Consequently, the new study published in the journal Nature Communications could explain the appearance of the first living organisms on the primordial Earth, solving one of the oldest and most controversial riddles in science.
From drops to living organisms
According to specialists Muneyuki Matsuo and Kensuke Kurihara, their tiny drops could you explain how molecular assemblies that allowed the development of life managed to proliferate from small molecules. The blood cells are called coacervated drops: they would be the inorganic building blocks that, by increasing in complexity, eventually gave rise to cell-like structures.
In general, the coacervation It occurs when amino acid derivatives, which are the basis of proteins, are mixed under certain environmental conditions: at that moment, they reorganize and self-assemble into small droplets.
Through the absorption of other elements related to proteins and present in the environment in which they evolve, the tiny droplets gain size and become unstable until they break: the resulting products “gestate” a new “daughter” with constituents similar to the original drop or microsphere.
In the seas of the early Earth?
The repetition and increasing complexity of this process would have allowed the emergence of the first living organisms in the seas of early Earth, which had the appropriate environmental conditions, solar energy and the chemical elements necessary for the “mechanism” to reproduce.
In this way, the tiny inert droplets derived in molecules that, later, made possible the cellular development that allowed the emergence of the first living organisms. For scientists, this would explain how life arose in a scenario in which only self-replicating genetic material existed, prior to the evolution of DNA and proteins.
The key would be the genetic material
The Japanese researchers reproduced the indicated conditions in an experiment: understanding that the amino acid derivatives they would be the precursors of primitive cell self-assembly, they were added to a container with water at room temperature and under atmospheric pressure.
They observed that amino acid derivatives were condensed and organized into peptides (molecules containing two or more amino acids), and then spontaneously form droplets. Subsequently, the droplets grew in size and in number when they were fed more amino acids.
At the same time, scientists discovered that the droplets could concentrate nucleic acids or genetic materialgenetic, having a greater probability of surviving against harmful external stimuli when they developed this function. The experiment thus showed results similar to the way in which these processes would have taken place in the initial moments of life on our planet.
In short, this could be precisely the “basis” that made possible the development of primary marine life: the drops with the greatest “potential” managed to evolve, replicated themselves and evolved to form molecules and then protocells or primitive cells, culminating in the creation of living organisms.
Proliferating coacervate droplets as the missing link between chemistry and biology in the origins of life. Muneyuki Matsuo and Kensuke Kurihara. Nature Communications (2021). DOI: https://doi.org/10.1038/s41467-021-25530-6
Photo: a self-replicating “drop” from which molecules, protocells and, finally, living organisms would have arisen. Japanese scientists found the missing link between chemistry and biology at the origins of life. Credit: Muneyuki Matsuo, Hiroshima University.
Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.