How did life arise from inert matter? This question remains one of the deepest mysteries of science. Roland Riek, professor of physical chemistry and deputy director of the new Interdisciplinary Center for the Origin and Prevalence of Life at ETH Zurich, claims that the traces leading to life's origins have been erased by evolution over the past three to four billion years. Thus, science must rely on hypotheses and support them with experimental data.
Riek's team focuses on the idea that protein aggregates, known as amyloids, might have played a key role in the transition from chemistry to biology. They have demonstrated in the laboratory that amyloids can easily form under conditions similar to those of early Earth, simply from amino acids and volcanic gases. These peptide chains spontaneously assemble into fibers.
Amyloids can also replicate, thus meeting a crucial criterion to be considered as precursor molecules of life. Moreover, recent research shows that amyloids can bind to RNA and DNA. These interactions, partly based on electrostatic attraction and nucleotide sequence, could represent a primitive form of the universal genetic code.
Another advantage of amyloids is their ability to increase the stability of genetic molecules. In the "primordial soup," where biochemical molecules were highly diluted, this increased stability could have been crucial. Long-lived molecules accumulate more strongly than unstable substances, suggesting that molecular cooperation, rather than competition, could have been a determining factor in the emergence of life.
Riek emphasizes that while competition is central in Darwin's theory of evolution, cooperation also played a significant role. The stabilizing interaction between amyloids and RNA or DNA molecules benefits both classes of molecules. This discovery could revolutionize our understanding of the origins of life.