How organisms develop from inanimate matter is one of the biggest questions in science. Although many possible explanations have been proposed, there are no definitive answers. That’s no surprise: these processes took place three to four billion years ago, when the conditions on Earth were completely different from today.
Justifying hypotheses with experimental data
“Over this vast period of time, evolution has thoroughly obliterated the traces that lead back to the origins of life,” says Roland Riek, Professor of Physical Chemistry and Associate Director of ETH Zurich’s new interdisciplinary Centre for Origin and Prevalence of Life. Science has no choice but to formulate hypotheses – and to substantiate them as thoroughly as possible with experimental data.
For years, Riek and his team have been pursuing the idea that protein-like aggregates, known as amyloids, might have played an important role in the transition between chemistry and biology. Riek’s research group’s first step was to demonstrate that such amyloids can be formed relatively easily under the conditions that probably prevailed on the early Earth: in the laboratory, all it takes is a little volcanic gas (as well as experimental skill and a lot of patience) for simple amino acids to combine into short peptide chains, which then spontaneously assemble into fibres (see ETH News).
Precursor molecules of life
Later, Riek’s team demonstrated that amyloids can replicate themselves (see ETH News) – which means that the molecules fulfil another decisive criterion for being considered precursor molecules of life. And now the researchers have taken the same line for a third time with their latest study, in which they show that amyloids are able to bind with molecules of both RNA and DNA.
