Evrim Yazgin
Cosmos science journalist
A team of researchers say their latest attempts to understand how molecules chemically reacted to form the basic building blocks of life on Earth are promising.
There has long been debate about the origins of the basic building blocks of life on Earth. Did these first organic compounds form through processes on our planet, or were they brought to Earth on asteroids which battered the planet when it was still forming?
Now researchers have challenged the notion that early chemical evolution before the first life would have been too chaotic, showing that the chemical precursors to life were able to evolve in an ordered way on young Earth.
Researchers simulated the wet-dry cycles of early Earth to see how they would have impacted on chemical mixtures to create the molecular foundations of the first life on our planet.
The research, published in Nature Chemistry, shows that organic molecules in these conditions underwent continuous transformation, selective organisation and synchronised population dynamics.
Instead of random chemical reactions, molecules would have organised and evolved following predictable patterns.
They argue that is how the “primordial soup” where life is theorised to have begun, evolved more than 4 billion years ago.
Eventually, the first biological molecules would have come together into the first single-celled organism. This first life is referred to as LUCA, the last universal common ancestor. LUCA is the hypothesised common ancestor of all 3 domains of life – Bacteria, Archaea and Eukarya.
The team used mixtures of organic molecules with a range of functional groups. They included carboxylic acids, amines, thiols, and hydroxyls.
The chemical mixtures were subjected to repeated wet-dry cycles to mimic the environmental fluctuations on early Earth. They found the mixtures evolved without reaching chemical equilibrium, didn’t become uncontrollably complex and showed synchronised population dynamics within different molecule types.
“This research offers a new perspective on how molecular evolution might have unfolded on early Earth,” says lead researcher Frenkel-Pinter from the Hebrew University of Jerusalem. “By demonstrating that chemical systems can self-organise and evolve in structured ways, we provide experimental evidence that may help bridge the gap between prebiotic chemistry and the emergence of biological molecules.”
The researchers say the study has relevance beyond understanding the origins of life. Their findings could have applications in synthetic biology and nanotechnology.
Controlled chemical evolution could be used to design new molecular systems with specific properties and lead to innovations in materials science, drug development and biotechnology.
