In a chicken-and-the-egg type of problem, scientists have never been sure how the very first living cell — and therefore the simplest life form — c
In a chicken-and-the-egg type of problem, scientists have never been sure how the very first living cell — and therefore the simplest life form — came into being.
It would somehow have to build itself without any pre-existing ‘code’ to tell it how.
Researchers have put forward new evidence that phosphates — an essential part of the ‘backbone’ of DNA — came from meteorites or comets in outer space.
“On Earth, phosphine is lethal to living beings,” said lead author Andrew Turner, a professor at the University of Pikeville, in the September issue of Nature Communications.
“In the interstellar medium, an exotic phosphine chemistry can promote rare chemical reaction pathways…”
Professor Andrew Turner
“But in the interstellar medium, an exotic phosphine chemistry can promote rare chemical reaction pathways to initiate the formation of biorelevant molecules such as oxoacids of phosphorus, which eventually might spark the molecular evolution of life as we know it.”
In simpler terms, chemical reactions that would be impossible to occur naturally on Earth have the right conditions in space.
Scientists used a high vacuum chamber cooled down to a bitterly cold -268°C (the minimum possible temperature, ‘absolute zero’, is -273°C) to replicate space conditions.
They simulated cosmic rays using high-energy electrons and then phosphoric acid (the acid part of DNA — deoxyribonucleic acid) and diphosphoric acid were formed from phosphine, carbon dioxide and water.
Professors Andrew Turner and Ralf Kaiser, University of Hawai’i at Manoa, worked with Cornelia Meinert of the University of Nice and Agnes Chang of National Dong Hwa University Taiwan.