For many years, scientists have been debating whether life started on Earth or began in space. While we have no definite answer, researchers have uncovered important information regarding this fascinating topic. Now, a team from the University of York have discovered some intriguing chemistry in interstellar ice.
The scientists found that amino nitriles, the precursors of amino acids, can use molecules to form 2-deoxy-D-ribose, the backbone of DNA. This research, published in Chemical Communications, suggests that the building blocks of DNA might have come from space.
“The origin of important biological molecules is one of the key fundamental questions in science," senior author Dr Paul Clarke said in a statement. "The molecules that form the building blocks of DNA had to come from somewhere; either they were present on Earth when it formed or they came from space, hitting earth in a meteor shower.
“Scientists had already shown that there were particular molecules present in space that came to Earth in an ice comet; this made our team at York think about investigating whether they could be used to make one of the building blocks of DNA. If this was possible, then it could mean that a building block of DNA was present before amino acids.”
In the more traditional view, the amino acids present on Earth are responsible for the formation of DNA, but based on this research, the important bits of the "life molecule" might have already been assembled as they rained on Earth from the cosmos.
The study focused on the behavior of amino nitriles and a similar molecular species known as amino esters in interstellar space. The team noticed that these molecules were capable of acting as a catalyst to change organic compounds like formaldehyde into the building blocks of DNA.
“We have demonstrated that the interstellar building blocks formaldehyde, acetaldehyde and glycolaldehyde can be converted in ‘one-pot’ to biologically relevant carbohydrates – the ingredients for life,” Dr Clarke continued.
“This research therefore outlines a plausible mechanism by which molecules present in interstellar space, brought to earth by meteorite strikes, could potentially be converted into 2-deoxy-D-ribose, a molecule vital for all living systems.”
Recently, researchers estimated that 40 percent of Rosetta’s comet is organic material, and that the material possibly formed before the Solar System. Similar comets hitting our planet might have brought with them these materials, allowing for life to eventually develop.