The question of how chemistry became biology – arguably the most thrilling scientific question of our time – has plenty of answers, but none of them are conclusive. Scientists aren’t even sure how DNA and RNA, DNA’s chemical “cousin”, came about.
Although there are some compelling ideas being thrown about, even the repertoire of chemicals required to kick-start biology remains unknown. A new Nature Chemistry study, however, may have identified a compound that was responsible for all of the above – a chemical named diamidophosphate (DAP).
As far as is known, in order for biology to arise, you need three classes of chemicals: Peptides, which are the primary drivers of cellular activity; lipids, to encase cells and structures in protective membranes; and short nucleotides, which store genetic information. Think of them as the engines, the shields, and the blueprints of cells.
Life likely has a realistic chance of developing only if all three chemical types emerge simultaneously – otherwise, cells wouldn’t work properly. Their existence allows for a type of pre-biological chemistry that wouldn’t have existed before.
Scientists have been attempting to find out how this could have come about for some time, and now it appears that a team from The Scripps Research Institute (TSRI) have reached the proverbial finish line. Using a range of painstakingly precise chemistry experiments, the researchers have concluded that DAP may be the catalyst that everyone’s been searching for.
Using primitive chemical compounds that were extremely likely to have been present on Earth more than 4 billion years ago, the team confirmed that when DAP is added, the engines, shields, and blueprints of cells could spontaneously emerge. Importantly, these reactions occurred under a range of temperatures and conditions, which suggests DAP is a fairly resilient molecule.
“With DAP and water and these mild conditions, you can get these three important classes of pre-biological molecules to come together and be transformed, creating the opportunity for them to interact together,” senior study author Ramanarayanan Krishnamurthy, an associate professor of chemistry at TSRI, said in a statement.
“It reminds me of the Fairy Godmother in Cinderella, who waves a wand and ‘poof,’ ‘poof,’ ‘poof,’ everything simple is transformed into something more complex and interesting,” he added.
The study authors acknowledge that this is difficult to prove, but to be fair to them, they’re in the same situation as similar papers in this regard.
Still, it’s marvelous to think that one compound, DAP, may be responsible for everything living you see around you today. Could it be the chemical key that bonds all of life together?