Life on Earth may have started in ocean spray thanks to a chemical Big Bang, scientists believe.
They made a ‘dramatic discovery’ that the building blocks of all living things arise spontaneously when water droplets meet air.
“This is essentially the chemistry behind the origin of life,” said the researchers at Purdue University in Indiana.
Most scientists agree that the chemicals necessary for life were brought to Earth on asteroids and comets, which also deposited water.
But they have long been in doubt about how these simple molecules and amino acids could have come to life.
Life on Earth may have started in ocean spray thanks to a chemical Big Bang, scientists believe
PANSPERMIA: HOW LIFE CAME TO EARTH FROM THE STARS
Panspermia is a theory that suggests that life spreads across the known physical universe, hitchhiking on comets or meteorites.
Extremophiles able to survive the inhospitable conditions of space may be trapped in debris ejected into space after collisions between asteroids and planets that harbor life.
These dormant life forms can then travel for extended periods of time before randomly colliding with other planets.
One argument supporting the panspermia theory is the emergence of life shortly after the earth’s heavy bombardment period between 4 and 3.8 billion years ago.
Tthe earliest evidence of life on Earth suggests that it was present about 3.83 billion years ago, which overlaps with this bombardment phase.
It had been thought that the ingredients came together slowly bit by bit, but this new theory suggests life happened all at once in a chemical Big Bang.
Lead author Professor Graham Cooks of Purdue University in Indiana said: ‘This is essentially the chemistry behind the origin of life.
‘This is the first demonstration that primordial molecules, simple amino acids, spontaneously form peptides, the building blocks of life, in drops of pure water.
“This is a dramatic discovery.”
The discovery may even hold the key to better medicine for humanity’s most debilitating diseases, according to the American team.
Professor Cooks added: ‘The speed of reactions in droplets is anywhere from a hundred to a million times faster than the same chemicals reacting in bulk solution.’
Speeding them up makes catalysts unnecessary. Understanding how this process works is the ‘holy grail’ of chemistry, experts say.
It sheds light on why life happened and informs the search for it on other planets, or even moons.
For decades, scientists have theorized that it began in the oceans, but the chemistry remained a mystery.
When Earth formed 4.5 billion years ago, it was a sterile ball of rock – battered by meteorites and covered in erupting volcanoes.
But within a billion years it had been inhabited by microorganisms, and today life covers every inch of the planet, from the highest mountains to the deepest oceans.
For more than a century, the world’s greatest minds have debated what happened before barren rocks, sand and chemicals gave rise to life.
Raw amino acids – something meteorites deliver daily – can react and link together to form peptides.
But mysteriously, the building blocks of proteins – and life – also require the loss of a water molecule.
This is highly unlikely in a wet or marine environment.
This means that for life to form, it needed water, but also space away from water.
Professor Cooks, an expert in early Earth chemistry, spent more than 10 years using mass spectrometer scanners to analyze chemical reactions in droplets containing water.
“Water is not wet everywhere,” he said.
Most scientists agree that the chemicals necessary for life were brought to Earth on asteroids and comets, which also deposited water (stock image)
At the edge, where a droplet meets the atmosphere, incredibly fast reactions can take place which transform abiotic amino acids into the building blocks of life.
Places where sea spray flies into the air and waves crash on the land, or where fresh water rushes down a slope, were fertile landscapes for the potential development of life.
Understanding how amino acids built up into proteins and ultimately life forms could revolutionize chemical synthesis.
Faster responses are essential for discovering and developing new drugs and therapeutic treatments for life-threatening diseases.
Professor Cooks added: ‘If you walk through an academic campus at night, the buildings with the lights on are where synthetic chemists are working.
“Their experiments are so slow that they run for days or weeks at a time. This is not necessary.
‘Using droplet chemistry, we have built an apparatus that is being used at Purdue now to speed up the synthesis of new chemicals and potential new drugs.’
The study has been published in the journal Proceedings of the National Academy of Sciences.
LIFE ON EARTH MAY HAVE STARTED AS A MODIFIED VERSION OF MODERN RNA
Life on Earth may have started thanks to a modified version of today’s DNA’s sister molecule, scientists believe.
DNA is the backbone of life, and nearly our entire planet depends on it, but on primordial Earth, a primitive version of its lesser-known sister — RNA — was the linchpin of evolution, experts say.
RNA is structurally similar to DNA, except that one of the four basic pieces, thymine, is replaced by uracil.
This changes the shape and structure of the molecule, and scientists have long believed that this chemical was essential for the development of Earth’s first life forms.
An accidental discovery by Harvard academics published in December 2018 showed that a slightly different version of RNA may have been the key ingredient that allowed life on Earth to flourish.
Scientists claim that a chemical called inosine may have been present instead of guanine, allowing life to evolve.
This small change to the bases, known as nucleotides, may provide the first known evidence of the ‘RNA World Hypothesis’ – a theory which claims that RNA was an integral part of primitive life forms – they say.