Life on Earth may have started in sea spray thanks to a chemical Big Bang, scientists believe.
They made a “spectacular discovery” that the building blocks of all living things emerge spontaneously when water droplets meet air.
“It’s basically about the chemistry behind the origin of life,” said the researchers from Purdue University in Indiana.
Most scientists agree that the chemicals necessary for life were brought to Earth by asteroids and comets, which also deposited water.
But they have long puzzled over how these simple molecules and amino acids could have given rise to life.
Life on Earth may have started in sea spray thanks to a chemical Big Bang, scientists say
PANSPERMIA: HOW LIFE CAME TO EARTH FROM THE STARS
Panspermia is a theory that suggests that life spreads through the known physical universe, hitchhiking on comets or meteorites.
Extremophiles, able to survive the inhospitable conditions of space, could find themselves trapped in debris ejected into space after collisions between asteroids and planets that harbor life.
These dormant life forms can then travel for a long period of time before randomly colliding with other planets.
One argument that supports the panspermia theory is the emergence of life shortly after the period of intense bombardment of the earth between 4 and 3.8 billion years ago.
JThe earliest evidence of life on Earth suggests it was present around 3.83 billion years ago, overlapping with this bombardment phase.
The ingredients were thought to come together bit by bit, but this new theory suggests life suddenly happened in a chemical Big Bang.
Lead author Professor Graham Cooks, from Purdue University in Indiana, said: ‘It’s basically 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 droplets of pure water.
“It’s a dramatic discovery.”
The discovery may even hold the key to better drugs for humanity’s most debilitating diseases, according to the US team.
Professor Cooks added: “The rates of reactions in droplets are a hundred to a million times faster than the same chemicals reacting in bulk solution.”
Accelerating them renders catalysts useless. Understanding how this process works is the “holy grail” of chemistry, experts say.
It sheds light on why life has occurred and informs the search for it on other planets, even moons.
For decades, scientists theorized that it started in the oceans, but the chemistry remained an enigma.
When Earth formed 4.5 billion years ago, it was a barren ball of rock – battered by meteorites and lined with erupting volcanoes.
But within a billion years it had become inhabited by microorganisms and today life covers every square inch of the planet, from the highest mountains to the deepest seas.
For more than a century, the world’s greatest minds have debated what happened to cause barren rocks, sand and chemicals to give rise to life.
Raw amino acids – something meteorites deliver daily – can react and lock together to form peptides.
But curiously, the building blocks of protein – and of life – also require the loss of a water molecule.
This is highly unlikely in a humid or ocean environment.
This means that for life to form, it needed water but also space away from water.
Early Earth chemistry expert Professor Cooks has spent more than 10 years using mass spectrometer scanners to analyze chemical reactions in water-containing droplets.
“The water is not wet everywhere,” he said.
Most scientists agree that the chemicals needed for life were brought to Earth on asteroids and comets, which also deposited water (stock image)
At the margins, where a droplet meets the atmosphere, incredibly fast reactions can take place, transforming abiotic amino acids into the building blocks of life.
Places where sea spray flies through the air and waves pound the land, or where fresh water rushes down a slope, were fertile landscapes for the potential evolution of life.
Understanding how amino acids turned into proteins and eventually life forms could revolutionize chemical synthesis.
Faster responses are key to discovering and developing new drugs and therapeutic treatments for life-threatening diseases.
Prof Cooks added: ‘If you walk through a university campus at night, the buildings with the lights on are where the synthetic chemists work.
“Their experiments are so slow that they go on for days or weeks at a time. It’s not necessary.
“Using droplet chemistry, we have built an apparatus, which is currently in use at Purdue, to accelerate the synthesis of new chemicals and potential new drugs.”
The study was published in the journal Proceedings of the National Academy of Sciences.
LIFE ON EARTH MAY HAVE STARTED FROM AN MODIFIED VERSION OF MODERN RNA
Scientists say life on Earth may have started with a modified version of the sister molecule to modern DNA.
DNA is the backbone of life and almost our entire planet depends on it but, on primordial Earth, an early version of its lesser-known sister – RNA – was the focal point of evolution, experts say .
RNA is structurally similar to DNA except that one of the four building blocks, thymine, is substituted for uracil.
This changes the shape and structure of the molecule and researchers have long believed that this chemical was vital for the development of early life forms on Earth.
An accidental discovery by Harvard scholars published in December 2018 revealed that a slightly different version of RNA may have been the key ingredient allowing life on Earth to flourish.
Scientists claim that a chemical called inosine may have been present in place of guanine, allowing life to develop.
This slight change in bases, known as nucleotides, may provide the first known evidence for the ‘RNA world hypothesis’ – a theory that claims RNA was an integral part of early life forms – say -they.