Did life start on the surface of our planet in a ‘warm little pond’ as Charles Darwin believed - or did it bubble up from deep beneath the sea?
New research suggests that Darwin may have been wrong about the warm little pond and that, instead, life began in deep sea hydrothermal vents.
The finding could have an impact on where we search for extraterrestrial life.
Professor Nick Lane of University College London (UCL) said: “There are multiple competing theories as to where and how life started.
“Underwater hydrothermal vents are among the most promising locations for life’s beginnings — our findings now add weight to that theory with solid experimental evidence.”
The researchers believe that deep-sea vents had the heat and chemical make-up to kick-start life.
The vents are where seawater comes into contact with minerals from the planet's crust, reacting to create a warm, alkaline environment containing hydrogen.
Some of the world’s oldest fossils have been found in the vents.
The UCL researchers succeeded in creating self-assembling protocells (thought to be building blocks of life) in an environment similar to that of hydrothermal vents.
Dr Sean Jordan said: "In our experiments, we have created one of the essential components of life under conditions that are more reflective of ancient environments than many other laboratory studies.
"We still don't know where life first formed, but our study shows that you cannot rule out the possibility of deep-sea hydrothermal vents."
The researchers also pointed out that deep-sea hydrothermal vents are not unique to Earth.
Professor Lane said: "Space missions have found evidence that icy moons of Jupiter and Saturn might also have similarly alkaline hydrothermal vents in their seas. While we have never seen any evidence of life on those moons, if we want to find life on other planets or moons, studies like ours can help us decide where to look."