Scientists discover evidence of 3.7 billion-year-old life
Scientists believe they have found the remains of Earth's oldest organisms in a rock from the Isua Greenstone Belt in Greenland.
The microbes are around 3.7 billion years old and were discovered using a new laser scanning technique.
The findings could shed light on how life evolved on our planet, and could help to pinpoint traces of life in space rocks from other planets.
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Scientists believe they have found the remains of Earth's oldest organisms in a rock from the Isua Greenstone Belt in Greenland
Previously, the earliest life on Earth was thought to be in 3.48-billion-year-old rocks in Australia.Â
Researchers from the University of Copenhagen used a groundbreaking laser scanning technique to study the Greenland rock.
Speaking to Seekr, Dr Tue Hassenkam, lead author of the study, said: 'We cannot say exactly when life began on Earth, but we can now say with much more certainty that it existed 3.7 billion years ago.
'We can also say for sure that the microbes were living in a marine environment, since the biological remains must have precipitated on to the bottom of an early ocean.'
The technique used to find the microbes is called Atomic Force Microscopy (AFM), and involves using a laser needle to scan the rock.
Dr Hassenkam said: 'AFM can feel down rows of single atoms.
'By varying the wavelength of laser light, we could "feel" how the surface responded.
'The response depends on the chemical bonds in the surface at that spot.'
The technique helped the researchers to pinpoint exactly where the building blocks of life, including carbon, oxygen, nitrogen and phosphate, were found within the rock.
The only building block missing was hydrogen.
The technique helped the researchers to pinpoint exactly where the building blocks of life, including carbon, oxygen, nitrogen and phosphate, were found within the rock (pictured with arrow)
Despite this, the researchers determined that hydrogen is so small that it must have seeped through the rocks.
The elements they did find were trapped within garnet crystals in sedimentary rock.
Professor Minik Rosing, co-author of the study, said: 'The materials inside the inclusions were part of the sediment, which formed more than 3.7 billion years ago.'
The researchers believe that the building blocks of life within the rock are the remains of microbes â€" possibly bacteria.
Professor Rosin said that the elements were 'still tightly bound to each other within the scale of single-celled organisms inside the garnets.'
The elements the researchers did find were trapped within garnet crystals in sedimentary rock. Pictured are different angles of the garnet crystals
These inclusions were imaged immediately after the garnets were opened and contain what appears to be liquid
Previous studies have guessed that early life could be found in the Isua Greenstone Belt, and now this study confirms these speculations.
Greenland's icy conditions were likely to have been helpful in preserving this early life, according to the researchers.
Dr Hassenkam said: 'The rocks have recently been scoured by the Greenland Ice Sheet and have little or no vegetation.'
The technique used to find the microbes is called Atomic Force Microscopy (AFM), and involves using a laser needle to scan the rock. Pictured are the images collected by the laser
The researchers believe that this lack of plant life allowed the rocks to better preserve the early life.
Professor Rosing said: 'We did something similar to what is portrayed in the movie 'Jurassic Park', but with the difference being that our time capsules were not amber, but garnet, and our samples were 50 times older and, instead of mosquitoes, we had single-celled organisms.'
The earliest signs of life were discovered in the Isua Greenstone Belt on the western coast of Greenland
The AFM technique could have a range of uses â€" many of which go beyond our planet.
Dr Hassenkam added: 'If Nasa were ever to make a sample return mission from Mars, we would be able to analyse potential traces of life inside rock samples without the need to remove the traces.
'Mapping the traces in their contextual surroundings goes a long way towards removing lingering questions about possible contamination.'
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