Oldest known fossils prove life began more than 3.4bn years ago

 

The fossilised remains of the oldest known lifeforms on Earth have been discovered in samples of rock collected near a remote watering hole in the middle of the Australian Outback.

Scientists said that the microscopic fossils belonged to primitive bacteria that lived more than 3.4 billion years ago, when the Earth had emerged from a period when it was probably too hostile for life. The primitive microbes used sulphur instead of oxygen to generate energy from food and, the scientists said, they may be the closest that science will ever get to the mysterious origin of life on Earth.

The fossils were found in rocks that were originally formed in shallow seas near a coastline and suggest that beaches may have been the key habitat where the Earth's first lifeforms thrived, said David Wacey, of the University of Western Australia.

"The environment in which the microfossils were found is important – it extends the record of life in shoreline or beach-like environments by about 200 million years. This suggests that beaches could have been the setting for the origin of life itself," he said.

"The discovery gives good solid evidence for life over 3.4 billion years ago. It confirms there were bacteria at this time, living without oxygen."

The Earth is estimated to be about 4.5 billion years old but the planet's hostile, meteorite-bombarded environment is thought to have been too inhospitable for life to get going until about 3.8 billion years ago. Previous studies have indicated the presence of similar microfossils in 3.5 billion-year-old rocks but these claims have been disputed. The latest microfossils have been subjected to an exhaustive series of tests which have confirmed that they were once living cells, not merely the product of non-living chemical reactions. They were discovered in rock that was sandwiched between layers from two well-dated volcanic eruptions, which narrowed the fossils' date of origin to within a few tens of millions of years.

"That's very accurate when the rocks are 3.4 billion years old," said Professor Martin Brasier of the University of Oxford, co-leader of the study, published in the journal Nature Geoscience. "At last we have good solid evidence for life over 3.4 billion years ago. It confirms there were bacteria at this time, living without oxygen. Such bacteria are still common today. Sulphur bacteria are found in smelly ditches, soil, hot springs, hydrothermal vents – anywhere where there's little free oxygen and they can live off organic matter."

Oxygen appeared in significant quantities in the atmosphere only after the evolution many millions of years later of plant-like microbes which could use sunlight for photosynthesis, producing oxygen as a by-product. Until that point, life on Earth had to make do with sulphur, which can be metabolised in a similar way to obtain energy from food. "I believe we are as close as we have ever been to the very first microbes here... The problem we now have is that there are very few rocks older on Earth in which to search for anything more primitive," Dr Wacey said. The scientists found the microfossils in the Pilbara, a remote region of Western Australia with a harsh environment of spiky vegetation and red dust.

News
A Brazilian wandering spider
news

World's most lethal spider found under a bunch of bananas

News
people
Arts and Entertainment
Tim Wonnacott dancing the pasadoble
TVStrictly Come Dancing The Result
Sport
Mario Balotelli pictured in the win over QPR
footballInternet reacts to miss shocker for Liverpool striker
PROMOTED VIDEO
Voices
Sol Campbell near his home in Chelsea
voices
News
<p>Jonathan Ross</p>
<p>Jonathan Ross (or Wossy, as he’s affectionately known) has been on television and radio for an extraordinarily long time, working on a seat in the pantheon of British presenters. Hosting Friday Night with Jonathan Ross for nine years, Ross has been in everything from the video game Fable to Phineas and Ferb. So it’s probably not so surprising that Ross studied at Southampton College of Art (since rebranded Southampton Solent), a university known nowadays for its media production courses.</p>
<p>However, after leaving Solent, Ross studied History at the School of Slavonic and East European Studies, now part of the UCL, a move that was somewhat out of keeping with the rest of his career. Ross was made a fellow of the school in 2006 in recognition of his services to broadcasting.</p>
TV

Rumours that the star wants to move on to pastures new

News
Kimi the fox cub
newsBurberry under fire from animal rights group - and their star, Kimi
Arts and Entertainment
filmsIt's nearly a wrap on Star Wars: Episode 7, producer reveals
Life and Style
fashion
Arts and Entertainment
Russell Brand labelled 'left-wing commie scum' by Fox News
TV
News
ebooksAn unforgettable anthology of contemporary reportage
News
Paul Nuttall, left, is seen as one of Ukip's key weapons in selling the party to the North of England
i100
Arts and Entertainment
BBC's Antiques Roadshow uncovers a TIE fighter pilot helmet from the 1977 Star Wars film, valuing it at £50,000
TV

TV presenter Fiona Bruce seemed a bit startled by the find during the filming of Antiques Roadshow

News
people

Comedian says he 'never laughed as hard as I have writing with Rik'

News
i100
Life and Style
tech
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

1st Line Technical Support Engineer

£22000 Per Annum: Clearwater People Solutions Ltd: Our client based in Thame i...

Graduate Project Manager

£25000 Per Annum: Clearwater People Solutions Ltd: Our client based in Chelmsf...

Drama Teacher

£110 - £135 per day: Randstad Education Chelmsford: We are seeking a Drama tea...

Science teacher

£110 - £130 per day: Randstad Education Chelmsford: We are seeking a languages...

Day In a Page

Oscar Pistorius sentencing: The athlete's wealth and notoriety have provoked a long overdue debate on South African prisons

'They poured water on, then electrified me...'

If Oscar Pistorius is sent to jail, his experience will not be that of other inmates
James Wharton: The former Guard now fighting discrimination against gay soldiers

The former Guard now fighting discrimination against gay soldiers

Life after the Army has brought new battles for the LGBT activist James Wharton
Ebola in the US: Panic over the virus threatens to infect President Obama's midterms

Panic over Ebola threatens to infect the midterms

Just one person has died, yet November's elections may be affected by what Republicans call 'Obama's Katrina', says Rupert Cornwell
Premier League coaches join the RSC to swap the tricks of their trades

Darling, you were fabulous! But offside...

Premier League coaches are joining the RSC to learn acting skills, and in turn they will teach its actors to play football. Nick Clark finds out why
How to dress with authority: Kirsty Wark and Camila Batmanghelidjh discuss the changing role of fashion in women's workwear

How to dress with authority

Kirsty Wark and Camila Batmanghelidjh discuss the changing role of fashion in women's workwear
New book on Joy Division's Ian Curtis sheds new light on the life of the late singer

New book on Ian Curtis sheds fresh light on the life of the late singer

'Joy Division were making art... Ian was for real' says author Jon Savage
Sean Harris: A rare interview with British acting's secret weapon

Sean Harris: A rare interview with British acting's secret weapon

The Bafta-winner talks Hollywood, being branded a psycho, and how Barbra Streisand is his true inspiration
Tim Minchin, interview: The musician, comedian and world's favourite ginger is on scorching form

Tim Minchin interview

For a no-holds-barred comedian who is scathing about woolly thinking and oppressive religiosity, he is surprisingly gentle in person
Boris Johnson's boozing won't win the puritan vote

Boris's boozing won't win the puritan vote

Many of us Brits still disapprove of conspicuous consumption – it's the way we were raised, says DJ Taylor
Ash frontman Tim Wheeler reveals how he came to terms with his father's dementia

Tim Wheeler: Alzheimer's, memories and my dad

Wheeler's dad suffered from Alzheimer's for three years. When he died, there was only one way the Ash frontman knew how to respond: with a heartfelt solo album
Hugh Bonneville & Peter James: 'Peter loves his classic cars; I've always pootled along fine with a Mini Metro. I think I lack his panache'

How We Met: Hugh Bonneville & Peter James

'Peter loves his classic cars; I've always pootled along fine with a Mini Metro. I think I lack his panache'
Bill Granger recipes: Our chef's heavenly crab dishes don't need hours of preparation

Bill Granger's heavenly crab recipes

Scared off by the strain of shelling a crab? Let a fishmonger do the hard work so you can focus on getting the flavours right
Radamel Falcao: How faith and love drive the Colombian to glory

Radamel Falcao: How faith and love drive the Colombian to glory

After a remarkable conversion from reckless defender to prolific striker, Monaco's ace says he wants to make his loan deal at Old Trafford permanent
Terry Venables: Premier League managers must not be allowed to dictate who plays and who does not play for England

Terry Venables column

Premier League managers must not be allowed to dictate who plays and who does not play for England
The Inside Word: Brendan Rodgers looks to the future while Roy Hodgson is ghost of seasons past

Michael Calvin's Inside Word

Brendan Rodgers looks to the future while Roy Hodgson is ghost of seasons past