New evidence found for the oldest oxygen-breathing life on land

October 19, 2011

New University of Alberta research shows the first evidence that oxygen-breathing bacteria occupied and thrived on land 100 million years earlier than previously thought.

The researchers show the most primitive form of aerobic respiring life on land came into existence 2.48 billion years ago.

The research team, led by U of A geomicrobiologist Kurt Konhauser made their find by investigating a link between atmospheric oxygen levels and rising concentrations of chromium in the rock of beds. The researchers suggest that the jump in chromium levels was triggered by the land-based oxidization of the mineral pyrite.

Pyrite oxidation is driven by bacteria and oxygen. Aerobic bacteria broke down the pyrite, which released acid at an unprecedented scale. The acid then dissolved rocks and soils into a cocktail of metals, including chromium, which was transferred to the ocean by the runoff of .

Konhauser says the key to the process is oxygen in Earth's atmosphere that allowed bacterial oxidation of pyrite. The researchers dated the peak for chromium levels in marine was reached 2.48 billion years ago.

"This gives us a new date for the Great Oxidation Event, the time when the atmosphere first had oxygen," said Konhauser. "The rising levels of atmospheric fostered the evolution of new that survived by aerobic respiration on land.

"Our ancestors started off in an acid bath as oxygen-breathing bacteria."

The same bacterial life forms are alive and well today, living off pyrite and settling in the highly acidic waste waters of mining sites the world over.

The research by Konhauser and his team is published in the October 20 edition of the journal Nature.

Explore further: The earliest blacksmiths may have been bacteria

Related Stories

The earliest blacksmiths may have been bacteria

October 16, 2008

(PhysOrg.com) -- Talk about a Cold Case. This mystery goes back to when there was no oxygen on the planet and bacteria were the most sophisticated life form. But Kurt Konhauser holds a clue to answering some ancient questions. ...

Did a nickel famine trigger the 'Great Oxidation Event'?

April 8, 2009

(PhysOrg.com) -- The Earth's original atmosphere held very little oxygen. This began to change around 2.4 billion years ago when oxygen levels increased dramatically during what scientists call the "Great Oxidation Event." ...

Oxygen-free early oceans likely delayed rise of life on planet

January 10, 2011

Geologists at the University of California, Riverside have found chemical evidence in 2.6-billion-year-old rocks that indicates that Earth's ancient oceans were oxygen-free and, surprisingly, contained abundant hydrogen sulfide ...

Recommended for you

Growing Arctic carbon emissions could go unobserved

June 28, 2016

A new NASA-led study has found that in at least part of the Arctic, scientists are not doing as good a job of detecting changes in carbon dioxide during the long, dark winter months as they are at monitoring changes during ...

Previously unknown global ecological disaster discovered

June 28, 2016

There have been several mass extinctions in the history of the earth with adverse consequences for the environment. Researchers from the University of Zurich have now uncovered another disaster that took place around 250 ...

What did Earth's ancient magnetic field look like?

June 24, 2016

New work from Carnegie's Peter Driscoll suggests Earth's ancient magnetic field was significantly different than the present day field, originating from several poles rather than the familiar two. It is published in Geophysical ...

Study: Rotting trees caused mysterious holes in huge dunes

June 25, 2016

Mysterious holes that forced the closure of a massive dune at an Indiana national park after a 6-year-old boy fell into one and nearly died were caused by sand-covered trees that left cavities behind as they decayed over ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Martian
1 / 5 (2) Oct 19, 2011
I hope they got the date right this time.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.