The Washington Times-Herald

Community News Network

January 1, 2013

Fossils may date from 3.5 billion years ago

Scientists analyzing Australian rocks have discovered traces of bacteria that lived a record-breaking 3.49 billion years ago, a mere billion years after Earth formed.

If the find withstands the scrutiny that inevitably faces claims of fossils this old, it could move scientists one step closer to understanding the first chapters of life on Earth. The discovery could also spur the search for ancient life on other planets.

These traces of bacteria "are the oldest fossils ever described. Those are our oldest ancestors," said Nora Noffke, a biogeochemist at Old Dominion University in Norfolk who was part of the group that made the find and presented it last month at a meeting of the Geological Society of America.

Unlike dinosaur bones, the newly identified fossils are not petrified body parts. They're textures on the surfaces of sandstone thought to be sculpted by once-living organisms. Today, similar patterns decorate parts of Tunisia's coast, created by thick mats of bacteria that trap and glue together sand particles. Sand that is stuck to the land beneath the mats and thus protected from erosion can over time turn into rock that can long outlast the living organisms above it.

Finding the earliest remnants of this process required a long, hard look at some of the planet's oldest rocks, located in Western Australia's Pilbara region. This ancient landscape was once shoreline. Rocks made from sediment piled up billions of years ago are now exposed and available for examination. Relatively pristine in condition, such outcrops, along with others in South Africa, have long been a popular place to look for traces of life from the Archean eon, which ended 2.5 billion years ago.

There are older rocks on Earth, said Maud Walsh, a biogeologist at Louisiana State University in Baton Rouge. "But these are the best-preserved sedimentary rocks we know of, the ones most likely to preserve the really tiny structures and chemicals that provide evidence for life." Last year, another team of researchers published the discovery of microscopic fossils in Pilbara's Strelley Pool Formation, about 3.4 billion years old.

Text Only
Community News Network
  • Lindley, Tom.jpg Is this a commercial for batting gloves or a baseball game?

    Major league baseball desperately needs to speed up the action. Here's a place to start: Nix the mind-numbing ritual of hitters who first adjust the right batting glove, then the left one, after every single pitch.
     

    August 21, 2014 1 Photo

  • The Simpsons still going strong

    The groundbreaking animation first hit the air Dec. 17, 1989, but the family first appeared on television in "The Tracey Ullman Show" short "Good Night" on April 19, 1987.

    August 21, 2014

  • Does Twitter need a censor?

    Twitter decided last year to make images more prominent on its site. Now, the social network is finding itself caught between being an open forum and patrolling for inappropriate content.

    August 21, 2014

  • Police chief resigns over racial slur repost to Facebook

    A repost on his personal Facebook page of a racially-charged comment by the original poster of a comedy video has forced the police chief of an Oklahoma city to resign his office.

    August 21, 2014

  • sleepchart.jpg America’s sleep-deprived cities

    Americans might run on sleep, but those living in the country's largest cities don't appear to run on much.

    August 20, 2014 1 Photo

  • Who should pay for your kids ACT?

    Thirteen states paid for 11th-grade students in all public high schools to take the ACT college admission test this year, with several more planning to join them in 2015.

    August 20, 2014

  • Pets.jpg Why do people look like their pets?

    As much as we might quibble over the virtues and vices of Canis domesticus, however, and over whether human nature is any better or worse than dog nature, even dog fanciers don't usually want to look like a dog.

    August 20, 2014 1 Photo

  • Ice bucket challenge trending up

    Internet trends are a dime a dozen these days. Everything from Tebowing to planking to the cinnamon challenge can cause a wave of social media activity that can last for weeks before fizzling out.

    August 19, 2014

  • Africa goes medieval in its fight against Ebola

    As the Ebola epidemic claims new victims at an ever-increasing rate, African governments in Sierra Leone, Guinea and Liberia have instituted a "cordon sanitaire," deploying troops to forcibly isolate the inhabitants in an area containing most of the cases.

    August 18, 2014

  • Democrat? Republican? There's an app for that

    If you're a Republican, you might want to think twice before buying Lipton Iced Tea, and forget about Starbucks coffee. If you're a Democrat, put down that Reese's Peanut Butter Cup, and throw away the cylinder of Quaker Oats in your pantry.

    August 18, 2014