Deep beneath the surface, worms and ‘zombie microbes’ rule

2013-03-06 00:00

A DARK realm far beneath the Earth’s surface is a surprisingly rich home for tiny worms and “zombie microbes” that may hold clues to the origins of life, scientists said on Monday.

“It’s an amazing new world,” said Robert Hazen, head of the Deep Carbon Observatory, a decade-long $500 million project to study the planet’s carbon, an element vital to life and found in everything from oil to diamonds.

“It’s very possible that there’s a deep microbial biosphere that goes down more than 10 km, maybe 20,” Hazen told Reuters of the first book by the Observatory, published on Monday and written by more than 50 experts in nine countries.

Microbes had been reported, for instance, in rocks recovered by drilling more than six kilometres below the surface in China’s Songliao Basin, he said. And tiny worms have been found in fractures in rocks 1,3 km deep in a South African mine.

The single-celled microbes found deep underground include bacteria, which need water and nutrients to grow but not necessarily oxygen, and archaea, which can live off compounds such as ammonia or sulphur.

A lack of food in what the 700-page report called the “Stygian realm” — after the River Styx of the underworld in Greek mythology — meant some microbes might be “zombies”, or so slow-living as to seem dead.

The book, Carbon in Earth, said some microbes may live deep below ground and grow and reproduce extremely slowly or perhaps even “live without dividing for millions to tens of millions of years”.

Hazen, who works at the Carnegie Institution of Washington, DC, said the scientists working on the project, which began in 2009, were also studying the possibility that life on Earth might have originated underground.

“You have everything you need to make life,” he said, including energy, water and carbon-rich molecules that could have made the underground zone, rather than the surface of the planet, the cradle of the very first life on Earth.

“We think of the deep subsurface as extreme, but it’s really quite protected — from asteroids or from volcanic eruptions,” he said. “Deep sub-surface rocks are a nice, safe haven.”

And the ability of microbes to survive almost indefinitely in rocks on Earth also raises the possibility that rocks from Mars, which had liquid water before Earth, could have seeded our planet with life.

Rocks from Mars sometimes land on Earth after asteroid strikes on Mars blow debris into space. “It’s possible that every single cell on Earth is descended from a Martian. That’s not crazy science fiction,” Hazen said.

The scientists also found viruses deep underground. Unlike those at the surface, those in the energy-poor subsurface typically insert their genes into microbes without seeking to reproduce aggressively, apparently waiting for better conditions.

“This role of virus as parasite, as mutualist, and as a sharer of information through gene transfer may be a fundamental underpinning of life in the deep subsurface,” the book suggests.

It says underground microbial life should be studied more to ensure that plans for deep burial of nuclear waste, or carbon dioxide from power plants as part of a strategy to combat climate change, would not be destabilised by microbes.

Among other research, the scientists are trying to find out whether there are major sources of oil and gas and methane produced by chemical reactions deep in the Earth, rather than from the well-understood process of ancient surface vegetation being buried and crushed under high pressure.

They will also study diamonds, which form at high pressures deep in the Earth, beyond the depths of current drilling. And they will try to map where the Earth’s carbon is stored, from the crust to the core.

“A problem is that a huge part of the system is inaccessible,” Rajdeep Dasgupta, an expert at Rice University in Texas, said. Part of the study will aim to recreate temperatures and conditions of the deep in the laboratory.

— Reuters.

Join the conversation!

24.com encourages commentary submitted via MyNews24. Contributions of 200 words or more will be considered for publication.

We reserve editorial discretion to decide what will be published.
Read our comments policy for guidelines on contributions.
NEXT ON NEWS24X

24.com publishes all comments posted on articles provided that they adhere to our Comments Policy. Should you wish to report a comment for editorial review, please do so by clicking the 'Report Comment' button to the right of each comment.

Comment on this story
0 comments
Comments have been closed for this article.

Inside News24

 
/News

Book flights

Compare, Book, Fly

Traffic Alerts
There are new stories on the homepage. Click here to see them.
 
English
Afrikaans
isiZulu

Hello 

Create Profile

Creating your profile will enable you to submit photos and stories to get published on News24.


Please provide a username for your profile page:

This username must be unique, cannot be edited and will be used in the URL to your profile page across the entire 24.com network.

Settings

Location Settings

News24 allows you to edit the display of certain components based on a location. If you wish to personalise the page based on your preferences, please select a location for each component and click "Submit" in order for the changes to take affect.




Facebook Sign-In

Hi News addict,

Join the News24 Community to be involved in breaking the news.

Log in with Facebook to comment and personalise news, weather and listings.