StargateGirl
04-27-04, 03:17 PM
http://story.news.yahoo.com/news?tmpl=stor...destlifeonearth (http://story.news.yahoo.com/news?tmpl=story&cid=96&e=7&u=/space/20040422/sc_space/newcaseforoldestlifeonearth)
New Case for Oldest Life on Earth
Thu Apr 22, 5:11 PM ET
By Robert Roy Britt
Senior Science Writer, SPACE.com
Using a method never applied to rock from ancient Earth, researchers have found possible signs of biological activity dating back nearly 3.5 billion years, earlier than any other agreed-upon discovery of life on this planet.
The primordial life appears to have eaten rocks to survive.
Meanwhile, separate work is turning up intriguing similar structures in Mars rocks found on Earth, though no claims of life have yet been made with regard to this ongoing Martian investigation.
If the terrestrial finding is confirmed, it means life was thriving not long after this world had been presumably sterilized several times over by asteroid and comet impacts that were common in the earliest era of the solar system, which is about 4.6 billion years old.
The researchers found microscopic tubes in ancient, gl[arse]y lava that they say were created by microbes eating into the lava after it cooled on the ocean floor. Similar signatures of life, including genetic material, have been found in lava that formed more recently in Earth's history. Scientists generally agree that the tubes in the more modern lava were indeed creating by boring organisms.
The 3.5-billion-year-old tubes contain carbon and traces of carbonates that could represent organic material left behind by the primitive organisms. The research was led by Harald Furnes atNorway's University of Bergen and is reported in the April 23 issue of the journal Science.
Controversy continues
To me, it's unequivocal that the textures they see were created by microorganisms," petrologist Martin Fisk of Oregon State University told the journal. "I think they've got the best evidence I've seen for life at that time.
Microbial geochemist Jennifer Roberts of the University of Kansas called the evidence compelling but said it's not a smoking gun. She said nonbiological processes can create similar tube-like structures.
In a telephone interview, Fisk said he is "still open" to the interpretation that the tubes were created by something other than living things, but he added that no one has demonstrated what nonbiological process would actually be at work.
Fisk has been aware of Furnes' work for some time, and separately he's been trying to find similar microscopic signatures of life in Mars rocks that have been found on Earth. So far, he said, he's not found anything that conclusively suggests life on Mars. But in a few grains of the mineral olivine, from Mars meteorites, he's noted shapes similar to those found in terrestrial rocks by Furnes and others.
Fisk and his colleagues presented their preliminary findings last month at the Lunar and Planetary Science Conference, held in Houston.
Did Earth Life Come from Mars?
Read more--> http://www.space.com/scienceastronomy/sola...l_001025-1.html (http://www.space.com/scienceastronomy/solarsystem/meteorite_survival_001025-1.html)
New Case for Oldest Life on Earth
Thu Apr 22, 5:11 PM ET
By Robert Roy Britt
Senior Science Writer, SPACE.com
Using a method never applied to rock from ancient Earth, researchers have found possible signs of biological activity dating back nearly 3.5 billion years, earlier than any other agreed-upon discovery of life on this planet.
The primordial life appears to have eaten rocks to survive.
Meanwhile, separate work is turning up intriguing similar structures in Mars rocks found on Earth, though no claims of life have yet been made with regard to this ongoing Martian investigation.
If the terrestrial finding is confirmed, it means life was thriving not long after this world had been presumably sterilized several times over by asteroid and comet impacts that were common in the earliest era of the solar system, which is about 4.6 billion years old.
The researchers found microscopic tubes in ancient, gl[arse]y lava that they say were created by microbes eating into the lava after it cooled on the ocean floor. Similar signatures of life, including genetic material, have been found in lava that formed more recently in Earth's history. Scientists generally agree that the tubes in the more modern lava were indeed creating by boring organisms.
The 3.5-billion-year-old tubes contain carbon and traces of carbonates that could represent organic material left behind by the primitive organisms. The research was led by Harald Furnes atNorway's University of Bergen and is reported in the April 23 issue of the journal Science.
Controversy continues
To me, it's unequivocal that the textures they see were created by microorganisms," petrologist Martin Fisk of Oregon State University told the journal. "I think they've got the best evidence I've seen for life at that time.
Microbial geochemist Jennifer Roberts of the University of Kansas called the evidence compelling but said it's not a smoking gun. She said nonbiological processes can create similar tube-like structures.
In a telephone interview, Fisk said he is "still open" to the interpretation that the tubes were created by something other than living things, but he added that no one has demonstrated what nonbiological process would actually be at work.
Fisk has been aware of Furnes' work for some time, and separately he's been trying to find similar microscopic signatures of life in Mars rocks that have been found on Earth. So far, he said, he's not found anything that conclusively suggests life on Mars. But in a few grains of the mineral olivine, from Mars meteorites, he's noted shapes similar to those found in terrestrial rocks by Furnes and others.
Fisk and his colleagues presented their preliminary findings last month at the Lunar and Planetary Science Conference, held in Houston.
Did Earth Life Come from Mars?
Read more--> http://www.space.com/scienceastronomy/sola...l_001025-1.html (http://www.space.com/scienceastronomy/solarsystem/meteorite_survival_001025-1.html)