Aussie rocks could be earliest life forms
Ker Than
MSNBC
_____
They resemble upside-down ice cream cones or egg cartons, but a new analysis suggests that the odd sedimentary structures found in Western Australia are among the earliest signs of life on the planet.
Called "stromatolites," the structures are believed to be about 3.4 billion years old. Since they were first described nearly 30 years ago, scientists have see-sawed between attributing them to the work of ancient microbes or hydrothermal vent activity.
But in a new study detailed in the June 8 issue of the journal Nature, Australian researchers argue that the shapes of the stromatolites are too complex and diverse to have been formed by physical processes.
Abigail Allwood of Macquarie University in Sydney and colleagues analyzed a 6-mile stretch of the rock formations and identified seven different types of stromatolites.
Allwood said her team was able to recover a few scraps of organic matter from the site which they will begin analyzing soon. The sample is so small, however, that it is difficult to say much more about the organisms that made the stromatolites than that they were microbial, Allwood told LiveScience.
If the stromatolites do turn out to have a biologic origin, it could change how scientists think about life on early Earth.
If the stromatolites were formed by microbes, then life must have adapted to normal, non-extreme environments even as early in the planet's history as 3.4 billion years ago. Earth is about 4.5 billion years old. Furthermore, life by that time would have already diversified enough to form complex ecosystems.
June 07, 2006
Ker Than
MSNBC
_____
They resemble upside-down ice cream cones or egg cartons, but a new analysis suggests that the odd sedimentary structures found in Western Australia are among the earliest signs of life on the planet.
Called "stromatolites," the structures are believed to be about 3.4 billion years old. Since they were first described nearly 30 years ago, scientists have see-sawed between attributing them to the work of ancient microbes or hydrothermal vent activity.
But in a new study detailed in the June 8 issue of the journal Nature, Australian researchers argue that the shapes of the stromatolites are too complex and diverse to have been formed by physical processes.
Abigail Allwood of Macquarie University in Sydney and colleagues analyzed a 6-mile stretch of the rock formations and identified seven different types of stromatolites.
Allwood said her team was able to recover a few scraps of organic matter from the site which they will begin analyzing soon. The sample is so small, however, that it is difficult to say much more about the organisms that made the stromatolites than that they were microbial, Allwood told LiveScience.
If the stromatolites do turn out to have a biologic origin, it could change how scientists think about life on early Earth.
If the stromatolites were formed by microbes, then life must have adapted to normal, non-extreme environments even as early in the planet's history as 3.4 billion years ago. Earth is about 4.5 billion years old. Furthermore, life by that time would have already diversified enough to form complex ecosystems.
June 07, 2006
