Sci. & Tech.
Life begun on Earth 'earlier than thought'Washington (PTI): Complex life forms may have evolved on Earth 400 million years earlier than previously thought, a new study of fossils has suggested.
An international team, led by Birger Rasmussen of the Curtin University of Technology, has conducted the study in India which it claims opens a whole new window onto the beginning of life on our planet.
"New sampling of the Vindhyan basin in India has confirmed the presence of fossils older than has been previously accepted. These fossils, which are more than 1.6 billion years old, are likely to be more than a billion years older than what was previously accepted for fossils found in this region.
"They are also between 400 and 600 million years older than any multi-cellular life found anywhere on the planet," Prof Rasmussen said.
According to the researchers, the reason for the differences in the result from this test compared to earlier research was that the team used world's best practices to get the job done right.
"This was the first independent test done in the region. Previous reports were based on material separated in Indian labs, which may have been contaminated by other rock samples.
"The team that I worked with wanted to avoid prospects of contamination, so we made sure the fossils were separated from the surrounding rocks in labs that we were certain could do the job correctly.
"The age of the fossils was determined using lead dating of the phosphorate in the fossils. This is deposited with the organic material that becomes fossilised when it is buried in the sea floor, billions of years ago.
"This form of testing is generally very accurate when we are looking at a time scale of over a billion years," Prof Rasmussen said.
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http://www.hindu.com/thehindu/holnus/008200906231231.htm