Researchers propound new theory on evolution of complex life forms
28 Oct 2010
According to a new theory, the world was covered in ice 750 million years ago. Canadian and American researchers suggest that the theory could also explain the initial explosion of complex life on earth.
In their paper published in Nature, this week, biogeochemists at the University of California, the University of Manitoba and the University of Alberta conclude that the oceans in the period during the thaw of "Snowball Earth" were rich in phosphorous - an element essential to life in the oceans.
The Snowball Earth hypothesis, which finds much supporting evidence, suggests that the earth was covered in a thick blanket of snow and ice over millions of years in the Neoproterozoic era, between 750 million and 635 million years ago.
During that period, according to lead researcher Noah Planavsky and his adviser Timothy Lyons both from the University of California - large amounts of phosphorous were transferred by glacial erosion and chemical weathering from land to the oceans.
According to Lyons, while speculation that glaciation would have delivered phosphorus to the ocean have been there, no one had ever found evidence for it.
The team arrived at its conclusion after analysis of hundreds of iron oxide mineral samples from all over the world dating back to the era in question.
