'Microbe led to mass extinction 251m years ago'
LONDON: A humble microbe, instead of a devastating meteorite or a
catastrophic volcanic eruption, wiped off over 90% of the species on
Earth 251-million-years ago, scientists believe. According to prevailing
theory, the mass extinction at the end of the Permian period was
triggered by volcanic eruptions over a vast area of what is now Siberia, which led to a dramatic rise in greenhouse gas emissions.
However, according to Daniel Rothman of MIT, the scenario just doesn't fit the facts.
From his analysis of an end-Permian sediment sample from China, Rothman says carbon levels surged much too quickly for geological processes to be at work. Microbes can generate carbon compounds that fast.
As his group analysed the genome of Methanosarcina - a methanogen responsible for most of biogenic methane - they found that it gained this ability 231m years ago. Methanosarcina needs large amounts of nickel to produce methane quickly. The team discovered that nickel levels spiked 251m years ago in the sediment samples. This suggests Methanosarcina did trigger the extinction
However, according to Daniel Rothman of MIT, the scenario just doesn't fit the facts.
From his analysis of an end-Permian sediment sample from China, Rothman says carbon levels surged much too quickly for geological processes to be at work. Microbes can generate carbon compounds that fast.
As his group analysed the genome of Methanosarcina - a methanogen responsible for most of biogenic methane - they found that it gained this ability 231m years ago. Methanosarcina needs large amounts of nickel to produce methane quickly. The team discovered that nickel levels spiked 251m years ago in the sediment samples. This suggests Methanosarcina did trigger the extinction
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