Seems like big things do indeed come in small packages! For decades now scientists were more or less convinced that the great mass extinction that occurred towards the end of the Permian period was caused most likely by volcanic activity.
Nearly 90 percent of all known species on the planet were wiped out some 252 million years ago in one nig stroke. This is till date the largest known mass extinction in earth’s history and new evidence suggests that the murderers were Methanosarcina which sucked carbon out of the seas and turned it into carbon dioxide and methane.
This soon suffocated the existing life form and caused a catastrophic change in ocean cycles.
Dr. Rothman’s team collected evidence from three independent sources to prove this theory of extinction. First, the geochemical evidence in the oceans showed a sudden and major increase in carbon content during the end of the Permian period.
This was further supported by genetic proof that shows a change in Methanosarcina, a microbe that produces methane, at the same time.
Finally, a sudden spurt in carbon deposits along with nickel observed in the layers of earth belonging to the period, confirmed the theory. But Dr.
Rothman does not rule out the role of volcanoes completely and says that while the methane-making microbes were the major killers, carbon dioxide spewed from giant volcanoes of the time also helped in making the atmosphere even more poisonous. So, what is the verdict you ask? A gang of killers led by microbes have been pronounced guilty!