A Day and Night of Brahma: The Evidence from Fossil Records (cont.)
By Bibhu Dev Misra (IIT, IIM)
Certain variations of the 26 million year cycle have also been identified by other researchers. In 2005, two scientists of UC Berkeley, Muller and Rohde, relooked at the data investigated by Raup and Sepkoski, and identified a 62 million year cycle of mass extinction, which appears to be a 'multiple' of the 26 million year cycle identified by Sepkoski. Muller and Rohde presented their findings in the March 10, 2005 issue of the journal Nature. They had considered only 17,797 genera (out of the total 36,380 considered by Sepkoski) since they eliminated those with uncertain ages and those with only a single occurrence. Muller and Rohde then tried to fit a smooth, best-fit trend curve through the data, which did not accurately fit the data, since the periods of extinctions show a sudden drop while the period of recovery has gentle slopes. However, the 26 million year cycle has been corroborated by a number of detailed analyses carried out by Sepkoski, Rampino, Caldeira and other scientists, which establishes the periodicity of the mass extinction events and also confirms that there must be a single, cyclical underlying cause for these events.
It would be fair to conclude, on the basis of the above analysis, that the 24 million year cycle of creation and destruction, comprising of a 'Day of Brahma' and a 'Night of Brahma', is embedded in the fossil records of the planet earth. There is no consensus, however, in the scientific community regarding what causes these periodic extinction events. When Muller and Rohde had published their findings they conceded that they had carefully analyzed every conceivable phenomenon in nature in search of an explanation: "We've had to think about Solar System dynamics, about the causes of comet showers, about how the galaxy works, and how volcanoes work, but nothing explains what we've discovered," Muller said. "We're getting frustrated and we need help. All I can say is that we're confident the cycles exist, and I cannot come up with any possible explanation that won't turn out to be fascinating. There's something going on in the fossil record, and we just don't know what it is."