Scientists Find Mass Extinction Cycles
Posted on March 10, 2005
SFGate.com reports that two scientists from UC Berkeley have found an interesting, but alarming, discovery after studying Earth's fossil records of 500 million years.
The scientists found that the Earth goes through a massive extinction every 62 million years. The scientists found no deviation from this pattern. Unfortunately, it has now been 65 million years since Earth's last great extinction.
The scientists have only theories as to what causes these extinctions. Some of these theories include: periodic surges of volcanism, deadly comets from the Oort Cloud and an increase in galactic gravity that causes a deadly comet shower.
About the discovery James Kirchner, a professor of earth and natural scienes at UC Berkely, told SFGate, "Their discovery is exciting, it's unexpected and it's unexplained. Everyone and his brother will be proposing an explanation -- and eventually, at least one or two will turn out to be right while all the others will be wrong."