Spented twice time as much as any previous one, Scientists researched the so-called "extincted events" which has happened on earth over the past 5 billion years. This study proved mass-extictions happened with a regular time pattern.
Spentedtwicetime as much as anyprevious one, Scientistsresearched the so-called "extinctedevents" which has happenedonearthover the past 5 billion years.