(April 2, 2012 at 10:40 am)Phil Wrote:(April 2, 2012 at 10:38 am)Styper Wrote:(April 2, 2012 at 10:27 am)Chuck Wrote: Not true. We have no firm grounds to even count species for the 3.3 billion years before 540 million years ago. If average life span of a species is 5 million years, and did not simply change gradually into a daughter species, then only 95% ought to be extinct in 100 million years. If 10 million years, then 90%. if sizeable fraction of species are continuous evolving into daughter species and not just dying off leaving no descendants, then the rates would be lower.
Wouldn't new species be a branch of the former one? The concept of "daughter" would be if a species literally evolved into another, but what we get is a species branching from the original one and, in some cases, replacing it as the dominant form thus making it extinct.
Getting back to the original question, the estimate on wikipedia is 99.9%.
Thanks. Although we can't have a real number due to lack of information that seems about right.
“That which is asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
― Christopher Hitchens
