Originally Posted by Nick Hallandale
Quotation from Wikipedia..."EXTINCTION"
Through evolution, new species arise through the process of speciation—where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche—and species become extinct when they are no longer able to survive in changing conditions or against superior competition. A typical species becomes extinct within 10 million years of its first appearance, although some species, called living fossils, survive virtually unchanged for hundreds of millions of years. Most extinctions occur naturally, without human intervention: it is estimated that 99.9% of all species that have ever existed are now extinct
2.^ a b c Newman, Mark. "A Mathematical Model for Mass Extinction". Cornell University. May 20, 1994. Retrieved July 30, 2006.
3.^ a b Raup, David M. Extinction: Bad Genes or Bad Luck? W.W. Norton and Company. New York. 1991. pp. 3–6 ISBN 978-0-393-30927-0
Yeah, I've read that before. I'm not asking for an estimate. This is simple math -- if there are 2 million extant species on Earth, there should be 1.98 billion extinct species. Or 1.9 billion if you want to go with your original percentage. Has anybody got the numbers?