Claim: Fossil record shows more than 99% of all species in history now extinct

Factual Questions
1

In the January 2013 Scientific American (Vol 308, Number 1) a commentary by Jacob Tanenbaum repeats a claim I have heard in various forms.

This claim is made in the context of an article that chides literal Creationists for lack of scientific evidence. But where did he get his numbers?

I don’t see how the author’s claim could possibly be true. I’ve no doubt that huge numbers of species have gone extinct. And I find it quite possible in the eons of life’s evolution that many more have gone extinct than are alive today. But do we really have fossil evidence that supports this 99% claim?

This article from PLOS Biology estimates some 8.7 million species alive today. This article from livescience.com puts the estimated range at 5 to 100 million with the note that only about 2 million have been identified by science.

To uphold the author’s claim of fossil evidence for 99%+ species having gone extinct we would need fossil evidence of 861.3 million species based on the PLOS numbers. A range of 495 million to a staggering 9.9 billion species based on the livescience.com numbers - or a mere 198 million species if only counting identified species.

In an argument with Creationists using numbers you cannot support with evidence certainly does no favor to your side. So is there really fossil evidence for such huge numbers of extinct species or is this a claim that needs to be re-examined?

2

I always understood it to be an estimate. Some logical arguments go into it:

  1. Soft-bodied organisms will never be fossilized, except maybe their outer form which is rare (ex: stromatolites.) For a bony or hard-bodied organism, paleontologists give it a 1:1,000,000 chance that it will become a fossil (here’s another wild number.)

  2. Succession of flora and fauna in the fossil record tells you extinction of a species and emergence of a new one is the rule, not the exception.

  3. Because of #1, MOST (say, 99%?) of species that have lived and died out will never be known to us.

The above do not at all imply that all flora and fauna are going to die out anytime in the future. New species will keep emerging. What we worry about is depletion of flourishing species.

3

Already being discussed.

4

Since the OP has been under discussion for a few days in another thread, I’ll close this one.

samclem, moderator