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Re: Statistics and the fossil record



--Original Message-- From: Jonathan R. Wagner <znc14@TTACS.TTU.EDU>
Date: 07 November 1998 20:16



>        I must admit that I am neither a statistician, nor an avid follower
>of the statistics/fossilization/phylogeny arguments which have been
>occurring on the list. My brief perusal of these debates has lead me to the
>conclusion that participants may not be giving sufficient consideration to
>the nature of the terrestrial stratigraphic record as it relates to
>vertebrate fossil deposits.
[snip]
>        To help you along, I'll give a brief summary of some of the
>highpoints of the problem:
>        1) Rock does not equal time[snip]
>        2) Sedimentary rocks do not form everywhere: [snip]
>        3) Sedimentary rocks do not last forever: [snip]
>        5) Fossilization is rare: [snip]
>        6) Fossilization potential is variable: [snip]
>        7) Fossil accumulations are not always a snaphot of a fauna:[snip]
>        8) World faunal diversity is variable in space and time: [snip]
>


Thanks Jon, but I have taken all that into account.


> Your sample is therefore inappropriate for many statistical methods.

Do you mind if I take the liberty to repeat your first words here?:

>        I must admit that I am neither a statistician, nor an avid follower
>of the statistics/fossilization/phylogeny arguments which have been
>occurring on the list. My brief perusal of these debates . . .


A lot of people are saying they're not sure if stats can be applied to
fossils.  I would be more impressed if someone gave me an answer to the
question of why so many small pterosaurs are found in the J and not the K,
but pinnants (except Archae) are found in the K but not the J.  How much
evidence vs. absence of evidence do we need?  They have found small
olshevskyian bones in the Tendaguru, so some small arborial-type stuff was
found there, but no larger "cursorial" maniraptorans.  The ground there and
in the Morrison has been scoured.  Do you know how many turtles/crocs/small
herbivores have been found in just those two formations?

They've found as much dinosuar material in the tertiary as they have pinnant
material pre-Archae - but not many people say "Oh - geology is too
complicated, and you can't trust statistics, can you?  No, there may have
been be dinos in the tertiary."

JJ