Re: DINODNA

[chris brochu <cbrochu@fmppr.fmnh.org>]

>Does anyone have a reference for a recent technical paper that definitively
>refutes the presence of original DNA in dinosaur bones?

I was unable to locate the reference for the paper on dinosaur DNA
specifically - if I recall correctly, they showed a definite case of
contamination in the supposed sample taken from the bone fragment from Utah.

However, I was able to dig up these, which refer to the DNA allegedly found
in insects in amber.  People have found it very hard to replicate these
observations:

Austin, J.J., A.J. Ross, A.B. Smith, R.A. Fortney, and R.H. Thomas.  1997.
Problems of reproducibility - does geologically ancient DNA survive in
amber-preserved insects?  Proc. R. Soc. London B, 264:467-474.

Walden, K.K.O. and H.M. Roberston.  1997.  Ancient DNA from amber fossil
bees?  Molecular Biology and Evolution 14:1075-1077.

The upshot - to date, the only verifiable cases of sequenceable DNA from
extinct taxa are from the recently dead - thylacines, ground sloths,
mammoths and mastodons, qaggas, moas, and some of the extinct Malagasy
lemurs.  Most pre-Quaternary instances are either demonstrably contaminant
or, as in these cases above, difficult to replicate.

It's also important to distinguish some of what Mary Schweitzer has done
with those cases that have been tossed out.  IIRC, most of the nucleic
acids she has localized are not in the form of actual sequenced DNA.
There's a big difference between the general study of ancient biomolecules
and claims of partial genes from Mesozoic animals, many of which turn out
to be cold fusion.


chris

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Christopher Brochu, Ph.D.

Postdoctoral Research Scientist
Department of Geology
Field Museum of Natural History
Lake Shore Drive at Roosevelt Road
Chicago, IL  60605  USA

phone:  312-922-9410, ext. 469
fax:  312-922-9566

cbrochu@fmppr.fmnh.org