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Re: DNA at last
> I copied this out of the San Jose Mercury News this morning.
> US TEAM EXTRACTS FRAGMENTS OF DNA FROM DINOSAUR
> Paleontologist Jack Horner, and advisor on Steven Spielburg's hit
> about dinosaurs, managed to isolate fragments of DNA from the
femur of a
> Tyrannosaurus Rex, the Sunday Times reported.(me: what Sunday
times? The London Sunday Times?)
Betty sent this in. I guess that my earlier email did not transmit. I
copied the original from the Sunday Times and made a few comments
The method used is PCR (polymerase chain reaction). This method is
prone to contamination. I have heard of one case where an organism
being studied in an adjacent lab was able to contaminate a sample.
The sample was contaminated anyway by being touched, being in
contact with airborne organisms, and having been taphonomically
altered by bacteria. Basically, the PCR "amplifies" fragments of DNA
so that they can be identified. The problem is that the contaminents
are also "amplified" or multiplied, and it is virtually, if not wholly,
impossible to distinguish what is a fragment of dino-DNA and
I took part in a course on taxonomy at Glasgow recently where PCR
was covered. The conclusion was that the results obtained for fossil
material over 10,000 years old are unreliable.
Curator of Palaeontology
University of Glasgow
The first law of Geology is the law of supposition.
(Geological Howlers - ed. WDI Rolfe)