Re: Pliocene Park - 1.8 mya Hominid DNA

["Christopher Lavers" <Chris.Lavers@nottingham.ac.uk>]

If this does hold up it'd be extraordinary. The current survival limit for 
accesible and amplifiable unbound DNA (i.e. not tightly attached to a mineral 
surface) is widely thought to be c.50-100,000 years. On the basis of chemical 
kinetics alone this 'result' shouts contamination. Ready to eat my hat though...
C

>>> Richard W Travsky <rtravsky@uwyo.edu> 07/31/01 02:16am >>>
Not dinosaurs but interesting if it holds up. Might still be hope for
Crichton's mosquitos...

 http://allafrica.com/stories/200107260275.html 

 Links to Ancient Man in DNA Find?
 Mail & Guardian (Johannesburg)

 July 27, 2001 
 Posted to the web July 26, 2001 

 Shaun Smillie

 If the find at a local World Heritage Site is authenticated, it could be
 the oldest such sample yet extracted.

 Two researchers claim that they have extracted the DNA of a
 1,8-million-year-old hominid from microscopic traces of blood found on
 stone tools excavated at the Sterkfontein Caves.

 It is a discovery, scientists say, that could revolutionise the study of
 ancient DNA and the origins of mankind.

 "The DNA we have found is something between a chimpanzee and a human,
 which suggests a hominid," explains Wits University micro
 archaeologist Bonnie Williamson.

 Williamson and Professor Tom Loy of the University of Queensland believe
 that this DNA sequence is that of either our direct ancestor
 Homo habilis or Paranthropus robustus. If their findings are verified it
 would be the oldest DNA yet extracted.
 ...
 The DNA they have sequenced is one base point of that of human DNA. In
 comparison, the DNA of a chimpanzee, human's closest relative,
 is three base points away from that of a human's.

 What Loy feels gives credibility to the research is that both he and
 Williamson, his PhD student, got the same results using different
 techniques and working in laboratories on different continents.

 Loy had discovered the minute quantities of blood on the Sterkfontein
 stone tools several years ago while examining them under an electron
 microscope. "Blood is a remarkably tough residue that can survive for
 long periods of time. Even artefacts that have been washed in
 laboratories often still have traces of blood on them," he says.

 To extract the DNA from the blood sample Loy used a technique called
 polymerase chain reaction to replicate the short strands of DNA.
 Care had to be taken to avoid modern DNA contamination of the sample.

 Some scientists have expressed caution over Loy and Williamson's claim.
 There have been false alarms in the study of ancient DNA. In 1995
 a scientist announced that he had extracted DNA from an
 80-million-year-old dinosaur bone. Other researchers concluded that the
 dinosaur DNA was that of a mammal.
 ...
 "We took all the necessary precautions, we used bleach to sterilise
 surfaces and ultraviolet light to destroy any other modern DNA," says
 Loy, who in the past 12 years of ancient DNA research has had only one
 contamination.