From Steve (ste ves igns@bi gp ond.c om):
Re: Neanderthals had Siberian kin, study finds (Dec. 24): 30-40000 year old bones with genentic material still intact? Why is it then, that we have NO known dinosaur DNA? Most fossils only contain minerals - genetic material has long since vanished. The apparent ease with which modern DNA can infiltrate ancient remains has led many researchers to doubt even those studies employing the most rigorous methods to weed out contamination by modern genetic material. Professor Paabo told BBC News: That has made me think: 'how can I trust anything on this'?
1 Comments:
Neanderthal DNA may be more recent than that. Google "The Story of Zana." Russian colleagues unearthed her son's grave and procured his highly unusual skull, hoping to have ancient DNA studies done on it.
As for why DNA would survive in ancient Neanderthal but not dinosaur remains, suffice it to say that they were not fossilized whereas all known dino bones are fossils.
One thing ancient DNA recovery does is record and digitize gene sequences from the sample that can be run though a search program for matching sequences in a giant genome database. In the case of a contaminated sample, yes, the contaminant DNA would almost certainly be found and would show up in the genome database. After all, even a mouse shares 70% of our genes. However, a contaminant would hardly create an utterly "new" sequence and that's one of the things researchers are looking for in ancient DNA.
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