You might think that this debate over viable fossil DNA will persist for some time since there is yet no answer to the problem; However, this same kind of debate has occurred before. In the past, the fact that fossils still had identifiable amino acids after millions of years of being buried, and it had created quite a stir in the 1950s and 1960s. But since a reasonable answer that allows amino acids to still exist, after millions of years, was not forth coming, all research on the problem eventually stopped.
Contamination and the actual age of the samples are the two main alternate explanations to the long age explanation that the fossil DNA has been buried for an extremely long period of time. The contamination aspect of the Lab work is a very real possibility and thus it is one of the major addressed issues facing any project involving PCR amplification of Fossilized DNA. However, these workers are being extremely cautious in their work and I might not expect that all these groups would have contamination as their major product. . . Although it is possible.
One interesting possibility is that if these samples are truly much younger then expected, as would be expected in the Creationary model, then there should be more viable DNA then expected in the samples. That would make the contamination problem of PCR to be less of a problem. Of course, evolutionists would not expect their samples to be a younger. They would expect the contamination problem to be almost insurmountable. If DNA truly does not last for millions of years, as is expected from calculations, it would be expected that all PCR results would be that of contamination.
If you look at the reference (Halobacteria: the evidence for longevity. Grant WD, et. al. ) located below on this web page I think you will find this paper especially interesting!
They said that they might predict that the DNA code, when comparing similar bacteria found in the ancient evaporite with those in the surface environment, that a difference would be noted. Instead, they find essentially no difference. No difference after hundreds of millions of years? Either evolution has not occurred over millions of years or the two alternate explanations of contamination and sample age could be a very real possibility.
Very interesting. It seems that there should be some change after all that time. The two heterogeneous copies of the 16S rRNA gene show, according to current thinking, the possibility of evolutionary events, rearrangements of DNA, and or gene duplication. Etc. How would this non-difference between the two populations of bacteria, separated by time, affect our views on the Biological clock rates? (The changing of DNA over time.) How might it affect our understanding of how viable the theory itself is if we keep coming up with little or no change after as much as 250 million years? We will have to see if this absence of a trend, having little or no change in the genetic code, continues.
It is postulated that different species change (Biological clock rate) at different rate. The Halobacteria example might be considered to be an example where the evolutionary rate is frozen. I do not know enough about Biological clock rates to know if this is reasonable within evolutionary theory. Anyone out there know?
Presently, the likelihood is very good that either we are looking at contaminants or these samples are not as old as is being reported. If researchers continue to keep coming up with little or no change after long periods of time suggesting an absence of a trend, having little or no change in the genetic code; Then the possibility that the ages of the fossilized samples must be questioned.
Some of the journal articles are cited below with abstracts if available.
DNA sequences from a fossil termite in Oligo-Miocene amber and their phylogenetic
implicat