Ancient DNA indicates bacteria have not undergone millions of years of generations

Bacteria revived from ancient materials, including halite crystals, consistently show almost no divergence of sequences by comparison with their modern counterparts!This is leading mainstream researchers to briefly propose that the modern counterparts have also been dormant for the same time. This is immediatley rejected becasue this would require all bacterial taxa which have been compared with ancient sources to have had the same dormancy.The "most scrupulous and well-documented" procedures designed to rule out any chance of contaminaiton with modern sources has shown 250 My old bacteria sample "2-9-3", for example, to be almost identical to modern day Salibacillus marismortui at RNA and protein coding genes. These should have been significantly changed sequences after 250 My and yet show 99% identity at the DNA nucleotide level.

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Almost without exception, bacteria isolated from ancient material have proven to closely resemble modern bacteria at both morphological and molecular levels. H. Maughan et al Mol Biol Evol 19: 1637-1639 (2002)

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So much for the molecular clock. Either almost all bacteria have hybernated for the last 250 My, despite proliferating today, or maybe these ancient strata are not separated from us by millions of years. The molecular clock may simply measure taxonomic differnce and not time as this data cries out! It of course would measure time if that time had transpired. We do not doubt the principle of the clock but we doubt the reality of the time period.[This message has been edited by Tranquility Base, 10-21-2002]

MammuthusI appreciate your skepticism. However, if creationists are right then it all makes complete sense. The controls used in recent ancient DNA work are very carefully done. And this journal of high reputaiton as well as Maughan him/herself et al treat it seriously.For the laymen here let me outline the sorts of controls. You do the work with and without the halite crystal. You only get that bacteria when you use that crystal. OK so it could be something growing in the container that you kept the crystal in. So you keep a similar container for he same time without the crystal in it. And then when you get the sequence it is still unique even though it closely matches a modern strain. You can check up that it does not match any known strain exactly.I do not doubt the plasticity of the genome. I doubt how long it has been plastic.I think these studies have progressed to the next level Mammuthus.[This message has been edited by Tranquility Base, 10-21-2002]

MammuthusThe ancient DNA regions of this bacteria studied are coding regons (functional RNA and proteins) so we expect some degree of conservation. But not 99% if it were 250 My old. Much of the non-coding regions would have scrambled no doubt since it can happen in only 10,000 generations as you rightly point out.

MammuthusGetting into Nature isn't easy. They would have had to do pretty much state of the art controls. If you disagree I respect that but I still equally respect the Nature referees.YECism certainly does make the prediction that ancient bacteria would not deonstrate millions of years worth of mutations. I'll list a whole bunch of predicitons of YECism in a new thread when I've got time.I simply listed the obvious controls that would have been done and you listed some even better ones. Yes I am a layman on ancient DNA but not a garden variety one. I would be very surprised if their controls didn't eliminate every possibility other than the bugs having got into the crystal in situ (ie whilst in the stratum).Anyway, it's a pleasure to have 'met' a genuine ancient DNAer.