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Author Topic:   Blood in dino bones
JonF
Member (Idle past 283 days)
Posts: 6174
Joined: 06-23-2003


Message 16 of 138 (194375)
03-25-2005 7:18 AM
Reply to: Message 1 by simple
03-24-2005 10:10 PM


Photos (including SEM shots) and comments at Tyrannosaur morsels.
Caption: Exploded T. rex vessel showing small round microstructures partially embedded in internal vessel walls.
PZ quotes from the article and then comments:
quote:
quote:
we demonstrate the retention of pliable soft-tissue blood vessels with contents that are capable of being liberated from the bone matrix, while still retaining their flexibility, resilience, original hollow nature, and three-dimensionality. Additionally, we can isolate three-dimensional osteocytes with internal cellular contents and intact, supple filipodia that float freely in solution. This T. rex also contains flexible and fibrillar bone matrices that retain elasticity. The unusual preservation of the originally organic matrix may be due in part to the dense mineralization of dinosaur bone, because a certain portion of the organic matrix within extant bone is intracrystalline and therefore extremely resistant to degradation. These factors, combined with as yet undetermined geochemical and environmental factors, presumably also contribute to the preservation of soft-tissue vessels. Because they have not been embedded or subjected to other chemical treatments, the cells and vessels are capable of being analyzed further for the persistence of molecular or other chemical information.
So, basically, these cells were entombed in a thick mineral sarcophagus, protected from bacteria and other external insults. There have to have been other factors at playcells are full of enzymes that trigger a very thorough self-destruct sequence at deathso I'm definitely looking forward to the molecular analysis. Even if their form was preserved, I expect these cells to be denatured monomer soup on the inside.
More analysis expected Real Soon Now at The Panda's Thumb, which appears to be down right now.

This message is a reply to:
 Message 1 by simple, posted 03-24-2005 10:10 PM simple has replied

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JonF
Member (Idle past 283 days)
Posts: 6174
Joined: 06-23-2003


Message 17 of 138 (194376)
03-25-2005 7:26 AM
Reply to: Message 10 by simple
03-25-2005 3:58 AM


Re: fresh blood
There is no serious question about the age of the fossils
Based on what? decay rates?
Decay rates, stratigraphy, fossil correlations, ...
It's all one big, connected, consistent web of evidence. Including lots of evidence that decay rates haven't changed. Message 53:
Observations used to establish the constancy of decay rates, include (but are not limited to):
  • Observations of nuclear reactions in distant stars and distant galaxies (for which the reactions took place thousands or millions of years ago).
  • Inferences about nuclear processes in the very early universe before galaxy formation.
  • Cross checking of dates against other non-radiometric dating methods.
  • Cross checking of radically different radiometric methods.
  • Study of residues from the Oklo natural nuclear reactor, active nearly two billion years ago.
  • Theory of quantum mechanics, which is itself one of the most precisely studied and tested models in physics. Radioactive decay is a process that is well understood. We know a great deal about the relevant forces and the structure of atoms, and how and why they decay. In fact, I would say radioactive decay is substantially better understood than gravity. This illustrates the principal that confidence in scientific models is related also to how well the underlying principals are understood.
  • Testing of a range of conditions in which decay might vary. If decay rates have varied, then can we reproduce the conditions under which this occurs? In some cases, yes; and none of them make any difference to dating techniques.

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 Message 10 by simple, posted 03-25-2005 3:58 AM simple has replied

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JonF
Member (Idle past 283 days)
Posts: 6174
Joined: 06-23-2003


Message 91 of 138 (196635)
04-04-2005 8:36 AM
Reply to: Message 81 by Incognito
04-04-2005 12:52 AM


OT: Accountability
Horner's statement regarding cutting open more dinosaur bones makes a lot of sense in light of this kind of lack of accountability in the fields of anthropology/paleontology.
What you quoted is an example of accountability in the fields of anthropology/paleontology. Professor Reiner Protsch von Zieten cheated and got caught .. by scientists.

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