Re: How many sources? @Grikath @yet another AC
a quick google tells you the story from the horses' mouth:
"The obvious question, though, was how soft, pliable tissue could survive for millions of years. In a new study published today (Nov. 26) in the journal Proceedings of the Royal Society B: Biological Sciences, Schweitzer thinks she has the answer: Iron.
Iron is an element present in abundance in the body, particularly in the blood, where it is part of the protein that carries oxygen from the lungs to the tissues. Iron is also highly reactive with other molecules, so the body keeps it locked up tight, bound to molecules that prevent it from wreaking havoc on the tissues.
After death, though, iron is let free from its cage. It forms minuscule iron nanoparticles and also generates free radicals, which are highly reactive molecules thought to be involved in aging.
"The free radicals cause proteins and cell membranes to tie in knots," Schweitzer said. "They basically act like formaldehyde."
Formaldehyde, of course, preserves tissue. It works by linking up, or cross-linking, the amino acids that make up proteins, which makes those proteins more resistant to decay.
Schweitzer and her colleagues found that dinosaur soft tissue is closely associated with iron nanoparticles in both the T. rex and another soft-tissue specimen from Brachylophosaurus canadensis, a type of duck-billed dinosaur. They then tested the iron-as-preservative idea using modern ostrich blood vessels. They soaked one group of blood vessels in iron-rich liquid made of red blood cells and another group in water. The blood vessels left in water turned into a disgusting mess within days. The blood vessels soaked in red blood cells remain recognizable after sitting at room temperature for two years."
See? Nothing miraculous about it, the blood vessel experiment pretty much speaks for itself. The bone marrow is simply metal-tanned in situ. With the bone as a container ( note that the original bone was fossilised intact.) the marrow inside would have been pretty much sterile upon death so could actually be preserved in this way. Even a hairline crack would have ruined the process though, so you'd have a hell of a time finding another specimen.
As for the specific substances you mention: she did not find hemoglobin but heme, the active compound in hemoglobin. There's a reason that stuff is safely packed up in globins in your body, y'know... Collagen doesn't surprise me at all, since that's terribly hardy stuff. In fact.. stone/iron age clothing finds that were stitched with spun tendon filaments still hold their stitches up to this day. tanned in a sealed container? who knows how long that stuff can last. Actin and tubulin.. oh you mean muscle components. They're part of the inner workings of every cell, and also really, really resistant to anything but proteases. Which degrade much faster than actin or tubulin, so any amount released upon cell death would have had no chance to eat it all, and with no bacterial action the stuff would stay there, even if the cells themselves are gone. Osteocalcin, same thing. An extremely hardy protein that needs to be specifically degraded in the body to be disposed of at all. DNA? Yes, in fragments, which is as it should be. DNA is extremely stable, and the only reason it's so damned hard to find is that bacteria love a free lunch, as the components take a lot of energy to make. DNA itself, especially repeat sequences, is extremely stable. So stable, in fact that it self-mutates to the most stable form possible if given half the chance. If left undisturbed it does indeed have a half-time measured in millennia. Wouldn't trust the code on it for one bit though.
As far as C14 dating is concerned: As far as I can find out there have been no attemtps to use any C14 dating methods on the samples the good doctor acquired. I would love it if she does an attempt on the samples she did get, and do so as publicly and peer-reviewed as possible though. the result might surprise us, but I have 5-sigma confidence that they won't be able to find any C14 beyond background. It would at least cut off another avenue of waffling for the Apologeticists.