nlsherrill said:
I have read/heard about this for awhile now and I haven't really read any good explanations for this. Does anyone know how exactly soft tissue could be preserved for so long?...assuming it is indeed >60 million years old?
The article that you posted talked about the preservation of organic molecules millions of years after the animals died. Although this is rare, it does not violate any known laws of chemistry. There is no known law claiming that the chemicals in tissues have to disappear after a long time.
The main reasons of tissues decay is because microorganism eat the molecules. If the soft tissue is isolated from microorganisms soon after death, then the molecules can live a long time.
Proteins in an organism left to them selves are generally unstable because they polymerize. The smaller molecules start sticking together to form very long molecules. These long molecules often resist digestion by microorganisms. However, smaller segments of these long molecules have the same shape as the smaller molecules that made up the polymer. For example, if an antibody sticks to another protein molecule, the active site on the molecule may remain active. Unless some tough microorganism dissolves the polymer, the antibody may remain active a long time.
This is probably what happened to the tissues of the dinosaur. The tissues didn’t remain intact. Most of the molecules probably polymerized. This happens in mummies and other preserved bodies. Minerals definitely seeped into the tissues. Note that these tissues did not keep the consistency of the original tissues. Visually, they were indistinguishable from the rock. Some of the chemical properties remained the same, but the tissue was unrecognizable as tissue.
Some microorganisms digest their food externally. They emit chemicals that break down proteins and other molecules. This causes much of the decay seen in dead organisms. However, these microorganisms can live only under certain conditions.
Microorganisms need certain things to live. All microorganisms need water. If the body is dried out rapidly and stays dry, then some of the molecules can last forever. Egyptian mummies are the most famous case of bodies preserved by dessication. The most active microorganisms need oxygen to live. Therefore, isolating a body from oxygen slows down decay a long while even while the body is immersed in water. The bodies found in peat bogs are a famous example of preservation by anaerobic conditions.
There is no scientific evidence that organic molecules eventually break down without microorganisms. As far as has been established so far, most molecules in a dry anaerobic environment will last forever.
Most bodies are exposed to living microorganisms after death. Usually, the bodies are exposed to both water and oxygen sometime after death. The water contains microorganisms that eat up the soft tissues. However, this is not always the case.
Here are two articles on bodies that have been preserved under “natural conditions” for more than one thousand years. Although I have chosen examples of bodies “only” thousands of years, note that there is theoretical limit to how long these bodies could have lasted. The statement that body tissues can last “at most” a few thousand years is false.
http://en.wikipedia.org/wiki/Mummy
“Mummies that are formed as a result of naturally-occurring environmental conditions, such as extreme coldness (Ötzi the Iceman, the Ice Maiden, the Llullaillaco child mummies), acid (Tollund Man), salinity (Salt Man), or desiccating dryness (Tarim mummies), have been found all over the world. More than a thousand Iron Age corpses, so called bog bodies, have been found in bogs in northern Europe, such as the Yde Girl and the Lindow Man.[24] Natural mummification of other animal species also occurs; this is most common in species from shallow saline water environments, especially those with a body structure which is particularly favourable to this process, such as seahorses and starfish. Old mummies such as the dinosaurs Leonardo, Dakota, and the Trachodon mummy in America were very valuable discoveries.”
https://www.google.com/#hl=en&tbo=d...a378127ae23922&bpcl=39314241&biw=1024&bih=605
“The bog bodies of Northern Europe are human cadavers who have been naturally mummified within the peat bogs found in various parts of the continent. Such bodies, sometimes known as bog people, are both geographically and chronologically widespread, having been dated to between 9000 BCE and the Second World War.[1] The only unifying factor of the bog bodies is that they have been found in peat and are partially preserved; the actual levels of preservation vary widely, from those which are perfectly preserved to those who have survived as nothing more than a skeleton.[2]
Unlike most ancient human remains, bog bodies have retained their skin and internal organs due to the unusual conditions of the surrounding area. These conditions include highly acidic water, low temperature, and a lack of oxygen, combining to preserve but severely tan their skin. Despite the fact that their skin is preserved, their bones are generally not, as the acid in the peat dissolves the calcium phosphate of bone.”
The scientific study of what happens to bodies after death is called taphonomy.
http://en.wikipedia.org/wiki/Taphonomy
“The taphonomic pathways involved in relatively inert substances such as calcite (and to a lesser extent bone) are relatively obvious, as such body parts are stable and change little through time. However, the preservation of "soft tissue" is more interesting, as it requires more peculiar conditions. While usually only biomineralised material survives fossilisation, the preservation of soft tissue is not as rare as sometimes thought.”
