I was unaware of the dinosaur soft tissue issue.
"The controversial discovery of 68-million-year-old soft tissue from the
bones of a Tyrannosaurus rex finally has a physical explanation.
According to new research, iron in the dinosaur's body preserved the
tissue before it could decay.
The research, headed by Mary Schweitzer, a molecular paleontologist at
North Carolina State University, explains how proteins — and possibly
even DNA — can survive millennia. Schweitzer and her colleagues first
raised this question in 2005, when they found the seemingly impossible:
soft tissue preserved inside the leg of an adolescent T. rex unearthed in
Montana.
"What we found was unusual, because it was still soft and still transparent
and still flexible," Schweitzer told LiveScience.
T. rex tissue?
The find was also controversial, because scientists had thought proteins
that make up soft tissue should degrade in less than 1 million years in the
best of conditions. In most cases, microbes feast on a dead animal's soft
tissue, destroying it within weeks. The tissue must be something else,
perhaps the product of a later bacterial invasion, critics argued.
Then, in 2007, Schweitzer and her colleagues analyzed the chemistry of
the T. rex proteins. They found the proteins really did come from
dinosaur soft tissue. The tissue was collagen, they reported in the journal
Science, and it shared similarities with bird collagen — which makes
sense, as modern birds evolved from theropod dinosaurs such as T. rex.
The researchers also analyzed other fossils for the presence of soft tissue,
and found it was present in about half of their samples going back to the
Jurassic Period, which lasted from 145.5 million to 199.6 million years
ago, Schweitzer said.
"The problem is, for 300 years, we thought, 'Well, the organics are all
gone, so why should we look for something that's not going to be there?'
and nobody looks," she said.
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 lady
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. rexand 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. [Paleo-Art: Illustrations Bring
Dinosaurs to Life]
Searching for soft tissue
Dinosaurs' iron-rich blood, combined with a good environment for
fossilization, may explain the amazing existence of soft tissue from the
Cretaceous (a period that lasted from about 65.5 million to 145.5 million
years ago) and even earlier. The specimens Schweitzer works with,
including skin, show evidence of excellent preservation. The bones of
these various specimens are articulated, not scattered, suggesting they
were buried quickly. They're also buried in sandstone, which is porous
and may wick away bacteria and reactive enzymes that would otherwise
degrade the bone.
Schweitzer is set to search for more dinosaur soft tissue this summer. "I'd
like to find a honking big T. rex that's completely articulated that's still in
the ground, or something similar," she said. To preserve the chemistry of
potential soft tissue, the specimens must not be treated with preservatives
or glue, as most fossil bones are, she said. And they need to be tested
quickly, as soft tissue could degrade once exposed to modern air and
humidity.
Importantly, Schweitzer and her colleagues have figured out how to
remove the iron from their samples, which enables them to analyze the
original proteins. They've even found chemicals consistent with being
DNA, though Schweitzer is quick to note that she hasn't proven they
really are DNA. The iron-removing techniques should allow
paleontologists to search more effectively for soft tissue, and to test it
when they find it.
"Once we can get the chemistry behind some of these soft tissues, there's
all sorts of questions we can ask of ancient organisms," Schweitzer said.
Editor's Note: This article was updated at 2pm Eastern Nov. 28 to correct
unclear language about proteins and DNA.
***
and about your source....
"Bob Enyart is an American talk radio host, author, and pastor of Denver
Bible Church. He is best known for buying nearly $16,000 worth of O.J.
Simpson memorabilia, including his Hall of Fame induction certificate, at
an auction benefiting the families of Nicole Brown Simpson and Ron
Goldman in 1999, four years after the trial. He then led a group which set
fire to the items on the steps of a Los Angeles courthouse in protest at
the verdict in the O. J. Simpson murder case.[1][2] Enyart is also known
for his views on homosexuality and abortion. Enyart pickets the homes of
doctors performing abortions resulting in one Colorado town banning
such protests in residential areas.[3]Enyart also angered families of AIDS
victims when he read the men's obituaries on his television show calling
the deceased "sodomite"s.[4] Enyart has also led residential protests
against executives of a company which provided construction services for
Planned Parenthood offices leading to similar neighbor complaints.[5]
Most recently Enyart has criticised presidential candidates who do not
share his view on abortion.[6] Enyart is a proponent of corporal
punishment of children saying that their "hearts are lifted" by spanking.[7]
He was convicted for misdemeanor child abuse in 1994 after beating his
girlfriend's child with a belt so hard that the beating broke the skin.[8][9]
A series of late night phone calls by Enyart to the general manager of the
Kenosha, Wisconsin station which carried his program but publicly
disagreed with Enyart's views prompted Senator Russ Feingold to call for a
Federal Communications Commission (FCC) investigation to see if any
laws had been broken by the talk show host.[10]
In June 2009, Bob Enyart was convicted of criminal trespass following a
protest at Focus on the Family.[11]
Enyart is also the first cousin of Michael Galluccio, a gay rights activist in
New Jersey.[12]
Enyart has been called a mid-Acts ultradispensationalist.[13]
"Ultradispensationalism" is the point of view that the Church was founded
later than on the Day of Pentecost (Acts 2), persons with that point of
view differing in exactly when the Church was founded.[14]"
https://en.wikipedia.org/wiki/Bob_Enyart
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