Religions > Atheism > T. rex analysis supports dino-bird link {Cretinists are once again screwed}
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Religions > Atheism |
| User: |
"stoney" |
| Date: |
12 Apr 2007 02:02:37 PM |
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T. rex analysis supports dino-bird link {Cretinists are once again screwed} |
http://www.msnbc.msn.com/id/18075420/
T. rex analysis supports dino-bird link
Technique pioneers method for studying biology of extinct species
By Alan Boyle
Science editor
MSNBC
Updated: 2:44 p.m. ET April 12, 2007
For the first time, researchers have read what they say is the
biological signature of a tyrannosaur a signature that confirms the
increasingly accepted view that modern birds are the descendants of
dinosaurs.
The signature doesn't come from studying the shape of the 68
million-year-old dinosaur's fossilized bones, but from analyzing the
organic material found inside those bones. It's not DNA despite what
you've seen in movies like "Jurassic Park," that genetic material
couldn't be recovered. But researchers say it's the next-best thing:
collagen proteins that were isolated using techniques on the very edge
of what's possible today.
Those techniques, detailed in Friday's issue of the journal Science,
could open up "a new window into an entirely new approach" for
paleontology, one expert told MSNBC.com. What's more, researchers say
the methods are already being incorporated into improved tools for
detecting present-day diseases.
We dont know what the possibilities are, said Mary Schweitzer, a
paleontologist at North Carolina State University and the North Carolina
Museum of Natural Sciences who was one of the principal authors behind
the studies. Were starting right now with a particular goal in mind,
but the spin-offs
how this might apply to human health and our
understanding of disease
all of that is yet to be seen.
Schweitzer and her colleagues emphasized that the protein analysis was
just the first step in what could become a worldwide effort to
categorize extinct species according to their molecular makeup. Famed
paleontologist Jack Horner, another member of the research team, said he
would embark on a world-girdling series of expeditions this summer to
see if further samples could be found.
All of our morphological hypotheses based on fossils need to be tested.
Every one of them, said Horner, a paleontologist at Montana State
University and the Museum of the Rockies.
Tale of a T. rex
The tale of the T. rex began with Horner, back in 2003: He and his team
found the tyrannosaur's massive leg bone beneath 1,000 cubic yards of
rock at the Hell Creek fossil site in Montana, but had trouble fitting
the bone inside their helicopter for the airlift back to the lab.
When they broke the bone into pieces for transport, they were amazed to
find that some of the dinosaur's soft tissues appeared to be preserved
within. Previously, paleontologists had thought all the tissues of a
fossil turned to minerals over the course of millions of years.
After analyzing the tissues under a microscope, Schweitzer reported in
2005 that they looked similar to the cells and blood vessels found in
ostrich bones. But at that time, "we could not directly address what
that material was made of," she said during a teleconference with
journalists this week.
Schweitzer suspected that some of the material was preserved collagen
protein which is the main organic constituent of bone, left behind
when the minerals are removed. She said the material looked like
collagen, and it reacted like collagen when chicken antibodies were
applied to a sample.
But to confirm her suspicions, Schweitzer turned to John Asara, a
specialist in mass spectrometry at Harvard Medical School and Beth
Israel Deaconess Medical Center. Mass spectrometry is a technique for
identifying minute quantities of a substance by measuring its atomic
properties, molecule by molecule. Asara and Schweitzer had worked
together previously to isolate protein sequences from mammoth remains
that dated back 100,000 to 300,000 years.
The T. rex task was much more challenging: After removing the minerals
and impurities from the bone samples that Schweitzer provided, Asara had
less than a billionth of a gram of protein to work with. Nevertheless,
he and his colleagues were able to decode seven strings of protein
molecules. Those sequences were compared with a large database of
collagen data including sequences that Asara and his team isolated
from a modern ostrich and from mastodon bone fragments that were 160,000
to 400,000 years old.
Scientists hit protein paydirt
The researchers took pains to make sure that they had the right
sequences to compare, going so far as to create and analyze synthetic
proteins that were modeled on the natural proteins in order to check
their results. The 74 mastodon sequences were closely related to
sequences from the bones of mammalian species, ranging from humans to
elephants but four of them appeared to be unique to the mastodon,
Asara said.
In contrast, Asara's team had only those seven T. rex protein sequences
to work with, and it turned out all of them matched up with modern-day
sequences.
"Out of seven total sequences, we had three that matched chicken
uniquely," Asara told reporters. "We had another that matched frog
uniquely, one that matched newt uniquely, and a couple that matched
multiple sequences."
The bottom line was that the T. rex's biological signature was most like
a bird's, at least based on the first fragmentary data. "It looks like
chicken may be the closest among all species that are present in today's
databases for proteins and genomes," Asara said.
One reporter even wondered whether roasted T. rex might have tasted like
chicken. "That could be true," said Asara, going along with the joke.
The researchers said they were heartened to see that different sequences
matched the unique signatures of more than one species. That "pretty
much convinced us this was very unlikely to be due to contamination,"
Asara said.
Linkage to birds ... and more?
The close link to birds was also reassuring, said Thomas Holtz, a
paleontologist at the University of Maryland at College Park who was not
involved in the research but was familiar with the findings. "It would
be totally astonishing if it were any result but that," he told
MSNBC.com.
Like other paleontologists, Holtz said the most significant aspect of
the newly published findings was what they promised for the future: the
application of molecular biology to a field that in the past has been
based solely on fossils in rocks. He stressed that the true power of the
technique would come into play when other samples can be analyzed.
"Once more of them get sampled, then we can start being able to compare
the extinct with the extinct," he said. "Then they could really support,
or overturn, previous hypotheses. The results of this paper aren't so
much that they have made an important contribution to our understanding
of T. rex or mastodons, but rather that they are opening a window into
an entirely new approach to these fossils."
Horner told journalists that the findings already have strengthened the
dinosaur-bird connection: "It's the first way we can test the hypothesis
of relationships. ... This is a test, and we have failed to falsify that
dinosaurs and birds are related. It changes our hypothesis to a theory
now."
There'll be some changes made
The successful test could lead to changes in the way fossil-hunters do
their work. Schweitzer and her colleagues speculated that the tissue
within the Hell Creek leg bone was so well preserved because the fossil
was created in sandstone, where water and chemicals that might have
destroyed the proteins could leach away more easily. Also, Horner's team
did not apply preservatives to the broken bone that might have destroyed
the proteins.
"The big issue here is that these are special fossils," Phil Andrews, an
expert on protein analysis at the University of Michigan, told
MSNBC.com. "These Hell Creek fossils are exceptionally well preserved,
and that's what makes this possible."
Horner's expedition, involving more than 100 people on nine field crews,
would be aimed at finding other fossils that fit the specifications for
biological samples. "We're going worldwide looking for exquisite
preservation ... looking for specific specimens that are deep in
sediments," he told reporters. He said the first sites on his list were
Hell Creek and Mongolia's Gobi Desert.
Andrews said Asara's team employed some innovative methods to construct
the synthetic sequences that could be used for comparison. Those methods
as well as the search-engine techniques developed for matching up the
T. rex sequences could have wide application to other fields of study,
including evolutionary biology, Andrews said.
Peggy Ostrom, a zoologist at Michigan State University and a pioneer in
sequencing the proteins of extinct species, emphasized that the field
was still only in its infancy. She told MSNBC.com that the current
effort was like trying to reconstruct the contents of an entire
newspaper from just a couple of scraps.
"What we need to do is accumulate these mass spectra in huge
repositories, like ProteomeCommons.org, so we can compare those small
differences, and start developing an understanding of these evolutionary
relationships," Ostrom said.
Medical implications
The research has implications for human health as well, said Lewis
Cantley, a colleague of Asara's at Harvard and Beth Israel Deaconess and
a co-author of the Science research. He explained that the mass
spectrometry technique was initially used to develop new protein-based
tests for prostate cancer and other diseases and the advances made in
the course of the T. rex analysis would feed back into that effort.
"We're hoping that one can actually pick up mutations in the proteins
that would infer what the DNA mutations were," he said. That could lead
to new tests for catching cancer at the disease's earliest stages.
Asara said there were already experiments applying the new techniques to
human diseases, although he didn't go into detail.
"We are finding mutations at the protein level," he said. "The
bioinformatic technology that was developed for the fossil is being
applied to human disease."
In addition to Schweitzer, Horner, Asara and Cantley, the researchers
involved in the Science studies included Zhiyong Suo, Recep Avci, Mark
Allen and Fernando Teran Arce of Montana State University in Bozeman;
and Lisa Freimark and Matthew Phillips of Beth Israel Deaconess Medical
Center in Boston. The teams received financial support from the National
Science Foundation and the David and Lucille Packard Foundation.
Schweitzer had additional support from NASA, and Asara had added support
from the Paul F. Glenn Foundation.
--
Fundies and trolls are cordially invited to
shove a wooden cross up their arses and rotate
at a high rate of speed. I trust you'll
be 'blessed' with a plethora of splinters.
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| User: "johac" |
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| Title: Re: T. rex analysis supports dino-bird link {Cretinists are once again screwed} |
13 Apr 2007 01:40:39 AM |
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In article <mmvs13phvtgkqst6p1koq3di2852a9prhp@4ax.com>,
stoney <stoney@the.net> wrote:
http://www.msnbc.msn.com/id/18075420/
T. rex analysis supports dino-bird link
Technique pioneers method for studying biology of extinct species
By Alan Boyle
Science editor
MSNBC
Updated: 2:44 p.m. ET April 12, 2007
For the first time, researchers have read what they say is the
biological signature of a tyrannosaur a signature that confirms the
increasingly accepted view that modern birds are the descendants of
dinosaurs.
I think we just filled in another one of the 'gaps'.
<snip>
--
John #1782
"We should always be disposed to believe that which appears to us to be
white is really black, if the hierarchy of the church so decides."
- Saint Ignatius Loyola (1491-1556) Founder of the Jesuit Order.
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| User: "satyr" |
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| Title: Re: T. rex analysis supports dino-bird link {Cretinists are once again screwed} |
12 Apr 2007 08:37:08 PM |
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On Thu, 12 Apr 2007 12:02:37 -0700, stoney <stoney@the.net> wrote:
"Out of seven total sequences, we had three that matched chicken
uniquely," Asara told reporters.
Surprise, surprise. T. Rex tastes like chicken.
--
satyr #1953
Chairman, EAC Church Taxation Subcommittee
Director, Gideon Bible Alternative Fuel Project
Supervisor, EAC Fossil Casting Lab
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