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Posted on 11/13/2002 1:16:37 PM PST by dead
The first complete sequencing of protein from a fossil bone suggests that proteins can survive for millions of years - long enough to probe the evolution of many extinct species, including the ancestors of modern humans.
For many years, biologists have deduced evolutionary relationships from the visible features of living animals and fossils. Molecular biology has given them a new tool for living animals - comparing DNA sequences. However, DNA survives for only a short time after death, so paleontologists have been limited to comparing the shapes and sizes of the bones of extinct species.
But analyzing ancient proteins now gives them a new option, says Christina Nielsen-Marsh of the University of Newcastle, because their amino acid sequences reflect genetic codes.
The big advantage of proteins is their stability in suitable environments. Pieces of DNA large enough to sequence using sensitive amplification techniques can survive for 100,000 years in permafrost. But osteocalcin, a structural protein that bonds directly to the minerals of bone, lasts much longer.
Matthew Collins, also at Newcastle University, estimates that osteocalcin can survive for more than 100 million years at 0 °C, and for some 10 million years at 10 °C. That would be long enough to look back some six or seven million years to the last common ancestor of humans and chimpanzees.
Exact match
To show the potential of their technique, Nielsen-Marsh and colleagues sequenced the amino acids in osteocalcin extracted from bones of the extinct steppe bison (Bison priscus) found in permafrost in Siberia and Alaska. Both bones are a minimum of 55,000 years old, the limit of carbon dating.
The complete sequences of amino acids exactly matched that of the modern bison (Bison bison). They differ by a single amino acid from modern cattle, which are thought to have diverged from bison at least a million years ago. Previous work has detected - but not isolated or sequenced - proteins in 120 million year old dinosaur bone.
Although osteocalcin sequences diverge slowly, they can probe evolution over millions of years. "Human evolution, is the most exciting of the possibilities," says Peter Hauschka of the Harvard Medical School, US, who worked with Nielsen-Marsh. Osteocalcins differ by a few amino acids in humans, chimps and orangutans, he says, so they could help identify the nearest living relatives of suitable fossils.
Hominid fossils are few and far between, and it could be hard to persuade anthropologists to give them up for the destructive analysis. Yet teeth also contain osteocalcin, and they are much more common fossils.
Osteocalcin itself may not be able to determine the puzzling lineages of australopithecines and humans over the past two million years, but the method could be applied to other proteins that might give a clearer picture.
Journal reference: Geology (vol 30, p 1099)
A couple of comments. The precision seems to be quite good. The particular protein, osteocalcin, may not be very informative or specific for short time-frames, such as 55,000 years in the case of the bison, but it will be informative for long time frames. Can you see now how that can be a useful way of extracting more information from ancient fossils?
Originally the word liberal meant social conservatives(no govt religion--none) who advocated growth and progress---mostly technological(knowledge being absolute/unchanging)based on law--reality... UNDER GOD---the nature of GOD/man/govt. does not change. These were the Classical liberals...founding fathers-PRINCIPLES---stable/SANE scientific reality/society---industrial progress...moral/social character-values(private/personal) GROWTH(limited NON-intrusive PC Govt/religion---schools)!
Evolution...Atheism-dehumanism---TYRANNY(pc/liberal/govt-religion/rhetoric)...INCOHERENCE*
Then came the SPLIT SCHIZOPHRENIA/ZOMBIE/BRAVE-NWO1984 LIBERAL NEO-Soviet Darwin/ACLU America---the post-modern APE* age
*...new!
Now is your chance to make some accurate predictions, since this new technology has just been developed.
Make your predictions, and we will see just how accurate you are in a year or so.
Evolution...Atheism-dehumanism---TYRANNY(pc/liberal/govt-religion/rhetoric)...INCOHERENCE*
Then came the SPLIT SCHIZOPHRENIA/ZOMBIE/BRAVE-NWO1984 LIBERAL NEO-Soviet Darwin/ACLU America---the post-modern APE*age of switch-flip-spin-DEFORMITY-cancer...Atheist secular materialists through ATHEISM/evolution CHANGED-REMOVED the foundations...demolished the wall(separation of state/religion)--trampled the TRUTH-GOD...built a satanic temple/SWAMP-MALARIA/RELIGION(cult of darwin-marx-satan) over them---REDACTED and made these absolutes subordinate--relative and calling/CHANGING all the... residuals---technology/science === TO evolution via schlock/sMUCK IDEOLOGY/lies/bias...to substantiate/justify their efforts--claims...social engineering--PC--atheism...anti-God/Truth RELIGION(USSC monopoly)--and declared a crusade/WAR--JIHAD--INTOLERANCE/TYRANNY(breaking the establishment clause)...against God--man--society/FREEDOM/LIBERTY/SCIENCE!!
*...new!
Ted Holden, a/k/a medved, was banned in mid-September for re-posting some of his stuff that had recently been deleted. He came back, briefly, under another name, but was soon banned again.
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We know, that is why I was asking you to make some predictions. If your predictions turn out to be accurate, then you will have verified your side of the debate.
If they turn out false, then....
Everyone liked the guy and he did good work. But when he talked about a subject, it was impossible for anyone to figure out what he said. He could talk for 45 minutes about an issue, but nobody could figure it out.
He was very intelligent and you knew he was telling you something important. But try as we might, nobody was ever able to figure out what he was talking about.
One day a friend of mine made this simple observation:
"Listening to him is like reading a printout of a fragmented hard disk. You know there is important information contained in it, but it is so scattered, it is impossible to comprehend."
Just teasing, but you must admit, those previous posts on this thread are rather unique.
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