Dispatches from the Creation Wars

Recovering Ancient Proteins

Researchers have managed to reconstruct a protein from a T. Rex fossil and in the process they’ve provided more evidence for the bird/dinosaur link.

Researchers have decoded proteins from a 68 million-year-old Tyrannosaurus rex, the oldest such material ever found. The unprecedented step, once thought impossible, adds new weight to the idea that today’s birds are descendants of the mighty dinosaurs…

What Asara’s team found was collagen, a type of fibrous connective tissue that is a major component of bone. And the closest match in creatures alive today was collagen from chicken bones.

But beyond that specific finding, this ability to reconstruct protein sequences from tiny amounts of soft tissue preserved in a fossil that is otherwise mineralized could lead to something scientists have long thought impossible – the ability to compare protein sequences of living animals to extinct animals.

“The door just opens up to a whole avenue of research that involves anything extinct,” said Matthew T. Carrano, curator of dinosaurs at the Smithsonian’s National Museum of Natural History.

While dinosaur bones have long been studied, “it’s always been assumed that preservation does not extend to the cellular or molecular level,” said Mary Higby Schweitzer of North Carolina State University.

It had been thought that some proteins could last a million years or more, but not to the age of the dinosaurs, she said.

So, when she was able to recover soft tissue from a T. rex bone found in Montana in 2003 she was surprised, Schweitzer said.

And now, researchers led by John M. Asara of Beth
Israel Deaconess Medical Center in Boston have been able to analyze proteins from that bone.

The genetic code that directs the development of living things is the DNA, but that is more fragile and they didn’t find that.

“But proteins are coded from the DNA, they’re kind of like first cousins,” Schweitzer said…

Horner, who found the bones studied by Schweitzer and Asara, said this is going to change the way paleontologists go about collecting specimens — they will now be looking for the best preserved items, often buried in sand or sandstone sediments.

This summer, he said, his museum is organizing nine different field crews involving more than 100 people to search for fossils in Montana and Mongolia.

Asara explained that he was working on a very refined form of mass spectrometry to help detect peptides — fragments of proteins — in tumors as part of cancer research.

In refining the technique, he had previously studied proteins from a mastodon, and when he heard of Schweitzer’s finding soft tissues in a T. rex bone he decided to see if he could detect proteins there also.

He was able to identify seven different dinosaur proteins from the bone and compared them with proteins from living species. Three matched chickens, two matched several species including chickens, one matched a protein from a newt and the other from a frog.

Co-author Lewis Cantley of Harvard Medical School noted that this work is in its infancy, and when it is improved he expects to be able to isolate more proteins and seek more matches.

Every scientific advance seems to be sold in the popular media by breathless announcements, but this truly could be a revolutionary breakthrough for evolutionary biology. However, you will also immediately hear the young earth creationists claiming that this shows that those bones can’t really be millions of years old; it’s a stupid argument, but what else other kind do they have?

Comments

  1. #1 quork
    April 13, 2007

    Interesting, the same journalist is also credited with this story:
    Researchers decode T Rex genetic material
    Collagen is genetic material? And the article I found is dated a day later than yours. Weirdness.

  2. #2 dogmeatib
    April 13, 2007

    The first thing that ran through my head was creationists arguing, “See, this proves they died in the Flood!” Of course at the same time either ignoring the dino-bird link, or claiming that God was just reusing a “good code.”

  3. #3 SWT
    April 13, 2007

    However, you will also immediately hear the young earth creationists claiming that this shows that those bones can’t really be millions of years old; it’s a stupid argument, but what else other kind do they have?

    Or you’ll hear the usual suspects say that these results show common design … which is in the same category of argument …

  4. #4 Brian
    April 13, 2007

    You know, anybody who has taken biochemistry and has looked at the plots of free energy change by catalysis knows that things like hydrolysis of a single peptide bond have a half life in the range of hundreds of years. It’s always been somewhat hard to internalize that kind of knowledge – after all, leave your protein at room temperature on the bench overnight and it gets screwed up – misfolded, etc.

    But it’s amazing that if you bottle some protein up in bones for millions of years, you still have some surviving peptide chains. I doubt that this is going to be revolutionary for evolutionary biology – soft tissue in fossilized bones is vanishingly rare and not enough protein will survive to really do anything more than confirm what we already know. It’s still really cool though, and kind of a reaffirmation of what humanity can do. Yes, we do kill each other all the time, and when we get together in large groups we’re generally pretty terrible, but we can sequence 65 million year old protein.

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