Sunday, May 3, 2009

Dinosaurs Probably Did Walk With Humans

Multiple hadrosaur red blood "cells" surrounded by white, fibrous matrix (Image: Mary H. Schweitzer)

It’s official: soft tissue, including blood vessel proteins and structures resembling cells, have been recovered from dinosaur bone. Mary Schweitzer’s amazing claim in 2005 was subsequently disputed as possible contamination from biofilms. Now, Schweitzer and her team took exceptional precautions to avoid contamination by excavating hadrosaur bone from sandstone said to be 80 million years old. A short description of her findings, and a picture of the tissue, was announced today by New Scientist. The paper followed shortly after in the May 1 issue of Science.(1) A press release from Schweitzer’s institution, North Carolina State University, says that the preservation of soft tissue in this duck-billed dinosaur fossil was even better than the material from the T. Rex bone analyzed in 2005.

Robert F. Service commented on the finding in the same issue of Science.(2) He was a little cautious, putting the word ‘protein” in quotes in his title, but then he said this:

"A controversial finding that protein fragments can be recovered from dinosaur fossils has been replicated for the first time. Two years ago, Mary Schweitzer, a paleontologist at North Carolina State University in Raleigh, and colleagues stunned the paleontology community when they reported discovering intact protein fragments in a fossil from a Tyrannosaurus Rex that died 68 million years ago. The claim has remained contentious, because proteins in tissue normally degrade quickly after an animal dies. On page 626, however, Schweitzer and colleagues report finding an even larger number of protein fragments from an 80-million-year-old fossil from a duck-billed dinosaur, or hadrosaur, known as Brachylophosaurus canadensis.

'This will either be nothing or the biggest revolution in paleontology ever,' says Tom Kaye, a paleontologist at the Burke Museum in Seattle, Washington, and a critic of the original T. Rex study."

Service went on to say that “Collagen, the principal protein in connective tissue, is rarely found in fossils more than a few hundred thousand years old.” Taking five as a few, that means this discovery would require believing it has lasted 160 times as long.

In response to criticisms of the 2005 paper, Schweitzer’s team took extra care in the extraction and analysis of the specimen. They used sterilized instruments to extract the bone samples and rushed them to the lab in sealed jars. Two independent groups analyzed the samples. “Both groups then independently performed biochemical and antibody-binding studies that showed evidence of collagen as well as laminin and elastin, two proteins found in blood vessels,” Service reported. In addition, two independent teams used better mass spectrometry methods, and both confirmed the presence of collagen. One of the specialists, John Asara of Harvard Medical School, said, “This proves the first study was not a one-hit wonder.”

What will critics say now? Service ended by quoting Martin McIntosh of the Fred Hutchinson Cancer Research Center in Seattle, a critic of the first study. McIntosh appeared uneasy with the implications. “I’m not saying it’s true,” he said, holding out hope for an alternate explanation. “But I cannot right now make a plausible argument that it’s not true.” He added, “The door is closing on plausible alternatives.”

The original paper primarily documented the details of the extraction and analysis. Chris Organ (Harvard) also performed a phylogenetic analysis, indicating enough primary material was available for comparison. Despite the press release’s confidence that the proteins showed a link to birds, the data presented in the paper was more ambiguous and required some tweaking to produce a tree.(3) That, however, is what Science seemed to emphasize, stating in the summary that “Analysis of well-preserved tissues from an 80-million-year-old hadrosaur supports the dinosaur-bird relationship.”

Here’s how the original paper ended its announcement of replicated results that show the material is endogenous (original with the bone). With appropriate scientific caution, they listed the evidence pointing to the confirmation of the hypothesis that the protein fragments once were part of a living dinosaur:

"The hypothesis that endogenous proteins can persist across geological time, as first reported for T. rex (MOR 1125), was met with appropriate skepticism. However, the inclusion of additional sequence data from extant reptiles and B. canadensis strengthens the hypothesis that the molecular signal is preserved at least to the Late Cretaceous.

"The submicron differences in texture (Fig. 1 and fig. S1), elemental differentiation, sub-'cellular' inclusions in osteocytes and vessels, identification of the posttranslational Pro-OH modification not produced by microbes, differential binding of antibodies by both in situ and immunoblot studies, collagen protein sequences, and phylogenetic analyses do not support a microbial origin for either these microstructures or peptide fragments. Coupled with evidence for cross-linking and unusual chemical modifications, the congruence of evidence strongly supports an endogenous origin for this material. The most parsimonious explanation, thus far unfalsified, is that original molecules persist in some Cretaceous dinosaur fossils. Still unknown is the chemistry behind such preservation."

The paper also includes photographs of structures that resemble cells. While they were cautious not to call them cells, they sure look like the real thing. They used various lines of evidence to rule out bacterial contamination.(4) This indicates the protein studied with mass spectrometry was not relegated to isolated fragments, but was retained in original cellular structures. Were these cells really 80 million years old?
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1. Schweitzer, Zheng, Organ, Avci, Sui, Freimark, Lebleu, Duncan, Vander Heiden, Neveu, Lane, Cottrell, Horner, Cantley, Kalluri and Asara, “Biomolecular Characterization and Protein Sequences of the Campanian Hadrosaur B. canadensis,” Science, 1 May 2009: Vol. 324. no. 5927, pp. 626-631, DOI: 10.1126/science.1165069c.
2. Robert F. Service, “Paleontology: ‘Protein’ in 80-Million-Year-Old Fossil Bolsters Controversial T. rex Claim,” Science, 1 May 2009: Vol. 324. no. 5927, p. 578, DOI: 10.1126/science.324_578.
3. Excerpt from (1): “Under a majority-rule criterion to building a consensus tree, Dinosauria (the group containing the two extinct dinosaurs and the two birds) collapsed into a three-way polytomy. Removing T. rex from the phylogeny resulted in a three-way polytomy as well. The amount of missing data in B. canadensis and T. rex sequences relative to extant samples resulted in relatively low resolution within Dinosauria, but even so, the phylogenetic relationship of recovered B. canadensis sequences supports the species’ placement within Archosauria, closer to birds than Alligator. However, on the basis of well-established morphological analyses, we predict that T. rex is more closely related to birds than it is to the ornithischian hadrosaur B. canadensis. Despite ambiguity within Dinosauria, obvious phylogenetic signal resides within recovered collagen sequences, supporting endogeneity (fig. S11).”
4. “Ovoid red ‘cells’ with long filipodia, similar in morphology to extant osteocytes, were embedded in or associated with white matrix (Fig. 1J and fig. S1) or vessels (Fig. 1H). In some cases, these were attached by their filipodia to adjacent cells (Fig. 1J, inset), forming an interconnecting network as in extant bone. The cells contain internal microstructures suggestive of nuclei. Red filipodia extend from cell bodies into the white fibrous matrix (Fig. 1J and fig. S1), reflecting original chemical differences at submicron levels between cells and matrix and inconsistent with recent microbial invasion (7). Under FESEM (10), B. canadensis osteocytes and filipodia (Fig. 1K) are similar in morphology, surface texture, and size to extant ostrich osteocytes isolated from bone digests (Fig. 1L) (1, 2, 13, 14).”

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Dinosaur Blood Extracted From Bone
Scientists insist fossil is 80 million years old

Posted: April 30, 2009
WorldNetDaily

Collagen, hemoglobin, elastin, laminin and cell-like structures resembling blood and bone cells have been found in a dinosaur bone scientists still claim is 80 million years old, according to a report in Science magazine today.

Paleontologist Mary Schweitzer of North Carolina State University first claimed to have isolated soft tissues and collagen from a Tyrannosaurus rex leg bone several years ago.

But because the leg was broken during excavation, the evidence was damaged and could never be independently confirmed.

Schweitzer then examined a more pristine leg of a plant-eating hadrosaur excavated from sandstone and found even better samples of soft tissue, according to the report.

"Our findings demonstrated that it did contain basement membrane matrix," said Lewis Cantley, chief of the division of signal transduction at Beth Israel Deaconess, and a co-author on the Science study. Basement membranes, which degrade and regenerate during development and wound repair, comprise a continuous extracellular matrix that links endothelial, epithelial, muscle, or neuronal cells and their adjacent stroma.

In situ mass spectrometery independently verified amino acids in dinosaur tissues, including the collagen signature amino acid, hydroxylated proline.

While scientists previously questioned the possibility that soft tissue could survive tens of millions of years of fossilization, few seem to be questioning their assumptions that dinosaurs actually went extinct 65 million years ago.

Young earth proponents see something entirely different in the findings. As one creationist noted: "There’s no way this blood could be 80 million years old. The evolutionists are just saying so because they cannot bear the thought of recent dinosaurs causing their millions of years scenario to come crashing down. Without the millions of years, Darwinism is dead, dead, dead."

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