There are three different kinds of bone cells in vertebrates: osteoblasts, osteoclasts, and osteocytes. If you use a microscope, you can tell them apart just by looking at them. Osteoblasts are the cells that build bone, while osteoclasts are the cells that break down bone. Both are important, because your bones adjust to the needs of your body, so there are times that you will need to build more bone, and there are other times you will need to break down some bone. The third group of bone cells, osteocytes, are the most common. They maintain the bone.
The study that found bone cells in a mosasaur fossil found osteocytes, and that’s what Dr. Schweitzer’s team found as well. Now, of course, just because they found microscopic structures that looked like osteocytes isn’t necessarily surprising. After all, the fossilization process could be detailed enough to preserve the shapes of individual cells. If these structures really are just the fossilized shapes of the osteocytes, it is exciting, but not incredibly surprising. However, Schweitzer’s team has done some detailed experiments to show that these aren’t just shapes. Indeed, these osteocyte structures still contain proteins and probably even DNA!
One of the tests the team did was to produce an antibody (a protein used by the immune system) that binds to a variant of a protein known as PHEX. Most animals have this protein, and it is most common in bone cells. The antibody they produced binds only to a variant of the protein that is found in bird osteocytes. It is not even found in bird osteoblasts. So it is a strong indication of the presence of osteocytes. Since birds are thought to have evolved from dinosaurs, it made sense to the team that if the dinosaur osteocytes contained PHEX, it would be similar to the PHEX found in birds. They showed that the antibody did, indeed, bind to the osteocytes. This is strong evidence that the preserved osteocytes still contained large sections of the PHEX that characterizes them.
Even more intriguing, they exposed the osteocytes to antibodies that target DNA, and they found that the antibodies bound to things inside the osteocytes. Interestingly enough, however, the antibodies didn’t bind to everything inside the osteoctytes. Instead, they bound only to certain specific regions. This is exactly what you would expect if the antibodies were binding to DNA from the osteocytes, since DNA exists in specific regions of the cell, such as the nucleus and the mitochondria. This evidence indicates that the osteocyte remains still contain DNA!
In addition, they used mass spectrometry to analyze the osteocytes. Their analysis revealed three proteins (histone4, tubulin, and actin) that are all found in animal cells. To further show that these chemicals came from the osteocytes and not bacteria in the surrounding material, they exposed the surrounding material to antibodies that bind to those specific proteins, and the antibodies didn’t find anything to which they could bind. Thus, these chemicals really do seem to have originated from the osteocytes themselves.
Now don’t misunderstand these results. The osteocytes that Dr. Schweitzer’s team found were not alive. However, they still contained what appear to be the proteins you would expect to find in living osteocytes, as well as at least some remnants of DNA. That’s the amazing part of their results. These bones are supposed to be more than 65 million years old, yet they hold fossilized remains of cells that still contain their proteins and some DNA. It is thought that even under the best conditions, most proteins should decay away in about 30,000 years3, and DNA should decay away in about 125,000 years.4
The evidence is mounting that both DNA and proteins have been found in fossils that are supposed to be millions of years old. This means one of two things: Either DNA and proteins can be preserved a lot longer than anyone has expected, or these bones aren’t millions of years old. If I were a betting man, my money would be on the latter.
REFERENCES
1. Mary H. Schweitzer, Jennifer L. Wittmeyer,John R. Horner, and Jan K. Toporski, “Soft-Tissue Vessels and Cellular Preservation in Tyrannosaurus rex,” Science, 307:1952-1955, 2005
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2. Mary Higby Schweitzer, Wenxia Zhenga, Timothy P. Clelanda, and Marshall Bernc, “Molecular analyses of dinosaur osteocytes support the presence of endogenous molecules,” Bone, dx.doi.org/10.1016/j.bone.2012.10.010, 2012
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3. Bada, J. et al., “Preservation of key biomolecules in the fossil record: current knowledge and future challenges,” Philosophical Transactions of the Royal Society B: Biological Sciences, 354:77-87, 1999
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4. Nielson-Marsh, Christina, et al., “Biomolecules in fossil remains: Multidisciplinary approach to endurance,” The Biochemist, 12-14, June 2002
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This is especially interesting in the light of Allentoft et al.’s paper earlier this year claiming that DNA cannot be preserved more than around a million years, and then only in frozen environments. (http://rspb.royalsocietypublishing.org/content/early/2012/10/05/rspb.2012.1745.short)
I wasn’t aware of that paper, J.S. Thanks for posting it!
Brian Thomas posted about the Allentoft paper today over at ICR: http://www.icr.org/article/7088/
“…it would be similar to the PHEX found in birds. They showed that the antibody did, indeed, bind to the osteocytes.”
I’m a bit confused Dr Wile. Does this research lend support to the dinosaur to bird theory?
Jason, the research indicates that when it comes to the PHEX protein, birds and dinosaurs are very similar. Does that support the dinosaur to bird hypothesis? It depends. Sometimes, similarity in proteins is considered evidence for common ancestry. Sometimes, however, it is not. For example, the main protein behind echolocation in bats is nearly identical to the corresponding protein in dolphins. However, that doesn’t support the “bats to dolphins” hypothesis (or the “dolphins to bats” hypothesis), because no evolutionist wants to think that bats and dolphins are closely related. As a result, it is explained away as an example of convergent evolution.
So I suspect that most evolutionists will use the similarity in these PHEX proteins to support the birds to dinosaurs hypothesis, but only because it is convenient. If, later on, it is determined that birds and dinosaurs are not closely related, the similarity in the PHEX proteins will be explained away as convergent evolution.
There’s a new paper in Science that shows a mechanism for new functionality from gene mutations (i.e. new information). Summarized here http://www.sciencedaily.com/releases/2012/10/121022145340.htm
You have acces to Science, right? Will you post on this paper?
Thanks for the suggestion, Mia. I had already read that article and was planning to post on it. Not surprisingly, new information was not generated in the experiment. I was planning to post on it as a way of showing how desperate evolutionists are when it comes to finding a way for new information to arise in a genome.
Jay,
I have to admit that as an old-Earth geologist this is one of the very few (or perhaps the only) argument the YECs have that actually is a problem for us old-Earthers. I don’t know how to explain it.
My initial response when this came out a few years ago was that this was another YEC “it seems to me” sort of argument. “It seems to me that Cretaceous fossils should not contain soft tissue and such, so it must be young.”
The right thing for an old-Earther (and a YEC) to do in this circumstance is to think of all the possibilities for how DNA and proteins could be preserved for 65+ million years, and then to analyze each hypothesis. So far, we old-Earthers have not come up with a good scenario.
I’m baffled, but this one problem is not enough to make me seriously question the standard interpretation of the Hell Creek Formation fossils, any more than the prospect of a melting crust during the flood convinces YECs to abandon the RATE study.
Thanks for your reply, Kevin. I obviously disagree that this is the only (or even just one of a few) good young-earth argument. However, if I saw things that way, I would agree with you. One or two problems with a scientific position are not enough to discard the position. Indeed, there are problems with the young-earth view as well. I just find that scientifically, there are significantly fewer problems with the young-earth view than the old-earth view.
I am sorry to hear (but am not surprised) that there are those who question Dr. Schweitzer’s commitment to Christianity. It’s truly sad that a side issue can be magnified in some people’s minds to the point that it interferes with genuine Christian fellowship.
As a side note — Dr. Schweitzer is a Christian paleontologist. I’ve seen YECs label her a “so-called Christian” because in their mind she obviously could not be a real Christian and believe in evolution.
Actually, when you read the article from Schweitzer published in 2012, it shows that the antibody binds to a histone protein. So it’s a fact that proteins were found in that dinosaur tissue.
But there is a difference in decay of sequences. After 125000 years the DNA should be decayed, so that it cannot be sequenced anymore. That does not say that there will not be any DNA molecules or stretches of several nucleotides occuring throughout the cells.
Furthermore, proteins are generably known to be more stable than DNA molecules. So I don’t know where you get it from that protein molecules decay in 30000 years?
Johan, I agree that the antibody bound to histones. That was by design, because the way the antibody bound to the histones ruled out the possibility that the DNA came from bacteria. However, they confirmed that there was DNA bound to the histones with two stains that fluoresce when they attach to DNA. Those tests confirmed that the antibody was binding to DNA.
I agree that the 125,000 years number is for a decay of DNA sequence, not necessarily all DNA. However, if the sequence had, indeed, decayed, then the DNA would not have been bound to histones, and as a result, the antibody would not have bound. So even though the DNA was not sequenced, the fact that it had retained its chromatin structure indicates that it had not decayed to the point where it couldn’t have been sequenced. Thus, 125,000 years is the relevant number. Even if you don’t like that number, use the one in the paper that J.W. linked above. That says to get DNA to last even a million years, it needs to be kept at below 0 degrees C.
I got the 30,000 number from the reference given. As it says, “In bones, hydrolysis of the main protein component, collagen, is even more rapid and little intact collagen remains after only 1-3x10^4 years”.
Thanks for your reply. It’s merely a technical detail, but the antibody was binding to histone proteins, and the other compounds(DAPI, PI/) bind to the DNA and those three methods showed the same pattern throughout the cells.
So that suggests the occurence of DNA, but doesn’t automatically imply that the DNA is preserved in the chromatin structure. Just that it is located in the same location.
The fact that histone proteins were found and also DNA sequences just gives – in my opinion – more credibility to the hypothesis that DNA is there, but doesn’t give any sign about what state the DNA is in.
As of the decay rate of DNA and protein, I recently saw a report that said that proteins decay less than DNA, but the decay rate depends a lot on the environmental conditions (i.e. how the bone was fossilized & at which time the individual did die). So I expect that they are different for each different sample, and so far as I know as of now no theory has emerged that adequately explains the decay of DNA and proteins.
From my laboratory experiments, I know that DNA samples that are old, don’t perform that good. And that’s even frozen and kept in TE buffers, which is optimal for DNA storage.
But I can agree with your conclusion that given the current observations about the decay rate of DNA and proteins, which all imply that it’s much less than 78 million years, that does imply that the bones are not millions of years old.
And I agree that believers in an old earth have some explaining to do about those preservation rates of Protein/DNA
Another problem is that some of the dinosaur bones in the C-14 study that Dr. Wile posted about earlier are from the Hell Creek formation. That’s two lines of evidence contradicting the conventional dating of the Hell Creek.
Thanks again for another awesome alternative to the conventional paradigm.
WRT to the “dinosaurs to birds” hypothesis, I would add that this need not be problematic for those who believe in special creation: we would expect re-usage of code from an intelligent designer, the same way an intelligent programmer re-uses code. Unguided evolution need not monopolize homologous resemblance.
I find it frustrating that no matter how off the wall evolutionists get, if YOU draw a conclusion, or propose an hypothesis that they think is bogus, it’s “extrapolating” or…”bad science” because you’re drawing a conclusion from inconclusive data.
I have a friend who is an evolutionist (in that he was raised in public schools) and I linked him your article about finding soft tissue in dinosaur bones. He of course went on a whole tangent about how you were practicing bad science, that this stage in the data you can’t say anything for sure because there hasn’t been enough experimentation and study.
He’s completely missing the part of science where you form hypothesis! Meh, misunderstanding how science works sure is dangerous, especially when the media gets their hands on a “gem” of information that they would love to pervert and scare the public with.
I like your conclusion at the end of this article: that there are two possibilities, either there is a preserving method that we don’t know about, or the bones are much younger than is popularly thought. I just wish that the evolutionists would stop and consider doing “real” science instead of making things up, or claiming that YOU are practicing bad science when clearly you’re not!
Inazuma, I think it is easier for a lot of people to say, “you’re practicing bad science” that it is for them to engage the data and try to understand the implications.