“Soft Tissue” in Dinosaur Bones: What Does the Evidence Really Say?


(system) #1
Paleontologist Mary Schweitzer has found evidence of original material in dinosaur bones. Does that mean the dinosaurs only lived a few thousand years ago?
This is a companion discussion topic for the original entry at https://biologos.org/blogs/jim-stump-faith-and-science-seeking-understanding/soft-tissue-in-dinosaur-bones-what-does-the-evidence-really-say

How does BioLogos and its community respond to some of the Young Earth Creationists evidences and their "proofs"?
"Is genesis history?" film
(Brad Kramer) #2

Mary Schweitzer is not available to comment, but @Scott_Buchanan (the article author) is here to interact with commenters.


(Jim Lock) #3

@Scott_Buchanan Dr. Buchanan, Thank you for taking the time to write an fairly accessible article. As a Liberal Arts major, I find myself lost at a certain level of technical detail. :slight_smile: Given that, I have a few questions:

  1. Did Dr. Schweitzer find actual tissue or evidence of a tissue (structures in the bones where tissue used to be with small amounts of proteins)?

  2. Are the protein combinations collagen, actin, and tubulin all that common? In other words, do they find these three proteins crosslinked on a fairly regular basis? Or, is this something finally unique to these bones?

  3. Finally, my understanding is that the survived due to combination of the types of proteins found and a variety of other factors that scientists understand but can’t definitively apply to this situation. Therefore, scientists can’t definitively argue that this is evidence for a relatively young age because they don’t fully understand all of the factors that can slow protein degradation. Right? Thank you for the time!

Very Respectfully,
Jim


(sy_garte) #4

I heard Mary Schweitzer speak at the Biologos Conference in July. Her photos were quite striking, and I agree with Scott Buchanan that we dont really know how long cross linked proteins could survive in some conditions. But a couple of things bothered me, and I wonder if they could be addressed.

First, when asked about DNA (which is far more stable than proteins) Mary said “I dont really like DNA” an amusing but fairly shocking answer. Then she said that she had sent some samples to a lab, and they got lost, or something. I find this incredible. Any lab in the world would be thrilled to have samples of fossil dinosaur DNA. Without the DNA evidence, I remain a bit uncertain.

Also, I believe she said that they examined two dinosaurs, and both showed the presence of the same structures. My question then is does this mean that soft tissue may be expected to be found commonly in 50- 100 million year old fossils? IF not, was she lucky to have picked the two that she did? Was there something special about these two, in terms of location or surrounding substrate? IF not, and if soft tissue is not usually found, then I am again uncertain.

It is of course possible that my lack of enthusiasm for these results is entirely due to my own lack of appreciation for visual evidence as opposed to chemical evidence, which I find to be far more objective, although this is likely due to my own inexperience at interpreting photgraphic data.


#5

@jlocck
Jim,

  1. In the bone pores she found actual stretchy tissue that appears to be at least in part crosslinked proteins of the types expected for dinosaurs, as confirmed by various analyses.

  2. I did not understand Prof. Schweitzer’s articles to be saying that collagen, actin, and tubulin were crosslinking with each other. Rather, each protein domain formed crosslinks within itself, which served to maintain mechanical integrity and to cap off potentially reactive chemical sites. Crosslinking within collagen, for instance, is a well-studied phenomenon as you can find by doing a search on the topic.

  3. Right!

Best regards,
Scott


#6

@Sy_Garte
The original, longer version of this article, https://letterstocreationists.wordpress.com/dinosaur-soft-tissue/ , discusses the DNA evidence. It is not as clear-cut as the protein evidence, and so it is harder to summarize with precision. A few of the bone samples responded weakly but positively to tests that can detect short fragments of DNA. This suggests the presence of some highly degraded DNA, which might be consistent with the presence of preserved proteins in these bone pores. I did not see anything about lost DNA samples.

Regarding the dinosaurs – In my opinion, Prof. Schweitzer got lucky in 1997 when she happened to put a section from a T. rex bone under a microscope and saw what looked like red blood cells. From then on, (again in my opinion), she made her own luck. She did some tests which suggested the presence of heme, a robust portion of the hemoglobin protein. When she got ahold of thighbone fragments from a freshly-excavated T. rex in 2003, she did what no one else had thought of doing, which was to dissolve away the mineral bone portion to see if there was any non-mineralized tissue left. That is how the soft tissue was observed, which was a major discovery.

Some luck was involved in getting those freshly-excavated bone samples from that T. rex, which was buried in sandstone. There is some thought that the sandstone provides a better preservation matrix for these tissues, than, say, clay or shale. She then deliberately went after getting samples from a newly-excavated hadrosaur from sandstone, minimizing their exposure to atmospheric oxygen, etc. These special measures seem to have paid off, since tissues from that hadrosaur were even better-preserved than the earlier T. rex.

It is not the norm to find soft tissues in or on dinosaur bones, but it has been occasionally noted elsewhere. Prof. Schweitzer published a review, “Soft Tissue Preservation in Terrestrial Mesozoic Vertebrates”, Annual Review of Earth and Planetary Sciences Vol. 39: 187-216 (May 2011). Citing more than 200 studies, she discussed many prior instances of soft tissue finds among Mesozoic fossils. Most examples of tissue preservation are of the skin and its appendages, including scales, feathers, and claws. These consist largely of keratin proteins. Keratin has high preservation potential “because of its molecular structure, its tendency to form cross-links, and its abundant, nonpolar amino acids.”
Best regards,
Scott


(sy_garte) #7

Scott
Thanks for that thorough answer. I did look at the link, and it is highly informative. A very interesting subject for study, and I look forward to seeing confirmation of these findings from others, although I imagine that will take some time.


(GJDS) #8

@Scott_Buchanan
@Sy_Garte

“… buried in sandstone…” I am intrigued by this and would like some comment from you. If the sample was encased on solid sandstone, than I would assume a liquid slurry has initially covered the sample, and the formation of a stone encasement would be lengthy and subject to weather. I do not think samples would be well preserved in any slurry environment - but if you have some insights I would be interested to hear them.


#9

@GJDS

About “…buried in sandstone…” . . . I don’t recall which of Prof. Schweitzer’s articles mentioned this, but in one or two of them I recall reading the speculation that being buried in a somewhat permeable sand/sandstone may have allowed for the escape from the decaying carcass of the enzymes which are released from cells upon death which tend to tear everything apart. Whereas, burial in an impermeable mud/shale would have trapped these destructive enzymes in with the bones. I don’t know how much weight to give this proposal. The empirical observation was that the researchers found the best preservation in the sandstones.

I will offer another speculation, that burial in sandstone might be associated with rapid burial, e.g. if the dino got swept into a raging river which had sufficient velocity to carry large amounts of sand (not just silt), and then where the river emerged into a lake or sea and deposited the dino carcass, it would be rapidly buried and not torn apart by scavengers. Yet another speculation I have read is that unusual preservation of softer tissues may be associated with the carcass first drying out thoroughly in the desert sun, leading to much crosslinking, etc. , before it is later buried in sediments. There is still much to learn here.


(GJDS) #10

@Scott_Buchanan

Thanks for your remarks - I understand that much is speculation on this unusual find. I was more interested in how a rock may form after this specimen was encapsulated in some way. Ordinarily I would assume this is a slow process and the areas should remain undisturbed for a lengthy period.

I understand this is something geologists would comment. I have considered other substances that are formed after burial (eg, coal seems of 10-50 m deep, buried under 20-30 m of solid, are formed from vegetation - yet we are none the wiser on the physical activities that would ensure such seems are relatively free from soil and sand). I make this remark to illustrate the difficulties we may face when we examine events that occurred many million years ago.


(Dcscccc) #11

from the article:

" In contrast, the rates of nuclear decomposition of elements have been measured over and over again, and found to be essentially constant. As discussed in the main article, there are a few conditions where nuclear decay can be accelerated, but these conditions are known and predictable "-

not realy. first- we cant predict something that we dont know about it. in the past we dont know about “old carbon effect” that can make a living animal date about 3000 years. second- we know that an high heat can effect the radiometric acceleration up to 10^9 from the real age. and we know that this heat was in the past of the universe.


(Patrick ) #12

Your claim is completely false. The high heat that you claim can effect what you call “radiometric acceleration” is ONLY possible at the center of a massive star. Here on Earth, the planet you and I live on, temperatures never get into the millions of degrees (even in the summer) and never had in the 4.54 billion years of the planets exist. Earth was never massive enough to ignite the fusion process to generate the million degree temperatures to change the C-N-O process going on in the center of stars. Therefore nuclear decay constants are accurate to within 0.1% and your claims of making animal dates to 3000 years are bogus.


(Dcscccc) #13

patrick. first- how do you know that the earth never get this temp? maybe its from a process thet make the whole starts somtime in the past in even may near the big bang time? second- even if its true- its just show you that there some natural process that can effect the radiometric method by a factor of one bilion. so how do you know there is no other process that exist and effect this process?


(Patrick ) #14

Because that temperature requires nuclear fussion! Earth isn’t massive enough to have gravity compress its core so that nuclear fussion can begin to generate the required temperature.

Earth was formed 4.54 billion years ago and never was there a process on Earth that could change the radioactive decay rates of ALL the elements naturally part of the Earth. So your claim that radiometric acceleration up to 10^9 from the real age can make a 125 million year old fossil date to about 3000 years is FALSE.


(Dcscccc) #15

patrick. according to wiki its possible in starts:

"The most important fusion process in nature is the one that powers stars. In the 20th century, it was realized that the energy released from nuclear fusion reactions accounted for the longevity of the Sun and other stars as a source of heat and light. The fusion of nuclei in a star, starting from its initial hydrogen and helium abundance, provides that energy and synthesizes new nuclei as a byproduct of that fusion process. "


(Patrick ) #16

Yes, fusion goes on in stars, but fossil dating goes on here on Earth where there is no fusion going on. So the radioactive decay rates used for dating fossils is constant and very accurately known to about 0.1%. So when the authors says that a fossil was dated using radioactive decay rates of 125 million years, the accuracy of this results is ± 125,000 years. This is along way from 3000 years.


#17

Reading your dialogue, it seems you missed what dcscccc said, which was that a “living” animal was dated as being 3000 yrs old.

Also, fossils are not themselves dated by radioactive decay. They are dated by their proximity to various rocks that are thought to be dated radioactively. Fossils are found in sedimentary rock, which itself cannot be directly dated.


(Dcscccc) #18

earth isnt a stra? this temp may happaned in the formation of the earth or even before. so the atoms may effected by this heat.


(Patrick ) #19

Nope, not possible. Need millions of degrees to have the effect you talk about, earth never had the mass to ignite fusion to generate the high heat required.


(Patrick ) #20

a living animal being 3000 yrs old? How is that possible?