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Thursday, March 24, 2005

Tyrannosaur morsels

Look! A scrap of soft tissue extracted from dinosaur bone:

Tyrannosaur soft tissue
Demineralized fragments of endosteally derived tissues lining the marrow cavity of the T. rex femur. The demineralized fragment is flexible and resilient and, when stretched (arrow), returns to its original shape.

Dr GH has already promised to describe this new find in more detail on The Panda's Thumb, so I'm going to be very brief—keep an eye on The Thumb for more.

Anyway, it has been reported in Science this week that well-preserved soft tissues have been found deep within the bones of a T. rex, and also within some hadrosaur fossils. This is amazing stuff; fine structure has been known to be preserved to this level of detail before, but these specimens also show signs of retaining at least some of their organic composition. What the authors have done is to carefully dissolve away the mineral matrix of the bone, exposing delicate and still flexible scraps of tissue inside.

Here, for example, is a piece of endothelial tissue, or the tubelike epithelia that line blood vessels and form capillaries. It is compared to a similarly prepared piece from fresh ostrich bone; you can tell the T. rex fragment has undergone some changes, but it's comparable in size and organization to the bird sample.

Tyrannosaur soft tissue
(I) T. rex vessel fragment showing detail of branching pattern and structures morphologically consistent with endothelial cell nuclei (arrows) in vessel wall. (J) Ostrich blood vessel liberated from demineralized bone after treatment with collagenase shows branching pattern and clearly visible endothelial nuclei.

Looking more closely with a scanning electron microscope, here's a similar piece of T. rex blood vessel that has ruptured, spilling out its contents. Maybe those cells don't look perfectly preserved, but they're darned close.

Tyrannosaur soft tissue
Exploded T. rex vessel showing small round microstructures partially embedded in internal vessel walls.

And lastly, here's a closeup of the surface of that epithelia, compared with an ostrich epithelium. The cells here are very, very flat, and the nuclei are the thickest part, bulging up and giving the surface a pebbled appearance. The T. rex epithelium has a similar pebbly look, suggesting that just maybe there is even some subcellular structure preserved.

Tyrannosaur soft tissue
(E) Higher magnification of a portion of T. rex vessel wall, showing hypothesized endothelial nuclei (EN). (F) Similar structures visible on fixed ostrich vessel. Striations are seen in both (E) and (F) that may represent endothelial cell junctions or alternatively may be artifacts of the fixation/dehydration process.

How could this be? Here's the authors' explanation.

…we demonstrate the retention of pliable soft-tissue blood vessels with contents that are capable of being liberated from the bone matrix, while still retaining their flexibility, resilience, original hollow nature, and three-dimensionality. Additionally, we can isolate three-dimensional osteocytes with internal cellular contents and intact, supple filipodia that float freely in solution. This T. rex also contains flexible and fibrillar bone matrices that retain elasticity. The unusual preservation of the originally organic matrix may be due in part to the dense mineralization of dinosaur bone, because a certain portion of the organic matrix within extant bone is intracrystalline and therefore extremely resistant to degradation. These factors, combined with as yet undetermined geochemical and environmental factors, presumably also contribute to the preservation of soft-tissue vessels. Because they have not been embedded or subjected to other chemical treatments, the cells and vessels are capable of being analyzed further for the persistence of molecular or other chemical information.

So, basically, these cells were entombed in a thick mineral sarcophagus, protected from bacteria and other external insults. There have to have been other factors at play—cells are full of enzymes that trigger a very thorough self-destruct sequence at death—so I'm definitely looking forward to the molecular analysis. Even if their form was preserved, I expect these cells to be denatured monomer soup on the inside.


Schweitzer MH, Wittmeyer JL, Horner JR, Toporski JK (2005) Soft-Tissue Vessels and Cellular Preservation in Tyrannosaurus rex. Science 307(5717):1952-1955.


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Comments:
's avatar #19719: PZ Myers — 03/25  at  09:04 AM
Orac, in the justification, you'll have to promise to cure dinosaurian cancer.

And I know creationists are going to be jumping all over this in their usual clueless, dumb-as-a-stick fashion. Rather than looking for a reasonable explanation for this observation within local phenomena, they'd rather use it as an excuse to throw out all of physics and geology.

PZ Myers
Division of Science and Math
University of Minnesota, Morris



#19740: Orac — 03/25  at  12:29 PM
PZ,

Of course. Why else would one want to study dinosaurian angiogenesis...

--
Orac “A statement of fact cannot be insolent.”
http://oracknows.blogspot.com



#19756: — 03/25  at  01:22 PM
There's certainly hope that more than monomers remain. "Spongy organic material" likely means proteins have survived. It's going to take some kickass biochemistry to pull them out and determine the original amino acids sequence, true, but damn, what a goal!!



#19813: — 03/25  at  04:39 PM
Boy, are you guys slow. AIG almost scooped you on this one:

http://www.answersingenesis.org/docs2005/0325Dino_tissue.asp

So will this new evidence cause anyone to stand up and say there’s something funny about the emperor’s clothes? Not likely. Instead, it will almost certainly become an “accepted” phenomenon that even “stretchy” soft tissues must be somehow capable of surviving for millions of years. (Because, after all, we “know” that this specimen is “70 million years old”.) See how it works?

Schweitzer’s mentor, the famous “Dinosaur Jack” Horner (upon whom Sam Neill’s lead character in the Jurassic Park movies was modeled) is already urging museums to consider cracking open some of the bones in their existing dinosaur fossils in the hope of finding more such “Squishosaurus” remains. He is excited about the potential to learn more about dinosaurs, of course. But—nothing about questioning the millions of years—sigh!

I invite the reader to step back and contemplate the obvious. This discovery gives immensely powerful support to the proposition that dinosaur fossils are not millions of years old at all, but were mostly fossilized under catastrophic conditions a few thousand years ago at most.


Foucault



#19815: — 03/25  at  04:49 PM
Why do you wonder what creationists will think of it? Because you know deep down that this particular bit of evidence fits their model better than the long ages of evolution.

But instead of making up ridiculous parodies of creationists' responses, see what they really say at http://www.answersingenesis.org/docs2005/0325Dino_tissue.asp



's avatar #19823: PZ Myers — 03/25  at  06:56 PM
My prediction is fulfilled. Rather than trying to understand the mechanism of preservation, the creationists propose invalidating physics in order to make excuses for their ridiculous 6000 year old earth dogma.

PZ Myers
Division of Science and Math
University of Minnesota, Morris



#19826: — 03/25  at  07:21 PM
PZMyers wrote:
My prediction is fulfilled. Rather than trying to understand the mechanism of preservation, the creationists propose invalidating physics in order to make excuses for their ridiculous 6000 year old earth dogma.

The same sort of criticism can be levelled at the evolutionsts, as the AiG article did (my bolding):
Unfortunately, the long-age paradigm is so dominant that facts alone will not readily overturn it. As philosopher of science Thomas Kuhn pointed out, what generally happens when a discovery contradicts a paradigm is that the paradigm is not discarded but modified, usually by making secondary assumptions, to accommodate the new evidence.

That’s just what appears to have happened in this case. When Schweitzer first found what appeared to be blood cells in a T. Rex specimen, she said, “It was exactly like looking at a slice of modern bone. But, of course, I couldn’t believe it. I said to the lab technician: “The bones, after all, are 65 million years old. How could blood cells survive that long?’” Notice that her first reaction was to question the evidence, not the paradigm. That is in a way quite understandable and human, and is how science works in reality (though when creationists do that, it’s caricatured as non-scientific).

So will this new evidence cause anyone to stand up and say there’s something funny about the emperor’s clothes? Not likely. Instead, it will almost certainly become an “accepted” phenomenon that even “stretchy” soft tissues must be somehow capable of surviving for millions of years. (Because, after all, we “know” that this specimen is “70 million years old”.) See how it works?
What physics have supposedly been invalidated by the creationists? I presume you are referring to radiometric dating, but can you show where creationists propose invalidating physics to question the date? I reckon you can't.



's avatar #19828: PZ Myers — 03/25  at  07:37 PM
We always question the evidence. That's no surprise.

The determination that the earth is 4.5 billion years old is the work of physicists and geologists, not biologists. Anyone who wants to claim it is only 6000 years old had better be prepared to address the issues their ludicrous claims raise in those disciplines.

PZ Myers
Division of Science and Math
University of Minnesota, Morris



#19831: — 03/25  at  08:29 PM
Unfortunately, the long-age paradigm is so dominant that facts alone will not readily overturn it.


The age of the Earth is a measurement, not a "doctrine" or a "paradigm". Anyone who claims otherwise will have to show why the physicists can't do the measuerments they've shown they can do.



#19836: — 03/25  at  09:01 PM
But instead of making up ridiculous parodies of creationists' responses...


Parodies of creationists = coals to Newcastle. In the arena of ridiculousness, we are but the rankest of amateurs compared to them.



's avatar #19837: Ben — 03/25  at  09:09 PM
I presume you are referring to radiometric dating, but can you show where creationists propose invalidating physics to question the date? I reckon you can't.

It's easy when you realise that the figure of 6000 years is totally arbitrary. It's arrived at by summing the approximate ages of Biblical characters. Why not base the figure on the number of times Allah is mentioned in the Koran, or the number of e's in Through The Looking Glass? Why not just claim that the universe is 30 years old, and the rest is a Matrix style illusion? Skyhooks, my friend.

"The great trouble is that the preachers get the children from six to seven years of age and then it is almost impossible to do anything with them." --Thomas Edison.



#19841: — 03/25  at  09:47 PM
I may have missed someone else mentioning it, but this discovery was pure serendipity, and I'm not referring to finding the bone. It seems, at least according to the artiicle I read, that the bone was too big to fit into the truck to carry it back to their camp, so they broke it in two. Only then did they discover that it contained soft tissue. I can now see every paleontologist in the world with a collection of fossil dinosaur bones cracking them open one by one like some predator looking for a meal of marrow in his/her quest for a major discovery.



#19861: — 03/26  at  03:52 AM
PZ Myers wrote:
We always question the evidence. That's no surprise.
You missed the rest of the sentence: "[but] not the paradigm".
PZ Myers wrote:
Anyone who wants to claim it is only 6000 years old had better be prepared to address the issues their ... claims raise in those disciplines.
They do.

And I notice that you ignored my challenge to back up the claims you made.

euan wrote:
The age of the Earth is a measurement, not a "doctrine" or a "paradigm".
You cannot measure age. You measure isotopes and determine an age from that, based on several assumptions, including assumptions that deny the Biblical record. That puts it in the category of a doctrine.

Neil wrote:
Parodies of creationists = coals to Newcastle. In the arena of ridiculousness, we are but the rankest of amateurs compared to them.
More bluster, no substance.

I wrote:
I presume you are referring to radiometric dating, but can you show where creationists propose invalidating physics to question the date? I reckon you can't.
Ben responded:
It's easy ...
So why didn't you do it, instead of raising a new issue? Perhaps it's not so easy after all?

Ben continued:
...when you realise that the figure of 6000 years is totally arbitrary. It's arrived at by summing the approximate ages of Biblical characters.
Incorrect. It is derived by adding the ages of Biblical characters when they had their offspring. And that makes perfect mathematical sense. What is "arbitrary" about adding up consecutive periods of time to derive a total period of time? Whereas your alternatives are arbitrary, as they have nothing to do with adding consecutive periods of time.



's avatar #19862: Ben — 03/26  at  04:37 AM
Incorrect. It is derived by adding the ages of Biblical characters when they had their offspring. And that makes perfect mathematical sense. What is "arbitrary" about adding up consecutive periods of time to derive a total period of time?

Because you're not taking into account the fact that the source you're using to formulate the figure has ever been proven to be anything more than a popular work of fiction. Is the Bible any more credible a source than a random work by Lewis Carroll because it covers a greater time period? Nope, they're both equally pertinant to the issue of calculating the age of the universe: not at all.

"The great trouble is that the preachers get the children from six to seven years of age and then it is almost impossible to do anything with them." --Thomas Edison.



#19865: — 03/26  at  04:55 AM
The age of the Earth is a measurement, not a "doctrine" or a "paradigm".

You cannot measure age. You measure isotopes and determine an age from that, based on several assumptions,

Any constant-rate process produces an age, and nuclear decays are measured as constant rate processes.

including assumptions that deny the Biblical record. That puts it in the category of a doctrine.


Now who's blustering, Mr Hypocrite?



's avatar #19866: Ben — 03/26  at  05:11 AM
I think he's asserting that spurious and arbitrary data can be transmogrified into reasonable and accurate results as long as the method of analysis is sound. More skyhooks.

"The great trouble is that the preachers get the children from six to seven years of age and then it is almost impossible to do anything with them." --Thomas Edison.



#19867: — 03/26  at  05:16 AM
Ben wrote:
Because you're not taking into account the fact that the source you're using to formulate the figure has ever been proven to be anything more than a popular work of fiction.
The accuracy or otherwise of the Bible (which has been shown in many parts many times over) is a separate issue than the arbitrariness or otherwise of totalling time periods. Does switching arguments an acknowledgement that the argument of it being arbitrary holds no water?

euan wrote:
Any constant-rate process produces an age, and nuclear decays are measured as constant rate processes.
No, a constant-rate process produces the daughter product of the process. I already indicated that the process can be measured, but as I said, deriving an age from that depends on a number of assumptions. This is clear from the fact that derived ages don't always agree, and in these cases the different ages are often harmonised by modifying some of those assumptions.

Additionally, the methods have often been shown to be wrong on rocks of a known age, so why should they be trusted on rocks of an unknown age?

euan also wrote:
Now who's blustering, Mr Hypocrite?
Name-calling now? And how is what I said "bluster"?



#19868: — 03/26  at  05:19 AM
I garbled a sentence of mine in the previous post. It should have read: "Is switching arguments an acknowledgement that the claim of it being arbitrary holds no water?"



's avatar #19869: Ben — 03/26  at  05:33 AM
The accuracy or otherwise of the Bible (which has been shown in many parts many times over) is a separate issue than the arbitrariness or otherwise of totalling time periods.

Are you insane? The accuracy of the source is the FOUNDATION of whether or not data, and hence the arguments, are arbitrary. Explain to me how using the aforementioned method of analysis on the ages of Biblical characters has any bearing on the age of the universe, and I'll show you how the number of replies in this thread has any bearing on the dimensions of my bedroom.

"The great trouble is that the preachers get the children from six to seven years of age and then it is almost impossible to do anything with them." --Thomas Edison.



#19870: — 03/26  at  06:01 AM
Ben kindly asked:
Are you insane?
No.

Ben wrote:
The accuracy of the source is the FOUNDATION of whether or not data, and hence the arguments, are arbitrary. Explain to me how using the aforementioned method of analysis on the ages of Biblical characters has any bearing on the age of the universe, and I'll show you how the number of replies in this thread has any bearing on the dimensions of my bedroom.
If you use a correct method on bad data, you will get a bad result. But that doesn't therefore mean that it was not a correct method to use if the data was correct. Adding up the numbers of years since birth until the next measured offspring of a series of generations that claim to begin at the beginning of creation is therefore a valid—and therefore not "arbitrary"—method of calculating the age of the Earth and will therefore give a correct result if the ages are correct and do begin with creation. I know that you disagree with the last point, but that is a separate issue to whether or not the method itself is arbitrary.

I will be interested to see your explanation of how the number of replies in this thread are related to the dimensions of your bedroom, considering that the number of replies in this thread keeps changing. You must have an interesting bedroom!



's avatar #19871: Ben — 03/26  at  06:14 AM
Adding up the numbers of years since birth until the next measured offspring of a series of generations that claim to begin at the beginning of creation is therefore a valid—and therefore not "arbitrary"—method of calculating the age of the Earth and will therefore give a correct result if the ages are correct and do begin with creation.

Creation is an assumption. The correctness of Biblical ages is an assumption. The relevance of anything Biblical to the issue of the age of the Earth is an assumption. Any data or arguments extrapolated from these sources is arbitrary. The METHOD isn't arbitrary (I never said it was), but the DATA and the RESULTS are. As I said, you seem to be asserting that spurious and arbitrary data can be transmogrified into reasonable and accurate results as long as the method of analysis is sound. You'll need to do a better job of explaining how this is logically possible, or else your argument remains nonsensical.

"The great trouble is that the preachers get the children from six to seven years of age and then it is almost impossible to do anything with them." --Thomas Edison.



#19872: — 03/26  at  07:21 AM

No, a constant-rate process produces the daughter product of the process. I already indicated that the process can be measured, but as I said, deriving an age from that depends on a number of assumptions.

That the time of day can be derived fom counting the ticks of a clock is deriving an age from a constant rate process. That this doesn't apply to rocks is simply special pleading

This is clear from the fact that derived ages don't always agree, and in these cases the different ages are often harmonised by modifying some of those assumptions.

Really? Where is this happening? Which rocks? Which assumptions? By being vague about this you are not arguing with facts but with the bluster you deride in other people.


Additionally, the methods have often been shown to be wrong on rocks of a known age, so why should they be trusted on rocks of an unknown age?

Often? Can you produce many such an examples, or is this just you and AIG making shit up?

Name-calling now? And how is what I said "bluster"?

Because you offered no proof, only your own egotistic certainty.



#19874: — 03/26  at  08:32 AM
Ben wrote:
Creation is an assumption. The correctness of Biblical ages is an assumption. The relevance of anything Biblical to the issue of the age of the Earth is an assumption.
Both sides have assumptions. But at least creationists acknowledge theirs.

Ben wrote:
Any data or arguments extrapolated from these sources is arbitrary. The METHOD isn't arbitrary (I never said it was), but the DATA and the RESULTS are. As I said, you seem to be asserting that spurious and arbitrary data can be transmogrified into reasonable and accurate results as long as the method of analysis is sound.
You indicated that the result was arbitrary because of the choice of method. That amounts to the same thing. How can you claim that I argue that "spurious and arbitrary data can be transmogrified into reasonable and accurate results as long as the method of analysis is sound" when I specifically said that the accuracy of the results depended on the accuracy of the data?

euan wrote:
That the time of day can be derived fom counting the ticks of a clock is deriving an age from a constant rate process. That this doesn't apply to rocks is simply special pleading
Nice analogy! So you've never known a clock to be wrong?

euan wrote:
Really? Where is this happening? Which rocks? Which assumptions? By being vague about this you are not arguing with facts but with the bluster you deride in other people.
Not putting all the details in one post is not the same as throwing insults as a defence of an argument.

For starters, consider any of the arguments made to explain away evidence of wrong dates that creationists put forward. For example, from Talk.Origins:
Other factors can produce false isochrons (Stassen 1998; Zheng 1989). For example:
* Protracted fractionation. This requires slow cooling (over millions of years) and produces only a small error.
* Inherited ages as from partial melting. The age given by this method is the age of the source material. Furthermore, this factor requires unusual conditions and usually produces scatter in the isochron plot.
* Metamorphosism. This produces apparent ages younger than the age of the source material.

In other words, there are proposed to be various factors that need to be taken into account before the derived ages can be accepted. You do not simply measure an age. You measure isotope ratios and make a calculation based on what is believed to be the initial quantities, the likelihood of material leaching out or washing in, the likelihood of inclusions of other materials that affect the result, the likelihood of decay rates remaining constant over millions or billions of years, etc. etc. These factors are not directly measurable, as they are past events, so they remain assumptions, reasonable or otherwise. How reasonable are those factors? That depends on your paradigm—uniformitarianism or creationism.

euan wrote:
Often? Can you produce many such an examples, or is this just you and AIG making [deleted] up?
The examples I would quote are ones from AiG as detailed in various articles here. No, I'm not making them up, and neither is AiG. Most if not all the dates they quote are calculated by secular laboratories; they are not "made up". Do you have any hard evidence for your insinuation of fraud?

Good night; it's time for me to go to bed.



#19877: — 03/26  at  09:25 AM
"Nice analogy! So you've never known a clock to be wrong?"

I once saw a clock that stopped at 12:04:02 AM. Therefore, the evidence that the day is 24 hours long is inconsistent, and it may in fact be only four minutes long.



's avatar #19878: PZ Myers — 03/26  at  09:33 AM
Four minutes and two seconds. This is SCIENCE, so accuracy counts.

PZ Myers
Division of Science and Math
University of Minnesota, Morris



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