Dating Fossils

[Dinwar]

I don't have time to dig into it too much just now, but I looked through it. The first thing that struck me is that he used aluminum foil. This is a pretty big no-no in the vert paleo field, for cultural reasons. Scientists use newspaper, paper towels, toilet paper, and the like to jacket fossils; theives use aluminum foil. I don't know why it is, but that's the way I was trained. It doesn't make TOO much difference for the jacketing, as long as the foil doesn't have any breaks in it (the paper or foil prevents the plaster from touching the bone, which prevents it from seeping into the bone and prevents it from removing water from the bone, both of which damage the fossil), but it makes me twitch. Then again, that may be a mammology thing; dinosaur folks may operate differently.

The fact that the horn had a "muddy matrix imbedded deeply within it" doesn't tell you that the horn wasn't dessicated. Without a detailed taphonomic history of the fossil we just can't tell--it's entirely plausible that it desicated in one area and was subsequently carried downstream to another. There was a taphonomic study of a camel carcass that showed exactly that.

I didn't see anything immediately objectionable in the paper. I don't see anything that convinces me, either, but then this isn't my speciality (I do ecology, not fine-scale anatomy). I don't see anything that offers hope to Creationists. Then again, given the comments on the second link (apparently he believes the world to be 10ka to 20ka old), it's likely that this is part of a larger body of work intended to attack the concept of deep time. Which is patently nonsense at this point; it's like a mechanic denying that gasoline is flamible. If it's part of a larger body of work attacking deep time, then yeah, he should be fired--you CANNOT be a competant geologist or paleontologist without accepting an ancient age (4.6 ga or so) for the Earth. It's impossible.

All in all, I think the jury's still out on soft tissue from dino fossils. That said, most of what I've seen suggests that it doesn't happen, that it's biological contamination that fools people. Taphonomy is poorly known, even among paleontologists unfortunately.

 

[Correa Neto]

I am pretty sure that is the hypothesis, with a whole lot of strong evidence, even repeatable evidence from multiple sources.

The age thing bothers me just a bit though. What exactly is the scientific explanation? I get that carbon 14 can't be used over 50-60K years. It has to do with the 1/2 life of Carbon 14. Beyond a certain point the accuracy drops off because most the C14 is back to N14 in the absence of cosmic rays.

So what exactly would create a bunch more C14? Some samples I could understand being contaminated with younger material, but many samples tested many places? Did something happen that reset the C14 clock?

Let us assume no tampering or mishandling happened(*)...

The fossil was, for an unknown(**) and certainly quite large amount of recent time, near the surface. People found and collected it, right? At least part of it was outcropping otherwise it would not be found.

This means the fossil and enclosing rocks were subjected to soil formation and also have been exposed to ground water – even if the area has nowadays a dry climate. Biologic activity is surprisingly strong in such environments. It is quite possible that bacteria have been living at or penetrated small cracks and pores of the rocks and fossils for tens of thousands of years or even more. As the rock came closer to surface (uplift and erosion of overlying material), it eventually entered in contact with groundwater. As soon as this happened, things could live and thrive at the pores(***). Note also that plant roots can penetrate cracks. So, recent biologic activity may have produced the organic material, the alleged soft tissues found. Assuming, again, no tampering or mishandling(****) happened, then recent things which lived when the fossil was at the phreatic (just water at the pores) and/or vadose (water and air fill the pores) zones are the possible most likely sources of the material.

(*)Pretty big & risky assumption taking in to account we are dealing with creationists.

(**)Not exactly true. I bet the folks who study pedogenesis (it is about soil formation, no children involved) and landscape evolution of the area where the fossil was collected probably could provide some time estimates.

(***)Maybe even before; Google for deep biosphere and also note bacteria may have some roles on the lithification of sediments. But that would have been a long, long time ago, and thus far, far away from the reach of carbon isotope dating.

(****)Yes, confusing this recent material with something belonging to the fossil could be seen as mishandling; personally I would prefer to call it an error or ID SNAFU of the collected material. Contamination and errors on sample numbers and labels are more adequately described as mishandling.

 

[Dinwar]

(***)Maybe even before; Google for deep biosphere and also note bacteria may have some roles on the lithification of sediments. But that would have been a long, long time ago, and thus far, far away from the reach of carbon isotope dating.

The reason I didn't bring these critters up is that they almost certainly live on dead carbon. C14 is a cosmogenic nucleotide--the majority of the C14 on the planet comes from interactions between N14 and cosmic rays (the Sun being a main source). So stuff living deep in the Earth probably doesn't get too much C14 in its diet. Some, due to background radiation and the like, but not much.

Note also that plant roots can penetrate cracks.

And fungi.

 

[Red Baron Farms]

I just don't know. I am reading literally dozens of seemingly pretty conclusive studies from all over the world all concluding that somehow original organic material was preserved. Even many more than I already knew about. Not just bone and horn either. Skin, feathers, claws, even a dinosaur coprolite. All sorts of methods too.

BTW that's after filtering out all the YEC sites.

Here is one as an example: Infrared mapping resolves soft tissue preservation in 50 million year-old reptile skin

Here is an even more astonishing one, they not only have feathers, they can tell what color they probably were: Plumage Color Patterns of an Extinct Dinosaur

 

[Dinwar]

I just don't know. I am reading literally dozens of seemingly pretty conclusive studies from all over the world all concluding that somehow original organic material was preserved. Even many more than I already knew about. Not just bone and horn either. Skin, feathers, claws, even a dinosaur coprolite. All sorts of methods too.

It happens. There are fads in science just like everything else. Give it 20 years and we'll see which are true, and which are wishful thinking. My guess is most are wishful thinking--taphonomy is VERY harsh.

 

[Red Baron Farms]

It happens. There are fads in science just like everything else. Give it 20 years and we'll see which are true, and which are wishful thinking. My guess is most are wishful thinking--taphonomy is VERY harsh.

True. Even should soft tissue preservation survive peer review, it certainly is wishful thinking to call it evidence for YEC.

What do you make of this? 160 Ma Jurassic cephalopod ink sacs!!!! That is soft tissue!

Direct chemical evidence for eumelanin pigment from the Jurassic period

 

[Dinwar]

There's a vast difference between preserving a chemical and preserving tissue. I'm skeptical about the chemical (I'd need to see the preservation style), but even if it's true it's fundamentally different than preserving sheets of tissue.

 

[Red Baron Farms]

Absolutely! Bone, horn, skin, feathers, blood vessels, blood cells, internal cellular organelles, partially digested muscle tissue in coprolite, squid ink. They are all fundamentally different. But they are all organic remnants claimed to be preserved orders of magnitude longer than the traditional consensus asserts as possible.

That only leaves 3 options:
1) Organic material can be preserved much longer than previously thought.
2) These are not original organic material, but by coincidence have many/most the same properties as the original organic material.
3) They are not as old as previously thought.

I personally don't automatically jump to 3. In fact in my opinion that is the least likely of the 3. In my opinion 2. is pretty unlikely as well. After all we get ink like properties in ancient cuttlefish, and bone like properties in ancient bone, and collagen like properties in ancient connective tissue? How would bacteria in the earth "know" to mimic exactly the type of tissue expected in every case? Wouldn't bacteria with feather like properties be just as likely to replace blood vessels if it was some random bacteria?

Either way none seems a really good explanation IMHO. Something has to be going on here that is being missed.

 

[Dinwar]

Absolutely! Bone, horn, skin, feathers, blood vessels, blood cells, internal cellular organelles, partially digested muscle tissue in coprolite, squid ink. They are all fundamentally different. But they are all organic remnants claimed to be preserved orders of magnitude longer than the traditional consensus asserts as possible.

You missed my point. There's no real consensus as to how long a molecule can be and survive through geologic time--it is so dependent upon setting that any such estimates are meaningless. However, it's so much easier to preserve a few molecules of pigment than it is to preserve tissue that the two aren't the same game, much less in the same ballpark.

That only leaves 3 options:
1) Organic material can be preserved much longer than previously thought.
2) These are not original organic material, but by coincidence have many/most the same properties as the original organic material.
3) They are not as old as previously thought.

#3 isn't an option. There are so many lines of evidence pointing to great age that to even entertain the thought of a much younger age is dishonest. There's no other word for it.

In my opinion 2. is pretty unlikely as well.

Unless you are knowledgeable about the taphonomic setting of the specific fossils involved, your opinion isn't really worth anything. No insult intended here--NO ONE'S opinion is worth much without knowledge about the taphonomic setting. Correo Neto and I have knowledge about taphonomy in general, so we can formulate more informed opinions than most, but we'd still need site-specific knowledge in order to fully understand what's going on. Taphonomic processes are HIGHLY locality-specific.

How would bacteria in the earth "know" to mimic exactly the type of tissue expected in every case?

How did the rocks on Mars "know" to mimic a human face? There are two things going on here that you don't seem to fully appreciate: First, people are looking to make a name for themselves, and therefore they will look for spectacular finds. This leads to some folks degrading their standards in order to allow them to make grand sweeping conclusions, and allows them to more easily fool themselves into thinking they see something that's not there. How do you KNOW that feather-like bacterial contamination isn't there? All you know is that the folks involved didn't report it--and that very easily could be because they didn't see it, or because they saw it but knew to dismiss it as contamination, rather than because it wasn't there. If you're looking at bone you look for collagene, after all. Secondly, you don't fully appreciate how many bones we've found and studied. Almost no one does. The fossil record is so rich at this point that the mind absolutely boggles. We have studied several orders of magnitude more dinosaur fossils than any non-expert realizes. When you look at a few million fragments or more, the odds of finding a one-in-a-million weird occurrance are actually pretty good. Particularly if you're already primed to see something, which is why I advise extreme caution in accepting these results--a LOT of them will turn out to be folks who saw things because they wanted to see them.

 

[Red Baron Farms]

And the presence of hydroxyproline and hydroxylysine? [1] How would the bacterial biofilm hypothesis explain the presence of hydroxyproline and hydroxylysine in these dinosaur so called soft tissues?

 

[Dinwar]

I'm no expert (paleontologists tend not to study biochemistry in great detail, particularly those of us who came in from the geology side), but one option is that more than one process is going on. The chemicals may be present due to being deposited by groundwater from modern sources, while the bacterial film formed at a different time. You need to prove that these materials came from the original organism, not merely that they are present, and I've yet to see anything that even addresses that.

 

[Red Baron Farms]

I'm no expert (paleontologists tend not to study biochemistry in great detail, particularly those of us who came in from the geology side), but one option is that more than one process is going on. The chemicals may be present due to being deposited by groundwater from modern sources, while the bacterial film formed at a different time. You need to prove that these materials came from the original organism, not merely that they are present, and I've yet to see anything that even addresses that.

Doesn't that address it? I mean for example, there are differences in the types of connective tissue produced by bacteria and animals. So if the claimed "collagen" were a bacteria biofilm, then the type should match the type produced by bacteria. Specifically above in my first question, hydroxyproline and hydroxylysine were instrumental in the capability for multicellular life.

The development of entirely new amino acids was the key opening the way to complex multicellularity. It permitted evolution of the structural proteins needed to provide mechanical support for increased size and greater morphogenetic experimentation.

So isn't that addressing the way to tell if this is a bacteria biofilm or original material from the dinosaur? Forget WHEN the biofilm formed. Biofilms no matter when they formed don't contain hydroxyproline and hydroxylysine. No bacteria produces that type of material, much less that type of material in the exact forms seen in the fossils. (in the morphology of animal cells and animal tissues)

It's not a trivial question.

 

[Darwin123]

I recently saw at some CT web site that scientists had used ¹⁴C dating to determine the age of triceratops fossils at about 34,000 years.

I've done a little carbon dating in university, and I understand that the upper limit age limit using this technique is about 50,000 years.

I have a question: Is there a legitimate reason to ¹⁴C date something presumed to be >65 million years old?

The person who did it obviously didn't think 50 KY was a legitimate upper limit.He wants to show that carbon 14 dates are not correlated with the 'evolutionist age' of the fossil. Further, he wants to prove that the hypothetical limits of any radiometric age are arbitrarily chosen rather than reflecting an actual physical limit. In other words, the limits of a dating method are supposedly chosen with confirmation bias.

I have been looking through some Creationist literature. Most of them think that radiometric dating is off for all isotopes, not just carbon 14. They have the erroneous idea that the rate of radioactive decay is calibrated using the age of the fossil determined by 'evolutionary theory'. In their view, fossils are dated using techniques that are known to produces ages in the range of the fossils hypothetical age. Hence, the radiometric age determinations are supposedly based on circular logic.


Much of the effort goes toward debunking carbon 14 dates. Of course, carbon 14 can't be used to date dinosaur bones. However, the accepted range of carbon 14 dating overlaps historic artifacts including tree rings. Hence, the validity of carbon 14 dating has some confirmation from dating methods that don't use radioactive isotopes. So there is a little less circular reasoning for carbon 14 dating then with U-Th dating, supposedly. Hence, it becomes very important to show that carbon 14 dating is inconsistent with U-Th-Pb.

Some of these Creationists are scientists who are somewhat knowledgeable in their field. Some of them have applied radiometric dating to fossils whose U-Th age is outside the range of accepted C14 dating. They find a small C14 age, and then claim it shows the U-Th method wrong. They conveniently decide that both methods (U-Th-Pb and C12-C14) are wrong. So the earth must obviously be less than 7 KY old.

There are a couple of false hypotheses that they use in these analyses. One is that the acknowledged limits of radiometric dating don't have physically valid justifications. Their claim is that the limits were chosen just to confirm the theory.

One reason that radiometric dating methods stop working is that there is 'cross contamination' of the samples used to make the determination. For example, mass spectrometry is very often used in C14 determinations. If there is too little C14 in a sample, as when it is way to old, a small amount of contamination from a previously run sample can severely bias the measurement.

If a sample of a medium age is used in a mass spectrometer, then one can still evaluate samples of approximately the same age or younger. The contamination of the medium age sample isn't significant. If following the medium age sample, one tries to evaluate the age of a very old sample, the contamination could be significant. The only way to avoid this is to purge the mass spectrometer with huge amounts of nitrogen gas, or us careful sequencing of data.

So the companies that do radiometric dating are very careful to tell you what the range of their instrument is. If the sample has a completely unknown age, then they have to purge the chambers for a very long time. If you just send a very old sample without telling them, and they have been analyzing young samples, then for sure cross contamination will be a problem.

Also remember that carbon dating uses the hypothesis that all the carbon came from the atmosphere via plants. The carbon 14 clock starts from the minute the plant has died. If an animal eats it, the clock is still going for the animal fossil. If that animal got sunk in a pit of asphalt, for example, the clock starts at the origin of the asphalt. Asphalt is typically a petroleum based substance whose origin is the Carboniferous period, more than 300 MYA.


There are other physical processes that cause limits to the accuracy of a radiometric determination. However, the Creationist usually avoids the issue of the physical process that limits the radiometric method. They claim there is a mysterious calibration which is circular.

I think the issue of non atmospheric carbon is very interesting. I do wonder where the carbon 14 in that triceratops fossil came from. I would like to know how much C12 the fossil had, and compare it to the C12 in younger fossils. I suspect that there was very little C12 in that triceratops bone. I conjecture that what little carbon was there came from nonbiological carbon from rocks. Not all carbon in rock comes from either the atmosphere or plants. Volcanoes generate carbon dioxide which is not biological. I suspect nonbiological carbon severely biases the measurement.

Diamonds are found in igneous rock. The isotope ratio is not the same in diamonds as in plant life. Gypsum is usually not biological, but contains lots of carbon. So if the material of that bone was even partially replaced, the carbon 14 dates would be invalid.

However, there are other sources of error. I would suggest that the person should try doing a really blind test by telling the company that the fossil may be outside the C14 range. Challenge the company to find which fossils are likely to have false dates assigned to them.

When you meet such a Creationist you should ask him about cross contamination.You could look up articles on cross contamination with regard to fossils.


You could find out how these limits on radiometric dating are determined. It is not a matter of circular reasoning as Creationists would claim.

 

[Red Baron Farms]

Darwin,
Thanks for that. That settles the C-14 issue, at least for me. Can you settle the soft tissue issue as well?

 

[BenBurch]

Well, there can be soft material but also understand that such material is bio-available under the right circumstances and that bacteria could have infiltrated it at some point in recent history (like when it was near the surface before being found) and they would eat some part of the residue and leave their own C14 footprints because they were respirating.

 

[John Jones]

[...] Specifically above in my first question, hydroxyproline and hydroxylysine were instrumental in the capability for multicellular life. [...] Biofilms no matter when they formed don't contain hydroxyproline and hydroxylysine. No bacteria produces that type of material, much less that type of material in the exact forms seen in the fossils. (in the morphology of animal cells and animal tissues)

Citations, please.

 

[Red Baron Farms]

Citations, please.

I found it in this PLOS-ONE commentary of Dinosaurian Soft Tissues Interpreted as Bacterial Biofilms
[1]


In the review of the Kaye et al. biofilm explanation they explain why those Amino acids support the Schweitzer et al. explanation.

The Schweitzer et al explanation can be found in Science Vol 316 here: [2]

 

[Dinwar]

Doesn't that address it? I mean for example, there are differences in the types of connective tissue produced by bacteria and animals. So if the claimed "collagen" were a bacteria biofilm, then the type should match the type produced by bacteria. Specifically above in my first question, hydroxyproline and hydroxylysine were instrumental in the capability for multicellular life.

Re-read my post. My scenario involved the transportation of these molecules from chordates into the fossil, and the unrelated formation of bacterial biofilms. Your interpretation of these things completely ignores groundwater, an egregious error on your part that pretty much invalidates everything you have to say on the topic. No insult intended here--ignoring groundwater when interpreting near-surface material is like ignoring the fact that the gas tank is empty when trying to diagnose a car.

It's not a trivial question.

No, it isn't. Nor is my answer. So I would like you to actually read it.

 

[Red Baron Farms]

Re-read my post. My scenario involved the transportation of these molecules from chordates into the fossil, and the unrelated formation of bacterial biofilms. Your interpretation of these things completely ignores groundwater, an egregious error on your part that pretty much invalidates everything you have to say on the topic. No insult intended here--ignoring groundwater when interpreting near-surface material is like ignoring the fact that the gas tank is empty when trying to diagnose a car.

No, it isn't. Nor is my answer. So I would like you to actually read it.

I am not ignoring ground water. I am asking how relatively modern groundwater would contaminate the fossil with hydroxyproline and hydroxylysine from chordates and reform them via bacteria into the structures found mineralised inside the bones? I am not seeing the mechanism.

 

[Dinwar]

I am not ignoring ground water. I am asking how relatively modern groundwater would contaminate the fossil with hydroxyproline and hydroxylysine from chordates and reform them via bacteria into the structures found mineralised inside the bones? I am not seeing the mechanism.

I provided one. Chordates are known to make burrows--chrotovinia and the like. Arthropods of various sorts also take chordate bones (including human bones, in one rather spectacular case I've seen) into their burrows. Add groundwater and you can mobilize any number of chemicals, including organic mollecules. These will get deposited in various places, depending on the local biogeochemistry.

You are still assuming that the bio mollecules and the bactieral film are causally connected. I'm arguing that they're not--two SEPARATE processes are involved. Both are widely known and widely documented, and both happening at the same time is far more likely than preserving soft tissue for 68 ma. Add a healthy dose of folks being primed to see these structures, and it's relatively easy to get what appears to be ancient soft tissue and biochemicals when in fact what you're seeing is contamination.