Doubting doubts about the Squishosaur
2 August 2008[>
Public Library of Science (PLoS)
The structures recovered from dino bone by Thomas Kaye and colleagues, which they claim are not blood vessels but modern biofilms.
In late July 2008, the internet was abuzz with the news that some scientists had published research doubting the claim that blood vessels and other soft tissues were found in T. rex fossils. This was a claim that creationists have made much about. According to these researchers, the vessels were actually the result of ‘biofilms’.
We have had many questions already, so this weekend’s ‘feedback’ by Dr Carl Wieland will respond to the announcement in at least a preliminary way.
In March 2005, in an article entitled Still Soft and Stretchy, we wrote in some detail about the sensational discovery of soft tissue in a fossilized T. rex bone after the mineral matrix had been dissolved away by a weak alkaline solution (though a weak acid would have worked too, and many of the subsequent reports call it that). The images from that article are so important to this one that they are repeated here, along with the captions.
Dr Mary Schweitzer, the (theistic evolutionist) scientist responsible, had a few years previously discovered structures looking just like red blood cells inside blood vessels, in another piece of T. rex bone. Immunological tests even seemed to confirm the presence of hemoglobin, a complex and fragile molecule that should in no way be able to last for ‘millions of years’. The relevant portion of the bone in that case actually appeared to be unfossilized (see Sensational dinosaur blood report!)
In both instances, long-agers were keen to demolish the strong implications of such finds against long-age views, with very limited success. See for example, this response to a critic concerning the original red cells claim. And our article Squirming at the Squishosaur responds to various long-ager counterclaims about the soft tissue find.
This latest claim for biofilms needs to be considered carefully and unemotively. If a great argument for creation has to fall by the wayside, so be it. In my own public presentations that touch upon dinosaur issues, I have repeatedly indicated that it is surprising enough to have soft tissue like this after thousands of years even. And I have written:
‘Certainly it “taxes one’s imagination” less [but it still taxes it-CW] to believe that such structures have survived a few thousand years, as opposed to >65 million. Even the most rabid long-ager would surely have to agree with that simple proposition.’1
So far, Mary Schweitzer is unconvinced… she and her team considered this [biofilm] hypothesis as a possibility early on, and rejected it.
The point being that if these structures were to turn out not to be soft tissues after all, then this would not prove the millions of years by any means, as it would be quite within the bounds of likelihood to have no soft tissue remaining after the thousands of years since the Genesis Flood.
However, as will hopefully become clear, to conclude that no dino soft tissues have been found would be very premature and unwarranted, to put it mildly.
The bombshell report
The paper by Thomas Kaye and colleagues questioning the soft tissue finds was published 30 July 2008 in PloS ONE, the journal of the Public Library of Science. Being open-access on the web, all readers can check the original article for themselves, saving the need to go into too much detail.2
The introduction acknowledges that apparent soft tissue in ancient fossils is not just a ‘one off’ but has been confirmed now numerous times, ‘across a range of time and taxa’. The researchers were thorough—they used 200 hours of scanning electron microscope (SEM) time to look at the inside of dinosaur fossil bone, before the mineral was dissolved, in ‘seven geologic formations and more than fifteen taxa’. They also used infrared spectroscopy.
After this, they said that their findings caused them to reinterpret the original Schweitzer findings as being the result of bacterial biofilms. These are well-known types of structures that are often labelled as ‘slime’. (An example would be what appears on the walls of your fish tank, the stuff on which the watersnails feed.)
From the appearances they discovered under the SEM, they make a good case for evidence of past bacterial activity.
They claim that their findings indicate that the Schweitzer ‘soft tissues’ were produced by modern bacteria infiltrating the specimen and forming ‘endocasts’ of bacterial film that would preserve the shape of the blood vessels, for example. (An endocast is a cast made of the inside of a hollow cavity, preserving the shape of the cavity, for example.) Another claim, also with supporting evidence, is that the apparent red blood cells are actually iron-rich spheres called framboids.
These claims are probably bolstered in the eyes of the average reader by Kaye’s statement (untestable though it is) that he would have liked to have confirmed that soft tissue really had been found.
The suggestion would be more convincing if all that had been found were transparent blood vessels and some round lumps vaguely resembling red blood cells. However, it seems to require a fair amount of credulity to think that the biofilm/framboids explanation could cover the range of findings in the original report. This is why it was important to reproduce the illustrations here.
CREDIT: M. H. Schweitzer
Left: The flexible branching structures in the T. rex
bone were justifiably identified as ‘blood vessels’. Soft tissues like
blood vessels should not be there if the bones were 65 million years old.
Right: These microscopic structures were able to be squeezed out of some of the blood vessels, and can be seen to ‘look like cells’ as the researchers said. So once again there is scope for Dr Schweitzer to ask the same question, ‘How could these cells last for 65 million years?’
Consider that not only were there flexible transparent blood vessels found, but that these had inside them red blood cell structures with every appearance of still having nuclei, all in a substrate that could be squeezed out of the vessels like toothpaste. (Note that unlike mammalian red blood cells, reptilian ones keep their nuclei when fully developed.) Also found were clearly discernible bone cells (not shown here), called osteocytes, with a very characteristic appearance. (The Kaye team believes these were similarly formed by bacteria.) But one would think that of all the original Schweitzer finds, the most difficult to explain via the ‘bacterial films’ theory would have to be the flexible ligament-like structures shown in the diagrams below. I could not find these discussed anywhere at the date of writing.
Actually, there is no reason why both could not be present—bacterial biofilms (and/or their partially mineralized remnants) as well as elements of the original structure, something that fits all the evidence to date. That concept also fits with the observation that in one well known dinosaur location, the Hell Creek formation in Montana, palaeontologists have long known that most of the fossils when cracked open have the ‘smell of death’ (decomposing, cadaverous flesh) in them.3 This suggests not only that bacteria have indeed invaded the fossils, but still have organic material available to decompose. And since most bacteria require organic material to live on, the presence of soft tissue may be a good reason why they have migrated into the fossil-bearing rock in the first place.
What does Mary Schweitzer think?
To conclude that no dino soft tissues have been found would very premature and unwarranted, to put it mildly.
Schweitzer is apparently standing by her claims. Being an evolutionist, albeit a theist at last reckoning, she can hardly be accused of sympathy for biblical creationists. Schweitzer has in fact expressed dismay at discovering her work being utilized to defend Genesis history. It seems that so far she is unconvinced by the biofilm hypothesis, though acknowledging that some bacterial action could be involved. The Discover magazine’s site says that she claims that she and her team considered this biofilm hypothesis as a possibility early on, and rejected it.4 For one thing, she is reported elsewhere as saying, over time gravity should have made such films thicker at the bottom, contrary to observations.
Creationists have all along been keen to see the soft objects in Schweitzer’s discovery subjected to carbon dating.5 If they were millions of years old, there should not be any radiocarbon in them. So we would have anticipated, and welcomed, results giving any sort of radiocarbon date, as this would automatically weaken the claim of ‘millions of years’. But the first CMI has heard about such dating being carried out is in the Kaye et al. paper. It states that radiocarbon results on the structures they found ‘were “greater than modern”, indicating a modern origin for the material.’ In fact, such a result would also be expected by creationists as it certainly would inspire even more doubt about the idea that these dino tissues are ‘millions of years old’. Of course, the Kaye et al paper sees this radiocarbon result as confirmation of its claim that these were modern bacteria invading the fossil.
Interestingly, a report on PhysOrg.com says that carbon dating ‘placed the origin at around 1960’.6 Assuming that to be the case, then ignoring the huge limitations and error possibilities in such dating, are they saying that in this entire range of dino fossils—from many different geologic sites and levels, and all sitting there for millions of years—this slime has only been manufactured in the last few decades? Presumably further reports will shed more light on this.
Science via AP From www.msnbc.msn.com/id/7285683/)
A: The arrow points to a tissue fragment that is still elastic.
It beggars belief that elastic tissue like this could have lasted for 65 million
B: Another instance of ‘fresh appearance’ which similarly makes it hard to believe in the ‘millions of years’.
C: Regions of bone showing where the fibrous structure is still present, compared to most fossil bones which lack this structure. But these bones are claimed to be 65 million years old, yet they manage to retain this structure.
Note also that long-age views still have to contend with Schweitzer’s reports of the detectable evidence of the blood protein haemoglobin7, as well as the previously reported discoveries by others of the presence of the bone protein osteocalcin in fossil dinosaur bone.8 Such proteins are complex biological molecules, which have a relentless thermodynamic tendency to break down and lose their original structure over time, even if totally protected from such things as moisture and bacterial action. Furthermore, one protein from the Schweitzer specimens (using a technique which, when used on mammoth protein, confirmed that it was extremely close to modern elephants) was found to have an amino acid sequence which was close enough to that of a chicken for it to be used to bolster the claim that dinos and birds are evolutionary relatives. To quote one evolutionist source,
‘“The sequences are clearly from T. rex,” said John Asara of Harvard Medical School in Cambridge, Massachusetts, who led one of the studies.’9
The above brief and preliminary comments would at this early juncture appear to give good reasons to be extremely sceptical about the sweeping conclusion of Kaye and his colleagues. At the same time, I would concede the possibility, even likelihood, that their evidence points to bacterial action after the specimen was buried.
Our scepticism is shared by Dr Schweitzer herself, (and some other scientists, judging by the blogs). For instance, she says, quite reasonably:
Kaye et al. did not address our immunological data, and controls. They did not address the phylogenetic analyses of sequence as reported by Organ et al., 2008 or offer any explanation for how ‘biofilm’ proteins from dinosaur could cluster with chicken, while ‘biofilm’ from mammoth and mastodon cluster with elephant. Nor did they explain the internal, or ‘intracellular’ structure we report for observed osteocytes. And finally, they did not state how the rounded structures we reported could persist free floating in a hollow biofilm as we described for the ‘vascular’ inclusions in dinosaur vessels. Indeed, it seems that they only addressed aspects of our study that fit conveniently with their preconceived ideas, as they pick and chose what to focus on. As we stated often after our paper came out, morphology alone is insufficient to make any claims about the origin of such material, hence we provided a host of other data to support the hypothesis of endogeneity. Kaye et al. did less than this to support their claim that the material they observed is biofilm.
Then she continued in a technical area about spectroscopy, and my colleague Jonathan Sarfati, whose Ph.D. thesis specialized in vibrational spectroscopy, thinks she is right:
Kaye et al. also overstate their FTIR data, and show a misunderstanding of what these data can be used to say. There are many different molecular vibrations and rotational vibrational modes in a heterogenous sample as represented by their dinosaur material. It is far from a pure sample. In this case, IR absorption peaks overlie each other, and resolution of the spectrum is not high enough to separate them. The spectrum is dependent upon both the composition of the mixture and the relative concentrations as well. Combining all these variables to conclude that one reading is more similar to one than another is really meaningless, especially when trying to interpret peaks in the fingerprint region of 1500–400 cm–1. The low resolution IR spectra figured in this paper is not adequate to draw any conclusions about a heterogenous sample.
Creationists have found the soft tissue evidence to date extremely helpful, but don’t need it in order to maintain the young earth and the biblical Flood on the strength of all the other evidence.
On the other hand, any evidence for soft tissue in ‘millions-of-years-old’ fossils will cause an ongoing need for evolutionists to somehow ‘explain it away’.
If, as research progresses, the full scope of the Kaye et al. conclusion ever did become adequately supported by the evidence (which would require the objections raised here to be properly addressed, for a start) then most evolutionists would of course warmly welcome it. While that’s at least remotely possible, it does not yet warrant holding one’s breath, by a long shot. The outcome at this point looks likely to be a ‘hybrid’ of both explanations, retaining at least some very awkward questions for long-age philosophy.
There are sure to be evolutionists, at the very least the Schweitzer team, actively challenging the Kaye paper in detail, so we should be able to ‘watch from the sidelines’ for a while to see what other interesting results come up.
- See Squirming at the Squishosaur Return to text.
- Thomas G. Kaye, Gary Gaugler, Zbigniew Sawlowicz;
Dinosaurian Soft Tissues Interpreted as Bacterial Biofilms, PLoS One, 30 July
journal.pone.0002808>. Return to text.
- See Schweitzer’s dangerous discovery . Return to text.
Researchers Debate: Is It Preserved Dinosaur Tissue, or Bacterial Slime?, <blogs.discovermagazine.com/80beats/2008/07/30/researchers-debate-is-it-preserved-dinosaur-tissue-or-
bacterial-slime>, 30 July 2008. Return to text.
- See Why don’t they carbon-date dinosaur fossils? Return to text.
- New research challenges notion that dinosaur soft tissues still survive, <http://www.physorg.com/news136613903.html>, physorg.com, 30 July 2008. Return to text.
- Mary H. Schweitzer, Mark Marshall, Keith Carron, D. Scott Bohle, Scott C. Busse, Ernst V. Arnold, Darlene Barnard, J. R. Horner, and Jean R. Starkey (1997), Heme compounds in dinosaur Heme compounds in dinosaur Trabecular bone, Proceedings of the National Academy of Sciences of the USA 94, pp. 6291–6296, June 1997, <http://www.pnas.org/cgi/content/abstract/94/12/6291> Return to text.
- Muyzer G., Sandberg P. Knapen M.H.J., Vermeer C., Collins M.J., and Westbroek P. (1992) Preservation of bone protein osteocalcin in dinosaurs. Geology 20, 871–874. Return to text.
- Dinosaur Soft Tissue Sequenced; Similar to Chicken Proteins, <http://news.nationalgeographic.com/news/2007/04/070412-dino-tissues.html>, National Geographic News, 12 April 2007. Return to text.