An Explanation that is Not Exactly Iron-Clad

Tyrannosaurs like this one were thought to have gone extinct 65 million years ago, but soft tissue has been found in one Tyrannosaurus rex fossil. Soft tissue has also been found in several other fossils that are supposed to be millions of years old. (click for credit)

In 2005, Dr. Mary Schweitzer shocked the scientific world by reporting soft tissue in a Tyrannosaurus rex fossil that is supposed to be 68 million years old.1 While many scientists who are more interested in their preconceptions than they are in the data tried to dismiss her findings, several other examples of soft tissue in fossils that are thought to be millions of years old have been found (see here, here, here, here, and here). In the end, it has become nearly impossible for a thoughtful scientist to conclude anything other than the fact that there is soft tissue present in some fossils which are thought to be millions of years old.

Now, for someone who truly believes in an ancient earth, it’s very hard to explain how soft tissue can remain in a fossil that has been in the ground for millions of years. Even for a young-earth creationist like myself, it is still a difficult thing to understand. Soft tissue tends to decay in a matter of days or weeks. From a chemical point of view, it is hard to understand how it can stay soft for even a few years, much less hundreds, thousands, or even millions of years. Fortunately, Dr. Schweitzer has continued her studies on soft tissue in dinosaur fossils, and she has found at least one chemical mechanism by which soft tissue can be preserved for significantly longer than anyone expected.2

She and her colleagues began by examining soft tissue from her T. rex fossil as well as a Brachylophosaurus canadensis fossil. While the T. rex fossil is supposed to be about 68 million years old, the B. canadensis is supposed to be about 76 million years old. Nevertheless, under a transmission electron microscope, both are seen to harbor soft vessels that are probably blood vessels. Interestingly enough, however, the vessels have tiny particles of iron embedded in them.

Where did the iron come from? It came from the dinosaurs’ blood. When the dinosaurs were alive, the iron was tightly-bound to a blood protein known as hemoglobin. Once death occurred, however, the hemoglobin decayed, releasing the iron and allowing it to mix with the tissues. How does this help with preservation? Well, most biological molecules are polymers, which means they are long chains of repeating chemical units. Proteins, for example, are long chains of smaller chemicals called amino acids. It is well known that iron, especially when it has the chance to react with oxygen, can cause polymers to link together in a process called cross-linking. When polymers link together like that, they are more resistant to decay.

Since Schweitzer and her colleagues saw iron particles embedded in the soft tissue of their dinosaur specimens, they thought that perhaps the iron was cross-linking the biomolecules, and that’s at least part of how the soft tissue was being preserved. They decided to test this hypothesis by taking ostrich blood vessels and soaking them in one of three liquids: a concentrated solution of blood whose red blood cells had been destroyed, a pH-controlled saltwater solution, or sterile distilled water. They found that while the blood vessels soaked in distilled water and salt water degraded significantly in a matter of 3 days, the ones that had been soaked in the blood concentrate were intact after sitting at room temperature for 2 years! Obviously, then, something from the blood was able to preserve the vessels.

Interestingly enough, they stored some of the blood-soaked vessels in a normal environment, and they stored others in an environment without oxygen. They found that while both sets of blood-soaked vessels were preserved, the ones that had been stored in a normal environment were better preserved than those that were stored under oxygen-free conditions. This further supports their hypothesis that iron is the key to the preservation process, because it is well-known that iron produces cross-linking in the presence of oxygen better than it does without oxygen. The authors conclude:

The HB–oxygen interactions investigated here explain both the association of iron with many exceptionally preserved fossils and the enhanced preservation of tissues, cells and molecules over deep time. Iron and oxygen chemistry, at the centre of bioenergetics and terrestrial life, are now seen to play key roles in the preservation of biomaterials after death. [Note: HB is an abbreviation for hemoglobin.]

Have Schweitzer and her colleagues explained how soft tissue can be preserved in fossils that are millions of years old? If you read popular sources, you certainly get that impression. For example, here are three headlines for articles that discuss their study:

Mysteriously Intact T. Rex Tissue Finally Explained

Iron Preserves Ancient Dinosaur Soft Tissue in Fossils

Controversial T. Rex Soft Tissue Discovery Finally Has An Explanation

Of course, if you understand the study, you recognize that the press has completely mangled the science. While the study represents an excellent first step in understanding how soft tissue can be found in fossils, it doesn’t solve the mystery of how it could be preserved for millions of years.

There are at least three things that indicate lots more research has to be done on this issue:

(1) The ostrich blood vessels were preserved for “only” two years. While this is more than 240 times longer than what happens under normal conditions, it is still a far cry from millions of years. Hopefully, the authors are continuing the experiment to see how well the vessels remain preserved after a much longer timespan.

(2) The ostrich blood vessels were stored at room temperature throughout the course of the experiment. While this is a good first step, in order to really see how well this preservation holds, the authors need to vary the temperature in a way that is realistic. I would think that simulating the freeze/thaw cycle that happens every year would deteriorate the blood vessels over a long timespan.

(3) It’s not clear that iron is always associated with soft tissue in dinosaur bones. For example, consider one of the most striking examples of soft tissue preservation in a dinosaur fossil. If you look at the photos in that paper, you see no evidence of iron particles. I contacted the lead author of the paper, and he informed me that he saw no iron particles or crystals in association with the soft bone cells in his samples. The only place he saw iron was inside partially-degraded tissues. So while iron might help preserve some soft tissue, it is probably not responsible for all soft-tissue preservation.

In my mind, then, here’s what Schweitzer’s excellent study demonstrates: In at least some cases, iron can preserve soft tissue for a significant length of time. How long? That’s hard to say, especially since real-world conditions weren’t used in the experiment. Nevertheless, the study at least provides us with a starting point for explaining the preservation of soft tissue in fossils. If the study is extended and starts to use real-world conditions, it might explain how soft tissue can be preserved for hundreds or perhaps even thousands of years. I am not sure how it could be used to explain the preservation of soft tissue over millions of years, but I remain open to the possibility.


1. Mary H. Schweitzer, Jennifer L. Wittmeyer,John R. Horner, Jan K. Toporski, “Soft-Tissue Vessels and Cellular Preservation in Tyrannosaurus rex,” Science, 307:1952-1955, 2005
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2. Mary H. Schweitzer, Wenxia Zheng, Timothy P. Cleland, Mark B. Goodwin, Elizabeth Boatman, Elizabeth Theil, Matthew A. Marcus and Sirine C. Fakra, “A role for iron and oxygen chemistry in preserving soft tissues, cells and molecules from deep time,” Proceedings of the Royal Society B 281:20132741, 2013
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44 thoughts on “An Explanation that is Not Exactly Iron-Clad”

  1. “They found that while both sets of blood-soaked vessels were preserved, the ones that had been stored in a normal environment were better preserved than those that were stored under oxygen-free conditions.”

    Did Schweitzer et al. simulate sediment burial, or were the remains exposed? The problem is that bones normally don’t just lie about for two years–unless they’re buried deeply enough, they’re subject to being eaten by scavengers. Otherwise, the ground would be littered with remains of dead animals.

    And even if they’re buried, a correlation with rapid burial and rapid decay has been shown for shells, that would presumably apply for bones as well (

    So real-world conditions should include more than temperature variations; it seems to me that the scientists should simulate actual environments of deposition for this study to have more than anecdotal value.

    1. S.M., the samples remained in the lab the entire time. I agree that the authors need to be more realistic in their study, and simulating depositional environments would certainly make things much more realistic.

  2. I found it interesting that you said that the soft tissue in dinosaur bones causes problems for even the YEC account. So, in essence the issue is still in the same spot as it was before. The soft tissue is a puzzling enigma better accounted for on a YEC account than a OEC/Theistic evolutionary/Naturalistic evolutionary account.

    1. I would say that your summary is correct, Blake. It is a puzzle in all viewpoints, but the puzzle is significantly less enigmatic in the YEC view than it is in the OEC/Theistic evolutionary/Naturalistic evolutionary views.

  3. Hi, interesting post, I really enjoyed reading it. I do have one question, just out of pure curiosity: Did the authors ever mention why ostrich blood was selected for the study?

    1. That’s a great question, LswaN. The authors never indicate in their paper why they used ostrich blood vessels as a model. However, I suspect it is because of the currently-fashionable hypothesis that dinosaurs evolved into birds. There are a lot of problems with that idea (see here, here, here, and here), but many scientist still believe it.

  4. The presumed soft tissue was called into question by Thomas Kaye of the University of Washington and his co-authors in 2008. They contend that what was really inside the tyrannosaur bone was slimy biofilm created by bacteria that coated the voids once occupied by blood vessels and cells.

  5. I read the abstract but I have not seen the entire article. Two questions come to my mind. One concerns the presence of red blood cells in the preserved sample. The most amazing find of Schweitzer’s original discovery for me was the presence of what she called round red micro structures that looked identical to nucleated red blood cell. If red blood cells were supposed to have been preserved for millions of years then Schweitzer’s team should have included them in the sample. My guess is that lysis would have occurred in the concentrated blood solution that would have prevented their preservation, but again, I have not seen the entire article to see if they were included or preserved.

    The second question is how much degeneration occurred in two years to the ostrich blood vessels. If even one percent degeneration occurred in two years then it is very unlikely that the vessels would even last for a thousand years at that same rate of degeneration

    1. Thanks for your comment, Bill. In their paper (Figs. 4c and 4d), they show red blood cells in the 2-year-old ostrich tissue. They were found only in the sample that was exposed to oxygen. In a large sample of cells, lysis doesn’t happen all at once. While the authors don’t explicitly state this, I would suspect that they credit the preservation of red blood cells to the fact that iron from red blood cells that had already lysed ended up preserving some of the red blood cells that hadn’t yet lysed.

      The only discussion of degradation in the ostrich tissues involved visual cues from the microscope images. The authors say:

      HB-treated vessels have remained intact for more than 2 years at room temperature with virtually no change, while control tissueswere significantly degraded within 3 days.

      It’s not clear what “virtually no change” means. This is why I suggested following the tissues over a long time span. Something like a 1% degradation would be hard to see with a microscope. However, as you say, even if that level of degradation happened, this process can’t explain preservation over a hypothetical millions of years timeframe.

  6. Thank you for your response Dr Wile. Is the full article available anywhere other than from Royal Society publishing? I would prefer a free source for the information as opposed to the 29 dollar fee.

    The other question I have for you since you have read the full article is whether the source of the concentrated solution of blood had been treated in any way to preserve it for this experiment, or if it was fresh untreated blood. Obviously the addition of any blood preservative or anticoagulant would compromise the results of the experiment.

    It also seems strange to me that medical examiners around the world are not reporting portions of well preserved tissue in corpses that have had bleeding into the tissues or are lying in pools of blood for a prolonged time as a result of wounds. My understanding is that a body in a protected environment like a house with no insects or rodents will still decompose fairly rapidly. Perhaps I do not understand the situation correctly.

    1. I don’t know of a free source for the article, Bill. I have access to it through a service for which I pay. The blood was not treated with any kind of preservatives or anti-coagulants (it was treated with an anticoagulant, which was EDTA). However, it was concentrated so that the blood was very rich in lysed red blood cells.

      I don’t think you understand what’s being tested. Certainly a corpse of any kind decays rather rapidly. However, Schweitzer and the others haven’t found preserved dinosaurs. They have found small samples of soft tissue in a dinosaur fossil that comes from an almost completely-decayed corpse. All Schweitzer is doing is seeing if there is some way a small amount of soft tissue can be preserved as the rest of the body decays around it. Medical examiners would not be interested in this kind of situation, so they would have no reason to look for it.

  7. Thank you once again for your reply Dr Wile. I think we can all agree that there has to be some type of tissue preservation that has allowed researchers to find preserved dinosaur soft tissues that are at least thousands of years old. Dr Schweitzer’s research is valuable in provididing a possible mechanism of long term preservation in these tissues. While I find the leap in interpretation from two years to millions of years difficult to accept, I still appreciate her work as a research scientist.

    My point about the preservation of corpses was that I would expect some grossly observable differential decomposition pattern in the corpse if blood soaked areas could be preserved for longer periods of time. For example, some portion of a face that was in blood might be more recognizable after an extended period of time than the other side of the face not exposed to a pool of blood. Once again I am at a disadvantage of not being able to read the entire research paper. It sounds like Schweitzer’s team used concentrated hemolyzed blood, so that could possibly explain why corpse tissues are not differentially decomposed in blood since they would be soaked in whole blood.

    Your point is well made about smaller amounts of tissue being preserved. Perhaps there is differential preservation in a corpse that would only be observable microscopically. You have also answered a number of questions I had about the experiment that weren’t addressed in the abstract. Thanks again.

  8. It was interesting to read about your debate with Dr Martin on another blog. I have had an interest in the creation evolution debate for quite a while. Even though it is good to present well documented evidence during a debate, it seems the naturalistic evolutionary community can always put a spin on it that matches their view. A perfect example is the preservation of dinosaur soft tissue that was discussed in this blog. Two years of preservation is interpreted by the naturalist community to mean that the tissues can survive for millions of years.

    It seems to me that the bottom line of the entire debate is the intellectual basis of each position. The Christian position is that a supreme intelligence was and is responsible for the ultimate development of human life on this planet. It doesn’t matter if the Christian is young age or old age, all Christians believe in a supreme intelligence.

    In contrast, the naturalist believes that the intellectual basis of everything created is literally absolute stupidity. Nothing on the primordial earth had any more intelligence than rocks or chemicals according to their position. As a result they begin their argument from an intellectual position of absolute stupidity.

    Presupposing a reliable mind when you are postulating that it originated from an initial condition of absolute stupidity seems illogical to me. I don’t understand how proponents of naturalism could ever feel comfortable enough with their concepts of truth to feel that they could rationally defend their position. If I felt my truth concepts were derived from absolute stupidity filtered through a common ancestor brain that was dumber than a chimpanzee, I would seriously question my ability to argue logically for any position.

    Having said these things, I have a question for you Dr Wile. Do you believe a research scientist could prove his or her brain was logical and reliable? It seems to me that a reliable logical brain or mind is simply a presupposition all of us have to make. In order to prove a logical and rational mind, wouldn’t the scientist have to use logic and rationality to verify what they want to prove? It seems to me that type of proof would require circular reasoning. On the other hand if they relied on another researcher to prove their brain reliable and logical, wouldn’t they have to rely on the logic and rationality of their own brain to interpret the results of the other researchers experiment?

    I have no formal education in logic or philosophy so I would sincerely appreciate your thoughts on the matter.

    1. Thanks for your comment, Bill. I wouldn’t agree that the bottom line of the entire debate is the intellectual basis of each position. I do think that a person’s preconceptions affect the way he or she sees and interprets the data. As a result, if someone wants to believe in naturalistic evolution, he or she can always make up stories to explain around any contrary data that are presented. However, there are some people who will abandon their preconceptions when they have to make up too many outlandish stories. That’s what happened to world-renowned geneticist Dr. John C. Sanford. He was a evolutionist for a long time, but the more research he did in genetics, the more he realized that the stories one has to make up to believe in evolution are too outlandish. As a result, he became a creationist. So while preconceptions do play a strong role in the debate, sometimes the data can win out.

      In answer to your question, science cannot prove anything. However, I do think that a research scientist can (and does) build up evidence that his or her brain is reliable. Consider, for example, a scientist who is studying the nature of an atom. He or she does a lot of experiments and comes up with an idea of how the atom behaves. The scientist then uses that idea to make a prediction about how the atom will behave in a brand-new experiment that is unlike those he or she did to develop the idea. If the atom behaves as predicted, that’s evidence the scientist’s brain is reliable. The more predictions that can be made and confirmed by the data, the more evidence there is that the scientist’s brain is reliable.

      At the same time, arguably the most important Christian philosopher alive today, Dr. Alvin Plantinga, argues that while we can provide a lot of evidence that our brains are reliable, one wouldn’t expect that if there were nothing guiding evolution to produce rational human beings. Thus, he sees the very fact that our brains are reliable as evidence against naturalistic evolution. I am not persuaded by his argument, but it is interesting. You can read a bit about his arguments and my problems with it here and here.

  9. Thank you Dr Wile. I appreciate both your reply and your insight into these issues.

    I see from the other blogs you referenced that you were convinced by the evidence, so I understand your position. I also think it is great that you provide so much good scientific evidence for the theistic position. I would not for a moment suggest that it is not extremely valuable to provide such evidence.

    What I mean by the bottom line applies when two individuals are both entrenched in their respective positions of theism and naturalism. As you said – science can’t prove anything. Additionally there are many who aren’t persuaded by the evidence. In my opinion, philosophy is necessary to resolve the conflict. For me it is simple. Absolute stupidity and supreme intelligence are the only two basic initial intellectual positions I know about when it comes to the creation evolution controversy. Anyone holding the naturalistic evolutionary position must by default choose absolute stupidity. The theist will hold to belief in supreme intelligence as an initial intellectual position. When presented with these two options it becomes very clear to me which one is the most logical.

    I am familiar with Dr Plantinga’s Evolutionary Argument against Naturalism. If I were using his argument I would not begin with the starting point he does I would start with the earliest intellectual conditions on the primordial Earth. The naturalistic evolutionary landscape has to begin with an initial intellectual condition of absolute stupidity. It must then fairly rapidly (in evolutionary terms) produce the most complex coding system known to man. It must go from absolute stupidity to mind boggling brilliance in the first significant step. At the same time this initial absolute stupidity must also produce not just life, but a reproductive life form. Intellectually speaking this first life form is still no smarter than a rock. Once again I find this scenario completely illogical.

    As far as the naturalistic scientist studying the atom is concerned, that person must assume an initial reliable mind in order to conduct the experiments. All subsequent findings would be worthless unless he or she started with a reliable logical mind. I (like Dr Plantinga) see no reason why that person should be confident in his or her initial assumption of mental reliability if based on a naturalistic perspective. Of course we all have reliable minds. We have all been created by God. That is why it is difficult to follow Plantinga’s argument. What he says, and what I agree with, is that the naturalist has no logical basis upon which to initially assume a reliable mind.

    1. Thanks for your reply, Bill. I guess I would have to disagree with you to a certain extent. I agree that science became what it is today specifically because of the Christian worldview. As Dr. Loren Eiseley put it:

      In one of those strange permutations of which history yields occasional rare examples, it is the Christian world which finally gave birth in a clear, articulate fashion to the experimental method of science itself. [Darwin’s Century: Evolution and the Men who Discovered It, (Anchor Books: Garden City, NY, 1961), p. 62]

      The Christian worldview gave the natural philosophers of the Middle Ages the confidence that their minds were reliable. However, that assumption was made long ago, and evidence for its validity has been piling up since the Middle Ages. Thus, at this point, a scientist can believe the mind is reliable because it has been shown to be reliable through more than 1,000 years of science.

  10. Dr. Wile, just a slight clarification about John Sanford–it wasn’t just the scientific evidence that convinced him, he needed faith in a Creator first. In an interview with Creation magazine, he said, “I was totally sold on evolution. It was my religion; it defined how I saw everything, it was my value system and my reason for being. Later, I came to believe in “God”, but this still did not significantly change my intellectual outlook regarding origins. However, still later, as I began to personally know and submit to Jesus, I started to be fundamentally changed—in every respect. This included my mind, and how I viewed science and history. I would not say that science led me to the Lord (which is the experience of some). Rather I would say Jesus opened my eyes to His creation—I was blind, and gradually I could see. It sounds simple, but it was a slow and painful process. I still only see ‘as through a glass, darkly.'”

    This was the same experience that I had with geology. It wasn’t until after a conversion experience that I began to question the conventional old earth/evolution paradigm–faith came first, then reason followed. And, as Dr. Sanford says, it was a slow and painful process.

    1. Thanks for your comment, S.M. In his book, Genetic Entropy and the Mystery of the Genome, Sandford says:

      Late in my career, I did something which for a Cornell professor would seem unthinkable. I began to question the Primary Axiom [his phrase for macroevolution]. I did this with great fear and trepidation. By doing this, I knew I would be at odds with the most “sacred cow” of modern academia. Among other things, it might even result in my expulsion from the academic world. Although I had achieved considerable success and notoriety within my own particular specialty (applied genetics), it would mean I would have to be stepping out of the safety of my own little niche. I would have to begin to explore some very big things, including aspects of theoretical genetics which I had always accepted by faith alone. I felt compelled to do all this – but I must confess I fully expected to simply hit a brick wall. To my own amazement, I gradually realized that the seemingly “great and unassailable fortress” which has been built up around the primary axiom is really a house of cards. The Primary Axiom is actually an extremely vulnerable theory – in fact it is essentially indefensible. (p. vi)

      So I think what he is saying in the CMI interview is that his faith allowed him to question evolution. However, it was the evidence that convinced him that evolution is “essentially indefensible.” So he was convinced against evolution by the evidence. However, it was his faith that caused him to look at the evidence to begin with.

  11. Thank you Dr Wile. Your feedback and even disagreement is very helpful as I try to understand this issue.

    I think part of your difficulty may be that you are already using a mind that you have good reason to believe is logical rational and reliable based on your belief in God. Because of that you project that same reliable mind on others. I agree that in general we all have reliable minds based on creation, but I don’t believe the naturalist can logically make that same assumption.

    It is necessary to start with a naturalistic perspective in order to be able to properly understand Plantinga’s argument and the point I am trying to make. In order to accept any of the evidence you have suggested the naturalist first has to assume his or her mind is reliable enough to interpret that evidence.

    As a naturalist you would have to believe the following things.

    •First and foremost you would have to believe that no initial guiding intelligence was present during any of the initial evolutionary process. As I wrote earlier, absolute stupidity is your intellectual starting point

    •You would also have to believe that intellectual development that began with absolute stupidity has been attenuated only for survival and reproduction purposes for billions of years. True beliefs were not necessary to this process.

    •At some point, what began as absolute stupidity was filtered through a common ancestor brain. This creature was dumber than a chimpanzee.

    • A few million years of additional unguided evolutionary process was necessary to produce the brain you as a naturalist now possess. That brain must be used to produce whatever true beliefs you have.

    •You have a “true belief” that approximately half or more of the world population suffers from a serious delusion that was caused by adaptive evolutionary development. It is a delusion that seriously undermines and affects their view of reality – their belief in a god.

    •You are also aware that most of the men and women who established the principles of science to which you adhere were affected by this delusion.

    • You are unable to prove your brain is reliable scientifically since you would have to rely on the very instrument (your brain) that you are testing.

    If I held all of the beliefs listed above, I would be hard pressed to have any confidence that my belief in naturalism was not simply another delusional belief acquired through naturalistic evolutionary development. Thus, as Plantinga says, I would have a defeater for all of my beliefs, including any belief that prior scientific findings were accurate reflections of reality, and for my belief in naturalism itself.

    I want to be clear that my argument stated above is not the same as Plantinga’s. It is my way of rephrasing what I understand to be part of his argument. I will try to post a link to a video of his discussion with someone mildly skeptical of his argument. Even in this short version of the argument I had to watch several times to fully grasp what Plantinga was saying when I first viewed the video.

    1. Thanks for your reply, Bill. I understand what you are saying, but I still don’t see the problem for a naturalist of today. Once again, Christianity produced science specifically because of what you are saying. Early Christian natural philosophers understood that the universe was created by a Supreme Lawgiver, and so it made perfect sense to them that the universe should run by laws. Furthermore, since they believed that they were made in the image of God, they had faith that they could figure those laws out. Without those two fundamental assumptions, science would never have developed.

      However, now that it has developed, I don’t have to make any assumptions anymore. I know that science works, because I can repeat an experiment as much as I want and I always get the same answer. I can use what science has already learned to make predictions about what will happen in a new situation, and those predictions tend to be fulfilled. This tells me that regardless of a person’s starting point, he can be confident that his brain is able to learn things reliably.

      So…an ancient philosopher who was not a Theist would have the problem you are saying. He couldn’t have any confidence in the conclusions he draws, because he has to believe that non-intelligence produced intelligence. However, today’s scientist can clearly see that intelligence exists. I think he has a rough time explaining how intelligence can arise from non-intelligence, but he can be confident that intelligence exists.

      I think the strongest part of your argument is this:

      “You have a ‘true belief’ that approximately half or more of the world population suffers from a serious delusion that was caused by adaptive evolutionary development. It is a delusion that seriously undermines and affects their view of reality – their belief in a god.”

      Since today’s scientist has lots of evidence that the brain can produce true beliefs, then the naturalistic scientist has to believe that unguided evolution produces true beliefs most of the time, but every once in a while, it produces a real whopper of a delusion, such as the belief in a god. It’s hard to fathom how that can happen!

  12. Thank you Dr Wile. For your reply on Christmas Eve and for your continued skepticism which, believe it or not, I truly appreciate. I was privileged to spend Christmas Eve and Christmas day with my two daughters, their dogs, and my only grandson. I barely looked at the computer during that time. I hope your holiday was as enjoyable as mine.

    I was responsible for preparing only the turkey. I have a limited physical ability because of a long term generalized muscular problem. I function moderately well, but I can’t lift a lot of weight. Since the turkey was fairly heavy I had my son in law remove the bird from the oven. Once the bird was out of the oven I made sure the oven was turned off. An adult student of my other son in law lost his wife, two children and his father in law in a recent fire. I was not taking any chance that a similar event would occur at our home.

    When it came time for Christmas dinner I had all the confidence in the world that the meal was ready and complete. I knew that the bird was done and I had evidence from prior experience that my wife always provided a great meal. I was beaming with pride as my 17 month old grandson started the meal early with some of my turkey that was perfectly done. He loved the turkey. My wife then started to prepare the rest of the meal for him since he was eating early. She began by removing the sweet potatoes and her most well liked side item, the stuffing – from the oven that I had turned off 45 minutes earlier.

    Fortunately the microwave saved the day. My wife’s stuffing was a little soggy, but still edible and the sweet potatoes were fine from the microwave. The backlog on the microwave prevented the meal from being ready at the time it was planned. Unfortunately for me, I had a defeater for my belief that Christmas dinner was perfectly done. One small detail had derailed that “true belief”. The fact that the oven was off also created a secondary problem that affected my “true belief” that the meal was ready on time.

    As I wrote earlier, philosophy is not something I have studied formally. My analogy is a true story, but it is not a perfect analogy to the topic we have been discussing. It does however illustrate how even one small detail can derail an entire belief system.

    You accepted the delusional belief in a god as the strongest part of my argument. Using that argument alone, I see no reason for the naturalist to have any confidence in the reliability of his or her mind. Everyone has to begin with the assumption that his or her brain is reliable. In my opinion, only those with a belief in an initial supreme intelligence can reasonably make that assumption. If the naturalist “knows” that half the world population is already seriously deluded, what confidence can he or she have that the half they represent is not also deluded?

    I would ask you to be patient with me on this issue. You may still disagree with me, but please again watch the video I posted of Dr Plantinga from the 8:50 mark to the end. As I said earlier, I had to watch the video several times to fully understand what he was saying in the entire video.
    One of the most important points in the video for me is – if you have a defeater for the reliability of your mind, you have a defeater for all of the beliefs that mind produces. You, as a naturalist, “know for certain” that every once in a while the human brain has produced a whopper. What confidence can you have that the remainder of your beliefs are not simply whoppers or other deceptions that you don’t know about because you have been deceived by an unreliable brain.

    It seems illogical to me to both believe a mind can produce significant false beliefs and can also be considered reliable enough to properly interpret evidence for other beliefs that you hold to be true. As a result, I think it is most logical to believe that you would have a defeater for all your beliefs, including your belief that naturalism is true.

    1. Thanks for your comment, Bill. I am glad that the microwave was able to save the day. That microwave, of course, was built using the conclusions of someone’s brain, and it works incredibly well. This is just one of the many examples of how a naturalist need not assume his or her brain is reliable. The naturalist can simply use the conclusions of his brain (and others’ brains) to produce not only incredibly reliable technology, but also reliable conclusions. As a result, the naturalist need not assume a reliable brain. Such a thing can be demonstrated.

      I actually saw Plantinga give a presentation just like that in person, so the content of the video is not new to me. I strongly disagree with the argument. The statement, “if you have a defeater for the reliability of your mind, you have a defeater for all of the beliefs that mind produces” is quite false. For example, consider the strongest part of your argument – a naturalist must assume evolution produced a false belief (that of the existence of God) in the minds of lots of people. This has no bearing on whether or not all conclusions of the mind are reliable. Remember, there are lots of naturalists who don’t believe in God, and from the naturalist’s position, that belief was also produced by evolution. Thus, according to the naturalist, even when it comes to the existence of God, evolution can produce true beliefs. The fact that the majority might disagree with that belief only shows (in the naturalist’s mind) that some people are less evolved than others when it comes to their brain.

  13. Thanks again Dr Wile. As you said the microwave saved the day because it was produced by a mind that that was technologically savvy. I have not claimed that the naturalistic brain could not produce technologically superior products. The naturalistically produced brain functions for survival and reproduction. If something can be produced to help the naturalist survive or reproduce, that item will be retained and another item not useful to survival and reproduction will be discarded. My poorly done Christmas dinner analogy was intended to be more humorous than serious. If, however, many in the naturalistic population had used microwaves to rescue them from a kitchen dinner disaster, they would continue to use microwaves because they would have survived – not been killed by their wife for ruining her part of the dinner meal.

    What I wrote above is not intended to be a serious part of our discussion. Continuing on that path could lead us on a rabbit trail that would never end. I had just experienced the Christmas dinner episode and thought it might add a lighter note to our discussion.

    You wrote, “The fact that the majority might disagree with that belief only shows (in the naturalist’s mind) that some people are less evolved than others when it comes to their brain.” What you have written is true. The early naturalists also believed that many of the non white races were less evolved people groups. That belief, based on their philosophy at the time, did not make it true.

    Of course all the beliefs a naturalist holds would not be false. Many would be true and necessary for survival and reproduction. The question is which beliefs are true and how would the naturalist know for certain that they are true. Beliefs that produce functional products and technology are not necessarily related to higher belief systems. A person could for example believe he was living on the planet Mars and still produce a functional and technologically superior product while he was actually living on the planet Earth.

    I think we may have reached the point in our discussion where we must simply agree to disagree. You seem to feel that modern science provides clear evidence for the naturalist that her or his brain is reliable. At the same time the naturalist you are defending would argue with you that your brain has definitely been significantly deluded by your acceptance of a deity. A deity they believe is purely fictional. They would see much of the evidence from science that you provide from a completely different perspective. They would believe your less advanced naturalistically originating brain has produced a delusional belief that significantly alters your view of reality and of science.

    I understand that you want to fairly represent those who read your blog. I respect you for that. In my opinion you have represented the naturalist position quite well. It just doesn’t make sense to me to defend a position that is going to turn around and ridicule your own position by using the same argument against you that you are defending them against.

    Personally, I can’t even get beyond the naturalist belief that mind boggling brilliance (DNA) arose very rapidly out of absolute stupidity (rocks and chemicals). My position really hasn’t been swayed by what you have written, but I have enjoyed the discussion. I sincerely appreciate the opportunity to dialog with you about this issue.

    1. But Bill, what you said about technology tends to weaken your entire argument. The microwave could not be built without a lot of true beliefs regarding things like energy conversion, the nature of light, molecular de-excitation mechanisms, etc., etc. The same could be said for most technology – it is based on a set of beliefs about how the world works. If those beliefs are correct, the technology has a much better chance of working. Since technology leads to better survival, that means true beliefs lead to better survival, which means that evolution will select for them. That’s the real flaw in Plantinga’s Evolutionary Argument Against Naturalism. He claims that selection and true beliefs have no relationship, but to me, they clearly do.

      Your example regarding a person believing he is on Mars and still making good technology is not a good one. If the working of the technology depended on his belief of where he is, then the technology would be more likely to fail. If it didn’t depend on his belief of where he is, it would have no relevance to the technology. This, of course, is one reason a naturalist can accept that his brain is reliable even though others belief in what he considers a delusion: the existence of God. God’s existence, to the naturalist, was utterly irrelevant to the more ancient technologies, so it had no effect on survivability. However, as our technology gets to the point where belief in the supernatural hinders our ability to do science (and produce better technology with it), evolution is slowly selecting dor those who have no belief in God. That’s why the naturalist can have confidence in his own conclusions – he is more evolved.

      You ask, “which beliefs are true and how would the naturalist know for certain that they are true?” To the naturalist, the answer is quite simple: The beliefs he knows are true are the ones that are backed up by evidence. The more evidence that exists for the belief, the more confident the naturalist is that the belief is correct. This, of course, leads right to your very correct observation: the naturalist “would see much of the evidence from science…from a completely different perspective.” Once again, however, the more the naturalist has to explain around the data to allow for his beliefs to be true, the more he should see that his beliefs are wrong.

      Now please understand that I am not defending the naturalist position. I am simply telling you what a naturalist actually believes. It is very hard to communicate with people if you don’t understand what they believe. I want to communicate with naturalists, so I need to know what they actually believe. If you want to communicate with naturalists, you need to do the same.

  14. Thanks Dr Wile. My main focus is not to communicate with the naturalist. I am more interested in preventing young people from being overly influenced by what the naturalist believes and tries to teach our young people. I would love for the naturalist to be convinced by my argument or your evidence, but I think most hard core naturalists have deeper emotional reasons for rejecting what we as Christians believe. I agree that some in the hard core camp will eventually see the light, and be convinced by the evidence, but I think they will be in the minority. I started this discussion writing about a naturalist who is entrenched in his position. I continue to feel that person will seldom be convinced by the evidence.

    This is my first serious conversation with someone as knowledgeable about naturalist beliefs as you are. I can only learn so much by reading and watching on line videos. In addition, you dialog and debate with some seriously hard core believers in naturalism, I have had no opportunity to do that. I came to this blog site to learn, and you are helping to educate me about naturalism. I don’t expect to win any disagreements with you, but I may be able to give you and others a few things to think about. At the same time it will help me to better understand and communicate what I believe is true.

    Having said those things, I think you are right that the microwave argument I used weakens my position. It was initially part of the lighter story I was telling and not well thought out. As I thought more about it, after it was posted, I think it is highly unlikely that a naturalistic mind could produce high tech products. I allowed the naturalist the benefit of a reasonably reliable mind because that was the direction you had taken me.

    What you wrote earlier was: “Dr. Alvin Plantinga, argues that while we can provide a lot of evidence that our brains are reliable, one wouldn’t expect that if there were nothing guiding evolution to produce rational human beings. Thus, he sees the very fact that our brains are reliable as evidence against naturalistic evolution.”

    Since I see absolute stupidity as the intellectual basis for naturalism, I think his argument is much stronger than the one I made. I understand that you don’t accept Plantinga’s argument, but it makes more sense to me. A reliable mind for the naturalist is not a given for me. I won’t even give them that first initial gigantic leap from absolute stupidity to mind boggling brilliance. A naturalist who realizes he has a reliable mind that originated from an initial intellectual condition of absolute stupidity, which was filtered through the brain of a common ancestor dumber than a chimp, should be very suspicious that somebody smarter than a monkey has messed with his brain.

  15. For those interested in reading the relevant papers, they can be accessed directly from the researchers’ websites.

    “A role for iron and oxygen chemistry in preserving soft tissues, cells and molecules from deep time”

    Papers on the soft tissue discoveries (scroll down to publications)

    The latest release on Schweitzer’s page from her recent Bone article is a great read. Not only does it summarize the soft tissue discoveries to date, but it presents the evidence of endogenous (original) DNA in the center of the dino cells.

  16. Thanks for the links Jon. I am still trying to find the supplemental information, that includes materials and methods, for free. I have not been able to find it free on line. I would really like to know how they obtained the blood and how it was collected from the bird. Most shipped blood would have to be preserved in some way. Even if the researchers didn’t use preservatives, the people who collected the blood could have used them.

    I’ll try to post a link to a related ICR article many may have already seen. Maybe there has been a link to it already that I missed.

  17. Thanks Dr Wile, I missed the smaller type on the left that contained the link.

    Based on the information provided in the supplemental section, the preserved tissues were soaked in chicken blood or ostrich blood. In both cases the RBC’s (red blood cells) were rinsed and separated from the fluid portion of the blood before they were lysed.

    As you know, blood cannot be collected and stored for even a short period of time unless an anticoagulant is added to prevent clotting. The article states that EDTA was used in the chicken blood. I could not find what was used as an anticoagulant for the ostrich blood.

    A 2013 veterinary article from Cornell University indicated that RBC’s absorb some of the fluid (they used the word water) portion of the blood when they are stored in an EDTA solution for shipping to a laboratory. It does not say if some of the EDTA might also enter the RBC’s along with the fluid.

    A 1991 article from the Canadian Journal of Zoology noted the use of EDTA as part of a solution that was very effective at preserving avian tissue. The EDTA was used in combination with other agents, but it was included as part of the preservation process.

    20 ml of ostrich blood was collected at the local zoo. We are not told how the blood was collected. My guess is that it was collected in a 20 ml syringe that already contained the necessary anticoagulant needed to preserve the blood till it could be processed. An easy anticoagulant to use would have been EDTA. The amount of EDTA in the syringe could have been prepared in advance by the researchers, or the zoo personnel may have had access to EDTA solution to first draw into the syringe. Heparin could also have been used since it is readily available to the veterinary community. It would be easy to draw a couple ml of heparin into a 20 ml syringe before drawing the blood.

    I would like to briefly summarize some of the things that seem to be true.

    One- At least the chicken blood was collected and stored in EDTA.

    Two- The ostrich blood had to be collected in some anticoagulant.

    Three- According to the Canadian Journal of Zoology, EDTA was part of a mixture used to preserve avian tissues for long periods of time.

    Four-According to a Cornell veterinary clinical path article, RBC’s can absorb some of the fluid part of the blood while being shipped to a lab.

    Based on this information, I would be concerned that EDTA might be present in or on the RBC’s and thus in the lysed blood solutions used to soak the preserved ostrich tissue. Given the possibility of the presence of EDTA in the lysed RBC’s, the experimental result would have to be questioned. I don’t know how well EDTA alone would preserve tissues, but it would at least have to be considered a possibility to aid in long term tissue preservation. It definitely preserves blood cells so I think it is quite possible it could preserve a small amount of blood vascular tissue.

    The ostrich blood from the zoo may have also had EDTA used as an anticoagulant. There is also the possibility of a different blood preservative, such as heparin being used in the ostrich blood collected at the zoo. That substance might also help preserve tissue. We know for example that bone marrow is preserved by heparin.

    I don’t know how well or poorly chicken or ostrich RBC’s absorb EDTA, or possibly carry EDTA on their cell surface, when EDTA is used as an anticoagulant and preservative in the collection of blood from these two bird types.

    Based on all of the above, I am concerned that the preservation of the ostrich tissues may have been influenced by the presence of a potential tissue preservative in the lysed blood used to preserve the tissue. I suspect that at least EDTA may have been present in the lysed RBS’s. In addition, there is the possibility of another anticoagulant with tissue preserving potential that was in the ostrich blood from the zoo.

    These are just my thoughts. I can’t say for sure that EDTA remained in or on the RBC’s when they were lysed. On the other hand, I don’t think the researchers can say that it was not present unless they tested for its presence and quantity in the lysed blood at the time the experiment began. Perhaps they did test for anticoagulants in the initial blood and I missed that information when I read the article or they simply did not include that information.

    In defense of the researchers, the bones from the ostrich carcass had also been initially soaked in an EDTA solution to dissolve the bone. The tissues obtained after the bone was dissolved by the EDTA were rinsed well and did degrade significantly when soaked in water rather than the lysed RBC solutions

    I am not a research scientist. Perhaps all the EDTA was removed in the washing process the researchers used to prepare the RBC’s before thay were lysed. My concern is still that some EDTA might remain in or on the cells that were lysed. Unless the researchers can prove conclusively that no significant amount of EDTA or other anticoagulant was present in the lysed blood samples, I think the experiment would have to be considered inconclusive.

    In summary, ostrich blood vessels that were being evaluated for preservation were soaked in a solution of lysed RBC’s that themselves had been exposed to a known tissue preservative (EDTA) while being stored as whole blood – at least in the case of the chicken blood. I could not tell what anticoagulant was used with the ostrich blood.

    The question that remains for me concerns the presence of a possible tissue preservative that was present in the lysed RBC solutions.

    1. Thanks for your analysis Bill, but I don’t know how much I can agree with. Can you give me a reference to the 1991 article from the Canadian Journal of Zoology? As a chemist, I have worked with EDTA extensively, and I don’t see how it could preserve tissues. It is used as a preservative for color, because it tends to fight oxidative decoloration in the presence of metal ions, but that would not do anything to help preserve the structure of the tissues. Obviously, of course, there could be something of which I am not aware. That’s why I would be interested in seeing exactly how the 1991 article claims that EDTA can be used to preserve avian tissues.

      One other issue – any preservative in any of the blood samples would be present in the concentration necessary to preserve the blood. It wouldn’t be there in excess. In order for that preservative to also preserve the tissues, it would have to be present in excess, unless you postulate some preferential absorption of the preservatives by the tissues.

  18. Thanks Dr Wile. My understanding is that EDTA is used in blood collection tubes to prevent blood from clotting. I don’t understand the chemistry of how that works. If it preserves blood, is it possible that it would also preserve a small amount of tissue? I don’t know, but I was hoping you could help.

    I will try to paste a link to the article. As I mentioned earlier, I don’t have the full access to articles that you do, I was only able to read the abstract. Again, EDTA was only one of the agents used to preserve the tissue. As I also wrote, I do not know how well it alone preserves tissues for long periods of time.

    As far as your other issue, it is my understanding that only small tissue samples were used. If EDTA remained in the lysed cell solution it might be adequate to preserve small amounts of tissue. Hopefully you will be able to clarify the situation for me.

    I did write known tissue preservative at least once. It would have been better worded as a known blood preservative or possible tissue preservative.

    1. Bill, as I suspected, the Canadian Journal of Zoology article doesn’t indicate that EDTA preserves tissues. The dimethyl sulfoxyde is the preservative. EDTA is there simply as an anticoagulant in order to allow the dimethyl sulfoxyde the ability to mix evenly throughout the solution.

      You are correct that blood is a connective tissue, but EDTA doesn’t preserve it. In fact, it degrades it by destroying proteins in the coagulation cascade. This keeps the blood from coagulating, but it does not preserve the blood in any way.

  19. Dr Wile, I would like to add one additional comment please. After thinking more about your last post I decided to Google “is blood a tissue”. The answer from Wikipedia was “In terms of anatomy and histology, blood is considered a specialized form of connective tissue “.

    If blood is a connective tissue and EDTA preserves blood, it seems logical to me to call EDTA is a known tissue preservative.

  20. Thanks for your reply and your expertise Dr Wile. From what I was able to read of the article I could only determine that it was part of a mixture used to preserve tissue.

    You wrote that EDTA does not preserve the blood in any way. Did you mean long term preservation? If whole unprocessed blood was put in a plain tube and shipped to a lab for analysis, the lab would not be able to process the blood. If, on the other hand, it was put in a tube with the proper amount of EDTA it would arrive at the lab ready to be processed. To me at least, that seems to indicate the blood was preserved in some way. In addition, at least the chicken blood used in the experiment was preserved with EDTA. Without preservation that blood would have clotted within about 20 minutes after it was obtained and would have been useless for the research project.

    An additional question I had for you concerns the chelating effects of EDTA. Do you think the iron in the hemoglobin of the RBC’s could have been affected in any way by the chelating effects of EDTA? Since iron is proposed as the preservative, I wondered if the EDTA could have any influence on the process.

    1. Bill, a preservative halts the decomposition process for some amount of time. EDTA doesn’t do that. If you add EDTA to blood, it will not coagulate, but it will continue to decompose just as fast as blood that has no EDTA in it. Remember, coagulation is not a decay process. It is a function of the blood. EDTA interferes with that function, but it does not interfere with the decomposition process.

      EDTA does scavenge metal ions, including iron. If it had an effect, however, it would be to reduce the preservation. Remember the difference between the tissues stored in oxygen and those stored in an oxygen-free environment. The tissues stored in the presence of oxygen were better preserved, most likely because of an oxidative reaction with the iron. EDTA would have inhibited that reaction by scavenging the iron ions and not allowing them to react with oxygen. That effect would be small, however, because as I said before, the concentration of EDTA would be very low – just enough to keep the blood from coagulating. Thus, it wouldn’t be able to scavenge much iron.

  21. Thank you for the answer to my question about EDTA and iron Dr Wile. I am trying to understand this experiment and you have been very helpful.

    We must have a different understanding of what preservation means. That is why I asked if you meant long term preservation. As I wrote previously, blood drawn and not treated in any way begins to clot very rapidly. I consider that a form of decomposition.

    The chicken blood the researchers used is clinically acceptable for about three days if not refrigerated and about two weeks if refrigerated. That is according to a lab rep from Lampire biological laboratories (the lab the researchers used). I assume you think refrigeration is a method of preservation as I do, but whole untreated blood does not last more than about 20 minutes without clotting. From a practical clinical perspective, the blood is worthless in 20 minutes or less.

    Using the logic of the Schweitzer group that would mean whole blood is preserved over 200 times longer at room temperature when it is collected in EDTA versus no preservative. Blood collected in EDTA and kept at a cooler temperature would be preserved many times longer. I am using the term preserve in a practical clinical way. That is the way I interpret the term.

    1. Bill, blood clotting is not a form of decomposition. When your blood clots to seal a wound, has it decomposed? No. It has performed a function that it was designed to perform. When untreated blood clots, its cellular components do not degrade. They simply aggregate. This makes the blood unusable, but it does not involve decomposition. Decomposition is when a cellular organelle disintegrates into its component proteins. Those proteins then decompose by disintegrating into their amino acids. Those amino acids decompose by disintegrating into their elements. That’s decomposition, and a preservative halts or slows that process. EDTA just doesn’t do that.

    2. Bill, blood clotting is not a form of decomposition. When your blood clots to seal a wound, has it decomposed? No. It has performed a function that it was designed to perform. When untreated blood clots, its cellular components do not degrade. They simply aggregate. This makes the blood unusable, but it does not involve decomposition. Decomposition is when a cellular organelle disintegrates into its component proteins. Those proteins then decompose by disintegrating into their amino acids. Those amino acids decompose by disintegrating into their elements. That’s decomposition, and it is not related to coagulation, which is an actual function of blood.

  22. Dr Wile, I just want to make sure you understand I am writing this in a friendly manner. I know you discuss things with many people so I wanted to be sure you understood my intended tone.

    You made a very broad statement – that EDTA does not preserve blood in any way. I took that to mean exactly what you said. Since I did not agree with the statement I provided you with information to explain why I disagreed. My reason was that from a practical clinical perspective EDTA preserves blood.

    No physician would give a blood transfusion with unpreserved blood. Whole untreated blood if left for 20 minutes or longer would probably kill the patient whose life it was intended to save. I continue to maintain that EDTA preserves blood in exactly the manner I have described.

    In my opinion you are now making a different and narrower assertion. You seem to be convinced that clotted blood does not decompose, it simply aggregates. While you are correct that blood initially aggregates, I think it is unlikely that no decomposition takes place post clot. If you compared a tube of EDTA blood with a tube of whole untreated blood after 48 hours, I strongly suspect you would see significantly greater changes in the cellular structures of the untreated versus EDTA treated blood.

    A simple experiment could be done by making blood smears from each tube after they stood at room temperature for 48 hours. My suspicion is that the EDTA treated blood would still make reasonably good smears, showing many intact cells, while the whole untreated blood would have significantly fewer intact blood components.

    Again, I want to say that this is a friendly disagreement on my part. I continue to learn a great deal through our discussion.

    1. Bill, I completely agree that this is friendly disagreement. I try to be friendly with all disagreements, of course.

      I have not changed what I am saying at all. I just think you don’t have a chemist’s view of what a preservative is. Since EDTA doesn’t decrease decomposition, it is not a preservative. I would encourage you to do the experiment you suggest, because you will find out that EDTA does not stop decomposition at all. If you did examine blood that had EDTA in it and blood without EDTA after a length of time sufficient to see decomposition, you would find no significant difference in their states of decomposition. The non-EDTA blood will be clotted, but it will be no more decomposed than the blood with EDTA.

  23. Thanks for your reply Dr Wile. As you wrote, you are looking at blood from a chemist’s perspective. When you said EDTA does not preserve blood in any way I was looking at it from a practical clinical perspective. It was not clear to me that you intended the meaning to be only from the perspective of a chemist. That is why I so strongly disagreed with your statement.

    It seems to me that a person making an assertion is responsible for providing evidence that the assertion is true. I suggested the blood experiment so you would have a method of proving your assertion – if it is correct.

    I would appreciate your opinion on something else I have seen about EDTA. It apparently has some bacteriostatic or bactericidal effects depending on the concentration and the organism. In additional it also seems to have some anti fungal properties. In some studies it was used in combination with other drugs, in others it appeared to be evaluated as a sole agent.

    I mentioned earlier that I don’t have access to a lot of scientific information on line. I can sometimes get abstracts but not full articles. As a chemist you are better able to determine if it is the EDTA acting alone that is providing the antibacterial or antifungal effects or if it is only effective when combined with other agents. I will try to post one such abstract below.

    The other interesting thing I noted about the Schweitzer experiment was the very small amount of tissue that was illustrated in the photomicrographs as having been preserved. If I understand it correctly the tissues illustrated were less than 2mm in length. If that was the total tissue size, it would have taken very little of any substance to influence the results of the test. Maybe they just used a small portion of what they had preserved for illustrative purposes – or maybe I missed the information on a larger amount of tissue. My computer wouldn’t bring up all of the illustrations from the article so I may have missed some larger samples.

    1. Bill, you are the one making the assertion here. You are claiming that EDTA behaves in a way that is opposite of how it is known to behave. I told you before to remember the difference between the tissues stored in oxygen and those stored in an oxygen-free environment. If EDTA were the preservative, you would expect no difference between the oxygen and oxygen-free tissues, as EDTA has no oxygen affinity. However, a clear difference was found. In addition, EDTA’s main chemical feature is that it is a metal scavenger. If EDTA’s role in the experiment were large, that would inhibit the process that is thought to do the preservation. So in the end, you are making two claims: EDTA is behaving in a way opposite of how it is known to behave, and the preservation mechanism shown in the paper is not a preservation mechanism at all. Thus, it seems to me that you are the one who has to provide evidence for your assertion. What I (and the authors) suggest is completely consistent with the known chemistry of EDTA.

      EDTA (by itself) can be antibacterial for certain species, once again, because it is a metal scavenger. Those species that depend on specific metals can be inhibited in their growth by EDTA. However, EDTA has not been shown to be antibacterial for decomposing bacteria. It is generally seen to be antibacterial for parasitic bacteria, because those bacteria are typically much more dependent on the metal ions that EDTA scavenges. Also, that would have no effect on the study, because a lot of care was taken to remove bacteria, as can be seen in the supplemental materials.

      The illustrated tissues are not indicative of the total tissue size. You obviously cannot illustrate the microscopic features of all your tissue in a paper. It would make the paper far too long! In the supplementary material, they don’t say exactly how much tissue they use, but their methods show they are not using any microscopic tools for handling the blood vessels, so they are using macroscopic amounts. Also, if you look at the supplementary figures (especially S5), you will see that there seems to be a lot of vessels in each sample.

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