A new paper from a NASA scientist claims to present evidence for bacteria-like organisms in some meteorites. (Richard Hoover, 2011, Fossils of cyanobacteria in C11 carbonaceous meteorites. Journal of Cosmology 2011, vol 13.)
I don't know much about meteorites, but here's my evaluation: (Executive Summary: Move along folks, there's nothing to see here.)
What the author did:
He fractured tiny comet-derived meteorites (0.1 - 0.6 g) from two events and examined the freshly broken surfaces. He claims to have observed structures that are remnants of cyanobacteria.
These meteorites are of a special very rare type (only 9 are known). They are about 20% water, and soft enough to cut with a knife. They mainly consist of minerals cemented together with magnesium sulfate ('Epsom salts'). They come from asteroids and comets, not planets like the Alan Hills meteorite from Mars. Hooper's reasoning that they come mainly from comets seems reasonable to me.
They contain quite a bit of organic (carbon-based) material, but I don't know if this differs significantly from the polycyclic aromatic hydrocarbons known to be present in comets. It's true that PAHs found on Earth are usually biological in origin (think of the tarry crud that accumulates on your barbeque grill), but that doesn't mean that PAHs from space have biological origins.
An important concern with this kind of study is contamination with terrestrial organisms before examination. He doesn't say how the meteorites have been stored before he obtained them, nor how the surfaces of the meteorites were treated before being fractured and examined. He doesn't say how they were fractured - might they have been cut with a scalpel blade or just pressed on until they crumbled? He says that the tools were flame-sterilized, but not what the tools were or how they were used.
He used two examination techniques. FESEM is field emission scanning electron microscopy - this seems to be a higher-resolution form of scanning electron microscopy (SEM), with the usual risks of artefacts. The fractured surfaces were not coated with anything before being analyzed - I don't know what effect this might have. The other technique is energy-dispersive X-ray analysis - I gather that this is an add-on to SEM that can scan a specimen and report on the abundance of specific atoms at different positions. Its results can be reported as the distribution of atoms at a particular position or as an image of the specimen, shaded to show the varying density of a particular atom.
Results.
He shows an image and analysis of one filament from the Ivuna meteorite. It has more carbon than the surrounding material but no detectable nitrogen or phosphorus.
He bolsters his claim that it's a bacterium by showing an image of the giant bacterium Titanospirillum and an image of another filament from the meteorite. His claim that the sulfur granules in this second filament are like those of Titanospirilum is weakened by the very high sulfur in the surrounding material. And although this filament is similar in size and shape to Titanospirillum (upper images), the other filament is about 15 times smaller (bottom images, adjusted to approximately the same scale).
The image he shows of an inner surface of the Orgueil meteorite has more filaments (no attempt is made at quantitation). These are more complex in structure and fairly similar to each other, suggesting that they were formed by a single kind of process.
The atomic analysis is not at all convincing. He claims that different parts of the filament have different composition, but doesn't present any control analysis of the variability of the measurements or of the background values for positions away from the filaments. He claims that the atom-density scans show enrichment of carbon and oxygen in the filaments, but this looks very weak to me - the only strong signals are for magnesium and sulfur. Again there is no detectable nitrogen or phosphorus.
He spends a lot of text discussing the morpohlogical similarities of these filaments to cyanobacteria, but I don't regard these similarities as worth anything. Filamentous bacteria are very morphologically diverse, and additional variations in appearance are likely to result from inconsistent preparation for electron microscopy. It's probably pretty easy to find a bacterial image that resembles any fibrous structure. In the absence of any statistical evidence to the contrary, it's prudent to assume that such similarities are purely coincidental.
The author tacks on quite a bit of other less-than-compelling information intended to support his claim that life from space is plausible. For example, he shows photos of colonies of coloured microorganisms to support his argument that the colours seen on the surfaces of Europa and Enceladus are biological in origin.
Bottom line:
The Ivuna meteorite sample showed a couple of micron-scale squiggles, one of which contained about 2.5-fold more carbon than the background. One of the five Orguil samples had at least one patch of clustered fibers; these contained more sulfur and magnesium than the background, and less silicon. As evidence for life this is pathetic, no better than that presented by McKay's group for the ALH84001 Martian meteorite in 1996.
The Journal and the Editor aren't very impressive either:
The journal proudly announces that it is obtaining and will publish 100 post-publication reviews. But did it bother getting any pre-publication reviews? It will be shutting down in a few months, after only two years of on-line publication (the 13 'volumes' are really just 13 issues). Its presentation standards are pretty bad - there doesn't seem to have been any effort at copy-editing or formatting the text for publication (not even any page numbers).
Chandra Wickramasinghe is the journal's Executive Editor for Astrobiology, and presumably is the Editor responsible for this article. I heard him give a talk pushing panspermia about 10 years ago (the audience was an undergraduate science society at Oxford). The talk was very slick but dreadfully bad as science. The evidence he cited to support his arguments wasn't actually untrue, but he twisted everything to make his arguments seem stronger than they were. He argued like a lawyer - his only goal seemed to be convincing the audience that his conclusion was correct, regardless of the contrary evidence that an unbiased consideration of the evidence would provide. Thus I wouldn't trust his scientific judgment about anything concerning astrobiology.
Hoover, R. B. (2011). fossils of cyanobacteria in C11 carbonaceous meteorites Journal of Cosmology 13.
Great summary Rosie, its really essential that these publicly available post-review commentaries like yours are promoted. I dont know what your policy is on these things, but it might be nice to have a link to the article for those who want to go to the source.
ReplyDeleteMore broadly, what is up with NASA? I mean I can understand that extra-terrestrial life (or non-carbon life) is going to get the public's eyes, but they run a real risk of jeopardizing their esteem as a real scientific organization. It makes me sad in that NASA inspired so many people to get into science, and gave non-scientists a tangible appreciation of what scientists can do. Now they just seem like a desperate drug company excitedly pimping a crappy clinical trial.
I suspect it's a result of NASA being an organisation primarily composed of A) Bureaucrats, B) Engineers and C) Physicists, and we're expecting them to fact-check work from their collection of starry-eyed biologists, desperate to find evidence of life "out there".
ReplyDeleteFor my part (and speaking as a biologist), I'd be somewhat surprised if we *didn't* find some form of life elsewhere in the solar system, given how cushy everything is in our neighbourhood.
But, as Rosie points out, this is awful work and a very, very poor attempt to prove a pre-held supposition. To call it "evidence" is a joke and an insult to some of the more worthy work in astrobiology.
Nice review, but really, who cares if the editor can't give a talk? Rather gratuitous put-down that puts into question your entire evaluation.
ReplyDeleteBenoit, I've rewritten the last few sentences to clarify what I meant by 'argues like a lawyer' and why it's relevant to the paper.
ReplyDeleteDoes this paper have a twitter hashtag? I would vote for David Dobbs' #fibromyalien.
ReplyDeleteNot again! Groan... At least this doesn't come with the "arsenic bacterium" media juggernaut.
ReplyDeleteI consider myself to be an astrobiologist, and I will say that I know of no one that supports this claim. At least, I know of no one I consider to be a serious astrobiologist that thinks this has any merit whatsoever. (And no, the authors do not qualify as serious astrobiologists. Neither do the editors of this journal.) From what I have heard, this work was soundly rejected from two other (serious) peer-reviewed journals.
ReplyDeleteUnlike the Arsenic discovery, there is very little controversy about this paper, because in this case nobody believes the work. The arsenic discovery is controversial because quite a few think the authors are onto something, whereas others are very critical of the work.
So Roise's right. There's nothing to see here. Not even a controversy. Move along. :-)
"It's probably pretty easy to find a bacterial image that resembles any fibrous structure."
ReplyDeleteThis specific criticism seems like a logical error. The question is not whether there are many biological structures that resemble his fibers, but whether there are many non-biological structures that resemble his fibers. His argument is not dependent on which bacteria these are, just that they are (were) bacteria at all.
Nor was he claiming the first picture (which you rescale) was the bacterium you claim it is too small for.
His core argument is that these fibers have a distinctive shape that resembles common cyanobacteria colonies; they have elements in them that make them distinct from the surround rock (as shown in the xrays); that the rock itself is full of organics including amino acids; and that the lack of nitrogen and certain other amino acids matches what we see in terrestrial fossils, but not in recent organic matter.
While as a Bayesian I agree that the threshold of evidence is very high here -- and much higher due to the shoddy journal, poor proof-reading, and extraneous material (particularly at the end of the paper) -- it is still the case that, looking only at the claims themselves, the counter-argument needs to do more than was done here:
It needs to show how these fibers could occur non-biologically; it needs to show how that process could result in the distinctive elements found in them only; it needs to show how the organics found in the rock can arise in non-biological ways in some asteroids or comets; and it needs to explain the presence of amino acids along with an absence of others (and nitrogen) that makes these samples so chemically similar to fossils on earth.
Though I imagine its conclusions are correct, this brief blog post hasn't done proper justice to those arguments.
Thank you Rosie, brilliant review, this world needs more people like you. I was careful to buy into this, as I know these claims have been made before, only to be refuted later on.
ReplyDeleteAnd I agree with you, the fact that Chandra Wickramasinghe is the executive editor is significant, since he has always been a leading proponent of Panspermia.
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ReplyDelete@PRB: Thanks for laying out the issues so clearly. These are exactly the issues that the author should have resolved before publishing his claims.
ReplyDeleteThe Editors of Journal of Cosmology apparently don't think much of blogs (see http://www.wired.com/wiredscience/2011/03/aliens-riding-meteorites-arsenic-redux-or-something-new/), so I've emailed them a copy of this post as an unsolicited formal critique of the paper. Will they publish it?
ReplyDeleteI think its a little inaccurate to only say the compositional difference is the Carbon, Magnesium, and Sulfur elevations in the "fossil." What about the evidence of the indigenous amino acids and strong bio-markers present? The article finds 8 of the 20 amino acids for life exist within the freshly fractured rock. Hoover also shows older terrestrial fossils of organic life also only contain 8 of the 20 amino acids to show the absence of the the other 12 amino acids is not unexpected, but indeed identically consistent with known fossilized organics of a certain age. Any critique needs to either disagree with that data or the conclusion based on it to validly address his full claims. He also shows that the absence of nitrogen (used to prove it is not recent terrestrial material) is also not present in very old trilobyte fossils on earth, showing that after a certain age, nitrogen is no longer detectable in organic material - some critiques have ended with the statement that if there is no nitrogen then there is no life, which is false in the case of trilobyte fossils. This point is also lost on PZ Myers critique of Hoover when he says that "they seem to be proud of having analyzed flakes of mummy skin and hair from frozen mammoths, but I couldn't see the point at all — do they have cause to think the substrate of a chondrite might have some correspondence to a Siberian Pleistocene mammoth guard hair?" - well it does when it shows the level of nitrogen in organic material at the mammoth age still exists, and that it does not at the trilobyte fossil's age, just as we have with the meteroite "fossil." Put more simply, if the "fossil" is organic, we know that it must be older than the 32,000 year old mammoth hair because the hair (and mummy skin) still contains detectable nitrogen, and being able to decide the "fossils" age is pretty significant. Also absent in the critques is an alternative explanation for the structures observed. The critiques have been quick to distinguish the images from real bacteria and the differences, but with regard to the similarities what are the other plausible explanations then for what we are seeing? While I can understand the critique that it is the equivalent of reading rorschach test blobs, its a non-argument if you don't have a better explanation for the observed similarities we are seeing to known organic structures. What are we looking at then, if it is not what Hoover claimed?
ReplyDeleteAs a side note, after reading Hoover's article and the critiques of it (yours, Myers and Dobbs), it seems the critiques are extremely venomous. While your critique is the most on point, they are filled with knocks on the website design, the journal's editor, and many ad hominem attacks that have nothing to do with the data-- hoping to gain agreement from the reader early that Hoover is flawed and bogus and creating a biased mindset even before (cursorily and conclusionarily) addressing the objective data presented. The so-called objective-minded establishment scientists have disserviced themselves and the very principles they are simultaneously claiming are being so warped by Hoover. Hoover has data and is drawing conclusions based on it alone, why aren't the critiques simply doing the same???
@PRB: Thanks for laying out the issues so clearly. These are exactly the issues that the author should have resolved before publishing his claims.
ReplyDeleteThanks -- but I'm not sure how the author could have resolved them. He points out that the fibers closely resemble common bacteria; resolving the negative, that the could not have arisen by non-biological processes, is of course very difficult. He points to the presence of "organic" compounds (such as amino acids) and the different composition of the fibers versus the rock, but proving the negative, that these organic compounds and fibers could not have arisen naturally, is extremely difficult. And he shows that the nitrogen levels are low* and the amino acids present are in precisely the profile one finds in fossils but not in recently dead matter; but again, proving the negative, that this could not have arisen abiologically, is quite difficult.
Conversely, skeptics need only find a case of similar fibers and a similar profile of organics in a non-biological setting to disprove the whole thing. So I think he has done the best he can, given the difficulty of proving a negative. Whether that is enough to convince -- particularly given the journal -- is a separate question. But what other sort of due diligence should he have done?
(* Note that the nitrogen was low but not non-existant. The amino acids, present at the ppb level, of course have nitrogen in them; the argument about nitrogen levels in fossils -- Figure 6 -- is at much higher levels.)
@PRB: Perhaps this reflects a difference in expectations between biologists and physicists. One of the reasons biologists value pre-publication peer-review is that the reviewers ensure that the authors have done the obvious controls before the paper is accepted. Perhaps physicists are comfortable with controls only being done after the paper has been published.
ReplyDeleteyep, defiantly going to thrust the opinion of some random blogger with pink hiar
ReplyDelete@PRB re: Redfield
ReplyDeleteBoth of her responses have been vague general statements that might apply or might not but definitely don't really respond to you specifically or directly, I almost feel like she doesn't understand what you are saying and is just blurting out platitudes. Disappointing.
I agree that we have to be very cautious before such extraordinary claims, but we can't reject this paper right away. We need to hear from astrobiologists, chemists, physicists. Hoover is not and "ufologist" or a charlatan, he is a renowned NASA astrobiologist and these meteorites are very valuable and rare scientific material that deserves further studies.
ReplyDeleteRemember that Stanley Miller experiment was dismissed and criticized because his methods and techniques were faulty, but he was on the right track.
I invite anyone who even thinks of taking JoS seriously to google Rhawn Joseph and read his articles. He has 6 published there in the short lifetime of the journal (and 4 others by the publishers of JoS), including the journal's first article ever (which just so happened to be about how he was convinced that life on earth came from out of space). One of his works on JoC is about "Sex on Mars."
ReplyDeleteThey also issued a press release about their shutdown, which you can find at http://daviddobbs.posterous.com/journal-of-cosmology-going-out-with-big-bang . It's pretty preposterous.
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ReplyDeleteYes JoC is suspicious, but Dr. Hoover is not Dr. Joseph.
ReplyDeleteI am waiting for comments on the actual data, I couldn't care less about the Journal.
David and PRB bring some good points that deserve answers before one can completly reject this paper.
"I don't know much about meteorites"
ReplyDelete"I don't know if this differs significantly"
"I don't know what effect this might have."
So what do you know? I don't think that you're in position to question this research.
I am concerned about the degree to which the messenger is being tarred with the brush used for the vehicle of the message. It reminds me of the sort of vicious and spiteful reactions in the scientific community we've seen when others, like Jaynes and Penrose, have dared to defy purely political scientific conventions by publishing directly to the public.
ReplyDeletePeer review has become a weapon to enforce political orthodoxies, so it does not surprise me that growing numbers of scientists are choosing to sidestep this process when they have work which challenges the status quo.
I myself don't believe on panspermia. I think however that the question is rather irrelevant. My genes probably have their entire history on Earth. But if life is possible here, it should be possible anywhere else with some heat and the right molecules. All of that seems very abundant in the universe.
ReplyDeleteAbout this critique, I found it very weak, as David and PRB noted. I summarily reviewed some other papers on this subject, and of course plausibility and Occam razor principle are highly subjective. But I got somehow the impression in all cases that the counter-arguments were much more convoluted and hard to swallow than the arguments. Also, Hoover's paper states materials and methods, and the critiques don't.
About not why serious journals, several reasons come to my mind. First, "Nature" and "Science" are often highly political. Second, a highly polemical article like Dr. Hoover's deserve to be known by a wide public the sooner the better and not just by a tiny group of conservative referees that would almost surely reject it, probably in the grounds that "there is not enough nitrogen". Put it this way: we are all talking about it thanks to this dubious Cosmology journal.
The photos in the article should have been checked by a mineralogist. I have not de facto TA'ed mineralogy since 1973 so I am not used to hightech images of minerals.
ReplyDeleteThe "fossils" have Mg and S. Epsomite MgSO4 7H2O "usually fibrous to hair-like acicular [needle-like] crust, fiber axis c" Berry & Mason Mineralogy Freeman 1959.
Saturated epsomite solution in the dark interior of a metoerite parent body is an unfriendly place for cyanobacteria. The activity of water is low. So it would desiccate cyanobacteria. My best guesses is that epsomite fibers are the pseudofossils.
Anhydrite, serpentine, gypsum, brucite can all be fibrous. Even aragonite and magnesite can be fibrous. The meteorite obviously had liquid water. No due diligence seems to have been done. So fibers are pretty worthless biosignatures without a lot more info.
In defense of the ALH84001 paper: The ALH Mars rock had magnetite which is possible biosignature as it passes tests for biomagnetite. Magnetic microbes would have liked the vein environment on Mars so it is not silly like cyanobacteria in the dark. Most scientists want to set bar for Mars life higher, but work on magnetite was not silly. The weaker biosignatures and the morphological "fossils" would not have been taken seriously without the magnetite.
More on the Hoover paper: Cyanobacteria live by O2-making photosynthesis. Some species can do FeO H2 and sulfide photosynthesis facultatively. It is possible that one could act as acetogen and use H2 + CO2 to make CH2O in dark. Still cynaobacteria are far up on the tree of life. Photosystems I and II have a common ancestor.
The inside of meteorite parent body is dark. Liquid water cannot exist in the high vacuum near the surface. So it is highly unlikely cyanobacteria would evolve two complicated photosystems which would be useless.
The surface of the outer solar system satellites is extremely cold. The paper compares them with ice algae which is nonsense.
The "organic" carbon in chondrites is mixture of very many compounds. It does not have the small number of compounds that a biotic sample does. We use 21 amino acids of the same handedness not the hodgepodge of related chemicals. Chemical analyses of chondrites have been available for decades.
As a molecular biologist and a space exploration enthusiast, the discovery of a second life sample would make me ecstatic. That said, the proof has to be rock-solid. To say that this paper (and the arsenic one) did not meet burden of proof is an understatement. Such episodes only serve to make the public hostile and suspicious toward science and scientists.
ReplyDelete1. The author, Richard B. Hoover, has been presenting the same evidence without change since 1997.
2. The only CV I can find for Richard Hoover does not list a PhD in anything; some of his NASA entries list a B. Sc. in engineering (which is NOT biology, to those trying to expand the definition of astrobiology).
3. The evidence itself is so weak, stale, shoehorned and artifact-prone as to be non-existent. The presentation is also misleading: it juxtaposes suggestive pictures at different scales. It doesn't meet the criteria for publication in a reputable journal, let alone the justifiably high bar for such claims -- which may explain why the author approached Fox News instead.
4. The editors of JoC say that the paper will be peer-reviewed post-publication (file this under “unclear on the concept”).
5. The executive editor of JoC for Astrobiology is Chandra Wickramasinghe of the Hoyle and Wickramasinghe “viruses from space” panspermia theories – enough said.
6. NASA has detached itself from this debacle, stating that the Hoover paper failed to pass peer review three years ago and that its publication happened without the required internal NASA approval.
7. Penrose and others like him invoked in Hoover's defense are actually excellent examples of experts in one domain (usually engineers, computer scientists or physicists) thinking they are qualified to be considered experts in all others. Penrose was a genius astrophysicist, but the moment he started promoting quantum microtubules he entered la-la territory (so did Hoyle, Crick, Pauling... the list is long).
8. I sympathize with NASA scientists who are bona fide biologists. However, the solution to this problem is not to complain that critics are smearing them but to see if they can address the obvious problem within the agency culture (though I'm well aware of how hard this is).
9. I also sympathize with everyone who is eager to find extraterrestrial life. The biologists' reaction to the Hoover paper has nothing to do with politics, agendas, conspiracies, cabals -- it has to do with the fact that it's not science by any definition.
There's another factor at play here, and while no one can be certain how much or even whether it has played a role in this process, I strongly suspect it has. NASA (the agency) strongly hyped the arsenic life forms story while the govt was being funded under a Continuous Resolution (CR), leaving one to wonder how much of this was aimed at influencing congressional budget debates (Don't cut NAI, look at what they just discovered!).
ReplyDeleteFast forward to today - we have a new CR for a two week period and NASA (an individual scientist this time apparently) puts forward this garbage in a pseudo-journal while giving an interview to the least reliable source of "news" on the planet (Fox). Once again budgets are being debated - coincidence?? Worse, this time there's a "tea party" budget cutting mood in the Congress so draw your own conclusions.
Very nice, clear summary, Rosie.
ReplyDeleteI'd add that we've been down the "squiggles in rocks are not necessarily microfossils" road before, with Martin Brasier et al.'s refutation of Bill Schopf's Apex Chert "microfossils" (Nature 416: 76-81, 2002). And Garcia-Ruiz et al. showed that non-living processes could produce identical structures, with identical Raman spectra previously claimed as "biomarker" evidence (Science 302: 1194-1197, 2003).
Hoover's paper doesn't cite either of those references anywhere...
As for Wickramasinghe, he regularly pops up on Radio 4's Today programme in the UK claiming panspermia to be responsible for anything in the news, from HIV to BSE and SARS. He may be a fine astronomer, but he's no biologist.
What we really need to see are details of the names and full comments of the peer reviewers who examined this paper. The JoC proudly claims it rejects 80 percent of articles submitted to it without invitation, as if that is some measure of "quality" or "rigour". But if those 80 percent are articles that happen to contradict the *beliefs* of its editorial board, then that is a different matter. If the JoC cares about validity of this paper, then it needs to be fully open about the peer-review process that assessed it.
It has been inferred on this post that Richard Hoover is "not a real astrobiologist"
ReplyDeleteI suggest that everyone take a look at this page and after reading it tell me what the qualifications are for a real astrobiologist.
http://www.nasa.gov/centers/marshall/news/news/releases/2009/09-059.htmls
Well, actually having a Ph.D. would be a good start. And then, when one doesn't actually have a Ph.D., admitting it instead of publishing as "Richard Hoover, Ph.D." would be pretty marvy, too.
DeleteThe url on the previous post should be
ReplyDeletehttp://www.nasa.gov/centers/marshall/news/news/releases/2009/09-059.html
Please forgive the error
"The atomic analysis is not at all convincing. He claims that different parts of the filament have different composition, but doesn't present any control analysis of the variability of the measurements or of the background values for positions away from the filaments. He claims that the atom-density scans show enrichment of carbon and oxygen in the filaments, but this looks very weak to me - the only strong signals are for magnesium and sulfur. Again there is no detectable nitrogen or phosphorus."
ReplyDeleteI have worked extensively with EDS and inorganic materials analysis, so I was puzzled by this paragraph of yours.
You actually show two of his EDS graphs, one "on filament" and the other "beside filament". That does cover the background away from the filament question you pose in your second sentence above. I'm not sure what you are asking for regarding variability analysis, those spectra have fairly good count statistics based on the smoothness of the curves, and there is little doubt that the "on filament" spectra has higher C content then the "beside filament". I suppose its possible Hoover picked one filament that had an odd content, and deliberately avoided all the others, but there was obviously enough effort put into this work that it would be rather surprising to try to fudge something another person could test so easily. Any paper I've seen that used EDS in another field, such as crystallography, showed data much like this. Finally, the fact that virtually no nitrogen was detectable on a filament was one of his core arguments that these structures were not recent (last couple of centuries) colonization of the meteorites by earthly microbes.
So, while I was not convinced by the morphological identification of the structures as fossil bacteria, something I think is a much harder question to answer, the atomic analysis seemed solid to me.
Hi Gregory,
ReplyDeleteThe paragraph you quote was intended to refer to the Orgueil meteorite only.
Rosie
I find the number of comments posted here that essentially argue, "Until you demonstrate how this could happen through inorganic means, we should not dismiss the paper."
ReplyDeleteUntil we prove it isn't unprecedented life falling from space for which we have no other evidence, you're going to assume it is based on visual similarity? I've heard better arguments from ignorance from young Earth creationists!
Wait, wait, wait. Hoover "says that the tools were flame-sterilized"? Why on earth wouldn't they have been autoclaved?
ReplyDeleteI realize that this question is asked from a position of total ignorance, but is there any chance that the flame sterilization itself might have produced the carbon-based material present?
Numerous alien animal cellular fossils have been found and displayed at my website at http://wretchfossil.blogspot.com/
ReplyDeleteWhat happened to my comment?
ReplyDelete@Wretch Fossil: What happened to your critical thinking? You link to an image of Apex chert with arrows pointing to microscopic features formerly thought to be cellular but now thought to be non-biogenic hematite, and claim these are images of mammalian red blood cells????
ReplyDeleteI never said anything about non-biogenic hematite. It was the geologists at Kansas University who claimed hematite/quartz in the 3.5 billion year old Earthly chert. I marked red blood cell remains only in the following micrographs. The original figure was marked by geologists, not by me. Please don't be confused.
ReplyDeletehttp://www.wretch.cc/album/show.php?i=lin440315&b=22&f=1472468102&p=92
http://www.wretch.cc/album/show.php?i=lin440315&b=22&f=1472468103&p=93
http://www.wretch.cc/album/show.php?i=lin440315&b=22&f=1472468105&p=95
With comments like
ReplyDelete"5. The executive editor of JoC for Astrobiology is Chandra Wickramasinghe of the Hoyle and Wickramasinghe “viruses from space” panspermia theories – enough said."
It seems clear to me that there is a built in bias here and I simple do not trust the criticisms to be fair or accurate. I think it is only natural to attack a new interpretation of the data but there is no scientific value in much of these critiques.
I think in the end Hoyle and Wickramasinghe will turn out to be more correct than not even if the details are different. It is extremely silly to hold to the old idea, that has never been proven scientifically but only assumed as a matter of principle, that life had to have originated on the surface of this planet.
One should look at the data fresh and unbiased. There really is no actual evidence that life began here rather than came here and took root.
There is growing evidence that the chemicals of life, the conditions for life and probably some forms of life exist widely throughout the universe.
"The talk was very slick but dreadfully bad as science. The evidence he cited to support his arguments wasn't actually untrue, but he twisted everything to make his arguments seem stronger than they were. "
ReplyDeleteThat perception may be more about current biases which are frankly based on arbitrary assumptions, such as the standard concept that life must have started here on earth.
Outside the fact that life is here there really is no solid evidence that it started here yet that is the standard assumption most scientists make.
"I consider myself to be an astrobiologist, and I will say that I know of no one that supports this claim. At least, I know of no one I consider to be a serious astrobiologist that thinks this has any merit whatsoever. (And no, the authors do not qualify as serious astrobiologists."
ReplyDeleteYou think you "own" the field by deciding who is and who is not a "serious" astrobiologist and then denigrating those you deem unworthy.
This is exactly why people should distrust those who define and defend their field with very narrow parameters i.e. defending the standard view against new ideas.
Rosie, you are an expert in bacteria. Do you think there were bacteria over three billion years ago? I don't think so, as I think the evidences contain mammalian red blood cell and blood vessel remains. See http://wretchfossil.blogspot.com/2011/11/earths-oldest-fossils-are-mammalian.html
ReplyDelete@ Wretch fossil: What's the evidence that those particular streaks and splotches are fossilized mammalian red blood cells and blood vessels? If it's only their shapes, then there's no reason to postulate that they're anything but random streaks and splotches.
ReplyDeleteRegarding your statement "If it's only their shapes, then there's no reason to postulate that they're anything but random streaks and splotches.", please note mammalian red blood cells are unique in their morphology, and no other material shows their morphology. I can bet on that.
DeleteThe Journal of Cosmology is far, far worse than you have described.
ReplyDeletehttp://freethoughtblogs.com/pharyngula/2013/01/16/diatomsiiiiin-spaaaaaaaaaaace/
already necessary a Space-Command prepared for deflecting asteroids
ReplyDeleteare you still maintaining your position?
ReplyDelete