Mushrooms on Mars

So far loyal readers of Skeptophilia have sent me four different links to the same underlying story, along with a message along the lines of "Whaddya think of this?"  The links all take various angles on a paper by Rhawn Gabriel Joseph and Xinli Wei in Advances in Microbiology claiming that photos taken by the Mars rover Curiosity show the presence of live fungi.

Without further ado, here are the photos, which are real enough:

[Photos are in the Public Domain courtesy of NASA/JPL]

When I saw the top photo, my immediate thought was that if you think the only way to explain wiping away stuff and having it reappear is if the stuff is a living organism, you need to come take a look at how long furniture in my house remains clean after being dusted.  I'll admit that I'm kind of housework-impaired, and chances are one day I'll go missing and when people come to investigate they'll find me trapped inside an enormous dust bunny, but still, the fact remains that "dirt blows around" seems to be a universal tendency.  Second, the lower photo looks like a fungus or at least fungus spores, but saying "it looks like X, so it is X" is not how science is done.

The claim has generated a lot of hype and also a lot of backlash from actual science types, such as this scathing piece by Tristan Greene over at TheNextWeb, wherein Joseph and Wei basically get their asses handed to them for leaping to an entirely unwarranted conclusion based on a handful of photographs that can be explained by any number of other, more likely hypotheses.  There are lots of microscopic round things besides fungal spores, so without any sort of biochemical analysis there's no way these can conclusively be labeled as alive, much less as terrestrial-type fungi.

Rhawn Gabriel Joseph, however, is not a man to take this sort of criticism lying down.  Saying Joseph is "combative" is a little like saying Stalin had "anger management issues."  He has sued NASA for ignoring his previous claims about life on Mars, sued Springer (the academic publishing company that publishes the journals Nature and Scientific American) for retracting one of his papers, and on his website defiantly proclaims that he has "published major scientific studies in the fields of neuroscience, development, embryology, evolution, quantum physics, consciousness, genetics, and astrobiology."

Funny, if he's an expert in basically everything, how just about every reference to him in actual scientific journals describe him as a "crank," a "kook," and "a self-aggrandizing spotlight seeker."

Then there's the issue of the journal the paper is published in -- Advances in Microbiology.  AiM is one of the journals owned by SCIRP -- Scientific Research Publishing -- a China-based company long associated with predatory, pay-to-play practices:

[T]here may be some strong and honest articles published in SCIRP journals. However, these articles are devalued and stigmatized by association with all the junk science that SCIRP publishes.  The authors of the good articles are being victimized by the publisher’s policy of publishing pseudoscientific articles like “Basic Principles Underlying Human Physiology.”  SCIRP only rarely retracts articles, preferring instead to protect the interests of its customers, the paying authors.

Oh, and apropos of not much, here's the photo of himself he has on his website:

No, I'm not joking.

The issue here goes back to the ECREE Principle; Extraordinary Claims Require Extraordinary Evidence.  Okay, maybe those are Martian fungal spores.  But before you can conclude that, you'd better have some damn good evidence supporting your claim, something more than "we see stuff moving around":

Hundreds of dimpled donut-shaped "mushroom-like" formations approximately 1mm in size are adjacent or attached to these mycelium-like complexes.  Additional sequences document that white amorphous masses beneath rock-shelters increase in mass, number, or disappear and that similar white-fungus-like specimens appeared inside an open rover compartment.  Comparative statistical analysis of a sample of 9 spherical specimens believed to be fungal "puffballs" photographed on Sol 1145 and 12 specimens that emerged from beneath the soil on Sol 1148 confirmed the nine grew significantly closer together as their diameters expanded and some showed evidence of movement.

Look, no one would be more excited than me if the rovers did discover Martian life.  Honestly, it's not that I think microbial life on Mars is all that unlikely.  It's just that you don't support your claims in science by pointing and yelling, "Hey, lookit that!" over and over.  If these are fungal spores, then there are a lot of them, so it's only a matter of time before they'll be detected by the actual rigorous biochemical analysis the rovers are equipped to do.

And I can guarantee that the results will be published in a reputable science journal, not an open-access affair like Advances in Microbiology, and almost certainly the lead author won't be some Disco-Era refugee who claims to be the intellectual equivalent of Stephen Hawking, David Eagleman, Charles Darwin, Carl Sagan, and Gregor Mendel put together.

So, sad to say, that's where the issue stands.  If I'm wrong, I will happily eat crow and publish an update and/or retraction.  I'd like to think the firestorm Joseph has ignited will cause him to retreat in disarray, but his motto seems to be "Death Before Backing Down," so I'm guessing this isn't the last we'll hear from him on the topic.  Stay tuned.

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I have often been amazed and appalled at how the same evidence, the same occurrences, or the same situation can lead two equally-intelligent people to entirely different conclusions.  How often have you heard about people committing similar crimes and getting wildly different sentences, or identical symptoms in two different patients resulting in completely different diagnoses or treatments?

In Noise: A Flaw in Human Judgment, authors Daniel Kahneman (whose wonderful book Thinking, Fast and Slow was a previous Skeptophilia book-of-the-week), Olivier Sibony, and Cass Sunstein analyze the cause of this "noise" in human decision-making, and -- more importantly -- discuss how we can avoid its pitfalls.  Anything we can to to detect and expunge biases is a step in the right direction; even if the majority of us aren't judges or doctors, most of us are voters, and our decisions can make an enormous difference.  Those choices are critical, and it's incumbent upon us all to make them in the most clear-headed, evidence-based fashion we can manage.

Kahneman, Sibony, and Sunstein have written a book that should be required reading for anyone entering a voting booth -- and should also be a part of every high school curriculum in the world.  Read it.  It'll open your eyes to the obstacles we have to logical clarity, and show you the path to avoiding them.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Life in hell

Given my near-obsessive interest in extraterrestrial life, I suppose it was inevitable that I've now been sent links to the latest research on Venus over a dozen times.

The gist, in case you haven't read about it yet, is that astronomers have identified the absorption spectrum of a rare molecule -- phosphine -- in the upper atmosphere of the planet Venus.  Phosphine is produced in vanishingly small quantities on Earth by cloud-to-ground lightning strikes and volcanic eruptions, but the amount detected in the atmosphere of Venus is a full ten thousand times too high to be accounted for by any known inorganic chemistry or geology.

Ruling out one by one all of the inorganic sources of phosphine seems to leave only one remaining possibility; there are microbes in the Venusian atmosphere that produce the stuff.  There are a handful of species of terrestrial microbes that produce phosphine (here, it's in even smaller quantities than the inorganic sources).  But if these microbes (or something like them) existed on Venus, it could easily account for the excess.

You may be wondering how anything lives on Venus.  It's a good question.  The surface of Venus is a lot like our conception of hell.  For a long time people interpreted the constant cloud layers that obscure the surface as being made of water droplets, like they are on Earth; it led to some pretty cool speculative fiction about what could be down there (C. S. Lewis's novel Perelandra and H. P. Lovecraft's outstanding short story "In the Walls of Eryx" come to mind).  But that speculation was based on nothing but an absence of evidence.  As Carl Sagan put it so eloquently:

The chain of reasoning goes something like this: I can't see a thing on the surface of Venus.  Why not?  Because it's covered with a dense layer of clouds.  Well, what are clouds made of?  Water, of course.  Therefore, Venus must have an awful lot of water on it.  Therefore, the surface must be wet.  Well, if the surface is wet, it's probably a swamp.  If there's a swamp, there's ferns.  If there's ferns, maybe there's even dinosaurs.

Observation: I can't see a thing.  Conclusion: dinosaurs.

This whole thing got shot down pretty conclusively in the 1960s when the first unmanned (fortunately) probes to Venus dropped through the atmosphere and promptly were simultaneously crushed and fried by an atmosphere with ninety times the pressure of Earth's atmosphere at sea level and temperatures that hover around 460 C.  Further exploration showed that the clouds are largely sulfuric acid, and the atmosphere is 96.5% carbon dioxide (compared to 0.04% on Earth), leading to a runaway greenhouse effect.

The surface of Venus [Image is in the Public Domain courtesy of NASA/JPL]

It's not just hot, it's wracked with turbulence the likes of which we never see on Earth.  The heat provides a huge energy source for Venusian weather, mostly in the form of violent storms and updrafts.  As dubious as he was about life on Venus, Sagan had suggested these updrafts as a key to the possible terraforming of the planet, and proposed launching rockets with payloads of blue-green bacteria spores, set to detonate in the upper clouds.  As the spores fall through the relatively mild temperatures of the upper atmosphere, they begin to photosynthesize, using up some of the carbon dioxide.  Enough are kept aloft by the updrafts to keep the process going, and ultimately, the greenhouse effect would diminish and the temperature would fall to more tolerable levels.

Well, nature may have anticipated Sagan.  If there are anaerobic microbes riding the turbulence in Venus's upper atmosphere, it would be the first unequivocal example of extraterrestrial life ever found.  The scientists are being careful about overstating their conclusion, but even given the usual caution, the excitement is palpable.  "The non-biological production of phosphine on Venus is excluded by our current understanding of phosphine chemistry in rocky planets' atmospheres," said Leonardo Testi, astronomer with the Atacama Large Millimeter/submillimeter Array in Chile, one of the most sensitive telescopes in existence.  "Confirming the existence of life on Venus's atmosphere would be a major breakthrough for astrobiology; thus, it is essential to follow-up on this exciting result with theoretical and observational studies to exclude the possibility that phosphine on rocky planets may also have a chemical origin different than on Earth."

So it's premature to say "we've discovered extraterrestrial life," but this is the best candidate for it I can recall seeing, and in one of the most inhospitable spots in the Solar System.  If this is confirmed to be of biological origin, it gives a lot of support to the contention I've had all along -- that life will turn out to be common in the the universe.  It'd boost the enthusiasm for checking out other places in the Solar System that could host life (Jupiter's moon Europa and Saturn's moon Titan come to mind), because after all, if life can exist on Venus, it could exist damn near anywhere.

Still no dinosaurs, though.  None of Lewis's floating islands made of rafts of plants, either, nor Lovecraft's evil jewel-hunting reptilian natives.  But for now, it's good enough for me, as long as the astronomers don't find some kind of exotic Venusian chemistry that explains the gas's presence.

If the whole thing pans out, it really gives new meaning to Ian Malcolm's line from Jurassic Park, doesn't it?

"Life finds a way."

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This week's Skeptophilia book-of-the-week is about one of the most terrifying viruses known to man: rabies.

In Rabid: A Cultural History of the World's Most Diabolical Virus, by Bill Wasik and Monica Murphy, we learn about the history and biology of this tiny bit of protein and DNA that has, once you develop symptoms, a nearly 100% mortality rate.  Not only that, but it is unusual amongst pathogens at having extremely low host specificity.  It's transmissible to most mammal species, and there have been cases of humans contracting rabies not from one of the "big five" -- raccoons, foxes, skunks, bats, and dogs -- but from animals like deer.

Rabid goes through not only what medical science has to say about the virus and the disease it causes, but its history, including the possibility that it gave rise to the legends of lycanthropy and werewolves.  It's a fascinating read.

Even though it'll make you a little more wary of wildlife.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

The power of "only"

Today, I ran into a story that got me thinking about how powerful a single word can be in changing the gist of a claim.

An article in Online Medical Daily entitled "'Seeds Of Life' Collected During Perseid Meteor Shower: Scientists Say Algae 'Can Only Have Come From Space'," writer John Ericson describes an unusual find on the (formerly) sterile sides of a British research balloon.

In a study described at the Instruments, Methods, and Missions for Astrobiology conference in San Diego, British biologist Chandra Wickramasinghe told attendees about a discovery, that (if true) revolutionizes what we know about the origins of life on Earth.  Wickramasinghe and his colleagues launched a balloon into the stratosphere during the annual Perseid meteor shower, and upon retrieval, found that the surface had a microscopic blob of microorganisms stuck to it.  "The entities varied from a presumptive colony of ultra-small bacteria to two unusual individual organisms - part of a diatom frustule and a 200 micron-sized particle mass interlaced with biofilm and biological filaments," Wickramasinghe said, in an interview with The Daily Mail.

Diatom frustules (skeletons)

"By our current understanding of the means by which such particles can be transferred from Earth to the stratosphere they could not - in the absence of a violent volcanic eruption occurring within a day of the sampling event - make such a journey," Wickramasinghe explained.  "If there is no mechanism by which these biological entities could be elevated from Earth to the stratosphere then it must have arrived from above the stratosphere and have been incoming to Earth...  They can only have come from space."

What Wickramasinghe is claiming is not a new idea.  Called panspermia, the speculation is that the ancestors of all terrestrial species was a microorganism (probably an extremeophile) that rode in on a meteorite or on cometary debris.  Chemist Svante Arrhenius was fond of the claim, as was astronomer Fred Hoyle; but it's not much in vogue these days, largely due to slim evidence supporting the contention.  Wickramasinghe himself is kind of a fringe figure in the minds of much of the scientific community -- not only has he championed panspermia with a single-mindedness that approaches obsession, but he also testified for the defense in a 1981 McLean vs. the Arkansas State Board of Education trial, one of many cases that considered the constitutionality of teaching creationism in public schools.  During the trial, he referred to the famous fossil of Archaeopteryx as a "hoax."

None of this wins him any points in my book.

Of course, to be fair, you have to consider a claim separate from the person making it; even complete wingnuts can land on correct ideas sometimes.  And here, we have at least some sort of hard evidence -- traces of microorganisms on a sterile balloon that had taken a trip into the stratosphere during a meteor shower.  Has Wickramasinghe been vindicated?

There's the problem here, and it revolves around the use of the word "only."  Wickramasinghe said that his algae blob "can only have come from space."  Take out the word "only," and I'm with him 100%.  The blob could have come from space.  Its presence on the balloon is certainly suggestive.  But to say that it only can have come from space requires a great deal more than that.

Stratospheric dust collection is a notoriously difficult task.  Contamination is a constant hazard, especially if you are trying to obtain a pure sample of interplanetary dust -- i.e., material that did not originate on Earth.  Terrestrial dust, made up of windblown sediments, volcanic ash, and more prosaic materials such as pollen, can reach amazing heights in the atmosphere, and travel extraordinary distances.  A recent study found that dust from the Sahara can reach stratospheric heights -- and affect weather in western North America.

So even if Wickramasinghe's group was careful -- and I am not trying to imply that they weren't -- the possibility of contamination has to be weighed into any argument about the origin of the microorganisms on the balloon.  As NASA's page on "Cosmic Dust" puts it, "Once in the stratosphere this ‘cosmic dust’ and spacecraft debris joins terrestrial particles such as volcanic ash, windborne desert dust and pollen grains."

But of course, Wickramasinghe has a dog in this race, and once you take out the word "only," you don't have much of a story left.  Debris, some containing organic compounds or even microorganisms, has been found before and been alleged to have an extraterrestrial origin.  Thus far, none of these claims has been conclusively supported, so (to be fair) we have to consider the jury to be still out on the idea of panspermia.

Now, don't get me wrong.  No one would be more delighted than me if extraterrestrial life was discovered, even if it turned out just to be single-celled organisms.  I've long suspected that we're not alone in the universe -- what I know about evolutionary biology suggests to me that life is probably plentiful out there in space.  But if you make a claim to have discovered aliens, even microscopic ones, you have to be held to a higher standard of evidence than suspicions and suggestions.  And your case isn't made more watertight simply because of a judicious use of the word "only."