The worm turns

In the episode of The X Files called "Ice," Fox Mulder and Dana Scully are sent with a small team of scientists to a remote Arctic research station in order to investigate the murder-suicide of its entire crew.  When they get there, they find one survivor -- the station's mascot, a dog, who shows signs of hyperaggressive behavior (obviously) reminiscent of what afflicted the researchers.

They eventually figure out what happened, but not before two of the people accompanying them are dead, and both Mulder and the third scientist are obviously afflicted with the same malady.  In digging up and thawing out permafrost, the researchers had inadvertently reanimated a deep-frozen parasitic nematode that causes drastic behavioral changes, and is transmissible from bites.  They do find a way to get rid of the infection, saving the lives of Mulder, the infected scientist, and (thank heaven) the dog, but the U.S. government destroys the base before any further study of the worm or its origins can be made.

It's a highly effective and extremely creepy episode, doing what The X Files did best -- leaving you at the end with the feeling of, "This ain't actually over."

I was forced unwillingly to recall my watching of "Ice" by two news stories this week.  In the first, scientists have "reawakened" -- deliberately this time -- a nematode that has been frozen for 46,000 years in the Siberian permafrost.

Dubbed Panagrolaimus kolymaensis, it's a previously unknown species.  This doesn't mean it's a truly prehistoric species; Phylum Nematoda is estimated to contain about a million species, of which only thirty thousand have been studied, classified, and named.  So it could well be that Panagrolaimus exists out there somewhere, in active (i.e. unfrozen) ecosystems, and the invertebrate zoologists just hadn't found it yet.

Still, it's hard not to make the alarming comparison to the horrific events in "Ice" (and countless other examples of the "reanimating creatures frozen in the ice" trope in science fiction).  This reaction is somewhat ameliorated by the fact that two-thirds of the nematode species known are harmless to humans, and even the ones that are parasitic usually aren't life-threatening.  There are a few truly awful ones -- which, for the sakes of the more sensitive members of my audience, I'll refrain from giving details about -- but most nematodes are harmless, so chances are Panagrolaimus is as well.

On the other hand, it doesn't mean that thawing frozen stuff out is risk-free, and the problem is, because of climate change, thawing is happening all over the world even without reckless scientists being involved.  The second study, conducted at the European Commission Joint Research Centre, appeared in a paper in PLOS - Computational Biology and described a digital simulation of a partially frozen ecosystem (that contained living microbes in suspended animation).  They looked at how the existing community would be affected by the introduction of the now reawakened species -- and the results were a little alarming.

It has been tempting to think that because the entire ecosystem has changed since the microbes were frozen, if they were reanimated, there'd be no way they could compete with modern species which had evolved to live in those conditions.  In other words, the thawed species would be unable to cope with the new situation and would probably die out rapidly.  In fact, that did happen to some of them -- but in these models, the ancient microbes often survived, and three percent of them became dominant members of the ecosystem.  

One percent actually outcompeted and wiped out modern species.

"Given the sheer abundance of ancient microorganisms regularly released into modern communities," the authors write, "such a low probability of outbreak events still presents substantial risks.  Our findings therefore suggest that unpredictable threats so far confined to science fiction and conjecture could in fact be powerful drivers of ecological change."

Now, keep in mind that this was only a simulation; no actual microbes have been resuscitated and released into the environment.

Yet.

Anyhow, there you have it.  Something new from the "Like We Didn't Already Have Enough To Worry About" department.  Maybe I shouldn't watch The X Files.  How about Doctor Who?  Let's see... how about the episode "Orphan 55"?  *reads episode summary*  "...about a future Earth so devastated by climate change that the remnants of humanity have actually evolved to metabolize carbon dioxide instead of oxygen..."

Or maybe I should just shut off the television and hide under my blankie for the rest of the day.

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Life in the shadows

In Michael Ray Taylor's brilliant1999 book Dark Life, the author looks at some of the strangest forms of life on Earth -- extremophiles, organisms (mainly bacteria) that thrive in places where nothing else does.  Surrounding hydrothermal vents under crushing pressures and temperatures over 100 C, buried underground below the deepest mines, frozen in Antarctic ice, floating in boiling, acidic hot springs.  Taylor himself is a veteran spelunker and got interested in the topic after running into the aptly-named snottites -- biofilms found in caves that hang downward from the ceiling and are the consistency of, well, snot.

The brilliant colors of Grand Prismatic Spring in Yellowstone National Park are due, in part, to extremophilic bacteria [Image is in the Public Domain]

Taylor's contention -- that such bizarre creatures are so numerous that they outnumber all other life forms on Earth put together -- got a boost from a piece of research published in the Journal of Geomicrobiology.  Written by a team from the University of Toronto -- Garnet S. Lollar, Oliver Warr, Jon Telling, Magdalena R. Osburn, and Barbara Sherwood Lollar -- it describes the discovery, 7,900 meters underground, of a thriving ecosystem of microbes in a mine 350 kilometers north of Toronto.

The life forms are odd in a number of respects.  The first is that they're anaerobic -- they don't need oxygen to survive.  The second is that they metabolize sulfur, primarily in the form of iron sulfate, better known as pyrite or fool's gold.  It's a food chain completely unhooked from light -- for nearly every other organism on Earth, the energy they contain and utilize can ultimately be traced back to sunlight.  Here, if you follow the energy backwards, you arrive at the geothermal heat from the mantle of the Earth producing reduced (high energy) compounds that can support a food web, similar to what you see in deep-sea hydrothermal vents.

"It's a fascinating system where the organisms are literally eating fool's gold to survive," team member Barbara Sherwood Lollar said in an interview with NBC News.  "What we are finding is so exciting — like ‘being a kid again’ level exciting."  The ecosystem is in the Laurentian Shield, one of the oldest and most geologically-stable places on Earth, so it's likely that this thriving community deep underground has been there for a billion years or more.  "The number of systems we've looked at so far really is limited, but they probably had a single origin at some point in life’s four-billion-year history."  As far as their discovery, she added, "We see only what we look for.  If we don't look for something, we miss it."

And it's a lot to miss.  The current research springboards off a 2018 report sponsored by the Deep Carbon Observatory conducted by a team led by Cara Magnabosco, a geobiologist at the Swiss technical university ETH Zurich, which estimated that some 5 x 10^29 cells live in the deep Earth.

For those you who don't like scientific notation, that's five hundred thousand trillion trillion organisms.  Put succinctly, it's a really freakin' huge number.

Considering the (to us) inhospitable conditions a lot of these organisms live under, it raises hopes of finding life in other, perhaps unexpected, places in the universe.  Astronomers talk about the "Goldilocks zone," the region around a star that has temperatures where water is a liquid, and that to host life a planet would have to have a similar mass to Earth and be orbiting a star relatively similar to the Sun.  The University of Toronto research suggests that may be placing unnecessary and inaccurate strictures on where life can exist, and that we may have to rethink our definition of what we mean by "hospitable conditions."

"We're finding we really don't understand the limits to life," Sherwood Lollar said.

Which also raises the question of whether we'd recognize alien life if we saw it.  Star Trek may have been prescient; they expanded the boundaries of what we think of as life by featuring aliens that were gaseous, crystalline, thrived at searing temperatures, could tolerate the chill dark vacuum of space, or were composed of pure energy.  While some of these -- at least at first glance -- seem pretty far-fetched, what the current research suggests is that we shouldn't be too hasty to say, "Okay, that's out of the question."

"We've literally only scratched the surface of the deep biosphere," said Robert Hazen, mineralogist at the Carnegie Institution’s Geophysical Laboratory in Washington, and co-founder of Deep Carbon Observatory.  "Might there be entire domains that are not dependent on the DNA, RNA and protein basis of life as we know it?  Perhaps we just haven’t found them yet."

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Space germs

I'm fully in support of pure research, which should be obvious to anyone who is a regular reader of Skeptophilia.  But sometimes I run into a paper that leaves me scratching my head.

This happened this past weekend when I stumbled upon a press release from the University of Exeter entitled, "Mammals Could Struggle to Fight Space Germs."  The gist was that a team led by microbiologist Neil Gow did a series of experiments exposing mammalian cells to lab-synthesized peptides containing two amino acids that have been detected in space but not found in terrestrial proteins (isovaline and α-aminoisobutyric acid), and they found that the cell cultures had a "weak immune response."  From this, they concluded that if we're exposed to extraterrestrial microbes, we might really suck at fighting them off.

[Image licensed under the Creative Commons Phoebus87 at English Wikipedia, Symian virus, CC BY-SA 3.0]

This seemed like a rather overblown conclusion, so I went to the original paper (always a good idea; even university press releases are often oversimplifications or miss important points).  In this case, though, the press release was pretty much spot-on.  Here it is, straight from the paper:

The discovery of liquid water at several locations in the solar system raises the possibility that microbial life may have evolved outside Earth and as such could be accidently introduced into the Earth’s ecosystem.  Unusual sugars or amino acids, like non-proteinogenic isovaline and α-aminoisobutyric acid that are vanishingly rare or absent from life forms on Earth, have been found in high abundance on non-terrestrial carbonaceous meteorites.  It is therefore conceivable that exo-microorganisms might contain proteins that include these rare amino acids.  We therefore asked whether the mammalian immune system would be able to recognize and induce appropriate immune responses to putative proteinaceous antigens that include these rare amino acids. To address this, we synthesised peptide antigens based on a backbone of ovalbumin and introduced isovaline and α-aminoisobutyric acid residues and demonstrated that these peptides can promote naïve OT-I cell activation and proliferation, but did so less efficiently than the canonical peptides.  This is relevant to the biosecurity of missions that may retrieve samples from exoplanets and moons that have conditions that may be permissive for life, suggesting that accidental contamination and exposure to exo-microorganisms with such distinct proteomes might pose an immunological challenge.

Okay, I'll admit that this is one possible conclusion you could draw; it certainly has been riffed on often enough in science fiction, starting all the way back in 1969 with The Andromeda Strain.  (You could argue that it goes back further than that, given that at the end of H. G. Wells's 1898 novel The War of the Worlds, the invading Martians are destroyed by terrestrial microbes to which they have no natural immunity.)

The other possibility, however, is that the microbes wouldn't affect us at all.  When pathogens attack our cells, they usually obtain ingress by bonding to receptors on the surface.  Those receptors can be amazingly specific; this is why there are so many strains of flu, some of which only attack birds or pigs... or humans.  The immune species, in this case, lack the surface proteins that can form bonds to the viral proteins, so they don't get in.  The result: no disease.

In fact, it's even more specific than that.  In 2006, an outbreak of H5N1 bird flu generated worries about a pandemic, until it was learned that although highly contagious in birds, it only affects humans if the virus binds deep in the lung tissue -- the receptors in the upper respiratory system aren't able to bind to the virus efficiently (fortunately for us).  The only ones who became ill were poultry workers who were exposed to dust and debris in poultry houses.  No cases of human-to-human transmission were recorded.

So my suspicion is that extraterrestrial microbes probably wouldn't be able to attack us at all.  And given that our tissues would lack the two oddball amino acids the researchers used in their experiments, it seems pretty likely that if the microbes did get in, they'd starve to death.  (Put more scientifically, our proteins would lack two amino acids they need, so we wouldn't be of much use to them as a food source.)

Of course, it's possible that Gow et al. are right, and extraterrestrial microorganisms would consider the Earth an all-you-can-eat buffet.  But given that (1) the number of extraterrestrial microorganisms we've actually studied is zero, and (2) there are equally persuasive arguments to the contrary, it might be a little bit of a premature conclusion.

Now, that doesn't mean we should be bringing outer space debris to Earth, sans quarantine.  Hell, I've read The Colour Out of Space, and last thing I want is to have a gaseous entity from a meteorite cause my limbs to crumble and fall off.  COVID-19 is bad enough, thanks.  We really don't need any more reasons to panic, however.  So for now, let's confine ourselves to dealing with threats that currently exist.

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Being in the middle of a pandemic, we're constantly being urged to wash our hands and/or use hand sanitizer.  It's not a bad idea, of course; multiple studies have shown that communicable diseases spread far less readily if people take the simple precaution of a thirty-second hand-washing with soap.

But as a culture, we're pretty obsessed with cleanliness.  Consider how many commercial products -- soaps, shampoos, body washes, and so on -- are dedicated solely to cleaning our skin.  Then there are all the products intended to return back to our skin and hair what the first set of products removed; the whole range of conditioners, softeners, lotions, and oils.

How much of this is necessary, or even beneficial?  That's the topic of the new book Clean: The New Science of Skin by doctor and journalist James Hamblin, who considers all of this and more -- the role of hyper-cleanliness in allergies, asthma, and eczema, and fascinating and recently-discovered information about our skin microbiome, the bacteria that colonize our skin and which are actually beneficial to our overall health.  Along the way, he questions things a lot of us take for granted... such as whether we should be showering daily.

It's a fascinating read, and looks at the question from a data-based, scientific standpoint.  Hamblin has put together the most recent evidence on how we should treat the surfaces of our own bodies -- and asks questions that are sure to generate a wealth of discussion.

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

Life in the shadows

In Michael Ray Taylor's brilliant1999 book Dark Life, the author looks at some of the strangest forms of life on Earth -- extremophiles, organisms (mainly bacteria) that thrive in places where nothing else does.  Surrounding hydrothermal vents under crushing pressures and temperatures over 100 C, buried underground below the deepest mines, frozen in Antarctic ice, floating in boiling, acidic hot springs.  Taylor himself is a veteran spelunker and got interested in the topic after running into the aptly-named snottites -- biofilms found in caves that hang downward from the ceiling and are the consistency of, well, snot.

The brilliant colors of Grand Prismatic Spring in Yellowstone National Park are due, in part, to extremophilic bacteria [Image is in the Public Domain]

Taylor's contention -- that such bizarre creatures are so numerous that they outnumber all other life forms on Earth put together -- just got a boost last week from a piece of research published in the Journal of Geomicrobiology.  Written by a team from the University of Toronto -- Garnet S. Lollar, Oliver Warr, Jon Telling, Magdalena R. Osburn, and Barbara Sherwood Lollar -- it describes the discovery, 7,900 meters underground, of a thriving ecosystem of microbes in a mine 350 kilometers north of Toronto.

The life forms are odd in a number of respects.  The first is that they're anaerobic -- they don't need oxygen to survive.  The second is that they metabolize sulfur, primarily in the form of iron sulfate, better known as pyrite or fool's gold.  It's a food chain completely unhooked from light -- for nearly every other organism on Earth, the energy they contain and utilize can ultimately be traced back to sunlight.  Here, if you follow the energy backwards, you arrive at the geothermal heat from the mantle of the Earth producing reduced (high energy) compounds that can support a food web, similar to what you see in deep-sea hydrothermal vents.

"It's a fascinating system where the organisms are literally eating fool's gold to survive," team member Barbara Sherwood Lollar said in an interview with NBC News. "What we are finding is so exciting — like ‘being a kid again’ level exciting."  The ecosystem is in the Laurentian Shield, one of the oldest and most geologically-stable places on Earth, so it's likely that this thriving community deep underground has been there for a billion years or more.  "The number of systems we've looked at so far really is limited, but they probably had a single origin at some point in life’s four-billion-year history."  As far as their discovery, she added, "We see only what we look for.  If we don't look for something, we miss it."

And it's a lot to miss.  The current research springboards off a 2018 report sponsored by the Deep Carbon Observatory conducted by a team led by Cara Magnabosco, a geobiologist at the Swiss technical university ETH Zurich, which estimated that some 5 x 10^29 cells live in the deep Earth.

For those you who don't like scientific notation, that's five hundred thousand trillion trillion organisms.  Put succinctly, it's a really freakin' huge number.

Considering the (to us) inhospitable conditions a lot of these organisms live under, it raises hopes of finding life in other, perhaps unexpected, places in the universe.  Astronomers talk about the "Goldilocks zone," the region around a star that has temperatures where water is a liquid, and that to host life a planet would have to have a similar mass to Earth and be orbiting a star relatively similar to the Sun.  The University of Toronto research suggests that may be placing unnecessary and inaccurate strictures on where life can exist, and that we may have to rethink our definition of what we mean by "hospitable conditions."

"We're finding we really don't understand the limits to life," Sherwood Lollar said.

Which also raises the question of whether we'd recognize alien life if we saw it.  Star Trek may have been prescient; they expanded the boundaries of what we think of as life by featuring aliens that were gaseous, crystalline, thrived at searing temperatures, could tolerate the chill dark vacuum of space, or were composed of pure energy.  While some of these -- at least at first glance -- seem pretty far-fetched, what the current research suggests is that we shouldn't be too hasty to say, "Okay, that's out of the question."

"We've literally only scratched the surface of the deep biosphere," said Robert Hazen, mineralogist at the Carnegie Institution’s Geophysical Laboratory in Washington, and co-founder of Deep Carbon Observatory.  "Might there be entire domains that are not dependent on the DNA, RNA and protein basis of life as we know it?  Perhaps we just haven’t found them yet."

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This week's Skeptophilia book recommendation is pure fun: science historian James Burke's Circles: Fifty Round Trips Through History, Technology, Science, and Culture.  Burke made a name for himself with his brilliant show Connections, where he showed how one thing leads to another in discoveries, and sometimes two seemingly unconnected events can have a causal link (my favorite one is his episode about how the invention of the loom led to the invention of the computer).

In Circles, he takes us through fifty examples of connections that run in a loop -- jumping from one person or event to the next in his signature whimsical fashion, and somehow ending up in the end right back where he started.  His writing (and his films) always have an air of magic to me.  They're like watching a master conjuror create an illusion, and seeing what he's done with only the vaguest sense of how he pulled it off.

So if you're an aficionado of curiosities of the history of science, get Circles.  You won't be disappointed.

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