The last survivors on Earth

By Schokraie E, Warnken U, Hotz-Wagenblatt A, Grohme MA, Hengherr S, et al. (2012) CC BY 2.5 (, via Wikimedia Commons

From Eurekalert

Public Release: 14-Jul-2017

University of Oxford

The world’s most indestructible species, the tardigrade, an eight-legged micro-animal, also known as the water bear, will survive until the Sun dies, according to a new Oxford University collaboration.

The new study published in Scientific Reports, has shown that the tiny creatures, will survive the risk of extinction from all astrophysical catastrophes, and be around for at least 10 billion years – far longer than the human race.

Although much attention has been given to the cataclysmic impact that an astrophysical event would have on human life, very little has been published around what it would take to kill the tardigrade, and wipe out life on this planet.

The research implies that life on Earth in general, will extend as long as the Sun keeps shining. It also reveals that once life emerges, it is surprisingly resilient and difficult to destroy, opening the possibility of life on other planets.

Tardigrades are the toughest, most resilient form of life on earth, able to survive for up to 30 years without food or water, and endure temperature extremes of up to 150 degrees Celsius, the deep sea and even the frozen vacuum of space. The water-dwelling micro animal can live for up to 60 years, and grow to a maximum size of 0.5mm, best seen under a microscope. Researchers from the Universities of Oxford and Harvard, have found that these life forms will likely survive all astrophysical calamities, such as an asteroid, since they will never be strong enough to boil off the world’s oceans.

Three potential events were considered as part of their research, including; large asteroid impact, and exploding stars in the form of supernovae or gamma ray bursts.



There are only a dozen known asteroids and dwarf planets with enough mass to boil the oceans (2×10^18 kg), these include (Vesta 2×10^20 kg) and Pluto (10^22 kg), however none of these objects will intersect the Earth’s orbit and pose a threat to tardigrades.



In order to boil the oceans an exploding star would need to be 0.14 light-years away. The closest star to the Sun is four light years away and the probability of a massive star exploding close enough to Earth to kill all forms of life on it, within the Sun’s lifetime, is negligible.


Gamma-Ray bursts

Gamma-ray bursts are brighter and rarer than supernovae. Much like supernovas, gamma-ray bursts are too far away from earth to be considered a viable threat. To be able to boil the world’s oceans the burst would need to be no more than 40 light-years away, and the likelihood of a burst occurring so close is again, minor.

Dr Rafael Alves Batista, Co-author and Post-Doctoral Research Associate in the Department of Physics at Oxford University, said: ‘Without our technology protecting us, humans are a very sensitive species. Subtle changes in our environment impact us dramatically. There are many more resilient species’ on earth. Life on this planet can continue long after humans are gone.

‘Tardigrades are as close to indestructible as it gets on Earth, but it is possible that there are other resilient species examples elsewhere in the universe. In this context there is a real case for looking for life on Mars and in other areas of the solar system in general. If Tardigrades are earth’s most resilient species, who knows what else is out there.’

Dr David Sloan, Co-author and Post-Doctoral Research Associate in the Department of Physics at Oxford University, said: ‘A lot of previous work has focused on ‘doomsday’ scenarios on Earth – astrophysical events like supernovae that could wipe out the human race. Our study instead considered the hardiest species – the tardigrade. As we are now entering a stage of astronomy where we have seen exoplanets and are hoping to soon perform spectroscopy, looking for signatures of life, we should try to see just how fragile this hardiest life is. To our surprise we found that although nearby supernovae or large asteroid impacts would be catastrophic for people, tardigrades could be unaffected. Therefore it seems that life, once it gets going, is hard to wipe out entirely. Huge numbers of species, or even entire genera may become extinct, but life as a whole will go on.’

In highlighting the resilience of life in general, the research broadens the scope of life beyond Earth, within and outside of this solar system. Professor Abraham Loeb, co-author and chair of the Astronomy department at Harvard University, said: ‘It is difficult to eliminate all forms of life from a habitable planet. The history of Mars indicates that it once had an atmosphere that could have supported life, albeit under extreme conditions. Organisms with similar tolerances to radiation and temperature as tardigrades could survive long-term below the surface in these conditions. The subsurface oceans that are believed to exist on Europa and Enceladus, would have conditions similar to the deep oceans of Earth where tardigrades are found, volcanic vents providing heat in an environment devoid of light. The discovery of extremophiles in such locations would be a significant step forward in bracketing the range of conditions for life to exist on planets around other stars.’


Notes to editors:

Full paper citation: ‘The Resilience of Life to Astrophysical Events’ Authors: David Sloan1, Rafael Alves Batista1, and Abraham Loeb2:

For interviews or supporting images please contact:

Lanisha Butterfield, Media Relations Manager on 01865 280531 or

The Mathematical, Physical and Life Sciences Division (MPLS) is one of four academic divisions at the University of Oxford, representing the non-medical sciences. Oxford is one of the world’s leading universities for science, and MPLS is at the forefront of scientific research across a wide range of disciplines. Research in the mathematical, physical and life sciences at Oxford was rated the best in the UK in the 2014 Research Excellence Framework (REF) assessment. MPLS received £133m in research income in 2014/15.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

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July 16, 2017 2:04 pm

What? Some beastie not affected by climate change? The researcher must be about to retire.

Reply to  Tom Halla
July 17, 2017 2:02 am

I suspect this is just the “set up” article.
Soon, there will be the follow up article that claims that even the indestructible tardigrades are going extinct. I bet you cannot guess why? OMG, it is worse than we thought!

george e. smith
Reply to  Tom Halla
July 17, 2017 11:23 pm

If you go to the Stanford mall on a Saturday morning, you can see yuppies walking around with those Tardigrades on a leash. They think it’s chic.
I even saw one woman sitting at the bar drinking a Martinus, with one of those things sitting in her purse on the bar.
Why people think it is chic to be seen at the Stanford mall with their family menagerie on a string, I have no idea.
Personally I’m quite fond of pink legged Tarantulas for string pets myself.

July 16, 2017 2:07 pm

“The world’s most indestructible species, the tardigrade…”
Nope. It’s a phylum.
Reply: I noticed that when I was copying and pasting the news release. I didn’t do anything. d’oh~ctm

Reply to  Jit
July 16, 2017 3:11 pm

Good that you didn’t. The ‘mistake’ is a tell about junk science. The 10 billion years is another, since the Sun is a main sequence star and its life cycle is quite well known. Two egregious blunders in one PR says a great deal about it. Nothing complementary.

Reply to  ristvan
July 16, 2017 3:41 pm

… PR …

We don’t know anything about the quality of the science without reading and understanding the original paper(s). One of my father’s most miserable experiences stemmed from trying to untangle the mess caused by a stupid PR flack.

Reply to  ristvan
July 16, 2017 3:57 pm

Wrote a whole book on that theme, The Arts of Truth. (Hint, even the title is a deliberate deception.) A modification of Reagan’s aphorism, an affirmation of the Royal Society motto, “Nullius in Verba”

Sixto Vega
Reply to  ristvan
July 16, 2017 4:16 pm

Here’s the original paper, sans paywall:

Alan Robertson
July 16, 2017 2:22 pm

Don’t think any water- dwelling creature will survive ’til the Sun dies, since there won’t be any water, the planet’s Hydrogen having long before, gradually leaked into the vacuum of Space.

Reply to  Alan Robertson
July 16, 2017 6:10 pm

Our final form in this world, like us. is maybe more provocative a title? Until the Sun dies sounds like Bakersfield country lyrics.

Sixto Vega
July 16, 2017 2:26 pm

They do sooner or later need water, however, which will disappear from the surface of the earth long before the sun goes red giant. Estimates vary from ~500 million to 1.75 billion years in the future, but some of the guesses rely on, you guessed it, general circulation models of the atmosphere.
The sun gains in power about one percent per 110 million years.

Sixto Vega
Reply to  Sixto Vega
July 16, 2017 2:43 pm

Although I suppose they might survive in pockets of water underground for a while longer.

Don K
Reply to  Sixto Vega
July 16, 2017 3:08 pm

“The sun gains in power about one percent per 110 million years.”
OMG. We’re all gonna DIE if we don’t do something about that. RIGHT NOW!!!
Is solar expansion factored into the GCMs?
BTW, there are possible tardigrade like animals known from the Cambrian — 500,000,000 years (give or take a few months) ago.

Reply to  Don K
July 16, 2017 3:36 pm

It is thought that most (‘all’) animal phyla emerged either in the Ediacarian or the Cambrian (the Cambrian explosion of Burgess shale fame when armored exoskeletons and eyes evolved). Even Chordata. Same is clearly not true for plants, interestingly. For example, the Carboniferous apparently started with the evolution of lignin bearing plants. The three land bryophyta clearly predate the two carboniferous Pteridophyta.
Evolutionary theory has been a hobby and deep reading interest since near 40 years and my direct exposure to then not yet famous but brilliant professor Stephen J. Gould. Paleontologist, geologist, evolutionary biologist all in one person. His theory of punctuated equilibrium was published the year I graduated from the college.

Reply to  Don K
July 16, 2017 4:31 pm

Cambrian water bears only had six legs.

Reply to  Don K
July 16, 2017 4:32 pm

No. The sun doesn’t make any difference. It’s all CO2. Just ask any respectable climate scientist.

Reply to  Don K
July 17, 2017 6:00 am

“Cambrian water bears only had six legs.”
Anthropocene ones will have nine ! 😉

Tim Groves
Reply to  Sixto Vega
July 17, 2017 1:02 am

However, the earth is taking evasive action by moving away from the sun at a rate of 15 cm per year. If this continues at the same rate the earth-sun distance will increase by 16,500 km in 110 million years from now. If my arithmetic is correct, that’s nowhere near a one percent increase, but it it’s a bit over one percent of one percent.

Reply to  Tim Groves
July 17, 2017 6:43 am

There are methods that can increase that rate.

Reply to  Tim Groves
July 17, 2017 10:07 am

Evict algore & michael moore to increase rate.

Steve Safigan
July 16, 2017 2:30 pm

Life won’t make it quite that long. From
“In 3.5 billion years, the sun will be 40 percent brighter than it is right now, which will cause the oceans to boil, the ice caps to permanently melt, and all water vapor in the atmosphere to be lost to space. Under these conditions, life as we know it will be unable to survive anywhere on the surface, and planet Earth will be fully transformed into another hot, dry world, just like Venus.
“5.4 billion years from now, the sun will enter what is known as the red giant phase of its evolution. This will begin once all hydrogen is exhausted in the core and the inert helium ash that has built up there becomes unstable and collapses under its own weight. This will cause the core to heat up and get denser, causing the sun to grow in size. It is calculated that the expanding sun will grow large enough to encompass the orbits of Mercury, Venus, and maybe even Earth. Even if the Earth were to survive being consumed, its new proximity to the the intense heat of this red sun would scorch our planet and make it completely impossible for life to survive.”
Holy global warming!

Walter Sobchak
Reply to  Steve Safigan
July 16, 2017 3:01 pm

You are wrong. The sun has no effect on the Earth’s climate. The IPCC said so. What’s a matter with you are you a science denier?

Reply to  Walter Sobchak
July 16, 2017 4:34 pm

Sorry WS – didn’t read yours before posting mine.

Reply to  Steve Safigan
July 16, 2017 3:23 pm

Now you’re sounding like an alarmist.

July 16, 2017 2:31 pm

no, it will not
“In approximately 5 billion years, the sun will begin the helium-burning process, turning into a red giant star. When it expands, its outer layers will consume Mercury and Venus, and reach Earth”

Crispin in Waterloo
July 16, 2017 2:51 pm

Rock digesting bacteria have been found in the deep mine shafts of South Africa where they have been living underground for several hundred million years. I think they are tougher and longer lasting that the little toughie above.
“Their most famous discovery, a bacterium named candidatus Desulforudis audaxviator (or “bold traveler”), in a nod to Jules Verne’s “Journey to the Center of the Earth,” has been determined to have lived as long as 3 to 40 million years deep underground without any contact with the surface – using the radioactive decay of nearby rock as its energy source and breaking molecules into bite-sized nourishment. [Strangest Places Where Life Is Found on Earth]”

July 16, 2017 2:53 pm

CTM, thanks for this post. The very first Oxford sentence about “world’s most indestructible species” is a dead giveaway tell that this is another very poor speculative ‘research’ mostly done for PR effect. The PR is already on Vox and WaPo, for crying out loud.
Tardigrades are a phylum, Tardigrada, containing classes, orders, families, genera and many, many quite different species. Fossil evidence dates Tardigrada back 530 mya to the Cambrian, proof they are rugged. Survived 5 mass extinctions already (but then, so did most other phlya even if entire classes within them did not, like the trilobite class within the arthropod phylum). To show the enormous variation within Tardigrada, DNA sequencing shows a range from ~70 to ~800 megabase pairs of DNA (and that is just what is known, as many Tardigrada species have not yet been sequenced). Some eat plants (moss, phytoplankton), some eat bacteria, and some eat other tardigrades. While it is true they are found all over earth, from deep marine water to tropical fresh water to high Alpine and Arctic conditions, these are all different orders, families and genera, not one super rugged super adaptable species.
The rest of the PR is not new news. Tardigrades have been known for decades to be super rugged within the specific environment the whatever genera adapted to. Wikipedia (I know) lists dozens of peer reviewed ‘rugged tardigrade’ papers.

Reply to  ristvan
July 16, 2017 4:12 pm

spot on…they were sent into space too

Reply to  Latitude
July 16, 2017 4:48 pm

“They were sent into space too”…..We should sprinkle a few onto Mars, just to see what happens, what is there to lose? I find it interesting we could bring life to other planets. If they don’t make it, so be it.
And to ristvan…I learnt something today, good overview.

Reply to  Latitude
July 17, 2017 2:18 am

“We should sprinkle a few onto Mars”
May already have happened. The early soviet probes were probably not very carefully sterilized.

Reply to  ristvan
July 16, 2017 4:46 pm

Since no phylum has gone extinct during the Phanerozoic Eon (that I know of), we’re all survivors of mass extinctions. Water bears are definitely tough, as you point out, and liable to outlive many another animal phylum, but I agree that this paper is yet another instance of the need to publish or perish producing a basic nothing burger of a study.

Reply to  ristvan
July 18, 2017 1:12 pm

You might be interested in this
Did life begin on land rather than in the sea?

michael hart
July 16, 2017 3:16 pm

Yum, yum. An edible octapod.
That’s what the global warmers will have us eating, because it seems their fantasies will also still be around when the sun explodes.
And the universe will explode later, for your pleasure.
Hey what?
Wow! What sort of drinks do you serve here? ]

July 16, 2017 3:28 pm

The only indestructible species on this planet is the Green.
We will be plagued by them for the rest of humanities time on earth.
Nasty, crawling, snivelling, pestilent little beasties.

Reply to  HotScot
July 16, 2017 8:00 pm

So are you saying that that is the worst picture of Al Gore you have ever seen?

Reply to  R2Dtoo
July 16, 2017 11:14 pm

That’s one of the better shots of him 🙂

M Seward
July 16, 2017 3:35 pm

I reckon its the Tardigrades wot are running the AGW scam. Its almost a perfect match for their world view and brain size in the binary model I have used to analyse the matter. I think we have consensus on that do we not?

Proud Skeptic
July 16, 2017 4:07 pm

Then, along comes a virus two weeks from now that kills them all.

Owen in GA
Reply to  Proud Skeptic
July 16, 2017 10:25 pm

Spread by the researchers studying them…it’s all to protect them donchano…

July 16, 2017 4:18 pm

Hmmmm, I think I first read this story in about 1985. One of the hallmarks of junk science is that which was old is new again. I hope that the plants which the water bears eat are as tough as the water bears. No organism is tougher than its food source. The story was written by somebody who has watched too many cheesy sci-fi movies where the survivors are still eating canned food 50 years after the apocalypse.

Reply to  BCBill
July 16, 2017 4:47 pm

Yep, I see canned food in a post-apocalyptic movie, it gets turned off. Now, Twinkies I would be able to suspend my disbelief…

Reply to  BCBill
July 16, 2017 4:54 pm

Water bears are a diverse phylum and eat a lot of different things.

Reply to  Gloateus
July 16, 2017 5:56 pm

Do any of the things they eat come in cans? Are any of their food sources hardier than the tardigrade? I believe that most of them suck on mosses and algae.

Reply to  Gloateus
July 16, 2017 6:06 pm

There are many canned goods upon which post-Apocalyptic water bears could feast, assuming the cans be opened.
Most consume plants and algae or bacteria, but others eat animals smaller even than themselves, to include other water bears.

john harmsworth
Reply to  Gloateus
July 17, 2017 2:30 pm

At the end time, they will feast on the abundant, fat carcasses of climate scientists.

July 16, 2017 5:49 pm

So if tardigrades outlive mankind, who will care?

David Ball
July 16, 2017 7:50 pm

Interesting subject matter. Excellent “showing the knickers” of the falsehood wrought by the mighty PR monsters.
Great post, CTM, imho.
Incidentally, is Pr not the symbol for balonium on the periodic table?

July 16, 2017 9:04 pm

“able to survive for up to 30 years without food or water, and endure temperature extremes of up to 150 degrees Celsius, the deep sea and even the frozen vacuum of space.”
It is things like this that make the faith in Evolution seem very silly.
OK: someone has presented an argument for how the complex Human Eyeball may have evolved (pure after-the-fact speculation, but none-the-less a “fact” and a marvel of science).
How does a species evolve to survive NO food for 30 years?
Was there a genetic mutation that allowed it to survive for 10 years? Then this just edged out longer and longer, like the giraffe who could NOT live without a longer neck, but none-the-less lived?
Did this critter go through the selective reproduction pressure to survive deep space before or after the selective pressures to survive the scalding ocean vents?

Reply to  TheLastDemocrat
July 16, 2017 9:12 pm

The fact of evolution requires no faith. It is observed all the time everywhere scientists look. For that matter not just scientists, but laymen willing to see with open eyes and minds.
You however need to study biology before presuming to comment upon it, unless you enjoy making a laughing stock of yourself.
There is no speculation involved in the evolution of human (ie vertebrate) eyeball. Every step in its evolution is visible not only in the fossil and embryological records, but indeed at the molecular biological and genetic level. Please make the least little effort to educate yourself before spewing lies and nonsense out of total ignorance.
As for water bears, the resilience of various species to challenges of different kinds is based upon their adaptations to differing environments. No mystery. Just science.

Reply to  TheLastDemocrat
July 17, 2017 3:17 am

“How does a species evolve to survive NO food for 30 years?”
It doesn’t do much

Reply to  TheLastDemocrat
July 17, 2017 6:48 am

Spores can survive for thousands of years.

john harmsworth
Reply to  TheLastDemocrat
July 17, 2017 2:33 pm

Conditions of existence change constantly over time. If all creatures were built to fit only one niche and unable to adapt or evolve they would ALL be extinct by now.

July 16, 2017 10:05 pm

” ‘Without our technology protecting us, humans are a very sensitive species. Subtle changes in our environment impact us dramatically. There are many more resilient species’ on earth.”
Just a hundred years ago, human population was restricted to that narrow band between the Arctic Circle and Cape Horn, in areas from desert to jungle, and only elevations from just below sea level to 12,000 feet. How many of the ‘more resilient species’ are visible to the naked eye, much less more than a few inches long?

Reply to  Ted
July 17, 2017 2:20 am

Highest town in Peru is at 17,000 feet.

Reply to  Ted
July 17, 2017 2:23 am

And even a hundred years ago tens of thousand people were living north of the Arctic Circle (and even farming there, in Norway, Sweden and Finland)

Reply to  Ted
July 17, 2017 6:50 am

A narrow band that just happens to encompass almost 90% of the earth’s surface?

Reply to  Ted
July 17, 2017 4:13 pm

My apologies for not being facetious enough to go without the /sarc tag.

Harald Elvebakk
July 16, 2017 11:37 pm

Also Rolling Stones guitarist Keith Richards will survive.

Reply to  Harald Elvebakk
July 17, 2017 6:05 am

? Something to do with in-build chemical cocktail ?

john harmsworth
Reply to  Harald Elvebakk
July 17, 2017 2:37 pm

If in fact he is alive now. Could just be a convincing post mortem nerve thing that has him twitching and mouthing unintelligible sounds!

July 17, 2017 12:57 am

1. Wouldn’t the most resilient form of life have to be… what they eat? Since these do, in fact, not live off of raw chemicals and sunlight.
2. [snip. let’s not start that flame war in this thread.~mod]

Ed Zuiderwijk
July 17, 2017 1:19 am

But what, or who, will they eat?

July 17, 2017 6:56 am

Fascists doing what Fascists have always done. Rape the Taxpayer using Govt forced subsidies then producing a PR campaign to sell the theft as something other than theft.. The broken window theory on Steroids. Funny how it takes a big degree to break a window nowadays.

July 17, 2017 10:04 am

“Without our technology protecting us, humans are a very sensitive species.”
Hmm. What kind of technology did mankind have to protect it prior to the last century? How did we ever survive? Was it because CO2 levels have been far lower during man’s reign than in the past or is it that natural selection no longer matters to the genetic advancement of mankind and we now need technology to survive?
Perhaps he means psychological sensitivity. Certainly this applies to the foolish humans that have bought in to the fears of a climate catastrophe and demand ‘safe spaces’ to insulate them from being exposed to opposing arguments.

July 17, 2017 12:56 pm

Well, what do you know. The most indestructible life-form known to science, and I’ve consumed and destroyed legions of them.

Gunga Din
July 17, 2017 2:29 pm

Back when I worked in wastewater treatment I’d do a microscopic examination of the Mixed Liquor Suspended Solids. (If you ever find this liquor in a bar, go to a different bar!) I was looking for rotifers as an indicator of the health of the bacteria population breaking down the … well, you know. (Rotifers feed on them.)
Occasionally I’d see a water bear.
What are these last living things, water bears, supposed to be feeding on? Each other? Will there be saber toothed water bears?

July 19, 2017 12:09 am

Unfortunately, for the tough little tardigrades, there is a threat to their existence on Earth – the Sun! Within the next 1bn year the energy output from the Sun will steadily increase until the Earth is outside of the ‘habitable zone’ and the oceans start to boil away. Water may continue to remain deep within the Earth’s crust, however, so they and other microscopic creatures may continue to survive – until the Sun becomes a red giant in 4.5bn years from now.

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