Hey Thoughty2 here.
Have you ever been cold?
And I don’t mean when your nipples get a bit frosty, I’m talking about freezing,
frostbite-inducing cold.
The coldest settlement on Earth is Oymyakon in Russia where temperatures average -50 degrees
C and can drop to -71 degrees.
At those temperatures if you cried, the tears would instantly freeze your eyes shut, blinding
you.
And without proper clothing you would be dead within the hour.
But there’s a living organism that’s been with us long before the dinosaurs, a creature
that has survived all five mass extinctions, that would find these frigid temperatures
no problem at all; the 600-million-year-old Tardigrade.
Tardigrades are micro-animals, approximately 0.5mm in length.
They have a digestive tract and eight little legs but that’s where the similarities to
other animals ends.
Unlike the residents of Oymyakon who would perish in minutes if they went outside without
at least 20 coats on, the Tardigrade can survive at temperatures as low as -272 degrees Celsius.
That’s one degree above absolute zero, the lowest temperature physically possible within
our universe.
Even when it can’t get any colder, the humble Tardigrade just keeps on going.
The Tardigrade, sometimes called a “water bear” because of its little claws, is the
most indestructible animal on the planet.
They are practically immortal.
As well as surviving the lowest temperatures in the universe, tardigrades can survive heat
up to 150 degrees Celcius, pressure six times greater than those found in the deepest ocean
trenches on Earth and ironizing radiation 100 times higher than the lethal dose for
a human.
This little guy could literally chill out inside the reactor core at Chernobyl and be
completely fine.
But most amazingly of all, and unique to this creature, the tardigrade can go without any
food or water for over 30 years.
But how?
Well, they die.
The tardigrade can dehydrate itself, like a ready meal from back to the future, to the
point where it is less than 3% water.
The human body is 60% water.
In this ultra-deep hibernation, known as cryptobiosis, the tardigrade has no need for any sustenance
and can sustain this state for 30 years, after which it simply re-hydrates itself and comes
back to life, to forage for food and reproduce, if it’s in the mood.
They don’t technically die whilst dehydrated, it’s more like a state of suspended animation.
A single tardigrade can live to be over a century old.
NASA sent thousands of tardigrades into space where they were sent out into the total vacuum
of space for days on end, where they were subjected to massive solar radiation.
They came back alive and well.
What’s more some of the tardigrades had given birth to lots of little tardigrade babies,
out in the vacuum of space, the most inhospitable place imaginable, and the space-babies were
also completely normal and healthy on their return to Earth.
To date, they are the only animal we know of that has gone defenseless into the total
vacuum of space and lived to tell the tale.
Some scientists even speculate that Tardigrades are aliens and actually came to our planet
from another planet such as Mars, over a billion years ago.
Because their DNA is strange, and unlike anything we’ve seen before.
But these aren’t some rare beast exclusively found under a single rock in Antarctica.
Tardigrades are everywhere, odds are you are only a few metres from a Tardigrade right
now.
That’s because they live in mosses and lichens, and where do you find moss?
Well it only covers the entire planet.
They feed on plant cells, so the moss and lichen provides the perfect, cosy and damp
home.
Although they mostly eat plants, tardigrades have been known to cannabalise each other.
And they’re not exclusive to moss either, they have also been found at the top of the
tallest mountains in the Himalayas, inside hot springs in Japan, at the very bottom of
the ocean and deep within the Antarctic wilderness.
So basically, everywhere.
Tardigrades just don’t care about anything.
One of the most amazing tardigrade abilities is how they deal with the extreme cold.
At extremely low temperatures ice crystals can form inside the cells of a life form,
ripping apart the cell’s vital components such as the DNA, which is always fatal to
that organism.
Some animals that have evolved to cope with the extreme cold.
For example, fish in cold regions make antifreeze that lowers the freezing point of their cells,
stopping ice from forming and preventing fatal frost damage.
Scientists have found no evidence of antifreeze inside tardigrades, they’re way too badass
for that.
Instead tardigrades simply tolerate ice forming inside their cells, they just don’t care.
Amazingly, they are able to quickly repair any damage caused by the ice crystals by rapidly
creating antioxidants.
They also produce nucleating agents that encourage ice to form around the cell instead of inside
it.
But what is truly baffling about this tiny immortal bear, is how it deals with extreme
heat.
At temperatures as high as 150 degrees Celcius, a cell’s membrane should unravel and it
would be torn apart, this would happen to all cells simultaneously, quickly killing
the cells’ host.
Tardigrades have been heated to 150 degrees C for 15 minutes and what happened?
Absolutely nothing.
It just carried on scuttling around as though it had been quietly sunbathing.
Scientists still have no idea how they do this, it shouldn’t be possible for cells
to survive at these temperatures, yet they do.
Naturally, scientists are now studying the microscopic tardigrade to try and unlock the
secrets of its immortality.
Maybe we can steal a secret or two for ourselves.
Thanks for watching.