Did life on Earth emerge spontaneously from primordial pools, or fall from the cosmos with meteoric fanfare? Not sure? Ponder the Tardigrade.

Tardigrade or “water bear” are the only known life form capable of surviving the airless vacuum of space and lethal radiation levels. Remarkable yes, mind blowing when considered with additional facts – they can survive six times the pressure of our deepest ocean, frozen to absolute zero (-273 C) or boiled above 150 C. Dehydrate a Tardigrade for years then add water, voila – business as usual. Eventually they do succumb to old age, but don’t hold your breath, life expectancy is 200 years.

Discovered by Italian Lazarro Sapallanzani in 1773, water bears are thought to have inhabited Earth for 530 million years. Measuring 0.5 mm – 1.2 mm in length, they can be found anywhere on Earth.

The Tardigrade begs evolution to explain why. Evolution adapts species for life on our planet, why would a species need to withstand ravages of time and space?

Magnified 500x: The green fronds seen here are tiny moss leaves


15 thoughts on “Tardigrade

    • Science is asking/exploring why a species on Earth would evolve with characteristics necessary to survive in space. One theory being they originated in space, and found their way to Earth in meteors.

      • I understand that. I’m just not convinced that the tardigrades get us any closer to finding out. They’re interesting little buggers though. However, though they’re very hardy, they aren’t considered extremohiles. ‘They are not considered extremophilic because they are not adapted to exploit these conditions. This means that their chances of dying increase the longer they are exposed to the extreme environments,whereas true extremophiles thrive in a physically or geochemically extreme condition that would harm most other organisms.’

      • That’s true but although extremophiles thrive around underwater volcanic vents or in Arctic ice they couldn’t survive the radiation or vacuum of space. Extremophiles adapted to life in some bat shit places, Tardigrade are everywhere without reason or logic. Why would a minuscule creature paddling about a pond in Wisconsin need to tolerate extreme doses of radiation, ridiculous temperatures or extreme pressure? I’m not sold on the theory, yet ponder the implication with wonder. 🙂

      • Cockroaches are cheeky little shits, no argument there but not even close to Tardigrade when it comes to withstanding radiation.Cockroach can live for up to a week without a head, Tardigrade can be dormant, blowing in the dust for up to 100 years then come back to life with a single drop of water.
        Can’t say where they came from, all I know is they kick ass. 🙂

      • One of the best things about doing anima;l physiology at unversity was I got to chop the heads off cockroaches. Bad ews was i had to put my hand in a sweetjar full of the little horrors.. The fact remains that cokroaches don’t need to be so radiation resistant. They just are.

  1. If the purpose of evolution is the ultimate survival of the fittest than this cuty looks like a winner. Imagine that: the final state of the universe is that where all planets are populated by tardigrates. All other life has either expired or occasionally a new tree of life flares up to die in time again.

      • It did occur to me that we may be doing the universe a favour by sending spacecraft full of tardigrades into a random direction and let evolution do its job.

        But even the tardigrades have a family tree. Their multi-cellular parents would have had single cellular grandparents who themselves would have great grandparents in the form of proteines.

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