Are tardigrades the most indestructible animal on earth? - Metafact

Are tardigrades the most indestructible animal on earth?

A news report suggests tardigrade (water bears) to be the most resilient animal ever. Can experts/evolutionary biologists confirm this please. Thanks

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Affirmative

From 8 verified experts:

5 answered Likely or higher


Doc Roc has answered Likely

An expert from McMaster University in Evolutionary Biology, Astrobiology

the answer to that question, of course, depends on what is intended by ‘indestructible’

tardigrades exhibit amazing resilience, arguably the most-impressive among animals

studies reporting surviving in a desiccated, ametabolic state for a century (contested) or in a frozen state for 30 years (uncontested) are remarkable

some data about tolerance to some ‘destructive’ factors are presented immediately below in point-form

·        desiccation: specimens in some species can be dehydrated, losing essentially all water, with reanimation following rehydration

·        radiation: 5000 Gy gamma radiation (the radiation type that, in the Marvel Universe, transformed David Banner into the Incredible Hulk; for reference, 1 Gy = one joule radiation energy per kilogram; 5-10 Gy kills humans)

·        temperature (low & high): -273 ØC (dehydrated) and -253 ØC (hydrated, for 35 minutes) have been reported but -180 ØC (dehydrated, 14 days) definitely is possible & 110-151 ØC (30 minutes)

·        specimens have been sent into orbit aboard spacecraft, showing tolerance to extreme conditions (vacuum, low temperature, high radiation) with extents determined by combinations (e.g., vacuum & temperature shielded from radiation, etc.) but surviving nevertheless

all these data are conditioned on the fact that only 1-2% among the 1400 species have been ‘tested’ experimentally; tolerance depends on multiple factors (including the state in which individuals are tested – e.g., hydrated or dehydrated – and usually only one extreme factor is tested in an experiment); and, of course, active individuals must eat to persist (i.e., specimens could be ‘destroyed’ through starvation)

Answered over 4 years ago

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Doc Roc

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