Tardigrades
Almost indestructible water bears. (The Bus 5.16)
Welcome aboard The Bus!
THURSDAY ARCHIVE EDITION - FIRST PUBLISHED (1.11) 12 MAY 2022
The Stop
Tardigrades, also known as ‘water bears’ or ‘moss piglets,’ are any of over 1200 species of microscopic and near microscopic invertebrates.1 They can be found on every continent in numerous habitats - damp moss, flowering plants, sand, and in both fresh and sea water. While their widespread adaptation is remarkable in itself, tardigrades also have the ability to withstand extremely low temperatures, extreme dryness, the vacuum of space - and exposure to radiation. In fact, tardigrades - according to researchers at the University of Wisconsin (Madison) - have survived all five of the mass extinction events on Earth since the group evolved roughly 500,000,000 years ago.
Discovered and named ‘little water bear’ by the German zoologist Johann August Ephraim Goeze in 1773,2 tardigrades ‘have a well-developed head region and a short body composed of four fused segments, with each segment bearing a pair of short, stout, unjointed limbs generally terminated by several sharp claws.’3 This creature - with no circulatory or respiratory systems, bones or spinal column4 - withstands extreme environments by becoming a dehydrated ball known as a ‘tun.’ This is an almost death-like state5 they create by expelling more than 95% of their body’s water while retracting their heads and legs and curling into a tiny ball.
In this state, the tardigrade’s metabolic activity drops to around 0.01% of its normal levels. Additionally, its cells are protected by water-soluble proteins unique to these creatures.6 When once again exposed to water, the tuns are rehydrated and the tardigrades revive, returning to their daily business.7
Remarkably, this daily business could potentially extend for quite a while. A 2017 Harvard and Oxford University study looked at the probabilities of extinction created by various astronomical events - asteroids, supernova blasts, gamma ray bursts, etc. - and found that while these would wipe out the Earth’s hardiest species - including humans - the tardigrades would inevitably survive.8
For a seriously geeky in-depth look at tardigrades, you can access the World Tardigrada Database, a rabbit hole documenting every one of the 1200+ species: Tardigrada
For a very in-depth look at all things tardigrade, visit the Goldstein Lab at the University of UNC Chapel Hill: Goldstein Lab (UNC)
For a less in-depth look, see this article about tardigrades from The Guardian: Tardigrades: Natures Great Survivors
And for a video which just tells you what you need to know, see this animated one from Ted-Ed: Meet the tardigrade, the toughest animal on earth
The Detour
Today’s Detour is to an article from Bon Appetit about predicted changes in food over the next 100 years. A group of scientists, building on what is and is about to be available regarding food technology, provides a sample menu for a dinner in 2032 and again in 2042. A group of science fiction writers offers a speculative menu for the year 2122. Yum. Check it out:
What Dinner Will Look Like in the Next 100 Years
The Recommendation
Today’s Recommendation is Merlin Sheldrake’s9 Entangled Life. The subtitle pretty much sums up the book - How Fungi Make Our Worlds, Change Our Minds, and Shape Our Futures. It is a fascinating look at many manifestations of fungi - and opens a perspective to a world that is all around, under, above and in us.
Reviews:
The Sounds
I’m not sure what the weather is like where you are, but at the moment in southern England spring is rather autumnal and today’s playlist reflects this reality:10 ‘Hell N Back’ (Bakar, 2023), ‘Cosmic Dancer’ (T Rex, 1971), ‘Jersey Thursday’ (Donovan, 1965), ‘Any Major Dude Will Tell You’ (Steely Dan, 1974) and ‘Miss Summer’ (ODIE, 2020). Enjoy!
The Thought
Today’s Thought is a word - one which might make you say, ‘I never knew there was a word for it - but I’m glad there is’:
“Kakistocracy: Government by the least qualified or worst persons.”11
If you have a thought on this Thought - or any part of today’s issue - please leave a comment below:
And that’s the end of this Stop - I hope you enjoyed a brief diversion from your regular journey!
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Until the next stop …
They are tiny - growing to about 1 mm (0.04 inch) or less in size.
Tardigrades received their name (generally meaning ‘slow stepper,’ as it toddles about) from the Italian biologist Lazaro Spallanzani in 1780.
For the source of this quote and other information for this Stop, see Tardigrade (Britannica). Information has also come from Tardigrade (Live Science).
Despite having none of those, it does have a nervous system which communicates between its brain and the rest of its body.
This is also known as cryptobiosis - a ‘state of extreme inactivity in which all metabolic procedures stop, preventing reproduction, development and repair.’ Other organisms with this capability include the majority of plant seeds and many microorganisms, including yeast. See Weird Science: Cryptobiosis
Cleverly known as … tardigrade disordered proteins (TDPs).
Some tuns have been revived after decades of dehydration, though a 1948 Italian claim of reviving one from a piece of 120 year old moss has not yet been repeated. As for the radiation claim, it appears some species have evolved with a sort of natural fluorescence that changes UV radiation into harmless blue light.
For a rather sobering (and technical) read, the report can be found here: The Resilience of Life to Astrophysical Events
Yes, that really is his name and he holds a PhD in tropical ecology from Cambridge. His father is the controversial scientist-turned-parapsychologist/philosopher Rupert Sheldrake. As child he, his brother (Cosmo) and his parents hung out with such people as Terrance McKenna, himself no stranger to the power of fungi (more on McKenna in a future Stop). In Underland (The Bus Issue 1.3 - Demeter) Robert Macfarlane meets him for an enlightening walk in Epping Forest. It really is all connected.
I didn’t plan this mix to reflect this feeling, but it was definitely present as I tested it wandering through the woodland behind our house this morning. Great tracks all, though my particular favourites are the ones by Bakar (introduced to me on Monday’s school run by my daughter) and Steely Dan. Enjoy - and here’s hoping the weather improves!
From Greek: kakistos (worst), the superlative of kakos (bad) + -cracy (rule). Ultimately from the Indo-European root kakka-/kaka- (to defecate), which also gave us poppycock and cacophony. Earliest documented use: 1829. (wordsmith.org)
😂 Kakistocracy - finally, a name for that quotidian feeling!
I second your recommendation of ‘Entangled Life’. Read it and never take fungi for granted again.