Researchers recently found the protein responsible for sensing cold in animals, from primitive worms to late-evolved bipeds who read blogs. The protein has a close association with nerve cells. What the researchers did not discover were the obvious implications of what they did discover.
The cold-sensing protein does not raise an alarm when it feels cool. Only when the cold becomes a hazard does the protein jiggle neighboring nerves. What this obviously means is that the protein is aware of its environment and decides to raise a fuss only upon feeling the onset of frigidity. To be aware requires consciousness. To render a decision requires a mind. What is not required, obviously, is physiological wetware – that is, something resembling a brain. So, cold-sensing proteins illustrate that macromolecules can be conscious and thoughtful.
The researchers discovered the cold-sensing protein by fiddling the genes of Caenorhabditis elegans, a tiny (1 mm) free-living temperate soil nematode. The protein was found by removing the gene which provides the instructions for making the protein. Without the gene, no cold-sensing protein, and thereby no cold avoidance behavior.
Ms. Elegans was the first multicellular organism to have its whole genome sequenced by humans, which is like having your entire wardrobe for living catalogued. Worms don’t bother with fashion magazines, so this distinction has gone unremarked among the worms of the world. Besides, all those humans do is step on or otherwise abuse worms, so why should a worm care about such hairless ape trivia?! But I digress.
That proteins associate with and inform others in a consensual way indicates a tremendous functioning bureaucracy. That specific blueprints exist for producing such proteins in faraway factories (ribosomes), then moving them into neighborhoods where they are needed further shows far-sighted management with impressive precision in demand-based production. Humans have not come anywhere near this level of operational efficiency, and what we are referring to is what happens inside a primitive worm as a regular procedure. The researchers involved in the work failed to mention the incredible coherence behind Nature which must diligently operate to keep worms, and everything else alive, in good working order; not to mention providing an orderly and seemingly comprehensible environment – Nature itself – for the worms to enjoy.
Cold sensing is just a hobby for these proteins. Their primary occupation is as a glutamate receptor. Glutamate is an anion of glutamic acid – a charge ion of an amino acid used by almost all living organisms. Animals with nerve cells use glutamate as part of the chemical complex for sending signals between cells – a neurotransmitter (which properly ought to be called a neurotransceiver, but modern scientists are notoriously sloppy in their terminology as well as in ignoring the subtle but rather obvious implications of their observations and experimental results).
The evolutionarily related family of animal glutamate proteins has a counterpart in plants. Plants use proteins which work with glutamate as a medium for sensing and signaling the statuses of nitrogen levels and nitrogen/carbon ratios; key elements in plant vitality and growth potential.
Unlike animals, there is no single plant protein responsible for sensing cold. Temperature sensing in plants is much more sophisticated than in animals, as plants closely monitor thermodynamic flows and trends to plan resource allocations based upon forecast weather patterns.
By comparison, animal reactions to the cold are simple: find warmer soil if you are a worm or put on a coat if you are standing on top of soil with worms searching for warmer soil. You may wonder how fashionable that coat is. The worms don’t care.
Sources:
Jianke Gong et al, “A cold-sensing receptor encoded by a glutamate receptor gene,” Cell (29 August 2019).
“This protein is how creatures sense cold, researchers discover – and it’s found in organisms ranging from tiny worms to humans,” University of Michigan Life Sciences Institute (29 August 2019).
Romola Davenport, “Glutamate receptors in plants,” Annals of Botany 90(5): 549–557 (November 2002).
Björn Lárus Örvar et al, “Early steps in cold sensing by plant cells: the role of actin cytoskeleton and membrane fluidity,” the plant journal (25 December 2001).