Homochirality: Reflections on Mirror Life

Above: Harry Worth demonstrating the comic potential of a mirror image in 1962 

Below: an illustration by N. Burgess showing the chemical structure of a naturally occurring 

amino acid with its mirror image, in Science vol. 386, issue 6728 (2024)

 

 

I. 

 

As if we didn't have enough to worry about, a concerned group of senior scientists are now warning of the unprecedented risk to life presented by research into so-called mirror life - i.e., the production of bacteria constructed from mirror images of molecules [1].

II. 

 

Apparently - and this is the first I've head of it [2] - all known life is homochiral and the molecules necessary for life "can exist in two distinct forms, each the mirror image of the other" [3]. 

 

Thus, whilst dexterous DNA is made from nucleotides on the one hand, sinister proteins are made from amino acids on the other. If you artificially reverse this process, you'll still produce life, Jim, but not as we know it [4].

 

 

III. 

 

Unfortunately, it seems that such experimental work could, potentially, put humans, animals, and plants at risk of deadly new infections, spread by synthetic organisms against which there would be no natural immunity. 

 

What's more, beyond causing lethal diseases, "researchers doubt the microbes could be safely contained or kept in check by natural competitors and predators" [5]. And don't think for one moment that present-day antibiotics will come to the rescue ...

 

 

IV.

 

Still, don't let any of this spoil your Christmas. 

 

Try to remember the old nihilist adage that, in the long term - whether mankind chooses to play fatal games with mirror matter, dark matter, or antimatter - nothing matters. The essential truth of the universe is ... extinction [6].   

 

 

Notes

 

[1] Concerns are raised in a 299-page report that is discussed in the journal Science, Vol. 386, Issue 6728 (Dec 2024), pp. 1351-1353. Click here to read online. Those who wish to plough through the full report will find it in the digital repository at Stanford: click here.   

 

[2] Despite my never having heard of mirror life until a few days ago, it seems that the possibility of such was already being discussed by Louis Pasteur back in the mid-19th century.

 

[3] Ian Sample, '"Unprecedented risk" to life on Earth: Scientists call for halt on "mirror life" microbe research', in The Guardian (12 December, 2024): click here. 

      

[4] It is unknown whether homochirality emerged before or after life; whether life must have this particular chirality; or indeed whether life needs to be homochiral at all. 

 

[5] Ian Sample ... The Guardian (12 Dec 2024).  

[6] As Nietzsche reminds us, even human knowledge and intelligence is only a passing phenomenon that arose by chance on a planet revolving around an average-sized star in a remote corner of the universe. Eventually, the star will die and so will the clever animal Man. In other words, even mind won't matter in the long run. 

      See Nietzsche, 'On Truth and Lies in a Nonmoral Sense', essay in Philosophy and Truth, ed. and trans. Daniel Breazeale, (Humanities press, International, 1990), p. 79.  

Why Arachnophobes Have Even More Reason to be Fearful Than They Ever Imagined

D. folliculorum as seen under an electron microscope 

(Credit: Power and Syred / SPL)

 

 

I.

 

Like many other people, a friend of mine - let's call her Miss Muffet - has an intense and irrational fear of spiders: If one were ever to crawl on me, I would die, she has said on more than one occasion. And so I've always resisted the urge to inform her about the existence of a genus of skin mites that live on the human face called Demodex ...

 

 

II.

 

Commonly known as face spiders [1], these tiny arachnids are divided into two species; those that live in hair follicles (D. folliculorum) and those that live in the sebaceous glands connected to hair follicles (D. brevis). 

 

Each has a semi-transparent elongated body, covered in scales, and consisting of two fused segments and eight short legs attached to the first body segment. Each also has a little mouth adapted to grinding up dead skin cells and sucking up the oils which accumulate in the hair follicles. 

 

Sleeping by day, at night they like to slowly stroll around the surface of the face in the hope of finding a mate. Once fertilised, eggs are laid inside the hair follicles or sebaceous glands and take 3-4 days to hatch. The larvae develop into adults within a week and then live out their brief lives within the facial pores of their human host.     

 

It's important to note - before you start scrubbing your face like a lunatic - that Demodex pose no threat to our wellbeing; unless they gather in unusually large numbers, in which case they may provoke certain skin conditions that necessitate a visit to the dermatologist. 

 

But that's rare; most people - including my friend Miss Muffet - live blissfully ignorant of the fact that their face is crawling with hundreds - maybe thousands - of microscopic mites, feasting and fucking [2].  

 

Notes

 

[1]  Actually, they don't look much like spiders and the name Demodex - derived from the Greek terms δημός and δήξ - gives us a better idea of their appearance (i.e., fat-bodied and fat-loving little worms). I'm not sure this will do much to calm my friend, however. 

[2] Interestingly, whilst Demodex might eat, sleep, and reproduce on your face, they're not shitting on it in a conventional sense as they possess no anuses via which to do so. What happens, rather, is that they retain their waste matter throughout their lives, then, at death, there's one large release of the stuff in what some describe (somewhat exaggeratedly) as an explosion of shit. It's thought that this might cause skin irritation and/or inflammation in some people.