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.  

Götzen-Dämmerung: Notes on Wandering Wombs, Spontaneous Generation, Bodily Humours and the Ancient Greek Soul

Sounding out idols of the mind since 1888 

 

I. 

 

It's easy (and thus tempting) to look back on humanity's past and smile at some of the odd things that people - including philosophers and men of learning - used to believe. 

 

I've already written, for example, about the theory of maternal impression - click here and here - but thought it might be interesting to briefly mention three other ancient truths that we now know to be false [1] ...

(i) The Wandering Womb

Belief in the wandering womb (as a cause of hysteria) can be traced all the way back to the ancient Greeks, though it persisted as a popular idea in European medicine well into the medieval and early-modern period. 

 

For celebrated physicians like Aretaeus of Cappadocia, writing in the 2nd century AD, the uterus was a free-floating organ which resembled an autonomous creature happily living within the female body, sensitive to smells and always in search of fluids to sustain it. 

 

It wasn't until our knowledge of anatomy improved from the 16th-century onwards that this idea of a wandering womb began to slowly lose credibility and female hysteria would eventually become a condition associated with the mind, rather than the uterus [2].      

 

(ii) Spontaneous Generation 

 

The theory of spontaneous generation held that living creatures (such as fleas and maggots) could arise from non-living matter (such as dust and decomposing flesh) and that such processes were all part of the natural order [3]. 

 

Again, we have the ancient Greeks to thank for this amusing idea. 

 

For it was Aristotle who synthesised earlier explanations provided by the natural philosophers [φυσιολόγοι] for the mysterious appearance of organisms, into a coherent theory which would be taken as a matter of scientific fact for the next 2000 years (it wasn't until spontaneous generation was disproved by Louis Pasteur and others in the 1850s, that the term fell out of favour within scientific circles).  

 

 

(iii) Bodily Humours 

 

Even the father of Western medicine, Hippocrates, subscribed to a few mistaken notions, central amongst which was the idea that vital bodily fluids (or humours) determined human health and disposition. 

 

Again, this theory persisted well into the modern era as doctors down the centuries vainly attempted to balance blood, phlegm, and two types of bile (black and yellow), in the belief that any excess or deficiency of any one of these four humours would result in illness or a bad character. 

 

It wasn't until the advent of germ theory, which demonstrated that many diseases previously thought to be humoral were in fact caused by pathogens, that physicians were able to move on (though such ideas persist in those parts of the world that still practice traditional medicine).  

 

II.

 

The point I'm trying to make here is twofold:

 

Firstly, I'm trying to illustrate how even the best minds can get things wrong and how certain ideas can become so ingrained within our thinking over such long periods of time, that they become unquestioned articles of faith and common belief (doxa). 

 

Secondly, I'm trying to encourage readers not to simply look back and laugh at the mistaken ideas of antiquity, but ask themselves what cherished beliefs they might subscribe to as truths which will one day be exposed as fallacious and fantastical ...

 

I'm thinking, for example, of the still widespread belief in the psyche - a concept often used by people who think mind is something separate from (and other to) brain activity, but who still wish to sound rational rather than religious and so try to avoid words like soul or spirit. 

 

Like all of the ideas examined above, this one can be traced back to the ancient Greeks; ψυχή is central to the philosophy of Plato, and Aristotle wrote a hugely influential work on the subject. Indeed, the latter's theory of the three souls - vegetal, animal, and human - would dominate the field of psychology until the 19th century.

 

I'm reminded at this point of Nietzsche's realisation that one day we will have to overcome the last trace of Greek influence on our thinking - as beautiful and as profound as it may have once seemed - and take a hammer to all the old idols of the mind [4] ...  

 

 

Notes

 

[1] The big one, of course, would be God, but I can't imagine anyone reading TTA needs reminding of the circumstances surrounding his death.  

 

[2] Today, of course, hysteria is no longer a clinically recognised condition and no one thinks the womb a thirsty roaming animal.  

[3] The imaginary process by which life was believed to routinely and rapidly emerge from non-living matter (such as the seasonal generation of mice and other animals from the mud of the Nile), is sometimes referred to as abiogenesis. It should be noted, however, that spontaneous generation has no operative principles in common with the modern hypothesis of abiogenesis used within evolutionary biology, which argues that life arose from simple organic compounds over a time span of many millions of years.

 

[4] It might be argued that the analytic philosopher Paul Churchland has pushed philosophising with a hammer to its extreme in his eliminative materialism, which, as Nietzsche might have said, is radikal bis zum Verbrechen. 

      Churchland is convinced that neuroscience will eventually spell the end for psychology, which he thinks a fundamentally defective and confused theory. The problem, however, is whilst with hindsight we can see the inadequacies and absurdities of ancient theories, it's not so easy to see these within contemporary theories that remain part of our Lebenswelt and which the majority of people still believe to be not merely true, but blindingly obvious to anyone with common sense. 

      Readers interested in Churchland's work might like to see his crucial essay 'Eliminative Materialism and the Propositional Attitudes', in The Journal of Philosophy, Vol. 78, No. 2 (Feb 1981), pp. 67-90. I refer to this essay in a previous (and related) post to this one: click here.