musingsonwomenshealth.com

Reflections on 40 years as a doctor in Women's Health

An interesting thought


An interesting question: what is extinction; I mean, really? When I was younger and further away from it myself, the answer was obvious: extinction meant something was no longer alive -or, perhaps more generally, even copies of whatever it was, no longer existed either. Given that I have children who (I hope) are partial copies of me, my own disappearance seems less onerous… although who am I kidding?

However, I was somewhat mollified when I happened upon an essay, titled Reversing Extinction, by Sadiah Qureshi, a historian at the University of Manchester.[i] Actually it seemed more about defining extinction, rather than quibbling about ways to reverse it, so it may be that an octogenarian like me is not out of the woods yet.

But, be extinction as it may, although I’ve had many good hikes in my life’s forests, I still decided delve further into the interstices of her essay with few regrets… I mean, you never know, eh? The author distinguished between true extinction -i.e. gone forever-  and ‘evolutionarily torpid’: when an animal’s tissues and cultured cells persist in a state of cryopreservation, and so is not really extinct. ‘In other words, the death of the last living animal is not an ending, merely a pause.’ Still, ‘what distinguishes being alive from existing as dormant genetic material?’ That seemed like an important question, and since I was already impressed with her use of the phrase ‘evolutionarily torpid’ I realized I was hooked -that’s not the same as being rabbit-holed is it?

At any rate, I’d always wondered how you could ever tell whether or not something was really extinct? I cast my mind back to what little remained of my university Philosophy and Logic stuff (of course, I also had a quick glance at Wikipedia to make sure I’d remembered correctly): Deduction is inference deriving logical conclusions from premises known or assumed to be true; Induction on the other hand, is inference from only particular evidence (a small sampling size) to a universal conclusion. So, if I see six crows and they’re all black I can -but shouldn’t- induce that all crows are black ( I mean, suppose there is an albino crow in another tree?)… or have I got my never- really-understood logic mixed up again? Anyway, I kept wondering whether either one of those methods was sufficiently reliable to decide if something was extinct just because it hadn’t been seen for a while.

The other thing is whether what might be reconstituted from cryopreserved tissues would just be a clone, and not the same as the individual from whom it was derived. Almost for sure, none of my revived tissue would know where I went for vacation in, say, 1988 or know the nicknames I gave my children when they were young. Of course maybe forgetting and never-knowing amount to the same thing in the end.

It also made me wonder about trying to de-extinct the remains of Martha, the last known passenger pigeon who died on 1 September 1914 at Cincinnati Zoo; in their heyday, there were apparently millions and millions of passenger pigeons ‘whose wings would darken the morning sky’. And anyway, even if you could resurrect Martha’s genes, they probably wouldn’t remember the flight path of her ancestors anymore; and as well as feeling lost, I suspect she’d be lonely, too -and like the protagonist in one of those apocalyptic films realize she was the last person alive on the planet; there’d be nobody to complain to and nobody with whom to share her shame about not knowing which direction to fly. Still, it begs the question about what being alive really means, and even if you managed to de-extinct something precisely, could it still survive and thrive in what would likely be a foreign ecosystem for it?

Of course, taking a step back, what does a normal (not yet extinct) population do when it breeds? In a sense it just redistributes its genetic material in differing amounts and combinations; that seems much different from de-extincting where you’ve only got one set of chromosomes to work with. I mean even if you managed to de-extinct two individuals from the only remaining DNA sample, and they managed to find each other attractive enough to marry or whatever, wouldn’t it be the same as marrying your sister…? And if it is (sort of) then what’s the point? How would it resupply genetic diversity and avoid the burden of, say, recessive genetic disorders to the resulting flock?

But, I suppose nowadays I’m sure the reconstitution of the ‘extinct’ genes it would be done differently: it would likely rely on the different but maybe close-enough genes of whoever was chosen to be the surrogate; maybe by promising some popcorn (it’s what my mother used to use) to a volunteer ‘street pigeon’ from one of our parks or city streets- but even with such perfidy, how could you call the result a passenger pigeon? I mean do we really want more pigeons? To paraphrase Juliet’s line in Shakespeare’s famous play, wouldn’t a pigeon by any other name, still be a pigeon?

I don’t want to come across as an elderly, head-in-the-sand scientific curmudgeon, but apart from the involved geneticist maybe winning a Nobel Prize, what has been gained in the process? Certainly not enough wings to again darken a morning sky -which romantic picture I assume would be the reason for the attempted de-extinction in the first place… Or, is that really the reason?

Well,  Ben Novak of Revive and Restore, a scientist who is trying to bring back the passenger pigeon, offers a different perspective on the effort: ‘In De-extinction (2018), he defined the process as ‘the ecological replacement of an extinct species by means of purposefully adapting a living organism to serve the ecological function of the extinct species’. According to this definition, the world’s first successful de-extinction happened decades ago, with the revival of the peregrine falcon in North America in the late 20th century. Okay… well I guess I’m okay with that… ‘Since public outcry had led to a DDT ban two years earlier, the new birds thrived: a new genetic lineage who performed the same ecological function as their lost kin.’ And those birds are hybrids… I mean they’re almost as good, eh?

Still, it seems like an incredibly expensive time consuming way to reverse the extinction. Perhaps, as Sadiah Qureshi suggests, ‘Instead of reducing life on Earth to genomes or existences that should serve our needs, we would gain far more by recognising species as ways of being with their own needs and rights, with their own forms of kinship and community, and the right to live as they are. Instead of relying on technology to create new lifeforms to assuage our guilt, we could truly rethink how we treat life on Earth.’

I would certainly not want to be de-extincted; I have already strutted and fretted my hour upon the stage, and despite the lack of applause, I would be quite happy accept that the wick on my candle had run its course. Unless, I suppose, I get to play Macbeth himself next time…

[i] https://aeon.co/essays/de-extinction-is-redefining-what-it-means-to-be-alive

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