Inheritance and environment's impact on ethics

Once discounted insights are now found important and have ethical consequences. Andrew Davison concludes his series on biology’s current developments.

Andrew Davison

Andrew works at the intersection of theology, science and philosophy. He is Canon and Regius Professor of Divinity at Christ Church, Oxford.

A wall tile shows a 1940s woman tend a stove below a washing line.

A commemorative tile honours Dutch woman who made 'something out of nothing. during the hunger winter.

Peter de Wit (FaceMePLS), CC BY 2.0, via Wikimedia Commons

There’s no more exciting work in biology at the moment than thinking about organisms in terms of their environment. That’s a crucial part of the lively current scene in evolutionary thought (which I described in my previous article), and part of how a new generation of fascinating writers is urging us to throw off the overly narrow perspectives of the twentieth century. It’s not that Darwin’s fundamental insights were wrong, just that some of his followers took them to rule out, or discount, features of biology that turn out to be real and important.

In fact, Darwin was often ahead of the game here. He was more interested in cooperation between species, for instance, than many writers who went on to champion his ideas. He wrote brilliantly about the relationship between moths and orchids, for instance, and between plants and earthworms. Similarly, as Jessica Riskin has recently pointed out, he never dropped the idea that what organisms do during their lifetime affects what they pass on to their offspring (what he called ‘use and disuse’). For much of the twentieth century, that idea, of passing on of acquired characteristics, was biological heresy, but today it’s making a comeback.

The excitement in contemporary evolutionary biology can usefully be gathered under two headings. Alongside ‘organism and environment’, there’s also ‘extended heredity’, although the two are closely related on some points. They’re both important as part of the sort of discussion presented on this site – run in conjunction with the Church of England, of all things – not just because it’s good for religious institutions to demonstrate enthusiasm for science, but also because they’re full of ethical consequences.

Passing on to the progeny

Take ‘extended inheritance’: extended, in the sense that there’s so much more that’s inherited from parent to child than just a DNA sequence. For one thing, every organism bequeaths a world to its progeny, which means a world that’s at least somewhat adapted: at least a little (as with some bacteria, although others are adept at ‘ecosystem engineering’) or massively, as when a beaver completely changes its surroundings by building a dam, or when human beings cover the Earth with marvellous and terrible things. The transformed landscape of the beaver and the human being, even of the bacterium, is part and parcel of what they each pass on to their progeny, and therefore part of biological inheritance. That really puts the environment back at the centre of our thinking about organisms and evolution.

Taking a wider view than genes-are-all-you-pass-on has no lack of consequences. In their accessible and endlessly fascinating 2018 book Extended Heredity, Russell Bonduriansky and Troy Day show that narrow-mindedness on that front has had terrible consequences. They see it behind the Thalidomide birth defect tragedy, for instance, and the strange unwillingness of medics, in the middle of the twentieth century, to take the dangers of foetal alcohol syndrome seriously. If it’s a matter of scientific dogma that all that matters is what genes parents give to their offspring, other factors – like bothering to monitor what effects alcohol have on pregnant women and developing child, or the effects on them of a new medicine – don’t look as important as they should.

Genes aren’t everything, especially in the developmental phase (from conception through childhood and adolescence). Throughout that period, in particular, genes and environment dance an intimate tango, with genes turning on and off in response to its experience of its environment, before and after birth. Moreover, recent science shows that what happens to you during your lifetime can even be passed onto your offspring, and even to their children after them.

That flies in the face of the idea that all you have to pass on is the genetic hand of cards you were delt at conception (or its equivalent, for instance for a plant). On that hallowed view, the most that life has to offer from that moment on is testing your ‘fitness’, to see whether you manage to pass those genes on, or not, or how abundantly. But that’s far too limited a picture. We don’t just pass on genes; we also pass on the pattern of how genes are tagged to be turned on or off, and that is changed by the conditions the organism has experienced.

Hunger lessons

The most striking, but gruesome, example involving human beings is the ‘Dutch Hunger Winter’ of 1944–45, when occupying German forces starved the Dutch population in retaliation for resistance victories. Children conceived during that period grew up with poor metabolism (or, to be more accurate, metabolism that would be good at surviving starvation, but was not well-adapted to healthier post-war life nutrition, which is fascinating in itself). So much for genes being everything. More startling still was the observation that their children also had poor metabolism: the grandchildren of the starved pregnant women. We can pass on acquired characteristics, which really puts the cat among the twentieth century Darwinian pigeons. As the prophet Ezekiel put it, ‘The parents have eaten sour grapes, and the children’s teeth are set on edge’. This is full of ethical freight. The way we treat other people, and ourselves, affects those who come after us: yes, socially and culturally, which is significant enough, but even in how their bodies are programmed to develop.

A stimulating environment

There’s a similar ethical charge to what is perhaps my favourite part of the newly boisterous world of biology: phenotypic plasticity. That’s the simple idea that the same genes (the ‘genotype’) will produce a differently structured organism (the ‘phenotype’) in response to different environments. In one sense, it’s obvious enough. If I go to the gym for a year – a particular kind of environment – I’ll look different afterwards than if I’d spend an equivalent length of time on the sofa.

But it goes much further than that. Various plants will produce different sorts of leaves, for instance, depending on whether they grow in more or less shady situations. Sometimes, one species can be mistaken for two, as happened with fish, called cichlids, in Lake Tanganyika (between Tanzania and the Democratic Republic of Congo). What scientists had thought to be separate species, because their jaws are so different, turned out to be the same species. If a fish grows up at the bottom of the lake, it develops one mouth shape, with large, strong jaws, for munching shellfish; if a it with the same genes grows up at the top of the lake, it develops delicate jaws, useful for eating other kinds of food.

Again, the repercussions of ethics are enormous, and that brings us back to the ugly subject of eugenics, mentioned in the first of these articles. At root, eugenics is based on the assumption that some people just are healthy, and others just are sick, because some have ‘good genes’, while others have ‘bad genes’. You are either blessed with the former, or doomed with the later, and that’s set in stone, from conception. It’s then (supposedly) the ‘right thing’ to promote the former when it comes to reproduction and, at its most horrific, to restrain, sterilise, or even slaughter the latter. Eugenics cast its shadow over more of the twentieth century than we might like to admit. At one time or another, it was the darling of both the political right and the political left. It hasn’t gone away.

Before we say anything else, there’s a moral flaw in thinking that concern for the gene pool trumps concern for suffering individuals. More than that, though, the biology shows eugenics to be flawed even on its own, supposedly scientific, terms. We aren’t just blessed or doomed by the genetic hand of cards we’re delt at conception. Like those plants, growing in sunlight or shade, what our genes will mean is also determined by our setting. Like those African fish, our genes can run more than one programme, so the environment matters.

Eugenics presents the all-to-convenient picture that the sick will be sick, the weak will be weak, and that’s that. But we’re not just doomed or blessed by genes. It matters, for instance, what sort of housing we have, how we’re fed, and whether we have access to fresh air and places for exercise, and to stimulus for the mind, and companionship. Putting people into groups (healthy and sick, or worthy and unworthy), then writing off one of those groups might be politically and economically convenient, but it’s bad science, as well as bad morals.

Reason to be curious

I started this series by mentioning how important the theology and philosophy of the Middle Ages has been for me, in working between theology and science. In one of his little read works, Thomas Aquinas (1224–1274) defended having the expansive curriculum used in training Dominican friars like himself. (It helped that this curriculum was being drawn up, in part, by Albert the Great – perhaps the greatest polymath of his century, and later patron saint of scientists.) One should be open to knowing about everything, Aquinas argued, because you never know what will come in useful later on. We have an excellent, and timely example of that, in how something as obscure as phenotypic plasticity bears on eugenics, and the eminently practical question of proper housing.

Recently, in fact, the Church of England has been working hard on housing. The Bishop of Chelmsford, Guli Francis-Dehqani, has the new housing brief among the bishops. The church’s council for Mission and Public Affairs has also been busy, not least with the publication of Coming Home: Christian Perspectives on Housing in 2020. What might have seemed like rather abstract wranglings among biologists, over where to put the emphasis in their theories about nature, turns out to show how right it is to be passionate about good housing (and, it turns out, about keeping abreast of biology).

Nuclear War A Scenario: the book that imagines the inconceivable

It's the most depressing book that you really need to read

Simon Burton-Jones

Simon is Bishop of Tonbridge in the Diocese of Rochester. He writes regularly round social, cultural and political issues.

A nuclear explosion glows red and orange against the night sky.

A test explosion, 1956.

Nuclear War A Scenario (Torva, 2024) by Annie Jacobsen is about the most depressing book you could ever read and, perversely, all the more reason to read it. Collectively, the human race has buried its head in the sand over the existence, power and proliferation of nuclear weapons. We are understandably focussed on the lasting impacts of climate change; however, nuclear war promises planetary destruction and the risks surrounding it have grown, rather than lessened, since the end of the Cold War.

To help us focus on what we would rather not, Annie Jacobsen gives her book a plausible but hypothetical scenario. It starts with North Korea, for there we have an unbalanced, remote individual; an empathy free despot with unfettered power and unimaginable weapons at his disposal that now have the capacity to reach the east coast of the United States.

We do not learn his reasons for launching missiles against the US in the scenario and never would, were it to happen, because Armageddon takes only minutes to unfold. Jacobsen is deeply informed round nuclear war, having talked to many highly placed American officials. One recurring anxiety she meets is that the decision to launch nuclear missiles is in the hands of the President alone and the US still operates on the so-called Launch on Warning doctrine.

Launch on Warning means America will fire its nuclear weapons once its early warning sensor systems merely warn of an impending nuclear attack. These systems are sophisticated, but they can also be wrong, as the US discovered in 1979 when it briefly believed it was under attack from the Soviet Union. In Jacobsen’s scenario, the President has six minutes to decide what measures to take and has something approximating a menu to assist with this. Ronald Reagan observed:

Six minutes to decide how to respond to a blip on a radar scope and decide whether to release Armageddon! How could anyone apply reason at a time like that?

The menu, a little like ordering pizza with preferred toppings, is supposed to help with that moment.

In Jacobsen’s scenario, US nuclear weapons are unleashed against North Korea but have to travel over Russia to get there. Russia’s early warning systems are less sophisticated and in the scenario these US missiles are believed to be an attack on Russia, not North Korea. This leads to Russia’s own uncompromising, near instantaneous response which leads to … well, you get the picture.

A one megaton thermonuclear weapon detonates at one hundred and eighty million degrees Fahrenheit, which is four or five times hotter than the temperature at the centre of the sun and creates a fireball that expands at millions of miles an hour. This alone is unimaginable; replicating it hundreds of times over is impossible. The injuries sustained among those left; the loss of food, water, sanitation; the breakdown of law and order; the arrival of nuclear winter where temperatures plummet for decades without any infrastructure led Nikita Khrushchev to say: ‘the survivors will envy the dead’.

Mark Lynas, a writer who for years has been helping the world to understand the science of climate change has recently turned his focus on the nuclear threat in his book ‘Six Minutes to Winter’. He observes:

‘There’s no adaptation options for nuclear war. Nuclear winter will kill virtually the entire human population. And there’s nothing you can do to prepare, and there’s nothing you can do to adapt when it happens, because it happens over the space of hours. It is a vastly more catastrophic, existential risk than climate change.’

Reaching the end of human capacity is an unsettling experience. Solutionism is the Valley’s mantra: technology can solve every human problem, but binary thinking neglects the social, political and moral complexity of many issues and, in any case, catastrophic nuclear explosions are as likely to happen by accident as design - and could do at any time. It’s not that we need more time for AI to resolve this existential threat; it’s that it never will.

This is where the moral strength of faith traditions come into play as people embrace the strange hope of the powerless. Christian faith in particular cannot succumb to fatalism or the hacking of the book of Revelation to interpret the end of all things as code for nuclear war. God is creator and we are co-creators with him; we are not called to destruction when he has promised to renew the face of the earth through the resurrection of Christ.

There is something specific about our generation. For eighty years, since the bombing of Hiroshima and Nagasaki, we have been the first generation with the capacity to destroy the whole world. Understandably, we do not want to think about this, but the fallout from this nuclear denial is that risks continue to multiply. More nations are thinking about developing nuclear weapons in an unstable world. In June 2025, the global nuclear watchdog, the IAEA said Iran was failing to meet its non-proliferation obligations for the first time in two decades and within days, Israel had launched missile strikes on Iranian nuclear sites – and many other targets – to set its nuclear programme back, followed in a significant escalation by US strikes. Nuclear weapons are a very present cause of insecurity, as the recent missile exchanges between India and Pakistan show so gravely.

Despots watched what happened to Muammar Gaddafi after he relinquished his designs on weapons of mass destruction following pressure from western powers and are unlikely to make the same mistake. No-one can be sure the current US administration will offer a nuclear umbrella to Europe, especially when the President’s instincts are not internationalist and his preoccupation is with a golden dome shielding continental America instead.

Almost no-one has agency in this, except for one vital piece of the puzzle: intercessory prayer, rooted in the promises of God. The ancient psalm writer prophesies:

He makes wars cease to the end of the earth;

He breaks the bow and shatters the spear;

He burns the shields with fire.

Be still, and know that I am God!

I am exalted among the nations,

I am exalted in the earth.

And something greater than the spear is among us today.

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