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Biology
Creed
7 min read

Not just red in tooth and claw: biology's big debates

In the second of a series, biologist and priest, Andrew Davison, examines why it’s important to keep up with biology’s big debates.

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

An osprey, in flight, holds a fish in its claws.
‘Wherever there’s water or air to navigate, the laws of fluid dynamics are bound to throw up wings, and bodies shaped like fish.’
Photo by Mathew Schwartz on Unsplash.

There’s hardly been a livelier time for evolutionary science than today; indeed, passions can run high. It’s not that Darwin’s vision of evolution is fundamentally in doubt: species adapt by natural selection, there’s variation between individuals, and those better adapted for their environment survive more often, passing on their genes to their children. In that, the theory of evolution stands, but many other parts of the evolutionary picture from the second half of the twentieth century are coming under criticism. That includes the following maxims:  

‘the only significant form of inheritance involves genetic code’, 

‘nothing that happens to an organism during its lifetime is passed on to its progeny’,  

‘we agree what we mean by “species”’,  

‘genes pass down the branches of the tree of life, not between them’,  

and ‘evolution is fundamentally all about competition, not cooperation’. 

Among the excellent crop of writers on these themes, Eva Jablonka and Marion Lamb stand out for their elegant prose, and a gift for communicating complex ideas clearly. As they recognise, the standard mid-twentieth century model of evolution might be worth criticising, but it’s also landed all sorts of important basic points. (They list ten.) The shortfall of the earlier, dominant theory was in being too narrow, with each insight too quickly eclipsing others.  

Here are two examples. First, the classic twentieth century picture saw inheritance in terms of DNA and genes, passed on by ‘germline’ cells, such sperm and pollen. That’s all true, but it shouldn’t restrict our wider view of inheritance to that. Today, writers such as Jablonka and Lamb stress that organisms inherit from their parents (or parent) in all sorts of ways.  

A second plank of the twentieth century picture is that evolution involves descent from a common ancestor. Again, that says something vital, even central, accepted by evolutionist old and new. The twentieth century position, however, added a restriction: that’s all that’s important on this score. The newer perspective recognises that while genes are – of course – central, and passed on from parent to child, organisms also swap genes between themselves (between branches of the tree of life, not just along those branches), even between very different species. 

If we’re not careful, what’s written and taught (not least by theologians), even with the best will in the world, will be thirty or even fifty years out of date. 

There’s a lot of excitement around these sorts of claims (and, remember, Jablonka and Lamb make eight more), and that can get quite noisy. Defenders of the older, narrower picture typically say that the newer themes are simply fuss over minor points. Advocates of the newer perspective disagree, saying that the twentieth century picture risks missing some important features of biology, which are now coming into better focus. 

Why such debates matters 

Why might this ferment among biologists matter for a site like this one, and for theologians, and discussions of religious matters? Well, for one thing, as I pointed out in my previous article, nothing quite dissolves the supposed animosity between science and religion (which is, after all, a relatively recent invention) like theologians and religious people getting excited about biology. It’s also important that any humanities scholar, the theologian among them, who’s engaging with science should keep up to date. If we’re not careful, what’s written and taught (not least by theologians), even with the best will in the world, will be thirty or even fifty years out of date. 

But there’s more at stake. As we have seen, the twentieth century picture, for all it brought an admirable clarity to evolutionary thought, was reductionistic. We see that in Jablonka and Lamb’s exhortation to scientists: ‘yes, stress x, but don’t think that means you have to deny y.’ A religious vision tends to be an expansive one. It wants to recognise the reality and value of all sorts of things. Yes, there’s matter, atoms, molecules, and genes, but there’s also organisms, agents, cultures, groups, economies, hopes, loves. They’re all real. We can’t reduce one to the other: not organisms to genes, or agents to economies. A turn from reduction is welcome. 

More than that, almost everything in the emerging twenty-first century view of evolution is fascinating from a theological perspective.  

Take convergence, for instance. It turns out that evolution isn’t just driven by randomness, or by the demands of the surroundings. Also important are various features of physics, or mathematics – the contours of reality – that throw up elegant solutions to evolutionary problems, which are adopted by evolution time and again. Wherever you need to sturdy and space-efficient packing of cells (as in a honey comb, or a a wasp’s nest), the hexagon is ready and waiting.  Wherever there’s water or air to navigate, the laws of fluid dynamics are bound to throw up wings, and bodies shaped like fish, dolphins, and penguins (which are all quite similar in shape).  

How do we know this? Because evolution has converged on wings and that body shape independently, many times, as also on eyes, and everything else that Simon Conway Morris lists in the nine closely printed columns of convergences in the index to his book Life’s Solution. Evolution certainly involves randomness and need, but alongside them is something more like Plato’s forms: timeless realities, there to be discovered and put to work. Among the more theological of these eternal verities, covered in Conway Morris’s book, are perception, intelligence, community, communication, cooperation, altruism, farming, or construction 

 Exceeding a zero-sum game 

Then there’s cooperation. Ever since Darwin’s Origin was published, and, even more, ever since Tennyson wrote about nature ‘red in tooth and claw’, theologians have been embarrassed about the place of cooperation in their vision of the world. Now, however, it turns out, competition isn’t the only force at work in biology or evolution after all. One of the features of reality that evolution discovers and puts to work again and again is cooperation, and ways to exceed a ‘zero-sum’ game. We see that in cooperation within a species, but also in cooperation between species, which is ubiquitous in nature: called mutualism, it’s found everywhere. As a rule, once two species stick around in proximity for the long run, down many generations, their relationship will turn to mutual benefit.  

Ethicists are often wary of the suggestion that we can look at the way things are, and read a moral code there (getting an ‘ought’ from an ‘is’), but it’s an unusual person whose vision of right and wrong isn’t shaped, to some degree, by a sense of what the world is like. Well, it turns out that nature bears witness to the enduring worth of cooperation, and not only to competition.   

In the first of these articles on biology, I pointed out the significance of ethics in thinking about biology, and about evolution in particular. For better or worse, and often for worse, thinking about evolution has been an ethical, social, political story. The evolutionary has been put to work for immoral, ends. It turns out to be wrong twice over to suppose evolution commends only competition. It’s wrong, first of all, because we are rational creatures, who can aspire to an understanding of good and evil that transcends the realm of nature. But also, as we now see, it’s wrong even to suppose the nature is only red in tooth and claw. There’s competition, but there’s also a lot of cooperation.  

 

Suggested further reading 

Archibald, John. 2014. One Plus One Equals One: Symbiosis and the Evolution of Complex Life. Oxford: Oxford University Press. An accessible introduction to biological mutualism, with an emphasis on the role of hybrid organisms (one living inside another) in major evolutionary transitions. 

Bronstein, Judith L., ed. 2015. Mutualism. Oxford: Oxford University Press. The new standard treatment of biological mutualism. 

Morris, Simon Conway. 2008. Life’s Solution: Inevitable Humans in a Lonely Universe. Cambridge: Cambridge University Press. A comprehensive discussion of convergence in evolution. 

Day, Troy, and Russell Bonduriansky. 2018. Extended Heredity: A New Understanding of Inheritance and Evolution. Princeton, NJ: Princeton University Press. An engaging introduction to a broadened picture of inheritance. 

Davison, Andrew. 2020a. Biological Mutualism: A Scientific Survey. Theology and Science 18 (2): 190–210. An accessible survey of some of the science of biological mutualism. 

———. 2020b. Christian Doctrine and Biological Mutualism: Some Explorations in Systematic and Philosophical Theology. Theology and Science 18 (2): 258–78. A foray into some of the significance of mutualism for Christian theology. 

Jablonka, Eva, and Marion Lamb. 2020. Inheritance Systems and the Extended Synthesis. Cambridge University Press. A short discussion of many of the more expansive aspects proposed for contemporary evolutionary thought. 

Jablonka, Eva, Marion J. Lamb, and Anna Zeligowski. 2014. Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life. Revised edition. Cambridge, MA: MIT Press. One of the most substantial discussions of the new perspective. 

Laland, Kevin, Tobias Uller, arc Feldman, Kim Sterelny, Gerd B. Müller, Armin Moczek, Eva Jablonka, et al. 2014. Does Evolutionary Theory Need a Rethink? Nature 514 (7521): 161–64. MA short two-sided piece, asking whether a transformation in evolutionary thinking is under way.  

Article
Belief
Care
Creed
4 min read

Understand what we thirst for

Whether for water or meaning, it’s a primal force.

Helen is a registered nurse and freelance writer, writing for audiences ranging from the general public to practitioners and scientists.

A child wearing a wool hat holds a glass and drink water from it.
Johnny McClung on Unsplash

Quenching thirst is a global problem. It can also be profoundly personal, impaired by illness. For nurses, it can be ethically and emotionally difficult, when treating dying patients. But is there ultimate relief? 

Thirst is the subjective sensation of a desire to drink something that cannot be ignored. The world is thirsty; globally, 703 million people lack access to clean water. That’s 1 in 10 people on the planet. 

Thirst is a life-saving warning system that tells your body to seek satisfaction through swallowing fluid. It works in partnership with other body processes - such as changes in blood pressure, heart rate and kidney function - to restore fluid, and salt, levels back to where they belong. Failure of any part of this beautifully balanced system leads to dehydration (or water intoxication), and perhaps to seizures, swelling of the brain, kidney failure, shock, coma and even death. 

Sometimes it’s difficult to quench thirst, because of problems with supply. According to the World Health Organization, at least 1.7 billion people used a drinking water source contaminated with faeces in 2022. Sometimes in war, water is weaponised, with systematic destruction of water sources and pipes. Water laced with rat fur, arsenic and copper has meanwhile been reported in prisons across the USA.  

At other times, there may be “water everywhere, but not a drop to drink” because of individual problems with swallowing. As a nurse, some of my most heartbreaking moments have been when I have been unable to fulfil a need as basic as a patient’s thirst; when even thickened fluids have led to intense coughing and distress, and a realisation that I can only moisten mouths and give so-called “taste for pleasure”: very small amounts of a favourite liquid or taste using a soft toothbrush, or a circular brush gently sweeping around the mouth and lips to release some of the liquid - even, and especially, at the end of life when the patient is unconscious. 

Difficulties in drinking are common in dementia when fluid can seem foreign and swallowing a surprise to the system. It’s thought that over 50 per cent of people in care homes have an impaired ability to eat or drink safely; 30 to 60 per cent  of people who have had a stroke and 50 per cent of those living with Parkinson’s may struggle to swallow. 

Other conditions that may affect swallowing include multiple sclerosis, cerebral palsy, and head and neck cancers. Diabetes is characterised by a raging thirst owing to problems with insulin (diabetes mellitus) or an imbalance in antidiuretic hormone levels (diabetes insipidus). In intensive care, patients are predisposed to thirst through mechanical ventilation, receiving nothing by mouth, and as a side effect of some medications. But thirst is a “neglected area” in healthcare, writes palliative care researcher Dr Maria Friedrichsen.  

“Knowledge of thirst and thirst relief are not expressed, seldom discussed, there are no policy documents nor is thirst documented in the patient’s record. There is a need for nurses to take the lead in changing nursing practice regarding thirst.” 

Is there another thirst that is also being missed in nursing, and in life in general – a spiritual thirst, beyond the physical desire to drink? In his book, Living in Wonder, writer Rod Dreher argues that humans are made to be spiritual, and that a critical sixth sense has been lost in a “society so hooked on science and reason”. We humans crave love in our deepest selves; we have an insatiable thirst for everything which lies within – and beyond – ourselves. Auschwitz survivor Viktor Frankl, who was later appointed professor of psychiatry at the University of Vienna, became convinced that human beings have a basic “will for meaning.” “The striving to find a meaning in one’s life,” he wrote, “is the primary motivational force in man.”  

In the harsh sun of a Middle East day, an ancient story of a man and a woman encountering each other at a water well illustrates this dual thirst for water and meaning. The man, Jesus, thankful for a drink of water given to him at the well by an outcast Samaritan woman, said that “Everyone who drinks this water will be thirsty again, but whoever drinks the water I give them will never thirst. Indeed, the water I give them will become in them a spring of water welling up to eternal life.” In that midday sun, such imagery made a powerful statement.  

Being mindful of spiritual thirst when drinking water is something also captured in a Ghanaian proverb and pictured perfectly in the many birds that drink by gravity, so tipping their heads back when they swallow.  

“Even the chicken, when it drinks, 

Lifts its head to heaven to thank God for the water”. 

Unsatisfied thirst is part of the human condition, we long for something more; it’s living proof of our immortality, says French poet Charles Baudelaire. Despite his Olympic success, athlete Adam Peaty said that society didn’t have the answers he was seeking, and that a gold medal was the coldest thing to wear. He “discovered something that was missing” when attending church for the first time, and now has a cross with the words “Into the Light” tattooed across his abdomen, symbolizing his spiritual awakening. We are more than mechanical machines with physical needs. We are rather gardens to tend in a dry and thirsty land, with souls in need of intensive care.