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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.  

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Understanding the power of blood

From hospitals to hymn books, it's significant for a reason.

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

A bag of blood connected to a drip.
Give blood.
Aman Chaturvedi on Unsplash.

With one billion molecules of oxygen packed into each of your 30 trillion red blood cells, blood is sometimes known as the red river of life. Countless lives have been saved through blood transfusion, but why, throughout history, across continents and cultures, has there been a special interest in the blood of one man crucified 2,000 years ago, believing it alone to have “wonder-working power”?  

Whether you are a newborn baby with half a pint of blood, or an adult with nearer nine pints, “what is certain is that you are suffused with the stuff”, writes author Bill Bryson in his book, The Body.  

Once thought to ebb and flow in waves like the sea, from the liver to other organs, having been heated in the heart, blood in fact flows in a network of vessels measuring some 60,000 miles, with the heart acting as pump, not heater. Cleverly conserved through a complex system of blood-clotting in the case of injury, blood is a precious resource that needs replacing if lost in large amounts. Victims of road traffic accidents can require up to fifty units of blood; significant amounts are needed for organ transplantation, severe burns or heart surgery. 

The first human blood transfusion in Britain, using blood from a lamb, was performed by Dr Richard Lower in 1667, given not to replace blood loss but to change character: could the old be made young, the shy be made sociable through blood transfusion? Apparently not.  

Safe transfusion awaited the discovery of blood types by Dr Karl Landsteiner in the early 20th century. Today, NHS Blood and Transplant deliver 1.4 million units of red cells to 260 hospitals each year for transfusion; about 85 million units are transfused worldwide, given to replace blood loss after accident, surgery, ulcer, ectopic pregnancy or for anaemia in cancer. Also used to boost blood cell numbers in malaria, sepsis, HIV, leukaemia and sickle cell anaemia, blood transfusion is now amazingly safe. Fatal reactions are extremely rare, “occurring only in one out of nearly two million transfusions”, writes physician Dr Seth Lotterman. “For comparison, the lifetime odds of dying from a lightning strike are about 1 in 161,000,” he adds. The risk of HIV infection has dropped dramatically, to less than one in seven million. 

History tells though of the danger of transmitting disease from the blood donor during transfusion. The World Health Organization recognises risk of infection with HIV, hepatitis, syphilis, malaria, and Chagas disease. The Contaminated Blood Scandal saw an estimated 30,000 people in the UK given blood transfusions and blood products infected with hepatitis C, hepatitis B and HIV. More than 3,000 people died as a result, and thousands more live with on-going health complications. For my final Christmas article for Readers Digest, I wrote on Stephen Christmas, a tireless campaigner for blood safety who lived with haemophilia and died in 1993, having contracted HIV through contaminated blood. 

I was a blood donor. However, I am now unable to donate blood or organs for the rest of my life since there is a possibility that my blood is ‘stained’, possibly with prion disease, after adopting embryos. The Blood Transfusion Service will not accept donations from women who have had various fertility treatments. 

And there’s another uncomfortable truth about blood donation – the NHS does not have enough blood, organs, tissues, platelets, plasma or stem cells to treat everyone who needs it. As a nurse, I remember caring for a man dying of liver cancer. Suffering from sudden, massive melaena (blood loss in black, tarry stools as a result of internal bleeding), he received emergency blood transfusion, with bag after bag of blood being infused, until the consultant called for the treatment to stop, because the bleed was too big – and blood supplies too scarce.  

Struggling to accept the stark reality of stained blood and dangerous shortages, I kept coming back to an old Sunday School song about blood, where absolute abundance and ultimate cleansing are instead promised. 

There is a fountain filled with blood 
   Drawn from Immanuel’s veins; 
And sinners, plunged beneath that flood, 
   Lose all their guilty stains. 

Gruesome and graphic in its imagery, but full of deeper meaning. And as a nurse, I’m accustomed to blood, sometimes lots of it. I’ve seen that man bleed out on the ward that night; I’ve attended a road accident, where a boy lost his leg – but not his life, because towels stemmed the massive flow of blood. I’ve raced a patient to the operating theatre after her aortic aneurysm burst within; I’ve stemmed arterial bleeding from the groin by applying prolonged pressure to the site punctured by a catheter during cardiac stenting. According to the World Health Organization, severe bleeding after childbirth is the leading cause of maternal mortality world-wide. Each year, about 14 million women experience postpartum haemorrhage resulting in about 70,000 maternal deaths globally.  

In the Bible, and in hymns of praise like this one, there is also no getting away from blood. “Like it or not, the Bible is a bloody book,” writes  Kyle Winkler. It runs through the book like a crimson thread. There’s a story of a woman bleeding for twelve years, until she touched the hem of Jesus’ garment and was healed.    

Elsewhere the Bible keeps returning to the idea of blood, shed in sacrifice, used to cleanse, save, and heal in a spiritual sense. In the Old Testament, animal blood was painted on doorposts at Passover as a sign of protection from judgment, and sprinkled ritually on the altar as a sacrifice for human sin, restoring relationship with God.  

On Good Friday, Jesus himself shed (and sweat) his blood, sacrificing his life on the cross to “wash our souls” once and for all. Millions of Christians across the world take a sip of communion wine each Sunday in commemoration of this act. It’s a beautiful gift, coming with a promise that the shed blood will “preserve thy body and soul unto everlasting life”, through the forgiveness of sins. It’s no wonder then that churches love to sing about this blood. “Would you be free from the burden of sin? There's pow'r in the blood, pow'r in the blood,” goes one hymn, while another simply says, “Your blood has washed away my sin, Jesus, thank you”.  

“God’s intention for blood isn’t gory—it’s beautiful! And I’m certainly not offended or scared by it,” writes Kyle. “Rather than question how little blood I can get by with, I’d rather stand under the cross to be covered in all that I can get!” Thank God for the fountain of forgiveness that flows from Good Friday. 

  

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