How to Grow a Human - Philip Ball

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to keeping general audiences engaged. I mean that our perception of what science means is shaped by narratives about it. There are narratives that society imposes on new discoveries and advances, which are often cut from older cloth. In biology – particularly developmental, cell and reproductive biology – these stories tend to come from myth, science fiction and fantasy, and they are often alarming: they might, for example, draw on Frankenstein, Brave New World, The Island of Doctor Moreau. But there are also narratives that scientists themselves create and recycle. It happens more in the biological sciences than in the others because biology is inherently a science of becoming, where history matters and where we seem compelled to speak about goals and purposes: what organisms, cells and genes “want”, what evolution “seeks to do”.

      A significant aspect of this book’s aim is to expose and explore these stories. They are by no means a bad thing. On the contrary, they are essential and often illuminating, for they fit with the way we humans make sense of our world, with our instinct to look for and find causation, reasons behind things. Yet there is a danger to them too, which is that we might begin to mistake them for descriptions of how things are.

      One of the classic examples of a framing narrative in biology is Richard Dawkins’s concept of the selfish gene. Dawkins has had to defend this idea against accusations that it attributes a kind of agency and intention to genes, for it is of course just a metaphor. The problem is that, when a metaphor gets this popular, it starts to be understood (and sometimes presented) as a plain account of “what things are like”. When Dawkins speaks of us – individual humans – as the “survival machines” for genes, he is not defining what a human is but is explaining what we are required to be within the narrative of the selfish gene. The narrative serves to convey a particular aspect of how genes function in evolutionary terms. If you don’t like this story, or don’t find it helpful, you are not obliged to accept it; there is nothing “real” about it. Dawkins has said as much: he admits in The Selfish Gene that it should strictly be called The Slightly Selfish Big Bit of Chromosome and the Even More Selfish Little Bit of Chromosome. (He was right to suspect the book would not have been so successful if he’d called it that.) He even admitted much later that the book could equally have been titled The Cooperative Gene. That would have been a different narrative, of course, and it would have served to illustrate another facet of how genes work.

      As Dawkins implicitly acknowledges here, biology is too complex and complicated to be reduced to a single story. That’s precisely why we need stories to tell about it: they give us something to cling to, some way of finding a path through the thicket. There is almost always more than one of them.

      It’s not just, though, that we must remember this is what we are doing. We must also keep in mind that stories are not neutral vehicles for understanding. When we frame some medical advance within the narrative of Brave New World, we are not simply saying, “hey, doesn’t this sound a bit like the people-growing hatcheries in Aldous Huxley’s book!”, but also “… and we should be suspicious, even frightened, of where it might lead.” Precisely the same applies to The Selfish Gene. The story’s subtext here is that Darwinian evolution is ruthless – that it makes for a dog-eat-dog world, a battle for survival from the bottom up. Dawkins explains that this does not imply that humans are themselves bound to be selfish; indeed, he shows how altruism can arise from “selfish genes”. But the implication remains that there is to nature a redness in tooth and claw, and indeed Dawkins advises that for this very reason we should strive to supersede the default and be kind to one another. The point is, though, that one can talk about Darwinian evolution and genes without invoking “selfishness” at all, and the story then has a different complexion in which all manner of behaviours appear not as emergent and perhaps counter-intuitive consequences of a selfish genetic strategy but simply as aspects of the complexity of biology: cooperation as well as the most beastly predation strategies, war and peace, love and cruelty. Each of those words is equally freighted with narratives that biology itself doesn’t impose.

      This is why I will be constantly alert to the narrative, and will ask, “why this story, and not some other?” Whether we are talking about cancer or immunity, cell signalling or tissue engineering, the science becomes packaged right from the outset inside a story, and this means that we impute agency, make choices about what to include and what not to, and suggest certain goals and not others. Even scientists speaking to other scientists need to use metaphors and narratives somewhere along the road, to give the mind purchase on concepts that are otherwise too slippery and too complex to comprehend. The only danger in all this, as in stories about “selfish genes”, is if we tell ourselves that all we are doing is relating objective truths.

      I’d suggest that you might want to be alert to the narratives that I shall deploy too – for I am no more immune than anyone else to the tendency, the need, to tell a story, and the habit of using framing devices unconsciously. Challenge me on it. I promise to try not to mind.

      It’s for this reason too that I think it is always important to know something about the historical context in which a scientific idea has arisen. We will see that, for example, cell theory was originally deemed to have a political dimension, and tissue culture was driven by social agendas. Some scientists might say, “oh, but that was then, and we have shed that baggage now and are dealing just with plain facts.” But I suspect that few scientists working on fertility and infertility would say this, and certainly they should not. They know very well that whatever they discover will be refracted through a complex social legacy of attitudes to baby-making, sex and gender. Geneticists labour under the shadow of the field’s eugenic past, and this goes beyond the stark fact that such work once led to enforced sterilization of the “unfit” in many countries and was embraced by the Nazis. Unease and dispute remain today over the implications of genetics for incendiary issues like race, class, intelligence and disability. What this means is that culture, past and present, may shape the scientific questions we ask, the models we develop, and the stories we tell.

      I know from experience that there is a kind of reader who says, “I don’t care about that, just give me the science!” If you are that kind of reader, I’d humbly reply: I cannot give you “just the science”, because it already comes with a story attached. In this field – which I find breathtaking, perplexing, occasionally disturbing – there is never “just the science”.

      When we ask, “how to grow a human”, we cannot possibly be asking “just” a question about science. That’s what makes the question so interesting.

       INTRODUCTION

       MY BRAIN IN A DISH

      In the summer of 2017, a small piece of my arm was removed and turned into a rudimentary miniature brain. This book is my attempt to make sense of that strange experience.

      On a hot day that July, I lay on a bed in the Institute of Neurology at University College London while neuroscientist Ross Paterson gouged a little chunk from my shoulder with a kind of miniature surgical apple-corer. A dab of local anaesthetic made it painless; to my great relief, there wasn’t much blood.

      Bathed in a nutrient solution in a test-tube, that piece of my flesh was the seed for what, eight months later, would resemble a tiny brain.

      It was my own “mini-brain”, a blob of neurons about the size of a lentil. They wired themselves into a dense network and could signal to one another in the way neurons do. I’m not going to say it was thinking; probably these signals were not much more than random sparks, incoherent noise, signifying nothing. But no one really knows how to think about what goes on inside a mini-brain, any more than they know what transpires in the formative brain of a fetus when it is of comparable pea-size.

      This process of culturing new tissues from a piece of arm is not the way to create a human. But it could one day become a basis for doing that.

      It’s not obvious why anyone, here and now, would think this a good idea. But the point is not that one day humans

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