What is life? A silly question

[This will appear as a leader in next week's Nature, but not before having gone through an editorial grinder...]

While there is probably no technology that has not at some time been deemed an affront to God, none invites the accusation to the same degree as synthetic biology. Only a deity predisposed to cut-and-paste would suffer any serious challenge from genetic engineering as it has been practised in the past. But the efforts to redesign living organisms from scratch – either with a wholly artificial genome made by DNA synthesis technology or, more ambitiously, by using non-natural, bespoke molecular machinery – really might seem to justify the suggestion, made recently by the ETC Group, an environmental pressure group based in Ottawa, that “for the first time, God has competition.”

That accusation was levelled at scientists from the J. Craig Venter Institute in Rockville, Maryland, based on the suspicion that they had synthesized an organism with an artificial genome in the laboratory. The suspicion was unfounded – but this feat will surely be achieved in the next few years, judging from the advances reported at a recent meeting in Greenland on the convergence of synthetic biology and nanotechnology and the progress towards artificial cells.*

But one of the views commonly held by participants was that to regard such efforts as ‘creating life’ is more or less meaningless. This trope has such deep cultural roots, travelling via the medieval homunculus and the golem of Jewish legend to the modern Faustian myth written by Mary Shelley, that it will surely be hard to dislodge. Scientific attempts to draw up criteria for what constitutes ‘life’ only bolster the popular notion that it is something that appears when a threshold is crossed – a reminder that vitalism did not die alongside spontaneous generation.

It would be a service to more than synthetic biology if we might now be permitted to dismiss the idea that life is a precise scientific concept. One of the broader cultural benefits of attempts to make artificial cells is that they force us to confront the contextual contingency of the word. The trigger for the ETC Group’s protest was a patent filed by the Venter Institute last October on a ‘minimal bacterial genome’: a subset of genes, identified in Mycoplasma genitalium, required for the organism to be viable ‘in a rich bacterial culture medium’. That last sounds like a detail, but is in fact essential. The minimal requirements depend on the environment – on what the organism does and doesn’t have to synthesize, for example, and what stresses it experiences. And participants at the Greenland meeting added the reminder that cells do not live alone, but in colonies and, in general, in ecosystems. Life is not a solitary pursuit.

Talk of ‘playing God’ will mostly be indulged either as a lazy journalistic cliché or as an alarmist slogan. But synthetic biology’s gradualist and relative view of what life means should perhaps be invoked to challenge equally lazy perspectives on life that are sometimes used to defend religious dogma. If, for example, this view undermines the notion that a ‘spark of humanity’ abruptly animates a fertilized egg – if the formation of a new being is recognized more clearly to be gradual, contingent and precarious – then the role of the term ‘life’ in that debate might acquire the ambiguity it has always warranted.

*Kavli Futures Symposium, 11-15 June, Ilulissat, Greenland.