We Are the 98% the Human Genome Than Meets the Eye JOHN PARRINGTON Nathaniel Comfort Unpicks the Metaphors in a Trio of Oxford Univ

SPRING BOOKS COMMENT systems evolve and can be locked into tra- huge value remains in his wisdom and his and economics. Stern is a big thinker, used jectories by incumbent industries, unless experience of international debates. to the broad sweeps of economic develop- strong pressures force a change in course. However, Stern’s coverage of lessons from ment and global issues. But the crux is local These strands of economics are crucial to economic history and theory is messier. It people and businesses. Voters might like the understanding the energy–climate nexus meanders through market failures, policy idea of clean energy, but oppose wind farms and policies for transformation. The econom- uncertainties, the European Union’s emis- next door; back emission reductions and pro- ics mainstream is still largely in thrall to the sions-trading system, the debate over reserves fess support for market-based solutions, but idea that competitive markets drive innova- of fossil fuels that must be left unburnt to sat- oppose increased energy prices. There is little tion, but liberalization of the energy sector isfy emissions targets, shale gas, the German on energy prices in Why Are We Waiting?, but destroyed UK energy research and develop- nuclear phase-out, failed Chinese dams and climate policy in Brussels and Washington ment. The energy literature explains why, but more. There are trenchant points about six DC is concerned with little else. Stern hardly touches on this and thus misses market failures and the six areas of policy The real challenge in controlling climate a chance to help to educate fellow economists. required to address them, but little structure change is many-layered, but must include Stern’s real speciality is displayed most in behind the tales, and no compelling narrative attempts to align global need for transforma- his discussion of the ethics of how to weigh on how policy failures might have been over- tion with the old adage that all politics is local. costs and benefits over time, as well as broader come. Instead, Stern embarks on a demoli- A brief reference to border measures, to deter issues in moral and political philosophy. The tion of his critics. The integrated assessment industries from migrating to escape carbon first is technical, but is at the heart of the post- models beloved of many technical analysts controls, signals a shift in Stern’s thinking; but Stern review debate: prevalent economic tools come in for particular ire. Stern views them the argument is not developed further. ‘discount’ almost anything more than a few as “simplistic attempts to shoehorn the deep Stern deserves much credit for moving decades ahead. Critics often cite philosopher and dynamic issues into inappropriate or the economics debate on so far in a decade. David Hume to support arguments that we narrow models”, noting that many “can be But Why Are We Waiting? is a depressing should weight impacts on future generations profoundly misleading”, and evoking John reminder of the sheer size of the elephant. on the basis of ‘revealed preference’ in mar- Maynard Keynes’ old punchline: “It is better The complexities of climate change are kets. To these critics, Stern cites Hume on the to be roughly right than precisely wrong.” beyond the ken of any individual, even such need for “governors and rulers” to overcome Most seriously, Stern has misdiagnosed the a big thinker as Stern. Developing the insti- the “impatience” of individuals. Stern maps major obstacles to climate action as a failure of tutions, intellectual frameworks and impact out his case with a precision reminiscent of policy-makers to understand the scale of the channels required for effective ‘solution sci- philosopher and mathematician Bertrand risks, to grasp that delay is dangerous or to ence’, matched to the sheer range and scale Russell. He demolishes economists who, try- appreciate the feasibility of and potential for of the problems and opportunities, remains ing to avoid explicit ethical debates, forget the low-carbon paths. These are not the root of very much a work in progress. ■ ethical assumptions of their discipline. the problem, and Stern never gets to it, despite Towards the end, Stern distils his thoughts providing much of the intellectual material. Michael Grubb is professor of international on the international climate scene. Although Most policy-makers accept the need for energy policy and climate change at University he overlooks some key respects in which a action. Ignorance, inattention and ideology College London, editor-in-chief of Climate binding treaty — the Kyoto Protocol — was have all played a part in the waiting game, but Policy, and author of Planetary Economics. crucial in forming European climate policy, it also springs from microrealities of politics e-mail: [email protected]

GENETICS Biocode: The New Age of Genomics DAWN FIELD AND NEIL DAVIES Oxford Univ. Press: 2015. The Deeper Genome: Why There Is More to We are the 98% the Human Genome Than Meets the Eye JOHN PARRINGTON Nathaniel Comfort unpicks the metaphors in a trio of Oxford Univ. Press: 2015. Junk DNA: A Journey Through the Dark books exploring the ‘junk’-ridden genome. Matter of the Genome NESSA CAREY Icon: 2015. he language of DNA is a veritable about 2% of the genome encodes proteins. cornucopia of metaphor and cliché. Much — but not all — of the remaining Since James Watson and Francis 98% is evolutionary detritus. In the 1960s, conceive the genome and in the writing itself. TCrick solved the double helix, biologists have researchers learned that non-coding DNA In September 2012, the ENCODE (Ency- imagined DNA as an information-storage can serve vital functions, such as regulating clopedia of DNA Elements) consortium device: magnetic tape, a computer program gene action and building ribosomes. The announced that its multi-year international or, most commonly, a book that contains the remainder they began to call junk. effort to catalogue the various types of DNA instructions for making a cell’s proteins. In Today, junk DNA is at the heart of the most sequence had assigned “biochemical func- multicellular organisms, this precious tome radical transformation of how we understand tion” to 80% of the human genome. Incau- is secured in the vault of the nucleus, the the genome since the information metaphor. tious reporters began shouting that junk membrane of which isolates and protects Three books — The Deeper Genome by John was bunk, even though scientific consen- nature from nurture. Parrington, Junk DNA by Nessa Carey and sus maintains that most genomes contain But if a genome is text, it is badly edited. Biocode by Dawn Field and Neil Davies — large amounts of it. The subsequent debate Most DNA is gibberish, full of stutters, snip- present a vision of the twenty-first-century upregulated public interest in non-coding pets of doggerel from other species, and ech- genome. Their relative success hinges on DNA — but how do we talk about DNA now? oes of quiescent viruses. In humans, only metaphor and imagery, both in how they The title Biocode forestalls any doubt

that the authors hew to the information metaphor. Breathlessly, Field and Davies survey the greatest hits and promises of genomics, including Jurassic Park-style reani- mation of extinct species, the microbiome and environmental engineering. The thin chapters blurt out strings of recent findings, each capped with a crescendo of sensational specu- lations that mostly rehearse familiar ethical questions. Critical distance is achieved with the time-honoured double negative: “Might a lawyer one day argue that deliberately not giving [our children] the best genes available is a form of abuse? It is not inconceivable to imagine a world where natural reproduction would seem primitive and even barbaric.” It concludes by exhorting us to set our sights on a global genome project to understand “the software that shapes our living planet”. The biocode is Gaia plus DNA. But two clichés do not make a right. Biocode simply extends the text metaphor to the macrocosm. The old metaphor is not wrong; it is incom- plete. In the new genome, lines of static code have become a three-dimensional tangle of vital string, constantly folding and rearrang- ing itself, responsive to outside input. The roots of this idea run deep. In her 1983 Nobel lecture, geneticist Barbara McClintock called the genome a “sensitive organ of the cell”. McClintock, who discovered mobile genetic elements in the 1940s, had named them con- myth that at first no one thought transposi- unbridled speculation and Panglossian opti- trolling elements because she thought they tion was real. The contested point was actu- mism. Junk DNA produces a lot of DNA junk. composed the regulatory system that gov- ally McClintock’s interpretation of mobile The idea that the many functions of non- erned gene action. In 1980, Ford Doolittle elements as controllers of gene action. coding DNA make the concept of junk DNA and Carmen Sapienza proposed that transpo- Parrington’s strongest chapters survey the obsolete oversells a body of research that is sons were molecular parasites, jumping into emerging view of gene regulation, includ- exciting enough. ENCODE’s claim of 80% genomes to propagate themselves. Parasitic ing DNA folding, epigenetics and regulatory functionality strikes many in the genome transposons are now textbook knowledge, but RNA. Overall, this is a faithful, engaging por- community as better marketing than science. McClintock’s larger point holds: the genome trait of the twenty-first-century genome. Still, as with McClintock, the larger point is dynamic, full of regulatory elements that Finally, Junk DNA, like the genome, is holds: the genome is more than a set of rules respond to environmental cues. crammed with repetitious elements and and parts descriptions. Finding apt imagery The Deeper Genome is the only book of superfluous text. Bite-sized chapters parade to replace the dead metaphor of the ‘instruc- the three that credits McClintock as a pro- gee-whizz moments of genomics. Carey’s The tion book of life’ could enable us to break free genitor of the three-dimensional genome. A Epigenetics Revolution (Columbia University of the cliché of nature versus nurture. It could scientist and journalist, Parrington covered Press, 2012) offered lucid science writing usher in a more democratic conception of life, the ENCODE story for The Times in 2012; and vivid imagery. Here the metaphors have in which all the world’s a cell, and all the genes his book enriches those accounts with his- been deregulated: they metastasize through and genomes merely players. ■ torical and scientific context. The science is an otherwise knowledgeable survey of non- better than the history. He provides a fine coding DNA. At one point, the reader must Nathaniel Comfort is professor of the discussion of recent support for McClintock’s run a gauntlet of baseball bats, iron discs, Vel- history of medicine at Johns Hopkins often-overlooked late work on how stress can cro and “pretty fabric flowers” to understand University in Baltimore, Maryland. He is activate transposition, but he perpetuates the “what happens when women make eggs”. The working on a biography of DNA. genome seems to provoke overheated prose, Twitter: @nccomfort NEW IN Neanderthal Man: In Search of Lost Genomes PAPERBACK Svante Pääbo Basic 2015 Pioneer of ancient-DNA studies Svante Pääbo was inspired in his youth by ancient Highlights of this Egyptian history. Feeling that this field moved too slowly, he decided to study medicine season’s releases instead, and went on to sequence the first full Neanderthal genome in 2010. Here he details the technicalities of his life’s work and the incremental discoveries, such as genetic intimations that modern humans and Neanderthals had mixed, which generated our theories of human evolution. (See Henry Gee’s review: Nature 506, 30–31; 2014.)