A Walk to the Gallows Could Scientific Advances Be Hastening the End of the World?

books and arts A walk to the gallows Could scientific advances be hastening the end of the world?

Our Final Hour: A Scientist’s Warning: How Terror, Error, and Environmental Disaster Threatens Humankind’s Future in this Century – On Earth and Beyond/ Our Final Century: Will the Human Race Survive the Twenty-First Century? by Martin Rees Basic Books: 2003. 256 pp. $25/ William Heinemann: 2003. £17.99

Don Brownlee COLLECTION/ALLIED ENTERTAINMENTS KOBAL I must admit I was startled when I first heard the title of Martin Rees’ new book, Our Final Hour. Is it really possible that our end could be so near? Could our species become extinct less than three centuries after the publication of Darwin’s Origin of the Species? We humans have only just begun to understand what we are and how we fit into the cosmos. How could the curtain fall on us so soon? My initial shock and knee-jerk scepticism was eased, at least a bit, when I found that the UK version of this book is titled Our Final Virtual reality? Computing advances leave us open to the risk of cyber-doom, as in Lawnmower Man 2. Century. As is the case with most apocalyptic assessments, the prediction may involve a simple reason that they do not have science focus is on our self-extinction. Having sur- few orders of magnitude of uncertainty. and technology, and so lack the tools to do vived predictions that the ‘electronic brain’ Gloom and doom is an intriguing and themselves in. We cry “save the whales”, but and the robot would have taken over long popular genre but it can also be disturbing. we may be the ones who need saving. ago, my personal guess is that cyber-threats Together with palaeontologist Peter Ward, There are some profoundly unsettling and killer nanobots will never be able to take I recently wrote The Life and Death of Planet aspects to this book. It is bad enough that the total control, but who knows? Earth (reviewed in Nature 422, 663; 2003). end might be near, but it is even worse that The threat of specifically designed killer In writing the book, and in numerous talks the cause of our demise could be science. As viruses or diseases seems more credible, and and interviews given after its publication, a scientist, I have always considered science new biological threats are sure to cause havoc we had to deal sensitively with people’s fears to be the most successful human endeavour. in the future. But can even the most deadly of an unpleasant, albeit distant, future. As The bootstrap aspect of science and the role designer bugs cause total human extinction? an astronomer and a palaeontologist we feel of nature as the ultimate arbiter of truth have The nastiest viruses are usually not very comfortable with the premise that the Earth led us far. Starting with sticks, fire, flint and successful because they kill their host before will lose its plants and animals in a billion pottery, our ambitions to comprehend and they can be transmitted. Life is actually years or less, its oceans and all life within utilize nature have led to indoor plumbing, pretty robust, the product of the tough several billion years, and ultimately become spacecraft, the Internet, a sophisticated view taskmaster of evolution. Viruses have been assimilated into the red giant Sun in about of the cosmos, and even a substantial glimpse attacking bacteria in the oceans for billions 7 billion years. We are at peace with our cos- into the intricate workings of biology. of years and, even though they outnumber mic fate, smugly encapsulated in the present If Rees is right, the continual advance of their hosts by orders of magnitude, the viral and well isolated from the future. But many science has been a walk to the gallows. Our attackers can never completely win. readers are genuinely disturbed that there hard-earned knowledge of natural processes In my mind, humans are nearly extinc- are bad things ahead, even if they are millions has led us to the threshold of destruction. tion-proof unless they are exposed to global or billions of years away. Within the next century, the ability to changes to which they cannot adapt. If a Now Martin Rees, Britain’s astronomer build designer viruses, nano-robots or even nanobot, or a microbial or nuclear attack, royal and an author entitled to be taken very some type of computer-instigated cyber- was only 99.9999% efficient, the remaining seriously on such a weighty topic, suggests that doom will have advanced to the point that isolated patches of humanity could live off our end is essentially here. He wagers that perhaps a single deranged individual will the largesse of the modern world for quite humans have a 50% probability of becoming have the ability to kill us all. There will always a while. The first serious global attacks on extinct by the end of this century. Ward and be lunatics, so if the power is there, we are humans are likely to be much less than I had conjectured that humans, being wily, doomed. This is the fundamental thesis 100% efficient. Even a minor kill-off would adaptive creatures perhaps immune to future proposed by Rees. provide quite an incentive for the survivors natural selection, might be among the last The book is a shopping list of how the end to prevent future attacks. of Earth’s animals to reach extinction. Rees might come. It includes exotic concepts of A quite remarkable aspect of this book suggests just the opposite: that nearly all of how our fiddling might end the world or is that the author, a famous scientist, Earth’s large mammals may outlive us for the even muck up the entire Universe, but the clearly assigns the blame for the anticipated

NATURE | VOL 423 | 19 JUNE 2003 | www.nature.com/nature © 2003 Nature Publishing Group 803 books and arts apocalypse on science. The core of the threat “squatting ground ape” is a recurrent motif is not only science but also knowledge. throughout the first part of the book. But in The book rings the alarm but provides no doing so, he neglects the wide palaeoecologi- answers because there are none. Scientists cal perspective that is otherwise the main are motivated by curiosity and a yearning to strength of this book. understand nature, but the real engines of The European hominoid with the widest science are business and war. Without global temporal and geographical range is Dryo- cultural revolution, business, war, science pithecus, a large-bodied arboreal ape and education will surely continue. Can we adapted for a diet of soft fruits. A slightly manage the dark side of science and prove more recent European ape is Ouranopithecus Rees wrong? Only time will tell. (also known as Graecopithecus), a hominoid I highly recommend this provocative and about the size of a female gorilla that is educational book. It is written for broad adapted to eating hard fruits. Dryopithecus appeal and even includes a crowd-pleasing is associated with swampy subtropical envi- array of references to popular culture. If we ronments (from Spain to Eastern Europe), do survive to see the twenty-second century, whereas Ouranopithecus (from Greece) and I hope that Martin Rees’ cautionary and close relatives from Turkey lived in rather alarmist book will be required high-school younger, more open woodland. reading, a twenty-first-century analogue of Does the available palaeontological and Rachel Carson’s Silent Spring. I also recom- palaeoecological information support the mend Future Evolution by Ward and Alexis dispersal of Dryopithecus or Ouranopithecus- Rockman (reviewed in Nature 416, 125–126; like forms from Europe into Africa? The 2002), a discussion of the fate of humans that ‘out of Africa and back’ hypothesis is essen- favours their survival but warns of dire tially based on ‘strong’ cladistic analyses effects on the rest of the planet’s inventory of (a procedure for organizing the evolution- plants and animals. I ary relationships among taxa on the basis of Don Brownlee is in the Department of Astronomy, shared anatomical characters) that represent University of Washington, Seattle, Washington Dryopithecus and Ouranopithecus as being 98195, USA. Face facts: Jonathan Kingdon highlights the sister taxa of the African ape–human clade. similar expressions of humans and orang-utans. This hypothesis is favoured by some authors because there was a ‘hominoid vacuum’ in evolutionary patterns of African hominins Africa between 12.5 million and 6 million as driven by physical limits between geo- years ago. But the large-mammal fossil Four legs bad, graphic regions (by ‘basin evolution’), and record in Africa is relatively poor for this discusses the role of brain expansion in time interval, so the absence of hominoid two legs good driving the modern diaspora. He repeatedly fossils cannot be taken as evidence that Lowly Origin: Where, When, and refers to “self-portraits”, both as an abstract hominoids were not living in this area Why Our Ancestors First Stood Up mental exercise comparing humans and during this period. by Jonathan Kingdon other primates or animals, and by including Dryopithecus was dependent on equable, Princeton University Press: 2003. 408 pp. illustrations of himself in comparison with subtropical temperate forests, below-branch $35, £24.95 other primates and humans — the example locomotion and a soft-fruit diet, so it is not Lorenzo Rook shown above is just one of many intriguing likely to have moved across the more open juxtapositions. As a “repentant vandal”, woodland of the southwestern Mediter- Jonathan Kingdon is not only a zoologist Kingdon summarizes in the final chapter ranean during the Late Miocene. Ourano- with a deep knowledge of African mammals, our status as the last survivors of the many pithecus is also an unlikely ancestor of the but also a fine narrator and a talented artist, bipedal African mammals that persisted until African ape–human clade, because its teeth so any new book by him is particularly recent times, and offers insight into the future and jaws had thick dental enamel and were welcome. In Lowly Origin he offers the of our species. adapted for a diet of hard fruits and seeds. As reader a finely illustrated book on human There are a few weak points, however. In such they were more comparable to the teeth evolution, focusing particularly on the tran- some places the ongoing debate on some of later mid-Pliocene to early Pleistocene sition from four-legged apes to two-legged crucial issues is missing and a definite posi- hominids (between 3 million and 1 million hominins. tion is taken instead. For example, the years ago) than to the thin-enamelled teeth The origin of our ability to walk on two recently described Sahelanthropus fossil of the early bipedal hominin of Ethiopia or legs is one of the most debated subjects from Chad is mentioned as a gorilla-like the earliest Late Miocene hominin from in anthropology. Here Kingdon attempts ape but is totally overlooked in the chapters Kenya or Chad. to explain to a wide audience, and to shed that discuss the earliest hominin. Despite its lack of discussion of these new light on, the origin and consequences Another case is the origin of the African issues, Lowly Origin should interest a wide of this turning point in human evolution. ape–human clade (the taxonomic group audience. It will serve as supplementary The book’s strength is its broad perspective, including Homo and his nearest living rela- reading for researchers and graduates, but bringing ecological, palaeoenvironmental tives, Pan and Gorilla). Some recent papers should also be accessible to lay readers. King- and palaeogeographical evidence into an have argued that the European Late Miocene don is an authority on Africa’s zoology, and analysis of our “lowly origin” (the title is apes were the ancestors of the African has merged his deep knowledge of mammal taken from the last two words of Darwin’s ape–human clade, suggesting that hominids evolution with his love for Africa and art. I The Descent of Man). left Africa for Europe about 20 million years Lorenzo Rook is in the Department of Earth Over ten chapters, Kingdon provides ago and returned some 10 million years later. Sciences and the Natural History Museum, views on the evolutionary trajectories of fore- Kingdon accepts this ‘out of Africa and back’ University of Florence, via G. La Pira 4, limbs since Palaeozoic tetrapods, ponders the hypothesis — the Eurasian origin of his 50121 Firenze, Italy.