You should spend about 20 minutes on Questions 1-14, which are based on Reading Passage 1 below.
EASY COME, EASY GO The dinosaurs went out with a bang, but they arrived after chaos.
Revolutions have unpredictable outcomes. Who is going to end up in power is rarely obvious at the start. That is as true in biology as it is in politics. Like political revolutions, though, biological ones often follow a predictable course. The old order is destroyed. There is a period of confusion. Then a new ecosystem emerges that looks surprisingly like the old one, but with different actors.
This cycle has happened five times in the history of modern life. The most famous occasion was 65m years ago, when the dinosaurs were wiped out and the mammals emerged victorious from the wreckage. A bigger mass extinction, at the end of the Permian period 251m years ago, killed 70% of the world's land vertebrates (and 96% of all marine animals) and paved the way for the age of reptiles.
Exactly which sort of reptile would come out on top, however, was not something that was decided until later – 201.4m years ago, to be precise. This was towards the end of the Triassic period. Then, the ranks of aetosaurs, phytosaurs, shuvosaurs and many other uncrocodile-like relatives of the crocodiles were suddenly thinned, and a previously obscure group came to the fore. The result, once natural selection had done its work over the course of millions of years, was the now familiar cast of Allosaurus, Diplodocus, Triceratops and Tyrannosaurus Rex.
Another one bites the dust
The dinosaurs were done for, as everybody knows, by a collision with an asteroid. The Permian was curtailed by massive volcanism. But what exactly happened towards the end of the Triassic has been much debated. A study just published in the Proceedings of the National Academy of Sciences, by Jessica Whiteside of Brown University in Rhode Island and her colleagues, pretty well nails it down. It was the geological chaos that created the North Atlantic Ocean.
Dr Whiteside used fossil evidence sandwiched between layers of lava from some of the earliest eruptions that accompanied the rift. Specifically, she located two sites in what is now eastern North America where a series of giant lakes had formed on the layers of cooled lava and plant matter had accumulated at the bottom of the lakes. Using detailed chemical analysis of waxy molecules extracted from the fossil plants, she examined the carbon isotopes they contained.
Non-radioactive carbon comes in two forms: 12C and the heavier (and much rarer form) 13C. The ratio varies in the atmosphere, depending on where carbon-rich gases, mainly carbon dioxide and methane, are coming from. Dr Whiteside found the ratio yawed around like a drunken sailor as the continents split apart and the lava started pouring out. First, the level of 13C plummeted. Then it shot up again, a long way over the recent historical average, before settling down.
Crucially, the period of plummeting coincides with a phenomenon called the late Triassic fern spike. This marks precisely – to within a few thousand years – the point of mass extinction on the land. What is believed to have happened is that something killed all the forests and with them the animals that depended on them. Freed from the competition for light (because the shade from the trees had gone), ferns flourished (their spores are ubiquitous in the rocks). Previous work has suggested that the oceans also became acidic at this time. Shelled creatures, whose calcium-carbonate-rich armour tends to dissolve in acid, suddenly became rare.
Put it all together and the probable course of events was this. The initial volcanism as North America split from Europe released carbon dioxide from deep inside the Earth. That produced a greenhouse effect which, in turn, melted seabed structures known as methane clathrates, which trap that gas in ice. This caused a massive release of 12C-rich methane into the atmosphere, explaining the initial drop in 13C concentrations. The methane, being a much more potent greenhouse gas than carbon dioxide, exacerbated things, while the carbon dioxide acidified the oceans, killing most of the animal shellmakers and fertilising the photosynthesis of planktonic plants. The subsequent plankton bloom sucked up the 12C and the isotope ratio veered off in the opposite direction.
The greenhouse warming and the acid rain also did for the forests and many of the reptiles. Only once things had settled down could the survivors regroup. New species of trees took over. The forests grew back. And a bunch of hitherto not-so-terrible lizards began their long march.
You should spend about 20 minutes on Questions 15-28, which are based on Reading Passage 2 on the following pages.
IT'S NOT EASY SEEMING GREEN A backlash to New Zealand's vow of purity
A Fans combing internet sites are not the only people eagerly anticipating a pair of epic fantasy movies based on "The Hobbit", by J.R.R. Tolkien, that it is planned will start filming this year. New Zealand's tourist industry, too, is eager to see the islands' sweeping and unsullied vistas revealed once more to millions of cinemagoers, as they were almost a decade ago when the first of the three films based on Tolkien's "The Lord of The Rings" was released. Those films did a great deal to boost the country's tourism trade (Air New Zealand promoted itself as the "airline to Middle Earth"), fitting nicely with the country's "100% Pure New Zealand" marketing slogan, first used a couple of years earlier.
B But how much of this is, indeed, a fantasy? Last November, in his "Greenwash" column for the Guardian, a British newspaper, environmental journalist Fred Pearce pointed out that New Zealand's greenhouse-gas emissions had risen 22% since 1990 (its commitment under the Kyoto Protocol was to keep them level) and were now 60% greater per head than Britain's. The image New Zealand attempted to show the world amounted to a "shameless two fingers to the global community" in the face of a far dirtier reality, including the world's third-highest rate of car ownership, and methane-belching cows that help to push agricultural emissions to almost half the country's total.
C When tackled on these claims by an Australian reporter, New Zealand's normally amiable prime minister John Key angrily dismissed them as "bollocks", pointing to his country's efforts to tackle its emissions by energetically planting trees that would re-absorb them. But local papers took up the theme. "New Zealand: 100 per cent pure hype" trumpeted the New Zealand Herald. "We are clean and green, but only relatively speaking and by accident rather than conscious effort." The ruggedness of much of New Zealand's terrain may have protected its film-friendly uplands, but at lower elevations farming has stripped away forests, eroded hills and clogged rivers with silt and fertiliser run-off.
D On previous occasions New Zealand has been able to see off threats to its green image. When concerns about "food miles" started to be widely voiced a few years ago, New Zealand's agricultural exports – 40% of its total exports – looked at risk. Few foodstuffs other than those on the space station rack up more miles than a leg of New Zealand lamb on a British dinner table. The government latched on to research by New Zealand's Lincoln University which showed that the country's agricultural exports were relatively efficient in terms of energy use, by comparison to agricultural production in Europe, even when shipping was taken into account. Europe's concerns, it was implied, had more to do with fear of competition from unsubsidised antipodeans than concern about environmental degradation.
E New Zealand has also followed some policies designed to match reality to green rhetoric. In 2007 an "Environmental Performance Review of New Zealand" by the Organisation for Economic Co-operation and Development (OECD) noted a bunch of improvements over the past ten years: better approaches to recycling and water treatment, reforestation of pasture to prevent erosion, strengthened efforts to preserve endangered species, the removal of agricultural and fishing subsidies, and by OECD standards, a high use of renewable energy sources, at 30% of supply. However, the report also pointed to new environmental pressures, such as growing demand for electricity that was leading to greater use of fossil fuels for power generation, and climbing car ownership unhindered by measures such as road pricing.
F Mr Key's centre-right government, elected in 2008, although less green-in-spirit than the previous Labour-led coalition, has taken some environmental action. Just before last year's Copenhagen summit, it enacted an emissions-trading scheme just as an Australian attempt to do the same was foundering. At Copenhagen, Tim Groser, the minister for climate-change negotiations and a pragmatic former trade diplomat, pushed strongly for a "global alliance" to research ways of reducing agricultural greenhouse-gas emissions.
G From an environmentalist's perspective, though, these positives are outweighed by much larger negatives. The emissions-trading scheme excludes agricultural emissions until 2015, and its generous allocations of free carbon credits to business have been lambasted by environmentalists. The country's transport strategy favours road-building over already-scant public transport, and there is much talk of the need to ease resource-management rules that act as barriers to business. In February, the government revealed it was considering opening some of the country's pristine public land up for mining – an activity to which the dwarves in "The Hobbit" are much given, but which is not popular with more elvish sensibilities. Energetic lobbying by environmental groups forced it to scale back the amount of land under consideration, but on March 22nd it announced that it still intended to open 7,000 hectares of conservation land to mining, with other conservation areas to be surveyed for their mineral potential.
H Even the government's boasts of reforestation to replace forests cleared for dairy farming are less green than they might appear. As the Guardian reported, these forests are not long-term sinks for carbon, but plantations, which will when harvested return carbon dioxide to the atmosphere. The Sustainability Council of New Zealand, an independent body, has also criticised this approach as playing games with Kyoto targets.
I In many ways, the dilemma New Zealand faces is not different to that of other rich countries – how to balance economic growth with the need to address environmental degradation. But it is particularly acute in a country so dependent on the export of commodities and landscape-driven tourism. The difference between New Zealand and other places is that New Zealand has actively sold itself as "100% Pure". Now that New Zealanders themselves are acknowledging the gap between the claim and reality, and the risk to their reputation this poses, it is time for the country to find itself a more sustainable brand, and soon.
You should spend about 20 minutes on Questions 29-40, which are based on Reading Passage 3 below.
WHEN YOUR CARPET CALLS YOUR DOCTOR The coming convergence of wireless communications, social networking and medicine will transform health care
Is it possible that amid all the hoopla about Apple's iPad, one potential use has been overlooked? Larry Nathanson, head of emergency-medicine "informatics" at one of Harvard Medical School's hospitals, has experimented with using the device in the casualty ward. He writes that "initial tests with our clinical applications went amazingly well... the EKGs look better on screen than on paper. It was great having all of the clinical information right at the bedside to discuss with the patient."
Dr Nathanson's enthusiasm hints at the potential of wireless gadgets to improve health care, and to ensure more personalised treatment in particular. Pundits have long predicted that advances in genetics will usher in a golden age of individually tailored therapies. But in fact it is much lower-tech wireless devices and internet-based health software that are precipitating the mass customisation of health care, and creating entirely new business models in the process.
Wireless health is "becoming omnipresent" in hospitals, according to Kalorama Information, a market-research firm; it estimates that the market for such devices and services in America alone will grow from $2.7 billion in 2007 to $9.6 billion in 2012. Don Jones of Qualcomm, a maker of networking technology, argues that the trend speeds diagnosis and treatment, and saves doctors' and nurses' time. GE, an industrial giant, and Sprint, an American mobile operator, have joined forces to offer hospitals such services. GE's Carescape software allows the secure monitoring of patients' health via mobile phones, as does rival software from Airstrip.
Doctors are an obvious early target for wireless health. A forthcoming report by the California HealthCare Foundation (CHCF), a think tank, estimates that two-thirds of American physicians already have smart-phones. Over one-third of American doctors use Epocrates, a program for mobiles and laptops which offers instant information on drug-to-drug interactions, treatment recommendations and so on. The software will soon be able to access electronic health records (EHRs) via mobiles – which the author of the CHCF's report thinks could be "the killer application" of wireless health.
The hope is that nimble new technologies, from smart-phones to EHRs to health-monitoring devices, will empower patients and doctors, and thus improve outcomes while cutting costs. The near ubiquity of mobile phones is the chief reason to think this optimistic scenario may come true. Patients with fancy smart-phones can certainly benefit from interactive "wellness" applications that track diet, exercise and vital signs. Apple's App Store, for example, offers thousands of health-related applications. Jitterbug, an American mobile operator that offers easy-to-use phones for the elderly, recently added more health services; rival mobile carriers are doing much the same.
But Carolyn Buck-Luce of Ernst & Young, a consultancy, points out that "mHealth" is transforming health care in poor countries as well as rich ones. Medicall Home, a Mexican outfit that provides medical consultations by mobile, already has millions of customers. Paul Meyer of Voxiva, an American technology firm that has set up mHealth systems in Rwanda and Peru, among other places, says that such schemes have been so successful in the developing world that they are now being adopted in the rich world too. His firm has helped the American government with its recent launch of Text4Baby, a public-health campaign to educate pregnant mothers (they receive free text messages with medical advice) that will soon become the biggest such effort in the world.
What is more, mobile phones are but one part of a broader wireless trend in health care that McKinsey, a consultancy, estimates may soon be worth up to $60 billion globally. Many companies are coming up with "home health" devices embedded with wireless technology. Some are overtly clinical in nature: Medtronic, a devices giant, is developing a bedside monitor that wirelessly tracks the blood sugar levels in diabetic children sleeping nearby. GE has come up with "body sensor networks", tiny wireless devices that track the vital signs of those who wear them.
The most successful gadgets may be, as Eric Dishman of Intel puts it, "surreptitious". His firm, a big chipmaker, is investing in devices to track the health of the elderly, such as "magic carpets" that sense erratic movements and thus can predict a fall. Continua, an industry coalition, is developing shared standards so that blood-pressure monitors and scales can wirelessly transfer readings to doctors' offices or personal HER services like Google Health.
All these devices and services do not just allow doctors to make more accurate diagnoses, prescribe more effective treatments and keep better track of patients' conditions. They also allow health services to tailor treatments depending on patients' personal preferences and behavioral foibles. Studies show, for example, that although some patients with chronic conditions are fastidious about taking pills or insulin properly, others are careless or forgetful. Some prefer efficient electronic reminders, whereas others respond best when a nurse calls home. A global consumer survey released on April 6th by PricewaterhouseCoopers (PWC), a consultancy, finds that the elderly prefer high-quality care with lots of personal attention, whereas younger types prefer low-cost care and wellness schemes.
Many health systems, PWC's accompanying report finds, are beginning to divide customers into different categories and customize treatments accordingly. For example, Discovery Health, a South African insurer, uses a variety of different methods to get patients with chronic diseases to follow through on their treatments, from text messages reminding them to take their pills to rewards for good behavior.
A similar scheme run by HealthMedia, a wellness firm owned by Johnson & Johnson, a big drugs firm, uses online tools (it calls them "digital health coaches") to help patients manage diabetes and lose weight. Its studies suggest that half of the digitally coached do lose weight, and the improved health of those with chronic conditions is worth $1,000 a year to their employers.
Virgin HealthMiles, an American rival, has taken the same idea a step further, using online social networks, through which co-workers or family members can cheer on or nag patients electronically, in order to encourage exercise or weight loss. Patients seem to like this kind of thing: one patient who suffers from ulcerative colitis, for example, has created a forum for fellow sufferers that can be accessed through an iPhone application.
All these initiatives are particularly promising because they help bring about behavioral change, normally the hardest element of any treatment. Patients often ignore doctors' lectures, but are more inclined to listen to supportive friends and family. By the same token, doctors and nurses are not always on hand to encourage healthy behavior, but mobile phones and other wireless gadgets can be. That is something that even personalized genetic therapies could not offer.