The God Species: How Humans Really Can Save the Planet...

Modern humans have at least dealt out death fairly: we began our existence by killing each other. In what looks like a prehistoric bout of all-too-modern ethnic cleansing, Homo sapiens probably drove its closest hominid relatives, Homo neanderthalensis and Homo erectus, to oblivion. A minority of archaeologists cling to the notion that some interbreeding must have taken place, but genetic studies show this is unlikely.

(#litres_trial_promo) Modern human DNA instead confirms that all of us are descended from the same small initial Homo sapiens population that migrated out of Africa 50,000 years ago.

(#litres_trial_promo) The last Neanderthals hung on in remote mountainous parts of France until 38,000 years ago, and in southern Spain until about 30,000 years ago. The very last families died a few thousand years later in Gorham’s Cave in what is now Gibraltar, when their final refuge on the extreme southern edge of the continent was overrun.

(#litres_trial_promo) Officially, the direct cause of their ultimate demise is a mystery, but I think we can guess who the culprit was.

There is certainly enough evidence to mark out a crime scene. One Neanderthal skeleton discovered in Iraq bears a peculiar puncture wound on one of its ribs – a mortal injury that is most consistent with a spear thrown by an anatomically modern Homo sapiens.

(#litres_trial_promo) In early 2009, the anthropologist Fernando Rozzi reported the discovery of a Neanderthal child’s jawbone, found together with anatomically modern human remains at the cave of Les Rois in southwestern France.

(#litres_trial_promo) The bone bore characteristic cut marks, similar to those found on butchered reindeer skulls, suggesting that the tongue had been cut out and eaten. Some loose teeth scattered around also had holes drilled in them, perhaps as parts of a morbid ceremonial necklace. Rozzi drew an unequivocal conclusion: ‘Neanderthals met a violent end at our hands, and in some cases we ate them,’ he said.

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There is even stronger evidence surrounding who killed most of the world’s largest animals, for their butchered bones are found stacked up everywhere humans invaded. As palaeontologist Richard Cowen writes in The History of Life, ‘From Russia to France, [archaeo-logical] sites contain the remains of thousands of horses and hundreds of woolly mammoths.’

(#litres_trial_promo) But the slaughter was far worse in the New World, where native species had no previous experience of this naked and harmless-looking but surprisingly rapacious two-legged predator. The North American death toll included six species of ground sloths, two species of mammoths, all mastodons, a giant bison, seven species of deer, moose and antelope, three species of tapirs, the North American lion, the dire wolf, the giant anteater, the giant turtle, the giant condor, all ten species of North American horses (then absent until reintroduced by invading sixteenth-century Europeans), two species of sabre-toothed cats, eight species of cattle and goats, the North American cheetah, four species of camels and two species of large bears.

But the biggest wipe-out of all took place in Australia, which saw a near-total extinction of large wild animals. The continent lost some extraordinary creatures: a gigantic horned turtle as big as a car, enormous flightless birds standing more than 2 metres tall and weighing half a tonne, a snake 6 metres long, and a giant predatory lizard that grew up to 7 metres in length and must have been the most fearsome reptilian predator since the dinosaurs. About twenty species of large marsupial disappeared, including a cow-sized wombat and a kangaroo 3 metres high. Quite how and when they died remains controversial: many archaeologists have tried to absolve Homo sapiens of the crime, pointing to the lack of kill sites and the low density of human population. But the extinction is roughly coincident with human arrival in the continent, and the pattern – affecting the largest species disproportionately – is exactly the same as everywhere else.

Further damning evidence comes from Tasmania, which retained its giant kangaroos (and various other megafauna) for four thousand more years, until falling sea levels allowed humans to finally invade – whereupon the island’s giant kangaroos (amongst six other large-bodied species) promptly died out.

(#litres_trial_promo) Any remaining doubters need only look to New Zealand. When Polynesian people first arrived by boat a mere 700 years ago, they found a unique island ecosystem where – thanks to millions of years of geographical isolation – birds rather than mammals or reptiles had evolved to become the dominant land animals. Giant flightless moas stalked the forests, whilst enormous eagles, the largest ever known, with wingspans of the order of 3 metres, soared above the mountains. Within as little as a century all – along with half of the islands’ other terrestrial vertebrates – were dead.

(#litres_trial_promo) This time there can be no dispute as to the cause of death or the identity of the killers, for Maori dwelling sites are surrounded by piles of moa bones – some so extensive that they have since been quarried for fertiliser. No doubt believing that the abundance of their moas would last for ever (another pattern that keeps repeating itself), the Maoris wastefully ate only the upper legs and threw the rest away.

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Only one continent’s large animals survived relatively unscathed. That continent was Africa, whose megafaunal inhabitants had co-evolved with hominids over millions of years and had therefore acquired a great deal of useful experience about living with Homo sapiens. As a result, Africa gives us the best idea of what a pre-human landscape might have looked like, with big animals like elephants browsing the undergrowth and herds of wild horses and cattle stirring up dust clouds across the savannah. Indeed, African ecosystems have been used as a model for proponents of ‘rewilding’ parts of North America; if cheetahs, elephants and camels can be imported into places like Montana, perhaps they could assume the ecological niches vacated by their extinct relatives, some have suggested.

(#litres_trial_promo) This is a romantic but vain hope, not least because the ancient homeland of these large surviving animals is seriously endangered by today’s generations of human beings. Africa is safe no more.

Right across the world, these lost big animals left ‘ghost habitats’ behind – trees that still bear specialised fruits hoping some long-gone giant will distribute them, or thorny bushes protecting themselves against browsing by extinct large herbivores. In Brazil, more than 100 tree species still produce obsolete ‘megafauna fruit’, evolved for dispersal by extinct elephant-like creatures called gomphotheres. Not surprisingly, with no living animals to disperse their seeds, these trees are now themselves becoming endangered. In Madagascar many plants grow thin zig-zag branches to protect themselves from leaf-munching elephant birds, another giant flightless bird that became a casualty of Homo sapiens – and that laid eggs so large it is thought to have inspired the legend of the roc in Sinbad the Sailor. Modern-day Siberia’s wet peaty tundra may stem from the loss of the mammoths, whose earlier grazing nourished a much more productive dry steppe-type biome before their extinction at human hands a mere 2,000 years ago.

(#litres_trial_promo) In Africa elephants play a key role in opening up forests by pushing over trees – a function their relatives in the Americas would also have served before being wiped out by man. In all cases, the vanished megafauna maintained a more diverse ecosystem than the simplified one that replaced them after their sudden demise.

All told, the Quaternary Megafaunal Extinction between 50,000 and 3,000 years ago carried off about a half of the world’s large animals (including 178 species of large mammals). This was an extinction wave that bears comparison with the largest in the geological record – but it is still only a prelude to what was to come. The wipe-out that accompanied human migration across the continents was restricted only to the most large-bodied and easily targeted species. In comparison, today not only are the largest animals still at risk, but also small amphibians, songbirds, flowering plants, insects and much else besides. The Sixth Mass Extinction, or the Anthropocene Mass Extinction, is already well advanced – and the death toll will soon rival that at the end of the Cretaceous, when the dinosaurs (and half of the rest of life on Earth) disappeared. Today the small as well as the large wait in line for the cull.

THE SAD STORY OF THE SEA

Perhaps the ecosystem that has been most depleted of its animals in the modern era is the least visible one: the sea. Whilst disappearances on land are comparatively easily studied and recorded, what goes on beneath the waves is an enduring mystery, and humans have traditionally – and tragically – viewed the sea’s bounty as limitless. History once again provides a cautionary tale: the whaling industry, for example, managed to reduce cetacean populations once in the hundreds of millions to near-extinction in just a couple of centuries. The sheer scale of the effort was enormous: in the mid-nineteenth century, when many Atlantic whale species had already been exterminated, some 650 whaling ships operated in the Pacific, employing 13,500 seamen.

(#litres_trial_promo) Southern right whales saw their population reduced to as few as 25 breeding females by 1925,

(#litres_trial_promo) after nearly two centuries of devastating slaughter: a low-end estimate is that 150,000 were killed between 1770 and 1900.

Today the eastern North Atlantic right whales are marked as ‘critically endangered, possibly extinct’ on the IUCN Red List, whilst in the western Atlantic a population of about 300 individuals qualifies merely for ‘endangered’ status.

(#litres_trial_promo) Several are still killed each year by collisions with ships and through entanglement in fishing nets. As each species was destroyed in turn in its primary areas, the industry moved further afield, killing whales from Antarctica to the Galapagos Islands. Calving grounds were often targeted: congregating mothers could be killed while at their most vulnerable and calves captured too or left to starve. Each population was exploited to near-extinction. Most whales are slow-breeding, and with reproduction rates of 1–3 per cent per year the economically rational whaler would gain more benefit from driving the species to extinction and investing the profits elsewhere (to accumulate interest at perhaps 5 per cent a year) than leaving any alive in the sea.

(#litres_trial_promo) Such is the remorseless logic governing the unregulated capitalist exploitation of nature.

As technology improved, so the slaughter worsened. Steam ships could pursue and kill the fastest species, whilst factory ships could process carcasses at sea without having to call at a port. One after the other, blue, sei, fin, humpback, sperm and minke whales were wiped out over most of the ocean. New whaling grounds would be exhausted at most after a decade, sometimes from one year to the next. All told, the twentieth century saw the slaughter of about 3 million whales, leaving only between 10,000 and 25,000 blue whales in the whole world. The killing goes on still, thanks to the ‘scientific whaling’ loophole (more like a chasm) in the current International Whaling Commission (IWC) system. Norway, Iceland and Japan continue to kill whales today using the fig-leaf of scientific research, and these countries and their allies have recently tried to overturn the whaling moratorium altogether at the IWC. Whilst it is plausible that stocks of smaller whales like minkes can support a sustainable annual catch, there is a stronger case for leaving the whales alone altogether until their numbers – and the marine ecosystem generally – can properly recover.

Although no whale species were driven to outright extinction, some marine animals have been extinguished completely. The Steller’s sea cow, a gentle and intensely social Pacific species, was wiped out for its meat and blubber in the mid-eighteenth century. The great auk – a flightless penguin-like seabird that once lived in huge numbers around the North Atlantic – was also exterminated in a determined campaign of slaughter. Once clubbed to death, the bodies would be plunged into boiling water, their feathers torn out (for stuffing pillows and mattresses, as well as adorning hats), whilst the carcass would be boiled for its oil (used for lighting lamps) and the remainder used to fuel the fires that powered the whole ghastly enterprise.

(#litres_trial_promo) Ship crews would move onto remote islands with the sole purpose of killing as many birds as possible during the summer months. Even on the brink of extinction, the hunting continued: the last breeding pair of great auks were beaten to death in Iceland on 3 June 1844, and their single remaining egg was broken.

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Early seafarers were not exactly sentimental about the creatures they encountered. William Dampier, writing about the fur seals he saw on Juan Fernandez island in 1709, marvelled at their beauty, agility and grace, ‘how they lie at the top of the water playing and sunning themselves’ as he put it. But like everyone, Dampier soon got down to business. ‘A blow on the nose soon kills them,’ he added helpfully. ‘Large ships might here load themselves with seal-skins and Trane-oyl [oil]; for they are extraordinary fat.’

(#litres_trial_promo) And large ships did just that, reducing the island’s enormous colonies of seals down to an eventual grand total of just two hundred individuals. One American naval captain related in 1891 how the shooting of fur seal females at sea left their offspring on the shore to starve: ‘Thousands of dead and dying pups were scattered over the rookeries, while the shorelines were lined with emaciated, hungry little fellows, with their eyes turned towards the sea uttering plaintive cries for their mothers, which were destined never to return.’

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Species after species was relentlessly pursued. Walruses were boiled down for their oil. Giant tortoises were seized in raids on the Galapagos Islands and kept alive by being turned on their backs in ships’ holds for months at a time before being eaten for their meat. In ‘one of the great wildlife exterminations of colonial times’, as marine historian Callum Roberts puts it, an original population of 50–100 million hawksbill turtles in the Caribbean was reduced to just a few thousand (it is still critically endangered worldwide).

(#litres_trial_promo) Sea otters, which once swam in their millions in Pacific coastal waters from Mexico to the Arctic, were reduced to fewer than two thousand by 1911. As industrialisation proceeded, the depletion of whole areas could speed up: when seal colonies were first discovered in the remote South Shetland islands in 1820, a quarter of a million were killed and the population brought to near-extinction within just three years.

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All this is in the past, of course. But its impacts are still very much with us, and in many different ways the global slaughter continues. There are no large wild animals left on our planet in anything like the abundance they once enjoyed. Those few hunted species that remain are still under intense pressure; it is as if humanity has learned nothing from past exterminations. Today the extinction of the bluefin tuna is an imminent threat: quotas set at the time of writing by the sadly misnamed International Commission for the Conservation of Atlantic Tunas are high enough to permit fishing boats to catch every single adult bluefin during next year’s season.

(#litres_trial_promo) The fish don’t have much of a sporting chance: illegal spotter planes guide industrial fleets to wherever the last few thousand individuals can be found.

(#litres_trial_promo) Nor have the economics changed much since the days of whaling: the trading conglomerate Mitsubishi was recently accused of stockpiling frozen bluefin in expectation of a post-extinction price bonanza.

(#litres_trial_promo) With individual fish worth up to $100,000 on the Tokyo sushi market, the tragedy of the commons plays out anew every time the tuna fleets set sail.

The destruction of fish habitat is also routinely ignored in the interests of short-term profit. The North Sea off England’s east coast, for example, was not always the murky and uninviting body of water it is today: once its waters were kept clean and sediment-free by rich oyster beds on the sea floor – but these have been ploughed up by trawlers and the sea bottom reduced to a muddy, turgid wasteland. The pressure is unrelenting: intensively fished areas can be hit tens of times in a single year. Deep cold-water corals thousands of years old, supporting flourishing colonies of other marine life, can be reduced to rubble by a single pass of a trawler. Photographs of trawled coral colonies show piles of stony wreckage like the ruins of a pillaged city.

Oceanic island birds are some of the most threatened species anywhere because they are particularly vulnerable to predation by introduced alien invaders. Half of Hawaii’s 140 native bird species are now extinct, thanks to the devastation wrought by introduced rats, pigs and cats. On Australia’s Christmas Island, the Pipistrelle bat population (I realise bats are mammals, but the point is the same) has plummeted by 90 per cent in the last decade (down to a mere 250 mature individuals), due largely to predation by invasive species like wolf snakes, rats and feral cats.

Consequently, one of the quickest wins for biodiversity conservation is the elimination of alien species from islands. In the biodiversity ‘hotspot’ of the Galapagos Islands, 140,000 marauding goats have been removed, whilst in the islands off western Mexico – well-known for their unique species and thriving seabird colonies – cats, rats, goats, pigs, donkeys and rabbits have all been removed to protect endemic animals and plants from destruction. The cost has been tiny, compared with the benefits achieved: just $20,000 per colony for 200 seabird colonies protected, and $50,000 per species for 88 endemic species that are found nowhere else on Earth.

(#litres_trial_promo) That any species anywhere else might be lost for the want of such paltry sums would be a terrible indictment of our current lack of concern for the myriad of plants and animals that share this planet with us.

BIODIVERSITY AND THE EARTH SYSTEM

Of course, we may fret about biodiversity loss, but life in general is incredibly resilient. Living species have colonised every nook and cranny of the planetary system. Spiders, anchored by tiny threads, whizz across the stratosphere carried by hundred-mile-an-hour jet-stream blasts. Thermophilic bacteria cluster hungrily around deep-sea volcanic fissures where temperatures soar well past boiling point. Oil-well samples show flourishing microbial life 2 kilometres or more below our feet.

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Extraordinary diversity is everywhere: a single 30 g sample of soil from a Norwegian forest has been estimated to contain 20,000 different species of bacteria.

(#litres_trial_promo) We are ourselves walking ecosystems: tiny mites crawl around in our eyelashes, whilst billions of bacteria populate our guts. Higher forms of life may be fewer in number, but are far more varied in form. All told, there are estimated to be 11 million species in the world – with countless more waiting to be discovered. Scientists working on a 2009 update for a global biodiversity report first issued in 2006 had to add 48 new reptiles, 200 new fish and 1,184 flowering plants, all identified for the first time in the intervening three years.