Inheritors of the Earth

by Chris D. Thomas

  That does not mean that animals and plants were unchanged by the new circumstances. Far from it. Mammals and birds certainly filled a void. The maximum body size of mammals gradually increased, and one-tonne animals were again roaming the Earth about 10 million years after the dinosaurs were gone. They continued to grow larger until about 35 million years ago, since when the largest mammals have remained about the size of the weightiest elephants, although relatives of the rhinoceros have on occasion been a little heavier.17 The evolution of dolphins and whales came later, the oceans having been emptied of their reptilian equivalents: the plesiosaurs, mosasaurs and ichthyosaurs. The Earth was gradually reverting back to its natural state of huge plant-eaters and uncomfortably large predators, a history that goes back for 200 million years. It stayed that way until humans came along and cleared the Earth of its largest mammals in an evolutionary blink of the eye.

  The asteroid that hit the Earth 66 million years ago was a calamity. In a matter of years or decades it wiped out three-quarters of the species that previously existed, leaving the Earth to be inherited by animals and plants that were regular creatures, which had already been around for many millions of years before that time. The future was already part of the past, in the same way that house sparrows and tree sparrows were regular animals ‘minding their own business’ before they found that the new human-transformed world was to their liking. The inheritors of the future Earth are already among us today, just as they were all those millions of years ago. Although some will be temporary good-news stories, perhaps profiting from methods of farming that will disappear within centuries of their invention, those that succeed in the long run can only come through the ranks of the initial survivors. Only they will be able to leave descendants millions of years from now. Life is the story of the winners.

  Back at the Smithsonian Museum, we consumed the success stories of the human epoch, surrounded by the fossils of extinct dinosaurs, the bones of mastodons and the stuffed bodies of species that still survive. The winners of modern times are in our glasses and on our plates. Living brewer’s yeasts are prospering, converting sugars from the fruits of cultivated European vines into intoxicants for our pleasure. Grape vines, whose fruits evolved to be attractive so that animals would move their seeds to new places, have been extremely successful because they attracted humans. First known from archaeological sites eight thousand years ago on Georgia’s Black Sea shores,18 grape vines are now grown from California to China, in Chile and South Africa, and in Australia and New Zealand. We broke bread made from the ground-up seeds of a human-made plant–wheat–which had arisen from the hybridization between different species of grasses from the Middle East. We ate the delicious muscles of sheep, animals that have come to look less and less like their mouflon ancestors, ten thousand or more years since they were first domesticated in western Asia. They now live throughout the world.

  For these chosen animals and plants and fungi, we have entered an era of mutual benefit. This might seem odd because we grind the grains of wheat and maize into flour and kill our cattle and sheep to eat their meat. This is hardly to their individual advantage. Yet this is little different from the way oak and pine trees benefit from the presence of squirrels and birds. Bushy-tailed squirrels scamper off with acorns that fall from tall oak trees, hoarding them for future use. The pied tails of Clark’s nutcrackers, a kind of seed-eating crow, can be seen disappearing into the distance as the birds traverse deep ravines, each taking a gulletful of whitebark pine seeds to its caches on high ridges in the Rocky Mountains. Later, when only the windswept ridges are free of winter snow or when they need an extra supply of food to feed their chicks, they will return to reclaim their buried seeds. Acorns and pine nuts will die. But the squirrels and nutcrackers will not necessarily remember the exact location of every buried store, and some of these animals will die before they have consumed their entire cache. The oaks and pines sacrifice most of their offspring to the rodents and birds that will harvest them. But, in the long run, the trees benefit because the squirrels and nutcrackers also plant their seeds in places where new trees will eventually sprout. The seeds that survive become the next generation of trees, akin to our own relationship with the crops we grow and the livestock we keep. Most individual crop plants and domestic animals will die to feed us, but humans ensure that some live, and these in turn spawn subsequent generations. The ecological success of humans is down to this arrangement.

  The plants may give up their fruits and seeds, but this is all part of the evolutionary deal. According to the United Nations Food and Agriculture Organization (FAO), maize, rice and wheat cover more than a third of all of the world’s cultivated land.19 They are the most successful plant species that exist today. It is entirely valid to think of them as having taken advantage of a gullible primate to prepare the land for them, sow them, fertilize them, ensure that they are free of pests and diseases, and then keep their seed safe until the next generation can be planted. Who is manipulating whom?

  It is bonanza time for animals that can consume these human-tended plants. Where wild beasts once roamed, livestock now graze. Around 30 per cent of the world’s productive land is covered by pasture, supporting enormous numbers of large mammals. Others just stand around in barns and wait for us to bring them their food. These animals might not be quite the largest that have ever lived, but cows and sheep are considerably more convenient than fields of mammoths. If we think of the entire planet as one big production system, with plants trapping energy from the sun to convert atmospheric carbon dioxide into sugars and thence into more plant material, animals eating the plants, and meat-eating animals consuming the plant-eaters, then the transformation of the Earth is amazing. Prior to this transformation, the million or so humans that were alive would have represented a small fraction of 1 per cent of the combined body mass (biomass) of all of the mammals that roamed the land, but by the year 2000 humans weighed in at about 30 per cent of the biomass of all land mammals, and most of the rest is our domestic livestock.20 Humans are hijacking over 97 per cent of mammal biomass to our own ends.

  Even more startling, the total amount of mammal flesh has increased–meaning that the weight of all individuals of all large land mammals added together is over seven times greater than it was before humans came along.21 There are about 1.5 billion cattle, 1.2 billion sheep and 1 billion goats alive, as well as a billion pigs, over 130 million water buffalo, perhaps 58 million horses, at least 40 million donkeys, 13 million camels, some 7 million llamas, over a million domesticated reindeer, and so on. As for carnivores, there are over 500 million domestic dogs and a similar number of cats, although this pales into insignificance compared to 7 billion meat-eating humans (an additional approximately 5 per cent of humans are vegetarian).

  Four of the world’s most successful mammal species in the modern era: a human (my daughter Lucy winning the ‘child handler of the year’ rosette at the village dog show in 2004), our Irish wolfhound, Rex, a skinny horse and a cow. There are over 7 billion humans (primate), half a billion dogs (carnivore), 58 million horses (odd-toed ungulate) and 1.5 billion cows (even-toed ungulate) in the world. Note the fifth successful species, a cattle tyrant (passerine bird) sitting on the horse’s back. These birds presumably used to feed by following extinct South American animals around, catching the insects they disturbed. Today they follow domestic cattle and horses, which are even more numerous.

  Not to be outdone, feathered dinosaurs–birds–are also thriving. There are about 22 billion chickens alive and half a billion turkeys. The total biomass of large birds has increased as we provide them with grain to eat, dose them with medicines and protect them from foxes. As a global production system, the present is not a dip in the total numbers or combined weight of large animals. Surprisingly, it is a substantial increase. The natural state of the world–to be full of large herbivorous animals and carnivores that eat them–continues to the present day.22

  Soon, the total weight of big land mammals will b
e ten times greater than it was in the pre-human world, as the human population continues to expand and meat becomes an increasing component of the global diet. In an evolutionary sense, there are now more copies of the genes of our domestic cows, pigs and sheep than there used to be, just as the number of copies of the genes of humans has increased because we eat them. And these species are geographically more widespread than they used to be. The world map of the current diversity of large mammals should really add humans and domesticated cows, sheep, goats, camels, water buffalo, horses, donkeys, pigs, llamas and alpacas. In most parts of the world, the ‘true’ current diversity of the megafauna is around seven to ten species higher than depicted. This mutually beneficial ‘arrangement’ (in terms of numbers of copies of genes, not individual welfare) between humans and our livestock means that the Anthropocene is just as much an age of mammals and birds as it ever was.

  The extinction of wild species and the rise of domestic animals mean that hunting is no longer required for our sustenance.23 Nor is it feasible. Ten thousand and more years ago, a mere one-thousandth of the current human population was capable of eating most species of large mammal to extinction, admittedly over a long period. If it were not for domestic animals, the 7-plus billion of us alive today might be expected to polish off all remaining large wild mammals in about a month. Where hunting large wild mammals for food persists, it is usually unsustainable. Bushmeat hunting in Africa, for example, is continuing to drive numbers down and the rational management of the oceans is still some way off. There is not enough wild meat to feed us. However, habits can be hard to break, especially when traditions become luxuries or are linked to particular beliefs. The Japanese do not need to eat whale meat to survive, and large wild animals continue to be hunted towards extinction for their ivory, horn, as pets (for example, killing the parents to obtain infant chimpanzees), traditional medicines, spiritual pick-me-ups and due to cultural tradition, rather than because we need their essential nutrients.

  Then there is the tradition of hunting itself, now a hobby more than a necessity. It is an activity enjoyed by those who appreciate the camaraderie among hunters and dream of a more natural past but who, in reality, are likely to spend their time dispatching commercially raised pheasants and quail. Sport hunting, originally the preserve of royalty, has become a tale of the unspeakable in pursuit of the plump, tasty and reasonably easily shot. Captive-reared and semi-tame Asian pheasants are released into the English countryside so that today’s spaniel- and labrador-owning townsfolk can have a ‘good’ day out with their mates in the surrounding fields.

  Yet traditions can change surprisingly quickly, all the more so once people are healthy, wealthy and secure. My great-grandmothers presumably looked fetching wearing the plumes of threatened birds in the Victorian era, and my grandmothers kept warm in fur coats and stoles. By the middle of the twentieth century, my mother wore dyed chicken and pheasant feathers in her hat, rather than egret, but still wrapped up in my grandmother’s fur coat on special occasions. My sisters wore rabbit-fur and sheepskin coats in the late 1960s and ’70s, but no one in the family would wear furs today,24 let alone the feathers of endangered birds. This complete change in societal norms has taken place in less than a century. Now, we live in an era where in many parts of the world the killing and wearing of large wild animals is no longer regarded as acceptable, although this social transition still has a way to go.25

  Take Walter Palmer, the dentist from Minnesota who in 2015 suddenly became one of the most hated figures on the internet because he had shot ‘Cecil the lion’ with his bow and arrow. As it turned out, he was taking part in a legal game hunt, and hunting preserves do protect a wide range of wild animals and plants that cannot live in regular farmland. Nonetheless, most people who had access to computers across the world regarded it as intolerable; and Walter’s sins were magnified because Cecil had been given a name. Online commentators were merciless with their barbed comments, just as he was when he dispatched the cat.

  As our nutritional needs are now provided by the crop plants we grow and the domestic animals we tend, our urge to hunt can be replaced by other enthusiasms, including conservation, tourism and photography. Shorn of the need to kill large wild animals for meat, bone, sinew, skin and fur, our slaughter has been reduced to the lowest levels in centuries in some parts of the world, especially in Europe and North America. We increasingly see these animals as a source of enjoyment and recreation, and conservationists have been able to enshrine their protection in law.

  In the United States, the birth rates of wolves and grizzly bears for the first time in many generations exceed the rates at which humans kill them–both of these rather dangerous animals again stalk the land, recolonizing from their Canadian strongholds. American bison is off the threatened list. The European bison is up from one wild population to thirty-three; the goat-like southern chamois has increased five-fold since 1970; there has been a 14,000 per cent increase in European beavers since the 1950s; and deer and wild-boar numbers have quadrupled in Europe.26 They are chewing and nose-ploughing their way through the vegetation to the point that conservationists have begun to discuss the ‘deer problem’ and the ‘wild-boar situation’. Their predators are needed to control them.

  No problem: bears, wolves, golden jackal, wolverine and lynx are repopulating Europe too–save for Britain, separated by a barrier of water from continental Europe. Wild geese, swans, storks, herons and cranes are returning as well, and the great whales, the largest animals ever to have lived on Earth, are once more plying their way across our seaways in growing numbers after centuries of unsustainable butchery. Once we stop killing them, large animals come back, rejoining the 90-plus per cent of smaller ones that never disappeared in the first place. Meanwhile, our domestic animals have reverted to the wild. Horses roam across North and South America. Water buffalo and camels populate the outback in Australia. Wild pigs are common in parts of the USA, and feral cattle populations have established themselves in the Hawaiian Islands, the Aleutians, Campbell Island, and elsewhere. The circle is nearing completion. First, we killed off most of the largest animals. Then we domesticated some of the survivors. And now that we rely on these domesticated animals for our food, it is possible for the still-surviving large animals to prosper once more. Unless some calamity befalls the world (which is entirely possible), there will be considerably more large wild mammals in existence one hundred years from now than there are today.

  A love of fur: guests at the wedding of my aunt and uncle Ruth and Harry Downing, in 1951. Relatives of the groom attended in wild-cat pelts, probably ocelot (top), while those of the bride wore the odd feather with their mink and muskrat coats and stoles (below). In times of post-war austerity, my mother, Diana (bottom right), borrowed her mother’s oversized coat for the occasion, and my eldest sister, Philippa, and brother, Jeremy, had been bought coats with arms that they would be able ‘to grow into’. Their descendants in the twenty-first century would not contemplate wearing furs. This change in attitude has enabled the numbers of large mammals and large birds to start to increase again in Great Britain, and in other countries where they are no longer persecuted.

  Where large animals have not returned fast enough for our liking, we have begun programmes of affirmative action, releasing wolves in the wilds of Yellowstone National Park in the States and beavers in Britain’s manicured river valleys and ponds. South Africans created Pilanesberg National Park as a deliberate, post-wildlife-apocalypse haven for large animals, a game reserve to service the tourist mecca of Sun City. Humans and their livestock were removed, their villages and farmsteads erased, waterholes added and the whole landscape secured behind a shocking fence. ‘Operation Genesis’ involved the release of over six thousand individual large mammals into the park in the 1980s: an early example of what is now known as ‘rewilding’, which is the idea that wildlife can be put back and then left alone to thrive. However, it is not quite so simple. The fence needs to be maintained, the elepha
nts and rhinos guarded, and it was later felt necessary to remove the (previously introduced) wild dogs to allow their prey to survive. Large animals may be thriving once more, but often within the confines of pseudo-wild worlds.

  As long as the human condition can be improved throughout the world (sufficiently for us to care more about saving than killing wildlife), such recoveries are likely to become more widespread–at least within human-managed enclaves. Yet, somehow, we yearn for something a little more natural: places that have always been truly wild, places where gargantuan animals still rule and where radical intervention is not required. Places like Danum Valley in Borneo, where I got caught in the middle of an elephant herd. But this sense of a wild world without humans is a mirage. We have transformed the whole planet.

  The rhinoceros that used to live in Danum have been hunted to extinction–the last one removed for its own protection–and the overgrown pygmy elephants that live there in their stead are not even native to Borneo. In 1750, the British East India Company gifted some of these great beasts to the Sultan of Sulu, who used to rule the north-eastern corner of the island of Borneo. The pygmy elephants that now live in Danum’s jungle are presumed to be descendants of these domestic animals because there are no well-substantiated remains demonstrating the historical presence of wild elephants on the island in the last ten thousand or more years; and ‘wild’ pygmy elephants are virtually confined to the parts of Borneo where the sultan once ruled.27 The native languages even lack a word for them.28