Darwin's Island (19 page)

‘Let them eat cake!’ said the Queen, and they did. Two centuries after the demise of Marie Antoinette, the poor are fat and the rich thin. Across the globe death from excess has, for the first time in history, overtaken that from deficiency. Eight hundred million people are hungry while a billion are overweight. The problem comes from evolution, as manipulated by man.

Darwin saw how farmers had bred from the best to produce new forms of life and used that notion to introduce the idea of natural selection. His argument is set out in the first chapter of
The Origin of Species
. Given time, and with conscious or unconscious selection of the best by breeders, new and modified versions of creatures from pigs to pigeons will soon emerge. Were they to be found in nature rather than in sties or lofts many would be recognised by naturalists as distinct species of their own.

In
The Variation of Animals and Plants under Domestication,
published in 1868, Darwin went further in exploring the tame as the key to the wild. The book speaks of ancient times, when ‘a wild and unusually good variety of a native plant might attract the attention of some wise old savage; and he would transplant it, or sow its seed’. That interesting event - the choice of favoured parents to form the next generation - was a microcosm of what had moulded life since it began. The variety of breeds seen on the farm was, he wrote, ‘an experiment on a gigantic scale’, both a test of his theory and a proof of its power.

Savages have been replaced by scientists. Their work has produced many new varieties of plants and animals and, on the way, has revealed the eccentric history of the food on our plates. Modern biology has transformed farming. Planned breeding - directed evolution - has led to an enormous drop in the effort needed to feed ourselves. The British spend a sixth of their income on breakfast, lunch and dinner, a proportion down by half in the past five decades and by far more in the past five centuries. For most people, shortage has given way to glut and for many citizens of the developed world food is in effect free.

The blessings so brought are equivocal. The real price of sugar, starch and fat - high energy but low-quality comestibles - has plummeted. Famine disguised as feast has spread across the globe. Evolution on the farm transformed society ten millennia ago and is doing the same today. Farmers have been powerful agents of selection on wheat, maize, cows, pigs, chickens and more, but the influence of those domestic creatures on the biology of the farmers themselves has been almost as great. Diet began to act as an agent of natural selection as soon as the wild was domesticated ten thousand years ago and caused people to evolve the ability to deal with new kinds of food. Today’s shift in what we eat will have equally powerful effects on the genes of our descendants.

A new global power - and a new agent of natural selection - is on the move. The empire of obesity began to flex its stomach in the 1980s and shows no sign of retreat. Twenty years before that dubious decade there was, in spite of a collapse in the real price of food, little sign of the coming wave of lard. Then, thanks to technology, came the industrialisation of diet; the last step in the scientific exploitation of the Darwinian machine. Now, a tsunami of fat has struck the world and its inhabitants are paying the price.

It does not take much to alter a nation’s waistline. The rise in American obesity over the past thirty years can be blamed on an increase in calories equivalent to no more than an extra bottle of fizzy drink for each person each day. At the present rate two-thirds of Americans and half of all Britons will be overweight by 2025 and Britain will be the fattest nation in Europe. Among industrial powers, only China and its neighbours are insulated from the scourge.

The twenty-first-century plague is a side-effect of the triumph of scientific agriculture. Many of those worst afflicted suffer because they bear genes that make it hard for them to deal with the new diet. Many of the obese will die young or fail to find a mate. As a result obesity will soon be - as farming itself was when it began - a potent cause of evolutionary change.

 

The people who laid out the first fields lived above the rivers that snaked across a green and leafy Levant. For millennia they hunted game and gathered seeds as man had done for the whole of history. Just after the peak of the last ice age the Middle Eastern weather became wetter and warmer and the grasses flourished. The gatherers prospered. Thirteen thousand years ago came a nasty shock, for the climate turned cold and dry for several centuries. The chill persuaded people to plant grains, rather than just to collect them. Soon the thermometer went up once more, the crops flourished and agriculture made its presence felt. Within a few centuries, the Fertile Crescent was filled with tillers of the soil.

A similar way of life, based on maize and rice rather than on wheat and chickpeas, soon got under way in South America and China and, in time, even in Papua New Guinea, where banana and sugar-cane cultivation emerged six and a half thousand years ago. The habit spread fast. Farming reached Britain some four thousand years ago. The shift to the new economy was quite rapid, and the pursuit of wild game was more or less replaced by agriculture within just a couple of centuries, although people still ate plenty of seafood (and that remnant of the chase persists today). As new crops emerged the locals began to husband animals that could feed on them. Soon a hundred people could live on the space that had previously supported but one.

The new economic system led to a grand simplification of diet.
Homo sapiens
has eaten some eighty thousand kinds of food since he first appeared on Earth. A dig in Syria of the homes of hunters who lived just before the new economy emerged revealed a hundred and fifty varieties of edible fruit, grain and leaf in that single society. Even in the nineteenth century, Queensland aborigines feasted on two hundred and forty different kinds of plant. As the new way of life spread, the cuisine became simpler. Within a few years, the Middle East had just eight crops: emmer and einkorn (antecedents of wheat), barley, peas, lentils, bitter vetch and chickpeas. Quite soon the people of the whole world considered together ate no more than half the number of plants once used by a single hunter-gatherer band. In most places just a couple of crops - rice, maize or wheat included - became the staple food. They kept that status for ten millennia.

Now, things have changed once more. Some lucky citizens have taken a great leap backwards. The middle classes have returned to the hunter-gatherer diet. They forage in pricey supermarkets for an eclectic range of edibles, from avocado to zucchini, imported from across the globe. The revolution of the rich began soon after Columbus, when exotic delicacies such as potatoes, peanuts and tomatoes were brought from the New World. Other delicacies went the other way, albeit sometimes after a long delay; broccoli, for example, was almost unknown in the United States until the 1920s. On both sides of the Atlantic, those who can afford it have put ten thousand years of dietary history into reverse.

The advocates of avocado are still in a minority. Many of their fellow Americans or Europeans have meals almost as dull as those of the first peasants, without the privilege of growing the raw materials themselves. Just as at the dawn of agriculture, their choices are narrower than were those of their parents and grandparents. Cheeseburgers, chips and sweet drinks are full of cheap energy and the poor have seized upon them. Nowadays, the British obtain twice as many calories from fats as did their immediate forebears and on average the intake of sodium has gone up by ten times and that of calcium down by half compared with earlier times.

The junk food revolution tells the tale of artificial Darwinism in all its details. The taming of the hamburger also shows how man, the most domestic creature of all, has paid a high price as he tests the biological limits set by his own evolution.

The first farmers, like the modern poor, became less healthy as their dietary options shrank. The symptoms were different from those of today, but the causes - an abundant but inadequate cuisine - were the same. Their bones show signs of deficiency disease and the average height of adults dropped by fifteen centimetres as the new way of life spread. The loss was not regained for several thousand years. In North America, where maize became the basis of almost every meal and where it was worshipped as a god, another problem was a shortage of iron, for maize lacks the mineral and also interferes with the ability to absorb it from meat. Many people became anaemic. No doubt they were tired, weak and depressed as they pursued their wretched lives as tillers of the soil. Deficiency and its diseases - lassitude, infirmity and sadness included - have returned, but disguised as excess.

Thirty thousand premature deaths a year in the United Kingdom are due to an expanded waistline and ten times that number in the United States, where, in 2005, obesity overtook smoking as the main preventable cause of mortality. It is more than a coincidence that as America’s spending on food as a proportion of national income went down by almost half, that on health care was multiplied by three times. In Central and Eastern Europe, even more healthy years of life are lost per head than in Britain. The present generation of men and women - those who grew up before the new age of edible trash - may be the longest-lived in history.

The problem for their children is fat. Medicine has long known how dangerous the blight can be; in Hippocrates’ words: ‘Corpulence is not only a disease itself, but the harbinger of others.’ Thousands have died before their time of heart disease, stroke, cancer and diabetes, the four horsemen of the obese. Many others suffer from gout, arthritis, bladder problems, reduced fertility and the other conditions that affect the fat far more than the thin. The most dangerous effect of gluttony is to grow to resemble an apple rather than a pear, for extra inches on the waist are much more harmful than the same on the backside - and the apples are taking over from the pears even among women, who used to put more on the bottom than the belly as their weight went up. The apple brigade store fat around their livers, where it is readier to spring into action and to release fat itself, hormones and agents of inflammation into the bloodstream.

In the modern United States, as in the New World at the dawn of agriculture, Native Americans have paid a particularly high price for the change in diet. A century ago, many kept to their traditional cuisine. The Pima Indians of Arizona - the Corn People as they called themselves - were thin as they ate their hearty meals of tortillas or porridge, based on maize. Now, they gorge on burgers, chicken and sweet drinks instead. In some ways, however, their food input has not changed for the Pima eat just as much maize as did their grandparents. The difference is that today it has been through a cow, a chicken or a soft-drinks factory first.

Cheap corn gave birth to fast food. One American meal in five is eaten in the car and the maize needed to feed its four passengers with a cheeseburger each would more than fill its tank. A Chicken McNugget has thirty-eight ingredients - and thirteen come from maize. The fizzy beverage that washes it down is based on corn syrup and the raw material of the post-prandial milkshake comes from a cow fed in a yard, on maize, rather than in a field, on grass. The ‘natural strawberry flavour’ that adds its dubious tang is natural only because it is made from corn and not synthesised from chemicals. A quarter of the food items in American supermarkets now contain maize, and their rows of cheap packaged products - and thousands are introduced each year - bear witness to the second agricultural revolution that has taken place in the lifetime of most readers of these pages.

Seed crops - maize most of all - transform sunshine into food. Even better, they are easy to store and to move. Cows evolved to eat grass in fields, but now it makes more economic sense to feed them on grain on giant lots. More than half the maize and soy grown in the world is eaten by animals. As a result, global meat production has gone up four times since the 1960s, and the amount of flesh available per head has doubled.

 

Scientific farmers have done in a few decades what took peasants centuries to achieve with no science at all, but the early farmers’ approach was, in its essence, identical to that of modern technologists. They understood little of what they were up to and may not even have made the tie between sex and reproduction. By the Middle Ages, the idea that attributes ran in families was accepted; as the 1566 book
The Fower Cheifyst Offices Belongyng to Horsemanshippe
put it: ‘it is naturally geven to every beast for the moste parte to engender hys lyke’. Soon artificial selection, conscious breeding from the best, was under way (even if the horse-racing and dog-fancying fraternities clung to the odd idea that qualities were passed only down the male line). In the eighteenth century, English improvers became aware of the need to mate animals of equal ‘beauty’ and agricultural science was born. Robert Bakewell, chief among the breeders, was frank about his motives. He called his barrel-chested New Leicester sheep ‘machines for turning herbage . . . into money’ and hired out his rams for stud at £1000 a season - a huge sum for those days.

Now animal breeding has become a massive business. Champion bulls and stallions can sire thousands of offspring, and new statistical methods allow their young to be compared over hundreds of farms to see which have done best. Often, the actual genes that lie behind their talents are not known. Milk yield in cows has doubled since the 1940s, but the sections of DNA that did the job stayed hidden for sixty years. Molecular biology is beginning to change that, with the DNA sequence of most domestic animals now complete, together with maps of hidden diversity that can track down where the most productive variants might be. The annual gain in meat or milk production brought by genetics is, in the developed world, around 1.5 per cent a year, well over a billion pounds’ worth in Europe alone. Artificial aids - mechanical cows into which bulls can ejaculate and have their semen smeared across the globe, cloned sheep, engineered crops and more - promise wondrous things. Even so, with the consumption of meat expected to double in the next decade that will not keep up with demand. Plant technology has been even more successful and many genes for high yield or disease resistance have been tracked down, with many brought in from the wild relatives of our domestic species. Agriculture now works with foresight, a talent quite unknown to evolution but used, at least subconsciously, by the first farmers of all.