The Rational Optimist_ How Prosperity Evolves - Matt Ridley [73]
There is one respect in which the environmental critique of modern agriculture has force. In the pursuit of quantity, science may have sacrificed nutritional quality of food. Indeed, the twentieth-century drive to provide a growing population with an ever faster-growing supply of calories has succeeded so magnificently that the diseases caused by too much bland food are rampant: obesity, heart disease, diabetes, and perhaps depression. For example, modern plant oils and plentiful red meat make for a diet low in omega-3 fatty acids, which may contribute to heart disease; modern wheat flour is rich in amylopectin starch, which may contribute to insulin resistance and hence diabetes; and maize is especially low in the amino acid tryptophan, a precursor of serotonin, the ‘feel-good’ neurotransmitter. Consumers will rightly be looking to the next generation of plant varieties to redress these deficiencies. They could do so by eating more fish, fruit and vegetables. But not only would this be a land-hungry option, it would suit the wealthy more than the poor, so it would exacerbate health inequalities. Arguing against vitamin-enriched rice, the Indian activist Vandana Shiva, echoing Marie-Antoinette, recommended that Indians should eat more meat, spinach and mangoes rather than relying on golden rice.
Instead, genetic modification provides an obvious solution: to insert healthy nutritional traits into high-yielding varieties: tryptophan into maize to fight depression, calcium transporter genes into carrots to help fight osteoporosis in people who cannot drink milk, or vitamins and minerals into sorghum and cassava for those who depend on them as staples. By the time this book is published soybeans with omega-3 fatty acids developed in South Dakota should be on the way to supermarkets in America. They promise to lower the risk of heart attacks and perhaps help the mental health of those who cook with their oil – and at the same time they can reduce the pressure on wild fish stocks from which fish oils are derived.
Chapter Five
The triumph of cities: trade after 5,000 years ago
Imports are Christmas morning; exports are January’s MasterCard bill.
P.J. O’ROURKE
On The Wealth of Nations
A modern combine harvester, driven by a single man, can reap enough wheat in a single day to make half a million loaves. Little wonder that as I write these words (around the end of 2008), for the very first time the majority of the world’s population lives in cities – up from just 15 per cent in 1900. The mechanisation of agriculture has enabled, and been enabled by, a flood of people leaving the land to seek their fortune in the city, all free to make for each other things other than food.
Though some came to town with hope and ambition, and some with desperation and fear, almost all were drawn by the same aim: to take part in trade. Cities exist for trade. They are places where people come to divide their labour, to specialise and exchange. They grow when trade expands – Hong Kong’s population grew by thirty times in the twentieth century – and shrink when trade dries up. Rome declined from a million inhabitants in 100 BC to less than 20,000 in the early Middle Ages. Since people have generally done more dying than procreating when in cities, big cities have always depended on rural immigrants to sustain their numbers.
Just as agriculture appeared in six or seven parts of the world simultaneously, suggesting an evolutionary determinism, so the same is true, a few thousand years later, of cities. Large urban settlements, with communal buildings, monuments and shared infrastructure, start popping up after seven thousand years ago in several fertile river valleys. The oldest cities were in southern Mesopotamia, in what is now Iraq. Their emergence signified that production was becoming more specialised, consumption more diversified.
It seems that farmers on the rich alluvial soils of the southern