The Next Species: The Future of Evolution in the Aftermath of Man (10 page)

China’s one-child policy has slowed growth there, but the momentum created by hundreds of millions of young Chinese still in their reproductive years continues to be a force in the other direction. The country’s current population is 1.3 billion. Today young couples are given housing subsidies as well as retirement benefits if they hold to one child. But even if they don’t have more children, they are still consuming larger portions of the country’s resources in terms of food, energy, and goods as their economy grows.

Population growth in Southeast Asia and the Middle East fuels strife. In rapidly developing countries, young men can’t find employment. However, some can make a living ambushing military vehicles or foreign supply trucks and dividing up the food, blankets, and spoils. Population experts say that 80 percent of the world’s strife since the 1970s has been driven by the explosion of youth.

Without employment, young men can’t save money for a dowry, without which many in the Middle East and Southeast Asia can’t get married. And their culture places heavy penalties, even death, on sex outside of marriage. An enormous youth population denied employment, money, and sex is a formula for disaster.

Two billion more people may be added to the world’s population by 2050, and most of them will come from the poorest countries in Asia, Africa, and Latin America. Security assessments by the US National Intelligence Council warn that climate change could harm food, water, and natural resource supplies, which in turn could lead to global conflicts.

Some say population growth may level off in the next hundred years, but this wouldn’t include human consumption of natural resources. Third World nations that are becoming industrialized want some of the benefits afforded to those that arrived earlier—like cars, electronics, and meat. Modern estimates for how many humans the world could support range from a high of 33 billion for people fed on minimum rations only, down to 2 billion if they all lived like middle-class Americans, a style of life many pursue because they watch it on
television.

The Population Bomb
was a book published in 1968 by Paul R. Ehrlich, a Stanford University professor, that warned of mass starvation as the result of overpopulation. The book was criticized for being alarmist. The cover of the book had this statement. “While you are reading these words four people will have died from starvation. Most of them children.” Ehrlich and his wife, Anne H. Ehrlich, recently revisited the population issue in the
Electronic Journal of Sustainable Development
and concluded that the message of
The Population Bomb
is even more important today than it was forty-five years ago. “Perhaps the most serious flaw of
The Bomb
was that it was much too optimistic about the future,” they wrote.

Their view is that humanity has reached a dangerous turning point in its domination of the planet. We are increasing our numbers and our appetites for our natural resources at the same time. This behavior simply cannot continue.

One of our looming problems is our soil, a vital resource needed to feed our exploding populations. But is the earth’s soil ready for the job?

T
HE RISE OF AGRICULTURE
about ten thousand years ago contributed to the historical population growth of man, but along the way we’ve been destroying the very soil we now desperately need to feed our growing population in the future. To get some perspective on this problem, I visited a number of spots around the world, including Rothamsted Research, the longest-running agricultural research station in the world. The institute, founded in 1843, is in the town of Harpenden in southeastern England, about thirty miles north of London, once dominated by stands of lindens mixed with oak and hazel.
This land was transformed into grasslands around 4500
BC
when immigrants crossed the English Channel and brought in domestic crops and animals.

I stepped off the train as clouds were receding in the sky. The village was flush with bright-green grasses, roughened sidewalks, and colorful ornamental flowers stippled with the early morning rain. Small agricultural fields surround the hedge-bordered town. I walked several blocks to the facility where I hoped to learn more about what the history of agriculture had done to the soils on our planet and what we might expect from them in the future.

Rothamsted Manor, solidly built with bricks and old timbers, lies in the middle of three hundred acres of rolling verdant agricultural lands a few blocks from the train station. The manor was first mentioned in historical documents dating back to the early 1200s. Since then it has grown, rooms have been added, and the title has changed hands at least five times.

John Bennet
Lawes, entrepreneur and agricultural scientist, assumed responsibility for the management of Rothamsted Estate in 1834 after leaving Brasenose College, Oxford. He started a number of agricultural experiments indoors and in the field. Justus von Liebig, a German chemist, taught him how to take bone and boil, grind, and treat it with acid to make fertilizer. Lawes was soon selling “superphosphate” made of powdered phosphate rock treated with sulfuric acid to all the locals. Superphosphate was a super success.

In 1843 he started a fertilizer factory in London, got married, and appointed Joseph Henry Gilbert to manage the field experiments—the official start of the Rothamsted Experimental Station (later Rothamsted Research).

To determine the best methods, Lawes and Gilbert planted two fields of wheat and turnips, divided these into twenty-four strips, and then applied different fertilizers and chemicals to each, refining the ingredients over time and adjusting them for different crops until they got optimum growth. They also took notice of the different effects on crop yields from inorganic and organic fertilizers and how they affected the biodiversity of the plants and animals around them.

Inorganic fertilizers came from mining or mechanical processes. Organic fertilizers came from animals and plants. Lawes and Gilbert determined that all plants increased yields with the addition of nitrogen and phosphorus, whether inorganic or organic. Trace minerals increased yields on some plants but not others. They added fish meal and animal manure from a variety of animals, which were fed different diets. In 1889 Lawes established a trust from the sale of his fertilizer business, and so experiments continued after his death in
1900. Rothamsted researchers began to test the pH level of the soil to determine its acidity or alkalinity, and then added chalk to vary those results and test the difference it made.

In general, fertilizers accelerated crop growth, but researchers also noticed that where inorganic fertilizers were added, waist-high crops grew on agricultural lands, but in nearby fields, species numbers declined. Up to fifty species of grasses, legumes, weeds, and herbs grew on fields away from treated lots, but as few as three species grew on lots adjacent to fertilized plots. Inorganic fertilizer improved crop yield, but it dramatically decreased biodiversity. The arrival of agriculture initiated the long decline of plant species numbers and is part of the biodiversity crisis we are now experiencing.

The spread of agriculture compounded the effects of man on nature and its suite of plants and animals. Most farmers went along with the
reduction of biodiversity, since a decrease of plant species led to fewer weeds. Still, modern agriculture has brought down the number of plant species on earth much like the volcanic eruptions that triggered the Permian extinction and the asteroid that ended the Cretaceous. Fewer species leads to the spread of disease by reducing the number of hosts that carry disease, some of which are better at spreading it than others.

Lawes had trepidation about the situation he had helped create. Though he had been one of the prime movers of inorganic fertilizers, he advised anyone planting vegetables or garden greens to find a location near a farm with a “large supply of yard manure at a cheap rate.” Organic fertilizers, particularly manures, were a better choice even to the inventor of many of our inorganic choices.

In the late 1800s, Europe was struggling to feed its burgeoning population as farmers desperately sought manures for their grains and vegetables. South Pacific islands were stripped of their guano; stables were ravaged for the smallest of droppings; and human refuse, delicately referred to as “night soil,” was tested as well. According to Liebig, even the horse and human bones (good sources of phosphorus) from the Battle of Waterloo were ground up and applied to crops.

Inorganic fertilizers were thought to be the only logical choice by the dawn of the twentieth century, and Queen Victoria knighted Lawes and Gilbert for their agricultural innovation and the benefits their work with fertilizers had brought to UK farmers. Rothamsted Manor, in the center of the fields, has now become a boardinghouse for visiting scientists from around the world. This research station still studies various fertilizers but also looks at refining crops for energy production along with the long-term effects of pesticides, herbicides, and genetic modification.

The agricultural history of the last 160 years is written in the samples of soils, crops, fertilizers, and manures that the research station keeps in its
“sample archive,” where we see indications of increased production after the green revolution as well as evidence of the rise of pollution and fallout from Chernobyl in that same period. This portends poorly for man, because agricultural scientists hope soil will play a big part in doubling food production over the next several decades. We would need to double the amount of crops if we are to have enough grain on the table, feed in the barn, and biofuel in the tank in the future for man to keep going. A polluted and depleted soil report is not a healthy place from which to launch this increase in production, particularly as this may be only the first in a line of requests for more grain. The UN reports that we’ll probably be pushing the limits of agricultural production into the next century.

To discuss the future of man and agriculture, we need to go back and take a closer look at the history of this relationship. At the end of the last ice age, about 12,000 years ago, as we entered the present interglacial period, the planet got warmer, rains fell more frequently, and plants grew bigger and faster than they had in over 100,000 years. Along the way, man realized that
tending plants was easier than hunting game. The push in this direction may have come as man encountered lower populations of game or even extinctions of some key animals brought on by the development of human hunting skills.

The first evidence of domesticated wheat and barley appeared around 9500
BC
, and shortly thereafter legumes such as lentils and peas. Farms were present first in the Fertile Crescent of western Asia. The idea quickly caught on, spreading to Egypt and India by 7000
BC
, and gradually moved into Europe. Rice and millet started popping up in China around this time.

Man began to domesticate animals about the same time he domesticated plants. Goats were tamed around 10,000
BC
in Iran and sheep around 9000
BC
in Iraq. Cattle appeared around 6000
BC
in India and in the Middle East. Agriculture spread more slowly over the northern and southern climates. It arrived even later among New World natives. Yet American Indians discovered maize and potatoes, some of the most important domestic plants in the world today.

Farming produced up to a hundred times more calories per acre than foraging, but it came at a cost to the health of new farmers. Hunter-gatherers rarely suffered from vitamin deficiencies, but farmers got scurvy, rickets, and beriberi because their diets were so base and unvaried. Infant mortality rose, also likely from poor diet. It seems that less protein, fewer vitamins, higher carbohydrates, and less movement were not what the doctor ordered. Humans who began to rely on agriculture shrank in height by almost five inches. Polynesians, American Indians, and Australian aborigines developed type 2 diabetes from their new high-carbohydrate diet and suffered a higher incidence of alcoholism. Alcohol consumption followed the growth of agriculture. There is some thought that barley was first domesticated for brewing beer rather than making bread. Tending crops, it appears, aroused a farmer’s thirst.

Eventually, agriculture did result in larger populations, which led to the establishment of governments to protect and distribute grain, resulting in less fighting and longer lives. About nine thousand years ago the Sumerians invented counting tokens inscribed with pictures that could be impressed in clay to document land, grain, or cattle ownership. Scribes began drawing them with styli made of reeds. The result was known as cuneiform, perhaps our first written language.

Around one hundred thousand years ago, the world had approximately half a million people—counting
Homo sapiens
, Neanderthals, and other hominids. There were about six million
Homo sapiens
twelve thousand years ago at the end of the Ice Age. But then along came agriculture, and from 10,000
BC
to
AD
1, populations exploded about a hundredfold.

Agriculture improved life because it decreased competition for hunter-gatherers for a while, but then population growth caught up with the increased food supply. Greater populations, confined living, and proximity to domestic animals increased human contact with disease. Our impact on the environment grew. Wild animal diversity shrunk.
While we were nomadic, our effect on the land wasn’t too drastic, but once we settled down all hell broke loose.

Back at the Rothamsted Institute, I followed Kevin Coleman, a research scientist, into the institute’s
sample archive, a focal point for visiting scientists. Housed in a warehouse on the Rothamsted grounds are rows upon rows of five-liter bottles, all dated and stacked on shelves sixteen feet high that hold harvest grain, stalks, seed, and soil from test plots going back 160 years. On one high shelf is a sample of Rothamsted’s first wheat field, dated 1843. To avoid mold, the bottles are all sealed with corks, paraffin, and lead. During World War II, samples were kept in discarded tins that once held powdered milk, coffee, syrup, and other wartime essentials.