Although there are popular debates about determining the oldest profession,
the growing of crops and the herding of animals are certainly among
the oldest of human activities that have lead to the development
of human society as it is known today.
Until about 10,000 BC, humans lived exclusively by hunting, fishing
and gathering their food and materials for clothing and shelter.
After the last Ice Age, the earth's climate warmed up in both the
eastern and western hemispheres to produce conditions that favored
fast-growing plants. In what is now called the Neolithic Revolution,
much of mankind gave up the nomadic life, settling in areas in which
crop plants could grow. The planting of crops and selection of seed
to be stored for next year's harvest developed. Soon after, sheep
and goats were domesticated. Finally, by about 6,000 BC, cattle were
brought under control. Milk, as well as meat, became staples in the human diet.
Although the stimulus for agriculture came mainly from the need for
food for an increasing population, people, even in prehistoric times,
were using many agricultural by-products: leather was tanned for
clothing; fibers from sheep and plants were spun and woven into cloth;
vegetable oils were burned in lamps to provide light and heat; soaps
were made from fats and wood ashes; medicinal herbs were used for
their physiological effects which, although not well understood at
the time, have proven to be useful in modern medicine.
Agriculture did not change much from 1,000 BC to 1500 AD despite
numerous advances in technology. Food preparation evolved. Spices,
imported from the East, were increasingly used for preservation and
to provide variety, and some new crops, such as potatoes, corn (maize),
potatoes, tomatoes and tobacco, were introduced after the discovery of the New World.
The industrial revolution at the beginning of the nineteenth century
and its profound changes in science and technology transformed the world of agriculture:
the canning process to preserve food was invented by Nicholas Appert;
the science of genetics and the basis for plant and animal breeders
to improve agricultural production in a systematic way was initiated
by Mendel after the publication of the results of his experiments
with pea plants in 1866; food spoilage and many important aspects
of food processing, e.g. pickling, brewing and bread making, was
explained by Pasteur in his research on microorganisms.
When petroleum-derived oil and natural gas became plentiful and cheap
at the beginning of the 20th century, many agricultural fuels for
heating and lighting stopped being used. The internal combustion
engine began to replace the horse as a primary means of travel and
transport, and the use of many agricultural products for industrial
purposes was discontinued, such as hemp in the making of rope. But,
even in the early part of the 20th century, many of the best innovators
believed that crops could be used as raw materials for a variety
of industrial products. For example, Henry Ford's new V-8 cars contained,
in 1934, half a bushel of soybeans in the form of paint, plastic
gear shift knobs and horn buttons. Ford's researchers produced textile
fibers from soybeans and, in 1941, a prototype automobile with a
plastic body composed largely of soybean- derived products was exhibited
by Ford. On his side, Thomas Edison searched for a domestic source
of rubber and found that goldenrod had good potential.