Although not normally what first comes to mind, many forms of human-derived agriculture clearly fit the
broad definition of "using a biotechnological system to make products". Indeed, the cultivation of plants
may be viewed as the earliest biotechnological enterprise.
Agriculture has been theorized to have become the dominant way of producing food since the Neolithic
Revolution. Through early biotechnology, the earliest farmers selected and bred the best suited crops,
having the highest yields, to produce enough food to support a growing population. As crops and fields
became increasingly large and difficult to maintain, it was discovered that specific organisms and their by-
products could effectively fertilize, restore nitrogen, and control pests. Throughout the history of
agriculture, farmers have inadvertently altered the genetics of their crops through introducing them to new
environments and breeding them with other plants — one of the first forms of biotechnology.
These processes also were included in early fermentation of beer. These processes were introduced in
early Mesopotamia, Egypt, and India, and still use the same basic biological methods. In brewing, malted
grains (containing enzymes) convert starch from grains into sugar and then adding specific yeasts to
produce beer. In this process, carbohydrates in the grains were broken down into alcohols such as
ethanol. Later other cultures produced the process of lactic acid fermentation which allowed the
fermentation and preservation of other forms of food, such as soy sauce. Fermentation was also used in
this time period to produce leavened bread. Although the process of fermentation was not fully
understood until Louis Pasteur's work in 1857, it is still the first use of biotechnology to convert a food
source into another form.
For thousands of years, humans have used selective breeding to improve production of