Synthetic fertilizers are manufactured using a technique that transforms nitrogen in the atmosphere into a form that can be applied to crops ammonia. These chemicals have dramatically increased short-term crop yields, though not without consequences.
The heavy use of synthetic fertilizers has become a hallmark of industrial agriculture. Freight train carrying grain across Washington state. Beyond synthetic fertilizers, other innovations in food production and distribution helped food supplies keep pace with population growth.
Expanded railways, shipping canals, and new machinery for storing and moving grain made it easier to transport food to where it was most needed. From to , the global population grew from 1. Still, the sheer volume of production dwarfs that of earlier generations. What has made such unprecedented abundance possible? Innovations in food production and distribution have thus far helped food supplies keep pace with population growth.
Crops indigenous to the Americas, such as corn, sweet potatoes, and cassava, spread across the globe. The nutrients provided by these prolific crops helped prevent malnutrition, supporting a widespread increase in population over the 18 th century. Of all the innovations in agriculture, arguably none has been more influential than synthetic fertilizers—chemicals manufactured using a technique that transforms nitrogen in the atmosphere into a form that can be applied to crops ammonia.
The following list of suggested resources is intended as a starting point for further exploration, and is not in any way comprehensive. Montgomery D. Dirt: The Erosion of Civilizations. Boston, MA: Houghton Mifflin; Kremer M. Q J Econ. Trinkaus E. Early Modern Humans. Annu Rev Anthropol. Diamond J. New York, New York: W.
Norton and Company; Evolution, consequences and future of plant and animal domestication. Macronutrient contributions of insects to the diets of hunter-gatherers: A geometric analysis.
J Hum Evol. Vasey D. An Ecological History of Agriculture: 10, B. The latest woolly mammoths Mammuthus primigenius Blumenbach in Europe and Asia: A review of the current evidence. Quat Sci Rev.
Simon Fraser University; National Research Council. Lost Crops of Africa. Washington D. Annu Rev Entomol. In Mexico, squash cultivation began around 10, years ago, but corn maize had to wait for natural genetic mutations to be selected for in its wild ancestor, teosinte. While maize-like plants derived from teosinte appear to have been cultivated at least 9, years ago, the first directly dated corn cob dates only to around 5, years ago. Corn later reached North America, where cultivated sunflowers also started to bloom some 5, years ago.
This is also when potato growing in the Andes region of South America began. Cattle, goats, sheep and pigs all have their origins as farmed animals in the so-called Fertile Crescent , a region covering eastern Turkey, Iraq and southwestern Iran.
This region kick-started the Neolithic Revolution. Dates for the domestication of these animals range from between 13, to 10, years ago. Genetic studies show that goats and other livestock accompanied the westward spread of agriculture into Europe, helping to revolutionize Stone Age society. While the extent to which farmers themselves migrated west remains a subject of debate, the dramatic impact of dairy farming on Europeans is clearly stamped in their DNA. Prior to the arrival of domestic cattle in Europe, prehistoric populations weren't able to stomach raw cow milk.
But at some point during the spread of farming into southeastern Europe, a mutation occurred for lactose tolerance that increased in frequency through natural selection thanks to the nourishing benefits of milk. Judging from the prevalence of the milk-drinking gene in Europeans today — as high as 90 percent in populations of northern countries such as Sweden — the vast majority are descended from cow herders. Photograph by Robert Madden. Fertile Crescent. Near East. Stone Age.
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Text Text on this page is printable and can be used according to our Terms of Service. Interactives Any interactives on this page can only be played while you are visiting our website. Related Resources. Agricultural Communities. View Collection. View leveled Article. The alternative scenario suggests that man had to reach a certain level of social organization or tool-making development, with a settled mode of life, before agriculture was possible, and this stage of human development was only reached 9 - 10 years ago.
The move from shifting agriculture to domesticated agriculture was preceded and made possible by the millennia of accumulated experience of wild plants and animals, and trial-and-error experimentation. There was probably a gradual shift from collecting to cultivation with continued reliance on hunting and gathering. Finally there was almost complete reliance on agriculture as the major source of nutrition.
In some areas of the world, primitive methods are still the most effective. Photographs Courtesy of Dr. The stages of harvesting, planting and storing imposed various artificial selection pressures such as the following:. Over time, these selection pressures produced changes in the crop and seeds that are characteristic of domesticated crops. These changes referred to as domestication markers are most pronounced when comparisons are made between the domesticated crop and its wild relatives.
Typical domestication characteristics exhibited by modern varieties of maize left and Wheat right. Galton - identified behavioural and physiologic characteristics of animals which would make them better candidates for domestication i. Goats exhibit more pre-adaptations to domestication than pigs. List 5 advantages and 5 disadvantages to a community that may arise when communities become sedentary. Can you find out using the internet the percentage of UK households that grow any of their own food?
The world was formed ca 4, million years ago. Eukaryotic life forms: ca. First hominid life forms 4 million years ago hunter gatherers. First human farmers: about 12, years ago. Global Agricultural Evolution: — AD. Modern Agricultural Evolution: - present. Social structure promote cooperation.
Knowledge of cultivation techniques. Cultivation involves the deliberate sowing or other management of plants which do not necessarily differ from wild populations. In short, domestication involves genetic change through conscious or unconscious human selection. Near East Fertile Crescent. South China Yangtze River.
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