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Genetic basis for rice domestication discovered |
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Written by Eric Watt
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Apr 01, 2006 at 08:38 PM |
Rice, along with other cereals, was one of the earliest domesticated plants, and helped give rise to the development of agriculture. Recent studies have helped discover the genetic basis for its domestication.
Around 10,000 years ago, humankind underwent a drastic transformation. We developed agriculture. This allowed us to expand both technologically as well as rapidly increase our population size. Termed 'The Neolithic Revolution', humans began to transition from a life of hunting and gathering to one of farming. Settlements became more permanent, and numbers began to grow. People were for the first time able to specialize in a particular task. Soon, large cities began to grow.
Needless to say, the development of farming has drastically shaped our world today, and continues to be a critical part of our lives. Scholars currently believe that farming arose independently in three places: the Fertile Crescent (currently the Middle East), Asia, and, to a lesser extent, Central America.
The earliest crops that were domesticated were the cereals, wild grasses with edible seeds. Wheat, barley, and others were farmed in the Fertile Crescent, rice was the main staple in Asia, and maize was cultivated in the Americas.
In wild grasses, it is necessary for the seeds to drop to the ground when they mature. While beneficial for the plant, this makes it harvesting the seeds for food very difficult. One of the earliest traits selected for in the domestication of these plants was the ability of the seed to remain on the plant until harvest. Until recently, it was not understood how this trait was controlled genetically.
A recent paper in Science (subscription required) found that it is a mutation that substitutes a single amino acid in a DNA binding domain gene is responsible for the ability of domesticated rice to hold on to the grain as it matures. It is interesting that this crucial feature of cereals, that was so necessary for early human domestication, can be controlled with such a simple mutation. Had it been required that multiple mutations were necessary for a reduction in grain shattering, perhaps early human agricultural development would have not been possible.
For further information on early agricultural development:
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Science Sunday 