第二篇：

　　TOPIC：Wild Crops Domestication in Southwest Asia 西南亚野生作物的驯化/种养

　　描述了西南亚野生作物驯化(domestication)的艰难。

　　第一段：理解西南亚农业文化的发展，不可避免的要理解小麦(wheat)、大麦(Barley)的驯养化(domestication)过程。最早进行驯养化的野生作物是豆荚(legume)("推理题"：选项为豆荚legume不是理解西南亚农业文化必不可少野生作物作物--小麦、大麦才是)。 在西南亚驯养化过程中，猪(pig)的地位比牛(cattle)、羊(sheep)重要。

　　第二段：野生作物的驯养化艰难。早期农民发现，只有在很多条件共同满足下才能得到饱满的稻穗：如阳光，水 和土壤(sunlight, water and soil)。所以如果野生作物不能发展出适应恶劣环境或者各种环境的特征，农民只能在稻田里收割到很少的作物，并且分布分散(scattered in the tract)。

　　第三段：稻穗中有一个重要的结构是连接茎秆(stalk)和穗头的部分的"柄"。通常野生作物的"柄"非常脆弱，风一吹或者动物一碰，穗头就会掉落，这给早期农民收割稻穗带来很大的麻烦。因为不能用镰刀(sickle)收割(镰刀太硬，碰落稻穗)。但是如果不用镰刀，收割作物是很困难的(这句为"插入提"， 插入句中有sickle这个单词，只有前面这一句提到了sickle)。

　　第四段：另一个驯养化困难是：野生作物有坚硬的外壳(husk)，以保护kernel不受霜冻和寒风的侵袭(frost and wind)。而人类的消化系统难以消化如此坚硬的外壳。还有一个困难是，野生作物的一株作物的麦穗只有两根，产量很低，现代驯养化的一株作物的麦穗有六根，所以野生作物需要发展出多麦穗的特征。

　　第五段：野生作物只有发展出以上所说的所有驯养化特征，才值得农民大面积"劳动密集型"耕作。(此举为"重述题")。

　　解析：本文话题属于生物学中的植物学和农业史的结合，与TPO中如the Origins of Agriculture较对应;本文结构从机经回忆来看，主体结构是分类，围绕野生作物驯化的困难分别来谈。本篇文章考生普遍反映难度较大，主要是所谈内容与城市日常生活较远，建议大家在平时复习时多积累一些各学科的基本知识。

　　Plant Domestication

　　The earliest human attempts at plant domestication occurred in South-Western Asia. There is early evidence for conscious cultivation and trait selection of plants by pre-Neolithic groups in Syria: grains of rye with domestic traits have been recovered from Epi-Palaeolithic (c. 11,050 BC) contexts at Abu Hureyra in Syria, but this appears to be a localised phenomenon resulting from cultivation of stands of wild rye, rather than a definitive step towards domestication.

　　By 10,000 BC the bottle gourd (Lagenaria siceraria) plant, used as a container before the advent of ceramic technology, appears to have been domesticated. The domesticated bottle gourd reached the Americas from Asia by 8000 BC, most likely due to the migration of peoples from Asia to America.

　　History of Wheat

　　History

　　Wheat likely originated in the so-called Fertile Crescent of the Middle East, land which extended from Israel along the Mediterranean Sea north to southern Turkey and east to Iraq and the Persian Gulf. It was also probably native to southwestern Asia. Some of the earliest specimens have been discovered in Jordan, Syria, and Turkey. Early types of wheat have been excavated in Iraq, dating to over 11,000 B.C. Archaeological research indicates that wheat was being farmed in Egypt's Nile Valley since before 5,000 B.C., and also in China and India. Sumerians (in what is now southeastern Iraq) around 3100 B.C. wrote about both bread and beer made from wheat.

　　Geography

　　Archaeologists have determined that agriculture began there in the Fertile Crescent region, when people began growing wheat and other crops rather than foraging for them. Other ancient cultivated crops include barley, grapes, dates, and nuts. People in this region also were the first to herd goats, pigs, and sheep. It took only a few centuries for people to do away with hunting and gathering as their main source of food, after many thousands of years obtaining food that way.

　　The first cultivated crop in the Americas was maize in Mexico, which was not purposely planted in large amounts until around 4,000 B.C..

　　Significance

　　Wheat is very significant in history because it is one of the crops which transformed hunter-gatherers into farmers. People had long gathered wheat where it grew wild, but with agriculture, a more dependable food supply was created. This in turn made life easier with more free time, and people were able to turn more attention to other pursuits such as creating textiles and pottery, and doing woodworking and making tools.

　　Agriculture, along with herding of animals, allowed for the growth of large permanent communities, as well as a privileged elite class in cities. It also resulted in battles for productive areas, evidenced early in the Bible after Moses led the Israelites to the promised land, where they then had to fight to get it away from the people already living there.

　　Egypt was the largest producer of wheat in ancient times, with enormous harvests unequaled even today. It became the basis of the nation's economy. Egyptians first created raised yeast breads as a contrast to the unleavened bread which had been the only type available before.

　　The objectives of wheat domestication

　　-To produce 'non-shattering' varieties that have seeds that are not lost by breaking off the plant before harvest. Wild grasses are adapted to dispersing their seeds by releasing them once ripe but grasses under cultivation, such as wheat, need to have seeds that are retained and only break off during the threshing process. Selection of non-shattering varieties would have occurred quickly once cultivation started, as it was only these plants that would have been successfully harvested.

　　-To produce large, plump seeds.

　　-To produce more seeds per plant by increasing the number of fertile flowers (termed florets in grasses).

　　-To produce 'free-threshing' or 'naked' varieties where the husk round the seed comes off during threshing. All's that needs to be done after threshing is for the grain to be winnowed so that the empty husks (i.e. chaff) are blown away from the seeds. Wild varieties of wheat are hulled - i.e. the seeds are covered by a tough husk that stays round the seed once it has been threshed. To get this husk off the seed, it has to be pounded in some way which is more laborious than winnowing the husks away and means the grain is broken and less suitable for storing.

　　-To produce seeds that germinate together. Wild forms are adapted to delay germination until there are suitable conditions and to vary the timing of germination so that seeds do not grow up and die altogether during a season of erratic and poor rainfall.