托福阅读背景材料(347)：部落迁徙

　　托福阅读背景知识/材料之部落迁徙，更多托福阅读背景材料/知识尽在新东方在线托福考试频道！

　　2014年6月21日托福阅读真题再现：

　　版本一：讲某个部落的人迁徙到一个新的地方。他们即是游牧的，但又会种植作物。但是最后不得不迁徙，因为人太多了。wild animal和作物都不够吃。

　　版本二：climate对N族人的影响 他们开始更大范围的hunt 种grain之类的

　　版本三：

　　一个人种(囧)在younger dryra年代的生活 【编者注：此处人种经查找很可能为“Natufian”】

　　一开始说因为河流和水源渐渐干涸，猎物(game)也随之越来越少(此处有题)，所以人们需要更精湛的捕猎技巧，也因为这个发明了一种新的arrowhead(有题)。

　　后来呢他们捕不到足够的猎物了就settled了，开始cultivated rye crop， 把野生的rye慢慢“驯化”了。考古学家还在一个村子里发现了公元前11100-11020的rye，这是最早的人工培育rye。

　　但是呢，cultivated rye也不能满足需求啊，所以他们又变回游牧了，然后domestic rye又变wild了(有题)。

　　最后一段说他们后来因为水源干涸放弃了祖先生活的woodland，改而搬迁到更富饶的约旦河边(jordan river)。哦这里也有题。

　　新东方富亦聪解析：

　　解析：历史题材文章结构为时间顺序，故而逻辑性较少，属于直线型文章。读文章时光看首句不一定能概括全段，需通过题目进行段意还原。而且还要多考虑各段之间的关系。

　　相关背景：

　　Younger Dryas

　　From Wikipedia, the free encyclopedia

　　Three temperature proxies showing the Younger Dryas event at around 12 ka BP. The NGRIP sequence (red – mislabelled as GRIP) uses the water molecule isotopic composition – δ18O. The Vostok and EPICA Dome C series show delta-deuterium. All 3 proxies use the same vertical axis.

　　The Younger Dryas stadial, also referred to as the Big Freeze, was a geologically brief (1,300 ± 70 years) period of cold climatic conditions and drought which occurred between approximately 12,800 and 11,500 years BP. The Younger Dryas stadial is thought to have been caused by the collapse of the North American ice sheets, although rival theories have been proposed.

　　It followed the B?lling-Aller?d interstadial (warm period) at the end of the Pleistocene and preceded the preboreal of the early Holocene. It is named after an indicator genus, the alpine-tundra wildflower Dryas octopetala. In Ireland, the period has been known as the Nahanagan Stadial, while in the United Kingdom it has been called the Loch Lomond Stadial and most recently Greenland Stadial 1 (GS1). The Younger Dryas (GS1) is also a Blytt-Sernander climate period detected from layers in north European bog peat.

　　The Dryas stadials were cold periods which interrupted the warming trend since the Last Glacial Maximum 20,000 years ago. The Older Dryas occurred approximately 1,000 years before the Younger Dryas and lasted about 3000 years. The Oldest Dryas is dated between approximately 18,000 and 15,000 BP.

　　The Younger Dryas, an intense cooling and drying event of global proportions, has been attributed a major causal role in the adoption of agricultural economies in the southern Levant. Here, the impact of the Younger Dryas on human adaptations is evaluated using a small game index that measures the efficiency of human foraging as a proxy for site occupation intensity. The study examines faunal assemblages spanning the agricultural transition and dating to the Early and Late Natufian and Pre-Pottery Neolithic periods (ca. 14,500 to 11,000 Cal. BP). The small game index and other supporting evidence document major fluctuations in human site occupation intensity across this critical phase. Site occupation reached an unprecedented high during the Early Natufian, but quickly reverted to pre-Natufian levels with the onset of the Younger Dryas in the Late Natufian phase. By decreasing site occupation intensity and increasing mobility, the Late Natufians implemented effective demographic strategies to cope with changing resource distributions. In contrast, there is no evidence for intensified resource use or food stress in the Late Natufian, at least in comparison to the Early Natufian phase. Although, it is tempting to assign the Younger Dryas a causal role in the adoption of agricultural economies, support for this hypothesis (in the form of food stress and resource intensification) does not currently exist.

　　Natufian culture

　　The Natufian culture /n??tju?fi?n/ was an Epipaleolithic culture that existed from 13,000 to 9,800 B.C. in the Levant, a region in the Eastern Mediterranean. It was unusual in that it was sedentary, or semi-sedentary, before the introduction of agriculture. The Natufian communities are possibly the ancestors of the builders of the first Neolithic settlements of the region, which may have been the earliest in the world. There is some evidence for the deliberate cultivation of cereals, specifically rye, by the Natufian culture, at the Tell Abu Hureyra site, the site for earliest evidence of agriculture in the world. Generally, though, Natufians made use of wild cereals. Animals hunted included gazelles.

　　The term "Natufian" was coined by Dorothy Garrod who studied the Shuqba cave in Wadi an-Natuf, in the western Judean Mountains, about halfway between Tel Aviv and Ramallah.

　　Settlements

　　Remains of a wall of a Natufian house

　　Settlements occur in the woodland belt where oak and Pistacia species dominated. The underbrush of this open woodland was grass with high frequencies of grain. The high mountains of Lebanon and the Anti-Lebanon, the steppe areas of the Negev desert in Israel and Sinai, and the Syro-Arabian desert in the east were much less favoured for Natufian settlement, presumably due to both their lower carrying capacity and the company of other groups of foragers who exploited this region.

　　The habitations of the Natufian are semi-subterranean, often with a dry-stone foundation. The superstructure was probably made of brushwood. No traces of mudbrick have been found, which became common in the following Pre-Pottery Neolithic A (PPNA). The round houses have a diameter between three and six meters, and they contain a central round or subrectangular fireplace. In Ain Mallaha traces of postholes have been identified. "Villages" can cover over 1,000 square meters. Smaller settlements have been interpreted by some researchers as camps. Traces of rebuilding in almost all excavated settlements seem to point to a frequent relocation, indicating a temporary abandonment of the settlement. Settlements have been estimated to house 100–150, but there are three categories: small, median, and large, ranging from 15 sq. m to 1,000 sq. m of people. There are no definite indications of storage facilities.

　　Sedentism

　　A semi-sedentary life may have been made possible by abundant resources due to a favourable climate at the time, with a culture living from hunting, fishing and gathering, including the use of wild cereals. Tools were available for making use of cereals: flint-bladed sickles for harvesting, and mortars, grinding stones, and storage pits.

　　Development of agriculture

　　According to one theory, it was a sudden change in climate, the Younger Dryas event (ca. 10,800 to 9500 BC), that inspired the development of agriculture. The Younger Dryas was a 1,000-year-long interruption in the higher temperatures prevailing since the Last Glacial Maximum, which produced a sudden drought in the Levant. This would have endangered the wild cereals, which could no longer compete with dryland scrub, but upon which the population had become dependent to sustain a relatively large sedentary population. By artificially clearing scrub and planting seeds obtained from elsewhere, they began to practice agriculture. However, this theory of the origin of agriculture is controversial in the scientific community.