Are models for the origins of agriculture in southwest Asia based on a misunderstanding of the relationship between wild and domesticated wheat?

农业被认为始于大约10,000年前的“新月沃土”，这是亚洲西南部的一个地区，包括美索不达米亚、叙利亚、以色列、约旦和巴勒斯坦的平原，以及安纳托利亚东部的一些山区。农业的开始是人类历史上最重要的事件之一，是人类第一次摆脱环境的限制，学会如何塑造环境以达到自己的目的。农业也对人类社会产生了深远的影响，最终导致了人口的快速增长和复杂文明的发展，如古典希腊和罗马。许多研究致力于了解农业的起源，但许多问题仍然没有答案。其中最重要的一个问题是，从狩猎采集到农业的转变是一个迅速的过程还是一个渐进的过程。最初，关于这一主题的观点受到实验研究的影响，这些研究表明，如果采用适当的饲养方法，那么野生谷物经历与驯化相关的遗传变化所需的时间可能短至几十年。一个有吸引力的想法是，一群开明的人可能在几代人的时间内驯化了一种或多种主要作物，这一想法得到了野生和栽培谷物第一次全面遗传比较的支持，这被解释为表明土耳其东南部卡拉卡达格地区的一粒小麦迅速驯化。其他遗传学研究支持谷物被迅速驯化的观点，但对个别作物的驯化过程发生的确切位置存在分歧。另一方面，考古学研究给出了相互矛盾的证据，表明谷物驯化是一个漫长的过程，需要几千年才能完成。那么，为什么对同一种作物的不同遗传分析会得出不一致的结果，为什么这些结果都与考古证据不一致呢？一个可能使遗传研究复杂化的未被认识到的因素是，驯化作物与其野生祖先种群之间存在网状关系，而不是线性关系。线性关系是指作物直接从野生种群遗传而来，而网状关系则是指作物与其并非直接遗传而来的各种野生种群之间的杂交。我们已经获得了初步证据，野生和驯化的二粒小麦之间的关系确实是网状的。在这个新项目中，我们计划获得更全面的遗传数据，看看事实是否如此。该项目很重要，因为目前的农业起源模型，无论是基于遗传学还是考古学，都倾向于假设野生植物和作物之间的关系是线性的。因此，证明这种关系更加复杂将改变我们对早期农业的思考方式，扩大可以考虑的模型范围。这些新模式之一是早期农民从新月沃地的不同地方收集野生二粒小麦的有趣可能性，这些不同野生植物的最有用的特征在作物中结合在一起。

Agriculture is thought to have begun about 10,000 years ago in the 'Fertile Crescent', a region of southwest Asia comprising the plains of Mesopotamia, Syria, Israel, Jordan and Palestine, and some of the mountainous areas to the east of Anatolia. The beginning of agriculture was one of the most important events in the human past, being the first occasion on which humans broke free from the limits imposed by the environment and learnt how to shape the environment to their own ends. Agriculture also had far reaching effects on human society, eventually resulting in rapid population growth and the development of complex civilizations such as those of Classical Greece and Rome. Much research has been devoted to understanding the origins of agriculture but many questions remain unanswered. One of the most important of these is whether the transition from hunting-gathering to agriculture was a rapid or a gradual process. Initially, views on this topic were influenced by experimental studies which showed that if appropriate husbandry practices were applied, then the period required for a wild cereal to undergo the genetic changes associated with domestication might be as short as a few decades. The attractive idea that a single group of enlightened people could have been responsible for the domestication of one or more staple crops within a few human generations was supported by the first comprehensive genetic comparison of wild and cultivated cereals, which was interpreted as indicating a rapid domestication of einkorn wheat in the Karaca Dag region of southeast Turkey. Other genetic studies supported the idea that cereals were domesticated rapidly, but disagreed about exactly where the process took place for individual crops. Archaeological research, on the other hand, has given conflicting evidence suggesting that cereal domestication was a protracted process that took several millennia to complete. So why do different genetic analyses of a single crop give inconsistent results, and why do none of these results agree with the archaeological evidence? One possible, unrecognised factor that might be complicating the genetic studies is that domesticated crops have a reticulate rather than linear relationship with their wild progenitor populations. A linear relationship is where the crop is descended directly from a wild population, whereas reticulation arises when there is cross-hybridization between the crop and various wild populations from which it is not directly descended. We have obtained preliminary evidence that the relationship between wild and domesticated emmer wheat is indeed reticulated. In this new project we plan to obtain more comprehensive genetic data to see if this is in fact the case. The project is important because current models for the origins of agriculture, whether based on genetics or archaeology, tend to assume that the relationship between wild plants and the crop is linear. Demonstrating that the relationship is more complex will therefore change our way of thinking about early agriculture, broadening the range of models that could be considered. One of these new models would be the interesting possibility that early farmers collected wild emmer wheat from different parts of the Fertile Crescent, the most useful features of these different wild plants becoming combined in the crop.