Domestication and agricultural origins

【Guangming Academic Writing】

Author: Li Shuicheng (Professor, Peking University, Chair Professor of Liberal Arts, Sichuan University)

Before the advent of agriculture, human beings went through a long stage of development. Between 12,000 and 10,000 years ago, due to climate change and human evolution, human society entered the origin stage of agriculture. The peak of the last Ice Age of the Holocene was between 21,000 and 15,000 years ago. After the end of the Ice Age, human society has undergone a series of development and changes, the biggest of which is reflected in cultural aspects, such as the standardization of stone tools, the emergence of religious rituals, the expansion of social network systems, including the emergence of agriculture and the subsequent emergence of settled societies, pottery and other processing tools.

When humanity began to enter the stage of domestication agriculture from the long hunter-gatherer society, it underwent an important change, that is, the emergence of the "broad-spectrum revolution" form. The ecological explanation is that humans have shifted from using "k-select resources" (large animals, with limited growth potential, overuse will lead to resource depletion) to "r-select resources" (small species with high potential yields and will not deplete resources due to exploitation). Climate change has led to the extinction or alteration of ranges of many large animals, forcing humans to seek new and more stable food sources beyond fishing and hunting.

What is "domestication"? With choice as a prerequisite, the growth and reproduction of animals and plants are changed by human activities, and a symbiotic relationship developed between animals and plants and humans is "domestication". And the amount of food obtained through active production exceeds half of the food needed by a society, and the domesticated animals are no longer confined to their natural habitat, and such a quantitative degree can be said to have entered the domestication stage.

The domestication of plants by humans is a very slow, complex process. The first is the cultivation and acquisition of wild crops, and then it can enter the real domestication stage. The emergence of a grain production system that includes partially domesticated crops and that requires systematic cultivation is a real sense of domestication. What are the signs of domestication? Taking barley as an example, the wild form of barley has defensiveness and diffusion, and the domesticated form of barley defense disappears, the size becomes larger, the growth is relatively stable and synchronized, and the self-pollination germinates rapidly, which is the domestication process of crops from the morphology.

Exploration and Practice of Domestication and Agricultural Origins. The early theoretical exploration of agriculture and domestication by European scholars is the "agricultural strip distribution theory". The theory holds that from the polar region to the tropics, polar hunters, nomadic groups, plough farmers, nomadic + hunter-gatherers, tropical growers + hunter-gatherers are distributed in turn. After the 20th century, botany, genetics and agronomy began to explore the origins of agriculture, and the Soviet scientist Vavilov made great contributions to the study of botany, genetics and plant populations. On the basis of plant taxonomy and distribution, he depicts and summarizes 7 domestication centers, including tropical South Asia center, East Asian center, Southwest Asian center, Mediterranean center, Ethiopia center, Central American center, and Andean (South American) center. But botanical conclusions do not solve the problem of crop domestication and agricultural origin in the true sense, and the real solution to the problem requires the intervention of archaeology.

The famous British archaeologist Childe was the first to put forward the theory of the "Neolithic Revolution". The advent of farming and the raising of livestock were a major turning point in human history, and this turning point occurred in the Near East, so this area is an important area for exploring the origins of agriculture. From the 1940s to the early 1950s, multidisciplinary comprehensive research gradually became the benchmark research method for the origin of agriculture. The American archaeologist McNeish, who began archaeological excavations and research in Central America in the 1950s and 1960s, believes that the initial stage of agriculture was not accompanied by the emergence of settled villages, pottery, polished stone tools, etc. that were listed by Childe as the basic elements of the "Neolithic Revolution". Therefore, McNiche proposed that the origin of agriculture was not a revolution, but a long evolutionary process.

Seven domestication centers in the world. Through archaeological discoveries, research and unremitting exploration, we can already determine that there are seven important domestication centers in the world, including the two river basins in western Asia, the Savannah region south of the Sahara Desert in Africa, North America, Central America, South America, and China's Yellow River Basin and Yangtze River Basin. The two river basins in western Asia, including the Levantine region in the west and the Zagros Mountains in the east, are very important areas of agricultural origin, especially the Levantine region on the eastern Mediterranean coast. The area is native to wild barley, one grain of wheat. The domestication lineage of wheat, through extensive archaeological, botanical, genetic, and genetic studies in the Near East, has been found to be from one wheat to two wheat and then to six wheat. Agriculture spread outward after the emergence of the Near East, showing a wave of spread to northwestern Europe, a process that lasted for more than 5,000 years. Agriculture in Africa enters the lower Nile valleys along the Mediterranean Sea from the southern Levant, but Africa itself has indigenous agriculture, mainly in the Savannah region of the southern Sahara Desert. The varieties of indigenous African agriculture are represented by pearl millet, sorghum and African rice. The domesticated crop species of the Americas are so abundant that they can account for 60% of our food species today, which has had an important impact on the composition of the world's crop varieties, including pumpkins, corn, potatoes, sunflowers, peanuts and legumes. Agricultural development in East Asia is mainly in China. The main domesticated crops in the middle and lower reaches of the Yangtze River are rice, and the jade toad rock in Dao County in southern Hunan and the site of the Immortal Cave in Jiangxi Are of great significance for studying the origin of rice farming. The earliest rice grains have been found at the Yutouyan site in Daoxian County, dating back to about 18,000 to 16,000 years ago, and the earliest pottery in China and even the world has been unearthed. About 10,000 years ago, rice cultivation in the middle and lower reaches of the Yangtze River has become quite popular. In the 1970s, the Hemudu cultural site in Yuyao, Zhejiang Province, also unearthed a large number of rice seeds and agricultural tools for growing rice. The Yellow River Basin and the dryland agricultural areas of northern China are also important domestication centers. The ancestral plant of the dry-land crop millet is the dogtail grass that we can see everywhere today, and the ancestor of the millet should have been a wild species that grew in the northern region at that time. Soybeans, the oil crop, are also important crops for domestication in East Asia. Many archaeological sites in the northern region have unearthed carbonized millet, millet, soybeans, and hemp. There is also a center of domestication, namely Southeast Asia and Oceania. The area is an island in the tropical ocean, and people eat a large number of tuber crops, such as potatoes, taro and so on.

Based on the above new archaeological data, it can be concluded that the origin of agriculture is not limited to individual parts of the world, but independently produces unique crop varieties in several scattered areas of the world. The Agricultural Revolution is often thought of as a shift from hunter-gatherer to settled agrarian society.

Domestication and the effects of agriculture. There are about 200,000 edible plant species growing on Earth, of which 2,000 to 3,000 have been used as food by humans and 200 have been domesticated by humans. 70% of the earth's arable land is grown with grain, and grain provides 50% of the heat to humanity. But agriculture is not a way of production that human beings aspire to or prefer, but is a change that human beings are forced to change under the influence of an external force. Some scholars have a negative view of this. However, domestication is, after all, the historical trend of human development. The stage of hunting-gathering activities in human history has completely relied on nature, and the domestication activities and the birth of agriculture have made human beings shift from simply relying on natural sustenance to active creation and acquisition, which has led to the development of society at an unprecedented high rate. As Arvin Toffler points out, the emergence of agriculture was the first of three great waves in the course of human history. Around 4500 years ago, human beings entered the early national stage, which reflects the great impetus that domestication and the birth of agriculture have had on human society.

Guangming Daily (2022-09-13 11 edition)

Source: Guangming Network - Guangming Daily