Group 1 - An international team, including Shandong University and Washington University in St. Louis, discovered carbonized small bean remains dating back 9,000 years at the Xiaogao site in Zibo, Shandong Province, which is 4,000 years earlier than previously found carbonized small beans in China [1] - The Xiaogao site is located in the lower Yellow River region and is associated with the Late Li culture, a culture that transitioned towards settlement approximately 9,000 to 7,000 years ago [1] - The research team identified 45 small bean grains at the Xiaogao site, although most had lost their seed coats and cotyledons [1] Group 2 - The findings indicate that 9,000 years ago, the lower Yellow River region had already formed the initial "millet + bean" composite crop system in East Asia, significantly influencing the development of settled societies and the origins of civilization in the Yellow River basin [2] - Beans played two crucial roles: they improved soil through crop rotation with millet and supplemented the protein and fat deficiencies in millet-based diets [2] - A comparative study of over 140 archaeological sites in East Asia revealed distinct evolutionary trajectories of small beans in the Yellow River basin, Japan, and Korea, with the Xiaogao site's small beans being the smallest recorded globally at an average volume of 5.8 cubic millimeters [2]

Core Insights - The archaeological discovery at the Xiaogao site in Shandong, China, revealed charred small beans (adzuki beans) dating back 9,000 years, which is 4,000 years earlier than previous similar findings in China [1][3] - This finding indicates that a dry farming system based on "grains + legumes" was established in the lower Yellow River region 9,000 years ago, providing groundbreaking evidence for the study of agricultural origins in East Asia [1][3] Group 1 - The Xiaogao site, a typical post-Li culture site, has revealed rich remains including house sites, ash pits, pottery, and stone grinding plates, dating from 9,000 to 7,500 years ago [3] - A systematic analysis of 891 flotation samples identified 30,000 charred plant grains, including millet, foxtail millet, rice, soybeans, and small beans, with 45 charred small beans being particularly significant as the earliest evidence of small beans in the Yellow River basin [3] - The discovery highlights that 9,000 years ago, the lower Yellow River had already developed a complex agricultural system combining grains and legumes, showcasing the ecological wisdom of early farmers in crop combination [3] Group 2 - Professor Lang Jianfeng from Shandong University noted that the domestication of small beans in East Asia is a long-term, multi-centered complex process [5] - The research team compared small bean remains from over 140 sites in East Asia and found distinct evolutionary trajectories in the Yellow River basin, Japan, and the Korean Peninsula [5] - The small beans from the Xiaogao site measured only 5.8 cubic millimeters, significantly smaller than modern wild varieties, indicating an early "primitive form" of domestication, with significant size increase in Chinese small beans occurring 4,000 years later [5]