山东发现9000年前炭化小豆遗存，打破日本学术界认为的“日本小豆起源论”

Core Viewpoint - The discovery of carbonized adzuki beans dating back 9,000 years in Shandong challenges the previously held belief in Japan's central role in the origin of adzuki beans, suggesting that China is also a significant origin point for this crop [4]. Group 1: Archaeological Findings - An international team, including Shandong University and Washington University in St. Louis, published findings in the Proceedings of the National Academy of Sciences, revealing the earliest known adzuki bean remains in the Yellow River basin, predating previous discoveries in China by 4,000 years [2]. - The Xiaogao site, located in the lower Yellow River region, is associated with the Late Li culture, which dates back approximately 9,000 to 7,000 years [2]. - A total of 45 adzuki beans were identified at the site, although most had lost their seed coats and cotyledons [2]. Group 2: Methodology and Analysis - The age of the carbonized seeds was determined using carbon-14 dating, which measures the remaining carbon-14 content to estimate the time since the organism ceased living [2]. - The research team compared adzuki bean remains from over 140 archaeological sites across East Asia, noting significant evolutionary differences between beans from the Yellow River basin, Japan, and Korea [3]. Group 3: Agricultural Implications - The findings indicate that 9,000 years ago, the lower Yellow River region had already developed an early "millet + bean" cropping system, which significantly influenced the development of settled societies and civilization in the area [3]. - Adzuki beans played two crucial roles: improving soil through crop rotation with millet and providing essential protein and fats in the diet [3]. - The average size of the adzuki beans found at Xiaogao was 5.8 cubic millimeters, the smallest recorded among archaeological sites, with significant size increases in Chinese adzuki beans occurring between 4,000 to 2,000 years ago [3].