Vertical and lateral aspects of Chinese dialect history

尽管有悠久的研究传统，但人们对汉语方言的起源和多样性知之甚少。究其原因，是中国特殊的社会语言环境造成的。两千多年来，在共同的文化和文字体系的屋檐下，无数难以理解的语言变体不断发展。在不同声望语言的向心力、地理距离的离心力以及不同的迁徙浪潮的影响下，出现了一个语系，其语言差异类似于罗曼语系，但其历史是如此复杂和交织，似乎不可能用经典的家谱来描述。这一点也反映在传统汉语方言学中，它局限于将汉语方言分成几个静态的组，而不试图发展关于这些组是如何出现的假设。在这一背景下，最大的问题之一是对继承(纵向)和借用(横向)特征的区分，而《中国》中广泛的语言接触大大加剧了这一问题。随着历史语言学最近的量化转向，生物信息学的许多方法被应用于语言问题。大多数新方法仅限于语言树的重建。他们含蓄地将语言进化与动物和植物的树状进化相提并论。然而，最近的研究表明，求助于已开发的生物网络方法来研究细菌进化可能更合适。由于横向基因转移在细菌进化中的作用与借用在语言发展中的作用类似，生物网络方法既提供了对语言历史的垂直和横向方面进行建模的正式手段，也提供了将它们区分开来的不同方法。在与来自巴黎的生物学家和汉学家的跨学科合作的基础上，本研究项目将利用网络方法详细地探索汉语方言历史的纵向和横向方面。现有的方法将进一步改进，适应语言需要，并应用于一个大型汉语方言词汇数据库，该数据库将专门为此目的而创建。这样，该项目将特别有助于汉语方言分类，并有助于对整个语言史进行量化建模。

Despite a long tradition of research, only little is known about the origin and diversification of the Chinese dialects. The reason for this is the specific sociolinguistic situation in China, where - for over two thousand years - countless, mostly mutually unintelligible linguistic varieties have been developing under the roof of a common culture and a common writing system. Under the influence of centripetal forces caused by varying prestige languages, centrifugal forces resulting from geographical distance, and different waves of migrations, a language family hase emerged whose linguistic divergence resembles that of the Romance languages, but whose history is so complex and intertwined that it seems impossible to describe it by means of a classical family tree. This is also reflected in traditional Chinese dialectology which confines itself to divide the Chinese dialects into static groups without trying to develop hypotheses as to how these groups have emerged. One of the biggest problems in this context is the distinction of inherited (vertical) and borrowed (lateral) features, which is immensely aggravated by the extensive language contact in China. Along with the recent quantitative turn in historical linguistics, many methods from bioinformatics were applied to linguistic problems. Most new methods limit themselves to the reconstruction of language trees. Implicitly, they draw a parallel between language evolution and the mostly tree-like evolution of animals and plants. Recent research, however, has shown that it may be more appropriate to resort to biological network approaches that have been developed to study bacterial evolution. Since lateral gene transfer plays a similarly important role in bacterial evolution as borrowing does in language development, biological network approaches provide both formal means to model vertical and lateral aspects of language history, and different methods to distinguish them from each other. Based on interdisciplinary cooperation with biologists and sinologists from Paris, this research project will use network methods to explore vertical and lateral aspects of Chinese dialect history in detail. Existing methods will be further refined, adapted to linguistic needs, and applied to a large lexical database of Chinese dialects, which will be created specifically for this purpose. In this way, the project will contribute to Chinese dialect classification in particular, and to quantitative modeling of language history in general.