波浪理论

该理论旨在替代树模型，后者似乎无法解释从祖语演化来时部分特征的存在，特别是在日耳曼语中。20世纪，波浪模型作为整体语言变化的模型几乎没有获得接受，而在方言连续体和区域现象的领域引起关注；由于树模型的缺点，它最近在历史语言学家中更受欢迎。

原则

树模型要求语言完全通过社会分裂和语言分歧来发展，一组方言发生的创新应立即导致它们与其他相关方言失去联系：这是解释树结构强加的子群嵌套组织的唯一方法。

波浪模型没有这样的要求，它可以很容易地适应交叉模式的创新分布。这是方言连续体的典型特征，即方言与不同邻居同时共享创新，其定义的谱系亚群形成交叉模式。这解释了波浪模型在方言学研究中的流行。

约翰内斯·施密特认为，至少有一部分语言是从一个连续统一体中形成的。连续统一体起初就像一条平滑的斜线，距离相近的说话者倾向于统一其语言，在斜线的基础上形成一条阶梯线，这些阶梯就是方言。随时间推移，一些阶梯变薄并消失，另一些则抢占了整个连续体。例如施密特说标准德语，它就被定义为符合某些方言，然后传播到整个德国，在许多情况下取代了地方方言。

遗留

现代语言学研究中，波浪模型通过比较法对改进树模型做出了巨大贡献。甚至有学者提出，波模型应该代替树模型来表示语言谱系。最近的研究也关注语链的概念，也即一个从古方言连续体演变来的语言系属分类，且不能用树来表示，必须用波模型来分析。

应用

• 波浪模型给语言学一些领域提供了关键的研究方法，如：
• 方言学
• 方言计量学
• 历史语言计量学
• 区域语言学
• 克里奥尔语言学

In historical linguistics, the wave model, or wave theory (German: Wellentheorie), is a model of language change in which a new language feature (innovation) or a new combination of language features spreads from its region of origin, being adopted by a gradually expanding cluster of dialects. Each innovation starts at a certain place, and spreads from speaker to speaker, from dialect to dialect, in the same fashion as waves on the water.

The theory was intended as a substitute for the tree model, which did not seem to be able to explain the existence of some features, especially in the Germanic languages, by descent from a proto-language. At its most ambitious, it is a wholesale replacement for the tree model of languages. During the 20th century, the wave model had little acceptance as a model for language change overall, except for certain cases, such as the study of dialect continua and areal phenomena; it has recently gained more popularity among historical linguists, due to the shortcomings of the tree model.

Principles

The tree model requires languages to evolve exclusively through social splitting and linguistic divergence. In the "tree" scenario, the adoption of certain innovations by a group of dialects should result immediately in their loss of contact with other related dialects: this is the only way to explain the nested organisation of subgroups imposed by the tree structure.

Such a requirement is absent from the wave model, which can easily accommodate a distribution of innovations in intersected patterns. Such a configuration is typical of dialect continua (and of linkages, see below), that is, historical situations in which dialects share innovations with different neighbours simultaneously, in such a way that the genealogical subgroups they define form an intersected pattern. This explains the popularity of the wave model in studies of dialectology.

Johannes Schmidt used a second metaphor to explain the formation of a language from a continuum. The continuum is at first like a smooth, sloping line. Speakers in close proximity tend to unify their speech, creating a stepped line out of the sloped line. These steps are the dialects. Over the course of time, some steps become weak and fall into disuse, while others preempt the entire continuum.

Legacy

In modern linguistics, the wave model has contributed greatly to improve, but not supersede, the tree model approach of the comparative method. Some scholars have even proposed that the wave model does not complement the tree model but should replace it for the representation of language genealogy. The recent works have also focused on the notion of a linkage, a family of languages descended from a former dialect continuum; linkages cannot be represented by trees and must be analysed by the wave model.

In A Thousand Plateaus, Deleuze and Guattari explicitly oppose arborescent models of language, instead opting for rhizomatic models that function like waves. They write: "Language stabilizes around a parish, a bishopric, a capital. It forms a bulb. It evolves by subterranean stems and flows, along river valleys or train tracks; it spreads like a patch of oil." Despite these similarities, it is unclear whether Deleuze and Guattari were explicitly aware of the wave model during the production of A Thousand Plateaus.

History

Advocacy of the wave theory is attributed to Johannes Schmidt and Hugo Schuchardt.

In 2002 to 2007, Malcolm Ross and his colleagues theorized that Oceanic languages can be best understood as developing through the wave model.

Applications

The wave model provided the key inspiration to several approaches in linguistics, notably:

Dialectology, the study of dialectal variation, which often takes the form of linguistic atlases and maps, displaying isoglosses and dialect boundaries (including fuzzy boundaries, cf. Croissant, Rhenish fan);

Dialectometry, the quantitative and computational branch of dialectology;

Historical glottometry, a quantitative and diffusionist approach to language subgrouping and genealogy: its main unit of observation are the individual innovations as they diffused across dialect networks and linkages (internal to a given family), resulting in genetic subgroups that form intersecting patterns;

Areal linguistics, the study of language contact (including across different families), and of the sprachbunds that result from long periods of language convergence;

Creole linguistics, the study of linguistic creoles and mixed languages, and of their genesis.