Grammatical forms are said to evolve via two main mechanisms. These are, respectively, the `descent' mechanism, where current forms can be seen to have descended (albeit with occasional modifications) from their roots in ancient languages, and the `contact' mechanism, where evolution in a given language occurs via borrowing from other languages with which it is in contact. We use ideas and concepts from statistical physics to formulate a series of static and dynamical models which illustrate these issues in general terms. The static models emphasise the relative numbers of rules and exceptions, while the dynamical models focus on the emergence of exceptional forms. These unlikely survivors among various competing grammatical forms are winners against the odds. Our analysis suggests that they emerge when the influence of neighbouring languages exceeds the generic tendency towards regularisation within individual languages.

翻译：语法形式的演化被认为通过两种主要机制进行。分别是“传承”机制，即当前形式可以被视为从古代语言的根源传承而来（尽管偶尔伴有修改），以及“接触”机制，即特定语言中的演化通过与其接触的其他语言进行借用而发生。我们运用统计物理学中的思想与概念，构建了一系列静态与动态模型，以一般性术语阐明这些问题。静态模型强调规则与例外相对的数量，而动态模型则聚焦于例外形式的出现。这些在各种竞争性语法形式中的“幸存者”乃是逆袭的赢家。我们的分析表明，当邻近语言的影响超过单个语言内部规则化的普遍趋势时，这些例外形式便会涌现。