Source-oriented explanation in typology challenges a number of well-established universals, including the correlational universals of harmonic ordering of heads and dependents. It dispenses with functional or cognitive explanations of these because harmonic orders may simply be explained as one order emerging from the other and thus as historical accidents. We provide twofold evidence against this approach and show that (i) universally preferred structures may emerge without any preconditions in the grammaticalization source and (ii) that universally dispreferred structures of the source disappear in the course of time. First, we demonstrate that the development of the three harmonic, head-first word orders (VO, AdpN, NGen) in Postclassical Greek can hardly be considered a historical coincidence, because they match chronologically and, at the same time, are entirely unrelated etymologically, and because neither of these had a bias for ordering heads before dependents in the source. The emergence of the three harmonic word orders is extremely improbable under the null hypothesis of a development by chance (odds 0.037). Secondly, we provide evidence for the reverse case: cross-linguistically dispreferred properties inherited from the source are abandoned in the course of the development.

类型学中以源为导向的解释挑战了许多公认的普遍性，包括头部和从属的谐波排序的相关普遍性。它免除了对这些的功能或认知解释，因为谐波阶次可以简单地解释为一个阶次从另一个阶次中出现，从而解释为历史事故。我们提供了反对这种方法的双重证据，并表明 (i) 普遍偏爱的结构可能会在语法化来源中没有任何先决条件的情况下出现，以及 (ii) 普遍偏爱的来源结构会随着时间的推移而消失。首先，我们证明了三个和声、以头为首的词序（VO, AdpN, NGen) 在后古典希腊语中很难被认为是历史上的巧合，因为它们按时间顺序匹配，同时在词源上完全不相关，并且因为它们都没有偏向于在源中的从属之前排序头部。在偶然发展的零假设下，三个和声词序的出现是极不可能的（几率 0.037）。其次，我们为相反的情况提供了证据：从源头继承的跨语言偏好属性在开发过程中被丢弃。