This article investigates the terminology and the processes underlying the fundamental historical relations between words in linguistics ( cognacy ) and genes in biology ( homology ). The comparison between linguistics and biology shows that there are major inconsistencies in the analogies drawn between the two research fields and the models applied in phylogenetic reconstruction in linguistics. Cognacy between words is treated as a binary relation which is either present or not. Words, however, can exhibit different degrees of cognacy which go beyond the distinction between orthologous and paralogous genes in biology. The complex nature of cognacy has strong implications for the models used for phylogenetic reconstruction. Instead of modeling lexical evolution as a process of cognate gain and cognate loss, we need to go beyond the cognate relation and develop models which take the degrees of cognacy into account. This opts for the use of evolutionary models which handle multistate characters and allow to define potentially asymmetrical transition tendencies among the character states instead of time-reversible binary state models in phylogenetic approaches. The benefit of multistate models with asymmetric transition tendencies is demonstrated by testing how well different models of lexical change perform in semantic reconstruction on a lexicostatistical dataset of 23 Chinese dialects in a parsimony framework. The results show that the improved models largely outperform the popular gain–loss models. This suggests that improved models of lexical change may have strong consequences for phylogenetic approaches in linguistics.

中文翻译：

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超越同源性：词语之间的历史关系及其对系统发育重建的影响

本文研究了语言学中的词（同源性）与生物学中的基因（同源性）之间的基本历史关系的术语和过程。语言学和生物学之间的比较表明，两个研究领域之间的类比和语言学系统发育重建中应用的模型存在重大不一致。词之间的同源性被视为存在或不存在的二元关系。然而，单词可以表现出不同程度的同源性，这超出了生物学中直系同源和旁系同源基因之间的区别。同源性的复杂性质对用于系统发育重建的模型具有重要意义。与其将词汇演化建模为同源增益和同源丢失的过程，我们需要超越同源关系并开发考虑同源程度的模型。这选择使用处理多状态特征的进化模型，并允许定义特征状态之间潜在的不对称过渡趋势，而不是系统发育方法中的时间可逆二元状态模型。通过在简约框架中测试不同词汇变化模型在语义重建中对 23 个汉语方言的词汇统计数据集的执行情况，证明了具有不对称转换趋势的多状态模型的好处。结果表明，改进后的模型在很大程度上优于流行的增益-损失模型。这表明改进的词汇变化模型可能对语言学中的系统发育方法产生重大影响。