Replicators at a Fork in the Road

In the figures below, time flows from left to right. In each case there is a language split (the division of a speech community into two communities separated by a communication barrier). A black diamond stands for the emergence of a pair of cognates caused by a such a split. A solid black dot stands for a duplication event (the emergence of a variant form in the same language). A white dot stands for the loss of a linguistic entity, and a linked pair of pentagons stand for an event of linguistic borrowing (apex down indicates the source language, apex up indicates the target language). The figures describe some commonly occurring “etymological scenarios” reconstructed by historical linguists. They will soon be followed by a series of posts illustrating those scenarios with real-life examples.

Fig.1. Simple coalescence

Fig.2. Lateral intrusion

Fig. 3. Deep coalescence

Fig. 4. Wanderwort invasion