A model of change in phonemic diversity through drift and recovery.

<p>At time two small populations, <i>B</i> and <i>C</i>, emigrate from population and colonize two different regions. Population <i>B</i> settles on a large landmass, and subsequently grows and diversifies linguistically. As a result, the average phonemic diversity of population <i>B</i> increases with time. Conversely, the phonemic diversity of population <i>C</i> remains stable through time because it occupies a small, isolated island. Therefore, the phonemic diversity of population <i>C</i> can be used to approximate what the phonemic diversity of population <i>B</i> would have been at time Large dots denote high phonemic diversity and small dots denote low phonemic diversity.