A widely accepted explanation for this loss is dialect contact. Manuscripts indicate that the northern and southern dialects of Middle English implemented the verb-second rule differently, resulting in minor differences in word order. At the contact boundary, children would have heard both, thereby receiving conflicting information about word order. This somehow caused them to prefer the modern word order.
My presentation will be about a dynamical system model of this change that shows how contact can cause a dialect to disappear. As contact between the two regions increases, a bifurcation occurs that annihilates the fixed point representing a population that stably maintains two dialects, and this is what drives the change. I hope to discuss the initial model and several extensions and generalizations. This is part of my research to understand why languages change (or don't).
This is an abstract of a talk to be presented at the
2004 SEAMS Workshop in Charleston, SC. For more information, visit
the workshop's homepage at math.cofc.edu/SEAMS.