Erik Elgh

The Dialect Continuum Tree

Erik Elgh & Harald Hammarström (Uppsala University)

Historical linguistics has struggled with the applicability of the tree model ever since the inception of the alternative wave model (Schmidt 1872, 27). The issue with the tree model arises because even though a tree should give a pattern of subgroups with strictly nested innovations, they often overlap variably across subgroups. This discrepancy can partially be explained by the formation and subsequent dissolution of dialect continua. Efforts have been made to either incorporate this process into a tree (Ross 1988, 7-11, Ross 1997, Pelkey 2015) or to discard the tree in favour of a modified mapping of isoglosses (historical glottometry, François 2014, Kalyan et al. 2018, Kalyan and François 2019). Although all the models combine aspects of trees and waves, they are somewhat lacking in explicitness on the formation and breaking of dialect continua.

Here, we present a new model and corresponding graph, the Dialect Continuum Tree (DCT), that explicitly takes into account the vertical descent and tree-like relationship of lects, as well as the lateral transfer of material between lects that are neighbouring and mutually intelligible. Through this, the DCT provides a framework that can accommodate both tree-like splits and wave-like dialect divergences. We also introduce the first step in the development of a maximum parsimony framework to evaluate different DCTs by how well they fit certain linguistic data.

References

François, A. (2014). Trees, waves and linkages: Models of language diversification.

Kalyan, S. and François, A. (2019). When the waves meet the trees: A response to Jacques and List. Journal of Historical Linguistics, 9(1):168–177.

Kalyan, S., François, A., et al. (2018). Freeing the comparative method from the tree model: A framework for historical glottometry. Senri Ethnological Studies, 98:59–89.

Pelkey, J. (2015). Reconstructing phylogeny from linkage diffusion: Evidence for cladistic hinge variation. Diachronica, 32(3):397–433.

Ross, M. (1988). Proto Oceanic and the Austronesian languages of western Melanesia. Dept. of Linguistics, Research School of Pacific Studies, The Australian National University.

Ross, M. (1997). Social networks and kinds of speechcommunity event. Archaeology and language, 1:209–261.

Schmidt, J. (1872). Die verwantschaftsverhältnisse der indogermanischen sprachen. H. Böhlau.