ABSTRACT
This chapter describes how phylogenetic methods can be used to construct language trees and to study the evolution of other biocultural traits on trees, illustrated by Bantu-speaking populations in Africa. It illustrates how a language tree may be used to test whether two cultural traits co-evolve, using a phylogenetic comparative method. To date, the most widely used phylogenetic method is maximum parsimony, an optimality criterion that minimizes the number of character changes on the tree. Phylogenetic methods have a number of advantages over previous methods for constructing language trees, including lexicostatistics and the linguistic comparative method. The Bantu language tree described here closely reflects archaeological evidence for the spread of farming across sub-equatorial Africa, supporting the hypothesis that Bantu languages were spread by an agricultural dispersal. The correlation between the Bantu tree and the spread of farming is consistent with the hypothesis that the Bantu languages were spread by farmers.
