Sophisticated application of a phylogenetic model in historical anthropology requires a rigorous methodology. Using our Polynesian case, we begin with the problem of correlating linguistic and archaeological evidence, followed by possible models for linguistic divergence. We will show that such models are not limited to strictly “tree-like” branching models; historical linguists have recently developed “network-breaking,” or “dialect-chain” models that are more appropriate to Pacific history. This in turn leads to matters of defining “homelands,” and of establishing time depth. All of these issues are essential to establishing a proper phylogenetic framework. The second half of this chapter examines what we call the “triangulation method” in historical anthropology, which allows one to achieve a reconstruction of the ancestral culture which lies at the root of a phylogenetic “tree.” The procedural details of the triangulation method will take us into the realm of lexical and semantic reconstruction, especially the “recovery of meaning” by using comparative ethnographic materials to develop specific semantic history hypotheses.