Cultural Evolution: Phylogeny versus Reticulation

The evolution of cultures and languages proceeds through changes in inherited patterns (phylogeny) as well as through changes stimulated by contact and diffusion (reticulation). The evolution of phylogenetic patterning occurs mainly through linguistic and cultural divergence, whereas reticulation proceeds mainly through processes of convergence or borrowing. Phylogenetic relationships reflect patterns of common ancestry within language families and sociocultural complexes, and so are of great importance because they imply radiation of an ancestral form, sometimes rapidly and over large distances. The resulting long-term trends within cultural evolution thus appear to oscillate between fairly brief periods of phylogenetic radiation, interspersed with much longer periods of reticulate ethnogenesis. This entry discusses the nature of both phylogeny and reticulation and refers to the example of prehistoric and ethnographic Polynesia as one in which phylogenetic and reticulative patterning in cultural diversity can be reconstructed fairly clearly on a broad scale. In other situations, for instance coastal New Guinea, the distinctions are far less clear owing to a greater intensity of cultural contact in recent millennia. In general, languages appear to reveal ancestral relationships more clearly than do archeological assemblages and ethnographic cultures.