ABSTRACT
The results of the comparative study described do not support the recent claim that blending, or ethnogenetic, processes such as trade and exchange have always been more important in macroscale cultural evolution than the branching, or phylogenetic, process of within-group information transmission plus population fissioning. According to the branching hypothesis, similarities and differences among cultures are the result of a combination of predominantly within-group information transmission and population fissioning. In contrast, supporters of the blending hypothesis believe that it is unrealistic "to think that history is patterned like the nodes and branches of a comparative, phylogenetic, or cladistic tree". The study by Guglielmino et al. explores the roles of branching, blending, and local adaptation in the evolution of forty-seven cultural traits among 277 African societies. Guglielmino et al. found that the "family and kinship" traits were best explained by the demic-diffusion model, whereas the "labor division by sex" and "various other" traits were best explained by the cultural-diffusion model.
