Narrow Results

In a recent work on the wave of advance of a beneficial technology and associated hitchhiking of cultural and biological traits, we simulated the advance of neolithic agriculture into Europe. That model embraced geographical variation of land fertility and human mobility, conversion of indigenous mesolithic hunter-gatherers to agriculture, and competition between invading farmers and indigenous converts. A key result is a sharp cultural boundary across which the agriculturalists' heritage changes from that of the invading population to that of the converts. Here we present an analytical study of the cultural boundary for some simple cases. We show that the width of the boundary is determined by human mobility and the strength of competition. Simulations for the full model give essentially the same result. The finite width facilitates irreversible gene flow between the populations, so over time genetic differences appear as gradients while e.g. linguistic barriers may remain sharp. We also examine the various assumptions of the model relating to purposeful versus. random movement of peoples and the competition between cultures, demonstrating its richness and flexibility.

Population geneticists have shown that the effects of local extinction and recolonization on selectively neutral genetic diversity are sensitive to the number of individuals that migrate between groups. Here, we employ a spatially explicit metapopulation model to investigate the extent to which the effects of local extinction on selectively neutral cultural diversity and change are sensitive to intergroup cultural transmission — the rate at which cultural variants are transmitted between groups. Our results show that the level of intergroup cultural transmission as well as the topology of the social network that mediates cultural transmission between groups influence the way in which local extinctions affect total diversity, group differentiation, and the rate at which copy errors accumulate in structured populations. The results are discussed in the context of the archaeological record of Middle and Upper Paleolithic societies.

This article focusses on the importance of space in mathematical models of cultural evolution, cooperation, niche construction and social learning. We discuss the benefits of including spacial effects in these evolutionary models and illustrate how the inclusion of space has changed accepted and long-standing results. We also briefly discuss the spatial dynamics of these systems and suggest future directions for research investigating spatial evolution.