Bernardo Rondelli

Cultural diffusion was the main driving mechanism of the neolithic transition in southern Africa.

It is well known that the Neolithic transition spread across Europe at a speed of about 1 km/yr. This result has been previously interpreted as a range expansion of the Neolithic driven mainly by demic diffusion (whereas cultural diffusion played a secondary role). However, a long-standing problem is whether this value (1 km/yr) and its interpretation (mainly demic diffusion) are characteristic only of Europe or universal (i.e. intrinsic features of Neolithic transitions all over the world). So far Neolithic spread rates outside Europe have been barely measured, and Neolithic spread rates substantially faster than 1 km/yr have not been previously reported. Here we show that the transition from hunting and gathering into herding in southern Africa spread at a rate of about 2.4 km/yr, i.e. about twice faster than the European Neolithic transition. Thus the value 1 km/yr is not a universal feature of Neolithic transitions in the world. Resorting to a recent demic-cultural wave-of-advance model, we also find that the main mechanism at work in the southern African Neolithic spread was cultural diffusion (whereas demic diffusion played a secondary role). This is in sharp contrast to the European Neolithic. Our results further suggest that Neolithic spread rates could be mainly driven by cultural diffusion in cases where the final state of this transition is herding/pastoralism (such as in southern Africa) rather than farming and stockbreeding (as in Europe).

Sickles and Forks: Traditional Rural Knowledge of Agricultural Practises and Its Possible Applications in Archaeology

This paper presents the results of ethnographic observations of non-mechanized crop-processing activities at two localities in Catalonia (Spain). The aim of the study is to analyze the patterns of phytolith deposition on threshing floors and to be able to reconstruct them. Phytoliths are extremely durable plant micro-remains that are commonly found in archaeological sediments and can provide information on the types and parts of plants used in the past. The preliminary results of phytolith analysis and geostatistic applications to the identification of spatial patterns of deposition are presented. The application of geostatistic techniques allows for the identification of general spatial patterns derived from the circularity of movement with which the crop processing took place. The combination of phytolith analysis and geostatistics could help to identify archaeological threshing floors, thus providing information on early crop-processing practices and the adoption of agriculture.

Population Spread and Cultural Transmission in Neolithic Transitions

The classical wave-of-advance model is based on Fisher’s equation. However, this approach leads to an unbounded wave-of-advance speed at high reproduction rates. In contrast, an integro-difference model leads to a finite upper bound for the speed, namely the maximum dispersal distance divided by the generation time. Intuitively, this is a very reasonable result. This demic model has been generalized to include cultural transmission (Fort, PNAS 2012). We apply this recent demic-cultural model to determine the percentages of demic and cultural diffusion in the Neolithic transition for two case studies: (i) Europe, and (ii) southern Africa (Jerardino et al., PLoS One 2014). The similarities and differences between both case studies are interpreted in terms of the three mechanisms at work (population reproduction, dispersal and acculturation).